query: are there serological tests that detect antibodies to coronavirus?

positive: Serodiagnostics for Severe Acute Respiratory Syndrome-Related Coronavirus-2: A Narrative Review Accurate serologic tests to detect host antibodies to severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) will be critical for the public health response to the coronavirus disease 2019 pandemic. Many use cases are envisaged, including complementing molecular methods for diagnosis of active disease and estimating immunity for individuals. At the population level, carefully designed seroepidemiologic studies will aid in the characterization of transmission dynamics and refinement of disease burden estimates and will provide insight into the kinetics of humoral immunity. Yet, despite an explosion in the number and availability of serologic assays to test for antibodies against SARS-CoV-2, most have undergone minimal external validation to date. This hinders assay selection and implementation, as well as interpretation of study results. In addition, critical knowledge gaps remain regarding serologic correlates of protection from infection or disease, and the degree to which these assays cross-react with antibodies against related coronaviruses. This article discusses key use cases for SARS-CoV-2 antibody detection tests and their application to serologic studies, reviews currently available assays, highlights key areas of ongoing research, and proposes potential strategies for test implementation.

positive: The use of enzyme-linked immunosorbent assay systems for serology and antigen detection in parvovirus, coronavirus and rotavirus infections in dogs in The Netherlands Abstract Complex trapping blocking (CTB) enzyme-linked immunosorbent assays (ELISAs) and indirect ELISAs for the detection of antibodies to canine parvovirus (CPV), canine coronavirus (CCV) and rotavirus in sera of dogs were established. Double antibody sandwich ELISAs for the detection of CPV-, CCV- and rotavirus antigens in fecal samples were also developed. Both the serological and antigen-detection ELISAs were used to screen samples from dogs in The Netherlands, with or without a history of acute diarrhea. It was shown that the results of the respective serological ELISAs correlated well and that CPV was the major cause of virus-induced acute diarrhea in dogs in The Netherlands.

positive: SARS-CoV-2-specific antibody detection for sero-epidemiology: a multiplex analysis approach accounting for accurate seroprevalence Background The COVID-19 pandemic demands detailed understanding of the kinetics of antibody production induced by infection with SARS-CoV-2. We aimed to develop a high throughput multiplex assay to detect antibodies to SARS-CoV-2 to assess immunity to the virus in the general population. Methods Spike protein subunits S1 and RBD, and Nucleoprotein were coupled to distinct microspheres. Sera collected before the emergence of SARS-CoV-2 (N=224), and of non-SARS-CoV-2 influenza-like illness (N=184), and laboratory-confirmed cases of SARS-CoV-2 infection (N=115) with various severity of COVID-19 were tested for SARS-CoV-2-specific concentrations of IgG. Results Our assay discriminated SARS-CoV-2-induced antibodies and those induced by other viruses. The assay obtained a specificity between 95.1 and 99.0% with a sensitivity ranging from 83.6-95.7%. By merging the test results for all 3 antigens a specificity of 100% was achieved with a sensitivity of at least 90%. Hospitalized COVID-19 patients developed higher IgG concentrations and the rate of IgG production increased faster compared to non-hospitalized cases. Conclusions The bead-based serological assay for quantitation of SARS-CoV-2-specific antibodies proved to be robust and can be conducted in many laboratories. Finally, we demonstrated that testing of antibodies against different antigens increases sensitivity and specificity compared to single antigen-specific IgG determination.

positive: An immunoelectron microscopic and immunofluorescent study on the antigenic relationship between the coronavirus-like agent, CV 777, and several coronaviruses A possible antigenic relationship between the porcine enteropathogenic coronavirus-like agent (CVLA) and 6 known coronaviruses was examined by immunoelectron microscopy (IEM) and by immunofluorescence (IF). CVLA did not show cross reactivity with infectious bronchitis virus, transmissible gastroenteritis virus (TGEV), canine coronavirus (CCV) hemagglutinating encephalomyelitis virus (HEV), neonatal calf diarrhea coronavirus (NCDCV) or feline infectious peritonitis virus (FIPV). Antigenic relationship was detected by IEM between TGEV and CCV, NCDCV and HEV and by IF between TGEV and CCV, TGEV and FIPV, HEV and NCDCV.

positive: Validation of a commercially available SARS-CoV-2 serological Immunoassay Aims: To validate the diagnostic accuracy of a Euroimmun SARS-CoV-2 IgG and IgA immunoassay for COVID-19 disease. Methods: In this unmatched (1:1) case-control validation study, we used sera of 181 laboratory-confirmed SARS-CoV-2 cases and 176 negative controls collected before the emergence of SARS-CoV-2. Diagnostic accuracy of the immunoassay was assessed against a whole spike protein-based recombinant immunofluorescence assay (rIFA) by receiver operating characteristic (ROC) analyses. Discrepant cases between ELISA and rIFA were further tested by pseudo-neutralization assay. Results: COVID-19 patients were more likely to be male and older than controls, and 50.3% of them were hospitalized. ROC curve analyses indicated that IgG and IgA had a high diagnostic accuracy with AUCs of 0.992 (95% Confidence Interval [95%CI]: 0.986-0.996) and 0.977 (95%CI: 0.963-0.990), respectively. IgG assays outperformed IgA assays (p=0.008). Considering optimized cut-offs taking the 15% inter-assay imprecision assessed into account, an IgG ratio cut-off > 1.5 displayed a 100% specificity (95%CI: 98-100) and a 100% positive predictive value (95%CI: 97-100). A 0.5 cut-off displayed a 97% sensitivity (95%CI: 93-99) and a 97% negative predictive value (95%CI: 93-99). Adopting these thresholds, rather than those of the manufacturer, improved assay performance, leaving 12% of IgG ratios ranging between 0.5-1.5 as indeterminate. Conclusions: The Euroimmun assay displays a nearly optimal diagnostic accuracy using IgG against SARS-CoV-2 in a samples of patients, without any obvious gains from considering IgA serology. The optimized cut-offs are fit for rule-in and rule-out purposes, allowing determination of whether individuals have been exposed to SARS-CoV-2 or not in our study population. They should however not be considered as a surrogate of protection at this stage.

positive: SARS-CoV-2 serology: Test, test, test, but interpret with caution! SARS-CoV-2 serological tests are a subject of intense interest and have the potential to significantly enhance the diagnostic capability of healthcare services in the current pandemic. However, as with all novel assays, significant validation is required to understand the clinical relevance of results.We present the first study to assess clinician interpretation of SARS-CoV-2 serology scenarios. We identify common key assumptions regarding patient infectivity and protection that are not currently supported by the SARS-CoV-2 evidence base. In this rapidly developing field, we therefore strongly recommend serological assay results are accompanied by clear interpretive support from laboratory and infectious diseases specialists.

positive: Longitudinal Change of Severe Acute Respiratory Syndrome Coronavirus 2 Antibodies in Patients with Coronavirus Disease 2019 BACKGROUND: A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has recently emerged and caused the rapid spread of coronavirus disease 2019 (COVID-19) worldwide. METHODS: We did a retrospective study and included COVID-19 patients admitted to Renmin Hospital of Wuhan University between 1 February and 29 February 2020. Antibody assay was conducted to detect COVID-19 envelope protein E and nucleocapsid protein N antigen. RESULTS: One hundred twelve patients were recruited with symptoms of fever, cough, fatigue, myalgia, and diarrhea. All patients underwent antibody tests. Fifty-eight (51.79%) were positive for both immunoglobulin M (IgM) and immunoglobulin G (IgG), 7 (6.25%) were negative for both antibodies, 1 (0.89%) was positive for only IgM, and 46 (41.07%) were positive for only IgG. IgM antibody appeared within a week post-disease onset, lasted for 1 month, and gradually decreased, whereas IgG antibody was produced 10 days after infection and lasted for a longer time. However, no significant difference in levels of IgM and IgG antibodies between positive and negative patients of nucleic acid test after treatment was found. CONCLUSIONS: Our results indicate that serological tests could be a powerful approach for the early diagnosis of COVID-19.

positive: A Guide to COVID‐19: a global pandemic caused by the novel coronavirus SARS‐CoV‐2 The emergence of the SARS‐CoV‐2 strain of the human coronavirus has thrown the world into the midst of a new pandemic. In the human body, the virus causes COVID‐19, a disease characterized by shortness of breath, fever, and pneumonia, which can be fatal in vulnerable individuals. SARS‐CoV‐2 has characteristics of past human coronaviruses, with close genomic similarities to SARS‐CoV, the virus that causes the disease SARS. Like these related coronaviruses, SARS‐CoV‐2 is transmitted through the inhalation of droplets and interaction with contaminated surfaces. Across the world, laboratories are developing candidate vaccines for the virus – with vaccine trials underway in the US and the United Kingdom ‐ and considering various drugs for possible treatments and prophylaxis. Here, we provide an overview of SARS‐CoV‐2 by analyzing its virology, epidemiology, and modes of transmission while examining the current progress of testing procedures and possible treatments through drugs and vaccines.

positive: Diagnostic performance of COVID-19 serology assays INTRODUCTION: The World Health Organization (WHO) declared COVID-19 outbreak as a world pandemic on 12th March 2020. Diagnosis of suspected cases is confirmed by nucleic acid assays with real-time PCR, using respiratory samples. Serology tests are comparatively easier to perform, but their utility may be limited by the performance and the fact that antibodies appear later during the disease course. We aimed to describe the performance data on serological assays for COVID-19. MATERIALS AND METHODS: A review of multiple reports and kit inserts on the diagnostic performance of rapid tests from various manufacturers that are commercially available were performed. Only preliminary data are available currently. RESULTS: From a total of nine rapid detection test (RDT) kits, three kits offer total antibody detection, while six kits offer combination SARS-CoV-2 IgM and IgG detection in two separate test lines. All kits are based on colloidal gold-labeled immunochromatography principle and one-step method with results obtained within 15 minutes, using whole blood, serum or plasma samples. The sensitivity for both IgM and IgG tests ranges between 72.7% and 100%, while specificity ranges between 98.7% to 100%. Two immunochromatography using nasopharyngeal or throat swab for detection of COVID-19 specific antigen are also reviewed. CONCLUSIONS: There is much to determine regarding the value of serological testing in COVID-19 diagnosis and monitoring. More comprehensive evaluations of their performance are rapidly underway. The use of serology methods requires appropriate interpretations of the results and understanding the strengths and limitations of such tests.

positive: Serological differentiation between COVID-19 and SARS infections. In response to the coronavirus disease 2019 (COVID-19) outbreak, caused by the SARS-CoV-2 virus, multiple diagnostic tests are required globally for acute disease diagnosis, contact tracing, monitoring of asymptomatic infection rates and assessing herd immunity. While PCR remains the frontline test of choice in the acute diagnostic setting, serological tests are urgently needed to fulfil the other requirements. Unlike PCR tests which are highly specific for each virus, cross-reactivity could potentially be a major challenge for COVID-19 antibody tests considering there are six other coronaviruses known to infect humans. Among the human pathogens, SARS-CoV is genetically most related to SARS-CoV-2 sharing approximately 80% sequence identity and both belong to the species SARS related coronavirus (SARSr-CoV) in the genus Betacoronavirus of family Coronaviridae. In this study, we developed and compared the performance of four different serological tests to comprehensively assess the cross-reactivity between COVID-19 and SARS patient sera. Our results indicate that there is a significant cross-reactivity when N protein of either SARS-CoV or SARS-CoV-2 is used. The S1 or RBD derived the spike (S) protein offers better specificity. Amongst the different platforms, capture ELISA performed best. Finally, we found that SARS survivors all have significant level of antibodies remaining in their blood 17 years after infection. We discovered that anti-N antibodies waned more than anti-RBD antibodies, and the latter is known to play a more important role in providing protective immunity.

positive: Validation of a chemiluminescent assay for specific SARS-CoV-2 antibody Objectives Faced with the COVID-19 pandemic and its impact on the availability and quality of both therapeutic and diagnostic methods, the Belgian authorities have decided to launch a procedure for additional evaluation of the performance of serological tests offered for sale on the national territory. This has been proposed with a double aim: (1) an in-depth verification of the analytical and clinical performances presented by the manufacturer and (2) an economy of scale in terms of centralized validation for all the laboratories using the tests subject to evaluation. Methods A retrospective validation study was conducted including the serum of 125 patients in order to determine the analytical and clinical performances of the LIAISON®SARS-CoV-2 from DiaSorin® detecting anti-SARS-CoV-2 IgG and to compare its clinical performance with the enzyme-linked immunosorbent assay (ELISA) test from Euroimmun®, one of the first commercially available tests allowing the detection of anti-SARS-CoV-2 IgA and IgG. Results The performances of the LIAISON®SARS-CoV-2 satisfied all the acceptance criteria and provided "real world" analytical and clinical performances very close to the ones reported by the manufacturer in its insert kit. Comparison between the LIAISON®SARS-CoV-2 and the ELISA method did not reveal any difference between the two techniques in terms of sensitivities and specificities regarding the determination of the IgG. Conclusions This study reports the validation of the LIAISON®SARS-CoV-2 allowing to detect IgG antibodies specifically directed against SARS-CoV-2. The analytical and clinical performances are excellent, and the automation of the test offers important rates, ideal for absorbing an extension of testing.

positive: Towards effective diagnostic assays for COVID-19: a review Countries globally are affected by the COVID-19 pandemic, with nearly two million cases and 120 000 deaths occurring within 4 months of the discovery of the severe acute respiratory syndrome coronavirus-2 in December 2019 in China. Accurate diagnoses of cases is key in managing the pandemic by identification, isolation and treatment of patients and defining the epidemiology of the virus. By mid-January 2020, a scientist from China published the full genome of the virus, which facilitated the development of accurate molecular diagnostic assays. By the end of January 2020, the WHO, in collaboration with laboratories in Asia, Europe and the USA, published several real-time reverse transcriptase PCR (rtRT-PCR) protocols that allowed identification of cases and development of commercial assays. Clinical investigations facilitated development of accurate case definition and guidance for laboratories on the optimum specimens and procedures for diagnoses. Currently, laboratory-based rtRT-PCR is the recommended test for diagnoses of acute cases to ensure patients can be identified and isolated and to facilitate the public health response. However, due to delays in diagnoses, severe shortage of tests and laboratory capacity, point-of-care molecular or antigen tests are becoming more attractive. Although serological tests are not suitable for diagnoses of acute cases, they are important to define epidemiological questions, including attack rate in the population, and to identify immune individuals. This review aimed to summarise the current available information for diagnoses of cases and to aid laboratories and healthcare workers to select the best assays and procedures.

positive: Diagnostic techniques for COVID-19 and new developments COVID-19 pandemic is a serious global health issue today due to the rapid human to human transmission of SARS-CoV-2, a new type of coronavirus that causes fatal pneumonia. SARS -CoV-2 has a faster rate of transmission than other coronaviruses such as SARS and MERS and until now there are no approved specific drugs or vaccines for treatment. Thus, early diagnosis is crucial to prevent the extensive spread of the disease. The reverse transcription-polymerase chain reaction (RT-PCR) is the most routinely used method until now to detect SARS-CoV-2 infections. However, several other faster and accurate assays are being developed for the diagnosis of COVID-19 aiming to control the spread of infection through the identification of patients and immediate isolation. In this review, we will discuss the various detection methods of the SARS-CoV-2 virus including the recent developments in immunological assays, amplification techniques as well as biosensors.

positive: Self-assembly into virus–like particles of the recombinant capsid protein of porcine circovirus type 3 and its application on antibodies detection PCV3 capsid protein (Cap) is an important antigen for diagnosis and vaccine development. To achieve high-level expression of recombinant PCV3 Cap in Escherichia coli (E. coli), the gene of wild-type entire Cap (wt-eCap) was amplified from clinical samples, and three optimized entire Cap (opti-eCap) and one optimized Cap deleted nuclear location signal (NLS) (opti-dCap) gene fragments encoding the same amino acid sequence with wt-eCap were synthesized based on the codon bias of E. coli. Those gene fragments were inserted into the pET30a expression vector. One recombinant strain with the highest expressed soluble eCap from four entire Cap (one wt-eCap and three opti-eCap) and one recombinant strain expressed opti-dCap were selected for further purification. The purified eCap and dCap were identified by transmission electron microscopy (TEM), a large number of round hollow particles with a diameter of 10 nm virus-like particles (VLPs) were observed in eCap, whereas irregular aggregation of proteins observed in dCap. After formation the VLPs were applied as a coating antigen to establish an indirect ELISA (I-ELISA) for detection of PCV3-specific antibody in swine serum. 373 clinical swine serum samples from China collected in 2019 were tested utilizing the VLP-based I-ELISA method under optimized conditions. To the best of our knowledge, this is the first report of self-assembly into VLPs of PCV3 recombinant Cap. Our results demonstrated that the VLP-based I-ELISA will be a valuable tool for detecting the presence of PCV3 antibodies in serum samples and will facilitate screening of large numbers of swine serum for clinical purposes.

positive: Antibody-Capture Enzyme-Linked Immunosorbent Assay for Detection of Antibody to Turkey Coronavirus Using Infectious Bronchitis Virus or Recombinant Nucleocapsid Protein as Coating Antigen Turkey coronavirus (TCoV) infection continues to threaten turkey industry. Because specific treatment and effective vaccination program are not available, rapid and cost-effective detection of antibodies to TCoV infection is an important control measure to monitor the disease status in the fields. Two antibody-capture enzyme-linked immunosorbent assay (ELISA) procedures for detection of antibodies to TCoV are outlined in this chapter. One ELISA method uses chicken infectious bronchitis coronavirus (IBV) as the coating antigen based on antigenic cross-reactivity between TCoV and IBV. The other method relies on a recombinant TCoV nucleocapsid protein. Both methods are useful for serological diagnosis of TCoV infection in the turkey flocks.

positive: Lessons from a rapid systematic review of early SARS-CoV-2 serosurveys Background. As the world grapples with the COVID-19 pandemic, there is increasing global interest in the role of serological testing for population monitoring and to inform public policy. However, limitations in serological study designs and test standards raise concerns about the validity of seroprevalence estimates and their utility in decision-making. There is now a critical window of opportunity to learn from early SARS-CoV-2 serology studies. We aimed to synthesize the results of SARS-CoV-2 serosurveillance projects from around the world and provide recommendations to improve the coordination, strategy, and methodology of future serosurveillance efforts. Methods. This was a rapid systematic review of cross-sectional and cohort studies reporting seroprevalence outcomes for SARS-CoV 2. We included completed, ongoing, and proposed serosurveys. The search included electronic databases (PubMed, MedRXIV, BioRXIV, and WHO ICTPR); five medical journals (NEJM, BMJ, JAMA, The Lancet, Annals of Internal Medicine); reports by governments, NGOs, and health systems; and media reports (Google News) from December 1, 2019 to May 1, 2020. We extracted data on study characteristics and critically appraised prevalence estimates using Joanna Briggs Institute criteria. Results. Seventy records met inclusion criteria, describing 73 studies. Of these, 23 reported prevalence estimates: eight preprints, 14 news articles, and one government report. These studies had a total sample size of 35,784 and reported 42 prevalence estimates. Seroprevalence estimates ranged from 0.4% to 59.3%. No estimates were found to have a low risk of bias (43% high risk, 21% moderate risk, 36% unclear). Fifty records reported characteristics of ongoing or proposed serosurveys. Overall, twenty countries have completed, ongoing, or proposed serosurveys. Discussion. Study design, quality, and prevalence estimates of early SARS-CoV2 serosurveys are heterogeneous, suggesting that the urgency to examine seroprevalence may have compromised methodological rigour. Based on the limitations of included studies, future serosurvey investigators and stakeholders should ensure that: i) serological tests used undergo high-quality independent evaluations that include cross-reactivity; ii) all reports of serosurvey results, including media, describe the test used, sample size, and sampling method; and iii) initiatives are coordinated to prevent test fatigue, minimize redundant efforts, and encourage better study methodology. Other. PROSPERO: CRD42020183634. No third-party funding.

positive: Evaluation of ELISA tests for the qualitative determination of IgG, IgM and IgA to SARS-CoV-2 Serological assays for anti-SARS-CoV-2 antibodies are now of critical importance to support diagnosis, guide epidemiological intervention, and understand immune response to natural infection and vaccine administration. We developed and validated new anti-SARS-CoV-2 IgG, IgM and IgA ELISA tests (ENZY-WELL SARS-CoV-2 ELISA, DIESSE Diagnostica Senese S.p.a.) based on whole-virus antigens. We used a total of 553 serum samples including samples from COVID-19 suspected and confirmed cases, healthy donors, and patients positive for other infections or autoimmune conditions. Overall, the assays showed good concordance with the indirect immunofluorescence reference test in terms of sensitivity and specificity. Especially for IgG and IgA, we observed high sensitivity (92.5 and 93.6%, respectively); specificity was high (>96%) for all antibody types ELISAs. In addition, sensitivity was linked to the days from symptoms onset (DSO) due to the seroconversion window, and for ENZY-WELL SARS-CoV-2 IgG and IgA ELISAs resulted 100% in those samples collected after 10 and 12 DSO, respectively. The results showed that ENZY-WELL SARS-CoV-2 ELISAs may represent a valid option for both diagnostic and epidemiological purposes, covering all different antibody types developed in SARS-CoV-2 immune response.

positive: Serological differentiation between COVID-19 and SARS infections In response to the coronavirus disease 2019 (COVID-19) outbreak, caused by the SARS-CoV-2 virus, multiple diagnostic tests are required globally for acute disease diagnosis, contact tracing, monitoring of asymptomatic infection rates and assessing herd immunity. While PCR remains the frontline test of choice in the acute diagnostic setting, serological tests are urgently needed to fulfil the other requirements. Unlike PCR tests which are highly specific for each virus, cross-reactivity could potentially be a major challenge for COVID-19 antibody tests considering there are six other coronaviruses known to infect humans. Among the human pathogens, SARS-CoV is genetically most related to SARS-CoV-2 sharing approximately 80% sequence identity and both belong to the species SARS related coronavirus (SARSr-CoV) in the genus Betacoronavirus of family Coronaviridae. In this study, we developed and compared the performance of four different serological tests to comprehensively assess the cross-reactivity between COVID-19 and SARS patient sera. Our results indicate that there is a significant cross-reactivity when N protein of either SARS-CoV or SARS-CoV-2 is used. The S1 or RBD derived the spike (S) protein offers better specificity. Amongst the different platforms, capture ELISA performed best. Finally, we found that SARS survivors all have significant level of antibodies remaining in their blood 17 years after infection. We discovered that anti-N antibodies waned more than anti-RBD antibodies, and the latter is known to play a more important role in providing protective immunity.

positive: Immunofluorescence Assay for Serologic Diagnosis of SARS We evaluated a virus-infected cell-based indirect immunofluorescence assay for detecting anti–severe acute respiratory syndrome-associated coronavirus (SARS-CoV) immunoglobulin (Ig) G antibody. All confirmed SARS cases demonstrated seroconversion or fourfold rise in IgG antibody titer; no control was positive. Sensitivity and specificity of this assay were both 100%. Immunofluorescence assay can ascertain the status of SARS-CoV infection.

positive: Laboratory testing of SARS-CoV, MERS-CoV, and SARS-CoV-2 (2019-nCoV): Current status, challenges, and countermeasures Emerging and reemerging infectious diseases are global public concerns. With the outbreak of unknown pneumonia in Wuhan, China in December 2019, a new coronavirus, SARS-CoV-2 has been attracting tremendous attention. Rapid and accurate laboratory testing of SARS-CoV-2 is essential for early discovery, early reporting, early quarantine, early treatment, and cutting off epidemic transmission. The genome structure, transmission, and pathogenesis of SARS-CoV-2 are basically similar to SARS-CoV and MERS-CoV, the other two beta-CoVs of medical importance. During the SARS-CoV and MERS-CoV epidemics, a variety of molecular and serological diagnostic assays were established and should be referred to for SARS-CoV-2. In this review, by summarizing the articles and guidelines about specimen collection, nucleic acid tests (NAT) and serological tests for SARS-CoV, MERS-CoV, and SARS-CoV-2, several suggestions are put forward to improve the laboratory testing of SARS-CoV-2. In summary, for NAT: collecting stool and blood samples at later periods of illness to improve the positive rate if lower respiratory tract specimens are unavailable; increasing template volume to raise the sensitivity of detection; putting samples in reagents containing guanidine salt to inactivate virus as well as protect RNA; setting proper positive, negative and inhibition controls to ensure high-quality results; simultaneously amplifying human RNase P gene to avoid false-negative results. For antibody test, diverse assays targeting different antigens, and collecting paired samples are needed.

positive: Patterns of IgG and IgM antibody response in COVID-19 patients.

positive: The laboratory tests and host immunity of COVID-19 patients with different severity of illness BACKGROUNDThe coronavirus disease 2019 (COVID-19), infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a severe outbreak throughout the world. The host immunity of COVID-19 patients is unknown.METHODSThe routine laboratory tests and host immunity in COVID-19 patients with different severity of illness were compared after patient admission.RESULTSA total of 65 SARS-CoV-2-positive patients were classified as having mild (n = 30), severe (n = 20), and extremely severe (n = 15) illness. Many routine laboratory tests, such as ferritin, lactate dehydrogenase, and D-dimer, were increased in severe and extremely severe patients. The absolute numbers of CD4+ T cells, CD8+ T cells, and B cells were gradually decreased with increased severity of illness. The activation markers such as HLA-DR and CD45RO expressed on CD4+ and CD8+ T cells were increased in severe and extremely severe patients compared with mild patients. The costimulatory molecule CD28 had opposite results. The percentage of natural Tregs was decreased in extremely severe patients. The percentage of IFN-Î³-producing CD8+ T cells was increased in both severe and extremely severe patients compared with mild patients. The percentage of IFN-Î³-producing CD4+ T cells was increased in extremely severe patients. IL-2R, IL-6, and IL-10 were all increased in extremely severe patients. The activation of DC and B cells was decreased in extremely severe patients.CONCLUSIONThe number and function of T cells are inconsistent in COVID-19 patients. The hyperfunction of CD4+ and CD8+ T cells is associated with the pathogenesis of extremely severe SARS-CoV-2 infection.FUNDINGThis work was funded by the National Mega Project on Major Infectious Disease Prevention (2017ZX10103005-007) and the Fundamental Research Funds for the Central Universities (2019kfyRCPY098).

positive: Diagnostic accuracy of an automated chemiluminescent immunoassay for anti-SARS-CoV-2 IgM and IgG antibodies: an Italian experience A pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading throughout the world. Though molecular diagnostic tests are the gold standard for COVID-19, serological testing is emerging as a potential surveillance tool, in addition to its complementary role in COVID-19 diagnostics. Indubitably quantitative serological testing provides greater advantages than qualitative tests but today there is still little known about serological diagnostics and what the most appropriate role quantitative tests might play. Sixty-one COVID-19 patients and 64 patients from a control group were tested by iFlash1800 CLIA analyzer for anti-SARS CoV-2 antibodies IgM and IgG. All COVID-19 patients were hospitalized in San Giovanni di Dio Hospital (Florence, Italy) and had a positive oro/nasopharyngeal swab reverse-transcription polymerase chain reaction result. The highest sensitivity with a very good specificity performance was reached at a cutoff value of 10.0 AU/mL for IgM and of 7.1 for IgG antibodies, hence near to the manufacturer's cutoff values of 10 AU/mL for both isotypes. The receiver operating characteristic curves showed area under the curve values of 0.918 and 0.980 for anti-SARS CoV-2 antibodies IgM and IgG, respectively. iFlash1800 CLIA analyzer has shown highly accurate results for the anti-SARS-CoV-2 antibodies profile and can be considered an excellent tool for COVID-19 diagnostics.

positive: Current and emerging diagnostic tests available for the novel COVID-19 global pandemic On March 11, 2020 the World Health Organization (WHO) upgraded the status of the coronavirus disease 2019 (COVID-19) outbreak from epidemic to a global pandemic. This infection is caused by a novel coronavirus, SARS-CoV-2. Several rapid diagnostic tests have been developed at an astonishing pace; however, COVID-19 requires more highly specific rapid point-of-care diagnostic tests. This review describes the currently available testing approaches, as well as the available test assays including the Xpert® Xpress SARS-CoV-2 test (takes (~)45 min) and Abbott ID COVID-19 test (5 min) as easy to use point-of-care tests for diagnosis of novel COVID-19 that have so far received the US Food and Drug Administration emergency use authorizations clearance. This review is correct as of the date published and will be updated as more diagnostic tests come to light.

positive: Risk factors associated with seropositivity to porcine respiratory coronavirus in Danish swine herds Abstract Serological screening of swine herds in 1984 indicated that porcine respiratory coronavirus (PRCV) had been introduced into Denmark. To determine risk factors associated with the introduction of PRCV, a cross-sectional study of 408 Danish swine herds was carried out between May 1985 and June 1986. The association between herd-PRCV serological status and possible risk factors, obtained from a field questionnaire, was assessed by unconditional maximum likelihood logistic regression. An increasing herd size, location in the Jutland peninsula (compared with location on the island of Funen) (OR = 7.9 in a multivariable logistic regression model not including interaction terms), the presence of a slurry system (i.e. pigs living on a slatted floor) (OR = 4.6) and purchase of pigs (OR= 1.7) were significantly (P < 0.05) associated with seropositivity. Two significant interactions, both involving herd size, were subsequently identified. The PRCV serological status of neighbouring herds was found to be related, and closeness of a seropositive herd was associated with an increased risk of a herd being serologically positive. The results of this study indicate that herd size may be an important determinant of airborne transmission of PRCV infection, and that herd size may modify the effect of other risk factors.

positive: Laboratory testing of SARS‐CoV, MERS‐CoV, and SARS‐CoV‐2 (2019‐nCoV): Current status, challenges, and countermeasures Emerging and reemerging infectious diseases are global public concerns. With the outbreak of unknown pneumonia in Wuhan, China in December 2019, a new coronavirus, SARS‐CoV‐2 has been attracting tremendous attention. Rapid and accurate laboratory testing of SARS‐CoV‐2 is essential for early discovery, early reporting, early quarantine, early treatment, and cutting off epidemic transmission. The genome structure, transmission, and pathogenesis of SARS‐CoV‐2 are basically similar to SARS‐CoV and MERS‐CoV, the other two beta‐CoVs of medical importance. During the SARS‐CoV and MERS‐CoV epidemics, a variety of molecular and serological diagnostic assays were established and should be referred to for SARS‐CoV‐2. In this review, by summarizing the articles and guidelines about specimen collection, nucleic acid tests (NAT) and serological tests for SARS‐CoV, MERS‐CoV, and SARS‐CoV‐2, several suggestions are put forward to improve the laboratory testing of SARS‐CoV‐2. In summary, for NAT: collecting stool and blood samples at later periods of illness to improve the positive rate if lower respiratory tract specimens are unavailable; increasing template volume to raise the sensitivity of detection; putting samples in reagents containing guanidine salt to inactivate virus as well as protect RNA; setting proper positive, negative and inhibition controls to ensure high‐quality results; simultaneously amplifying human RNase P gene to avoid false‐negative results. For antibody test, diverse assays targeting different antigens, and collecting paired samples are needed.

positive: Rapid and robust bioanalytical assays are critical for SARS-CoV-2 therapeutic and vaccine development and beyond

positive: Generation of antibodies against COVID-19 virus for development of diagnostic tools The COVID-19 China coronavirus started in Dec 2019 was challenged by the lack of accurate serological diagnostic tool for this deadly disease to quickly identify and isolate the infected patients. The generation of COVID-19-specific antibodies is essential for such tasks. Here we report that polyclonal and monoclonal antibodies were generated by immunizing animals with synthetic peptides corresponding to different areas of Nucleoprotein (N) of COVID-19. The specificities of the COVID-19 antibodies were assessed by Western Blot analysis against NPs from COVID-19, MERS and SARS. Antibodies were used for immunohistochemistry staining of the tissue sections from COVID-19 infected patient, as a potential diagnostic tool. A Sandwich ELISA kit was quickly assembled for quantitation of the virus/NP of COVID-19 concentrations in the vaccine preparations. Development of POCT is also aggressively undergoing.

positive: What to expect from antibody assays of SARS-CoV-2?

positive: The researchers taking a gamble with antibody tests for coronavirus.

positive: SARS-CoV-2 infection serology: a useful tool to overcome lockdown? The outbreak of 2019 novel coronavirus disease (Covid-19) caused by SARS-CoV-2 has spread rapidly, inducing a progressive growth in infected patients number. Social isolation (lockdown) has been assessed to prevent and control virus diffusion, leading to a worldwide financial and political crisis. Currently, SARS-CoV-2 RNA detection in nasopharyngeal swab takes place by real-time PCR (RT-qPCR). However, molecular tests can give some false-negative results. In this context, serological assays can be useful to detect IgG/IgM antibodies, to assess the degree of immunization, to trace the contacts, and to support the decision to re-admit people at work. A lot of serological diagnostic kits have been proposed on the market but validation studies have not been published for many of them. The aim of our work was to compare and to evaluate different assays analytical performances (two different immunochromatographic cards, an immunofluorescence chromatographic card, and a chemiluminescence-automated immunoassay) on 43 positive samples with RT-qPCR-confirmed SARS-CoV-2 infection and 40 negative control subjects. Our data display excellent IgG/IgM specificities for all the immunocromatographic card tests (100% IgG and 100% IgM) and for the chemiluminescence-automated assay (100% IgG and 94% IgM); IgG/IgM sensitivities are moderately lower for all methods, probably due to the assay viral antigen's nature and/or to the detection time of nasopharyngeal swab RT-qPCR, with respect to symptoms onset. Given that sensitivities (around 94% and 84% for IgG and IgM, respectively) implicate false-negative cases and given the lack of effective vaccines or treatments, the only currently available procedure to reduce SARS-CoV-2 transmission is to identify and isolate persons who are contagious. For this reason, we would like to submit a flowchart in which serological tests, integrated with nasopharyngeal swab RT-qPCR, are included to help social and work activities implementation after the pandemic acute phase and to overcome lockdown.

positive: A serological assay to detect SARS-CoV-2 seroconversion in humans Here, we describe a serological enzyme-linked immunosorbent assay for the screening and identification of human SARS-CoV-2 seroconverters. This assay does not require the handling of infectious virus, can be adjusted to detect different antibody types in serum and plasma and is amenable to scaling. Serological assays are of critical importance to help define previous exposure to SARS-CoV-2 in populations, identify highly reactive human donors for convalescent plasma therapy and investigate correlates of protection.

positive: Evaluation of the auxiliary diagnostic value of antibody assays for the detection of novel coronavirus (SARS-CoV-2) The spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has taken on pandemic proportions, affecting over 100 countries in a matter of weeks. The goal of this study was to assess the diagnostic values of different methods of detecting and estimating the SARS-CoV-2 infection, and the auxiliary diagnostic potential of antibody assays. By retrospectively analyzing the data of viral RNAs and serum immunoglobulin M-immunoglobulin G antibodies against SARS-CoV-2 from 38 cases with confirmed coronavirus disease 2019 in the Second People's Hospital of Fuyang, we found that, in the early phase of the illness, the viral RNA was most abundant in the sputum specimens, followed by that in the throat swabs, while the antibody assays identified fewer positive cases at this stage. However, the sensitivity of the antibody assays overtook that of RNA test from the eighth day of disease onset. Simultaneous use of antibody assay and reverse transcription-quantitative real-time polymerase chain reaction improved the sensitivity of the diagnoses. Moreover, we found that most of these cases with no detectable viral RNA load during the early stages were able to be seropositive after 7 days. Our findings indicate that the antibody detection could be used as an effective supplementary indicator of SARS-CoV-2 infection in suspected cases with no detectable viral RNA, and in conjunction with nucleic acid detection in confirming the infection.

positive: Antikörpertests bei COVID-19 - Was uns die Ergebnisse sagen INTRODUCTION: In the context of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the detection of virus-specific antibodies (AB) will play an increasing role. The presence or absence of such antibodies can potentially lead to considerations regarding immunity and infection. ISSUE: How reliable are inferences from positive or negative test results regarding the actual presence of SARS-CoV-2 specific antibodies? METHODS: Calculation of the probability that, depending on the pretest probability (prevalence of SARS-CoV-2 infection) and test properties, antibodies are present or absent in the case of positive or negative test results. RESULTS: Sensitivity and specificity of different SARS-CoV-2 AB test systems vary between 53 % and 94 % and between 91 % and 99.5 %, respectively. When using a test with high test quality, the positive predictive value (PPV) is 42 % and 7 9%, respectively, with a pre-test probability of 1 % to 5 %, as can currently be assumed for the general population in Austria or Germany. For persons with an increased pre-test probability of 20 %, e. g. persons from high-risk professions, the PPW is 95 %, with a pre-test probability of 80 % the PPW is almost 100 %. The negative predictive value (NPV) is at least 99.7 % for persons with a low pre-test probability of up to 5 % and 79.1 % for persons with a pre-test probability of 80 %. When using test systems with lower sensitivity and specificity, the reliability of the results decreases considerably. The PPV is 5.9 % with a pre-test probability of 1 %. CONCLUSIONS: A sufficiently high sensitivity and specificity are prerequisites for the application of antibody test systems. Positive test results are often false if the pre-test probability is low. Depending on the assumed prevalence of a SARS-CoV-2 infection, there are substantial differences in the significance of a concrete test result for the respective affected persons.

positive: Antibody response to infectious diseases and other factors accurately predict COVID-19 infection and severity risk 10–14 years later: a retrospective UK Biobank cohort study BACKGROUND: Several risk factors have emerged for novel 2019 coronavirus disease (COVID-19) infection and severity. Yet, it is unknown to what degree these risk factors alone or in combination can accurately predict who is most at risk. It is also worthwhile to consider serological antibody titers to non COVID-19 infectious diseases, which may influence host immunity to COVID-19. METHODS: In this retrospective study of multicenter UK Biobank participants, as of May 26(th) 2020, all COVID-19 testing data was collected by Public Health England for older adult in- and out-patients (69.6 ± 8.8 years). We used linear discriminant analysis with cross-validation and bootstrapping to determine the accuracy, specificity, and sensitivity of baseline data from 2006–2010 to predict COVID-19 infection and presumptive severity (i.e., testing at hospital). Receiver operating characteristic (ROC) curves were used to derive the area under the curve (AUC). FINDINGS: This retrospective study included 4,510 unique participants and 7,539 testing instances (i.e., test cases). Testing resulted in 5,329 negative cases and 2,210 positive cases, split into 996 mild and 1,214 severe disease outcomes. Baseline data including demographics, bioimpedance-derived body composition, vitals, serum biochemistry, self-reported illness/disability, and complete blood count. A randomized subset of 80 participants with 124 test cases also had antibody titers for 20 common to rare infectious diseases. Among all test cases, accuracy was modest for final diagnostic models of COVID-19 infection (70.2%; AUC=0.570, CI=0.556–0.584) and severity (58.3%; AUC=0.592, CI=0.568–0.615). In the serology sub-group, by contrast, final models predicted infection and severity with an accuracy of 93.5% (AUC=0.969, CI=0.934–1.000) and 74.4% (AUC=0.803, CI=0.663–0.943) respectively. Models included titers to common pathogens (e.g., human cytomegalovirus), age, blood cell counts, lipids, and other biochemical markers. INTERPRETATION: Risk profiles including serological titers and other risk factors could help policy makers and clinicians better identify who may get COVID-19 and require hospitalization.

positive: Serological tests facilitate identification of asymptomatic SARS-CoV-2 infection in Wuhan, China

positive: A how-to-guide to building a robust SARS-CoV-2 testing program at a university-based health system When South Florida became a hotspot for COVID-19 disease in March 2020, we faced an urgent need to develop test capability to detect SARS-CoV-2 infection. We assembled a transdisciplinary team of knowledgeable and dedicated physicians, scientists, technologists and administrators, who rapidly built a multi-platform, PCR- and serology- based detection program, established drive-thru facilities and drafted and implemented guidelines that enabled efficient testing of our patients and employees. This process was extremely complex, due to the limited availability of needed reagents, but outreach to our research scientists and to multiple diagnostic laboratory companies and government officials enabled us to implement both FDA authorized and laboratory developed testing (LDT)-based testing protocols. We analyzed our workforce needs and created teams of appropriately skilled and certified workers, to safely process patient samples and conduct SARS-CoV-2 testing and contact tracing. We initiated smart test ordering, interfaced all testing platforms with our electronic medical record, and went from zero testing capacity, to testing hundreds of healthcare workers and patients daily, within three weeks. We believe our experience can inform the efforts of others, when faced with a crisis situation.

positive: Characteristics and assessment of the usefulness of serological tests in the diagnostic of infections caused by coronavirus SARS-CoV-2 on the basis of available manufacturer's data and literature review Recognized in 2019 in Wuhan, China, the new SARS-CoV-2 coronavirus is responsible for the occurrence of a global pandemic disease called COVID-19. So far, confirmation of infection is based on the detection of virus RNA in a sample taken from a person meeting the suspected case definition. However, in the laboratory diagnosis of SARS-CoV-2 infections, in addition to genetic tests, serological methods can also be used to detect specific antibodies of the IgM, IgG and IgA class produced after contact with antigens or to detect viral antigen. Currently, a number of rapid immunochromatographic, chemiluminescent and ELISA immunoassay tests developed by different manufacturers for the diagnosis of COVID-19 are available on the market. Despite this fact, so far there is no WHO or ECDC recommendations or even reliable research regarding the usefulness of serological investigations in the laboratory diagnosis of infections caused by SARS-CoV-2.

positive: Rapid response flow cytometric assay for the detection of antibody responses to SARS-CoV-2 SARS-CoV-2 has emerged as a previously unknown zoonotic coronavirus that spread worldwide causing a serious pandemic. While reliable nucleic acid-based diagnostic assays were rapidly available, there exists only a limited number of validated serological assays. Here, we evaluated a novel flow cytometric approach based on antigen-expressing HEK 293T cells to assess spike-specific IgG and IgM antibody responses. Analyses of 201 pre-COVID-19 sera proved a high assay specificity in comparison to commercially available CLIA and ELISA systems, while also revealing the highest sensitivity in specimens from PCR-confirmed SARS-CoV-2 infected patients. Additionally, a soluble Angiotensin-Converting-Enzyme 2 (ACE-2) variant was established as external standard to quantify spike-specific antibody responses on different assay platforms. In conclusion, our newly established flow cytometric assay allows sensitive and quantitative detection of SARS-CoV-2-specific antibodies, which can be easily adopted in different laboratories and does not rely on external supply of assay kits.

positive: The value of hospital personnel serological screening in an integrated COVID-19 infection prevention and control strategy

positive: Antibody responses to SARS-CoV-2 in patients of novel coronavirus disease 2019 BACKGROUND: The novel coronavirus SARS-CoV-2 is a newly emerging virus. The antibody response in infected patient remains largely unknown, and the clinical values of antibody testing have not been fully demonstrated. METHODS: A total of 173 patients with SARS-CoV-2 infection were enrolled. Their serial plasma samples (n=535) collected during the hospitalization were tested for total antibodies (Ab), IgM and IgG against SARS-CoV-2. The dynamics of antibodies with the disease progress was analyzed. RESULTS: Among 173 patients, the seroconversion rate for Ab, IgM and IgG was 93.1%, 82.7% and 64.7%, respectively. The reason for the negative antibody findings in 12 patients might due to the lack of blood samples at the later stage of illness. The median seroconversion time for Ab, IgM and then IgG were day-11, day-12 and day-14, separately. The presence of antibodies was <40% among patients within 1-week since onset, and rapidly increased to 100.0% (Ab), 94.3% (IgM) and 79.8% (IgG) since day-15 after onset. In contrast, RNA detectability decreased from 66.7% (58/87) in samples collected before day-7 to 45.5% (25/55) during day 15-39. Combining RNA and antibody detections significantly improved the sensitivity of pathogenic diagnosis for COVID-19 (p<0.001), even in early phase of 1-week since onset (p=0.007). Moreover, a higher titer of Ab was independently associated with a worse clinical classification (p=0.006). CONCLUSIONS: The antibody detection offers vital clinical information during the course of SARS-CoV-2 infection. The findings provide strong empirical support for the routine application of serological testing in the diagnosis and management of COVID-19 patients.

positive: COVID-19 Serosurveillance May Facilitate Return-to-Work Decisions Public health measures are needed to resolve the novel coronavirus disease (COVID-19) pandemic, although a looming economic fallout merits close attention. Early safe reintroduction of immune individuals into the workforce may be essential to protecting the economic welfare of communities. Reverse transcriptase–polymerase chain reaction testing, our primary diagnostic tool to date, has sensitivity and timing concerns, owing to sampling/handling errors, as well as a complex virus–host interaction. Reverse transcriptase–polymerase chain reaction assays do not establish immune status once the virus has been cleared. Targeted serosurveillance for the determination of individuals’ potential for transmissibility, particularly if paired with direct pathogen testing, may aid in “cleared for business” decision-making.

positive: Brief clinical evaluation of six high-throughput SARS-CoV-2 IgG antibody assays Serological SARS-CoV-2 assays are urgently needed for diagnosis, contact tracing and for epidemiological studies. So far, there is limited data on how recently commercially available, high-throughput immunoassays, using different recombinant SARS-CoV-2 antigens, perform with clinical samples. Focusing on IgG and total antibodies, we demonstrate the performance of four automated immunoassays (Abbott Architect™ i2000 (N protein-based)), Roche cobas™ e 411 analyzer (N protein-based, not differentiating between IgA, IgM or IgG antibodies), LIAISON®XL platform (S1 and S2 protein-based), VIRCLIA® automation system (S1 and N protein-based) in comparison to two ELISA assays (Euroimmun SARS-CoV-2 IgG (S1 protein-based) and Virotech SARS-CoV-2 IgG ELISA (N protein-based)) and an in-house developed plaque reduction neutralization test (PRNT). We tested follow up serum/plasma samples of individuals PCR-diagnosed with COVID-19. When calculating the overall sensitivity, in a time frame of 49 days after first PCR-positivity, the PRNT as gold standard, showed the highest sensitivity with 93.3% followed by the dual-target assay for the VIRCLIA® automation system with 89%. The overall sensitivity in the group of N protein-based assays ranged from 66.7 to 77.8% and in the S protein-based-assays from 71.1 to 75.6%. Five follow-up samples of three individuals were only detected in either an S and/or N protein-based assay, indicating an individual different immune response to SARS-CoV-2 and the influence of the used assay in the detection of IgG antibodies. This should be further analysed. The specificity of the examined assays was ≥ 97%. However, because of the low or unknown prevalence of SARS-CoV-2, the examined assays in this study are currently primarily eligible for epidemiological investigations, as they have limited information in individual testing.

positive: Association between SARS-CoV-2 neutralizing antibodies and commercial serological assays Introduction Commercially available SARS-CoV-2 serological assays based on different viral antigens have been approved for the qualitative determination of anti-SARS-CoV-2 antibodies. However, there is limited published data associating the results from commercial assays with neutralizing antibodies. Methods 67 specimens from 48 patients with PCR-confirmed COVID-19 and a positive result by the Roche Elecsys SARS-CoV-2, Abbott SARS-CoV-2 IgG, or EUROIMMUN SARS-CoV-2 IgG assays and 5 control specimens were analyzed for the presence of neutralizing antibodies to SARS-CoV-2. Correlation, concordance, positive percent agreement (PPA), and negative percent agreement (NPA) were calculated at several cutoffs. Results were compared in patients categorized by clinical outcomes. Results The correlation between SARS-CoV-2 neutralizing titer (EC50) and the Roche, Abbott, and EUROIMMUN assays was 0.29, 0.47, and 0.46 respectively. At an EC50 of 1:32, the concordance kappa with Roche was 0.49 (95% CI; 0.23-0.75), with Abbott was 0.52 (0.28-0.77), and with EUROIMMUN was 0.61 (0.4-0.82). At the same neutralizing titer, the PPA and NPA for the Roche was 100% (94-100) & 56% (30-80); Abbott was 96% (88-99) & 69% (44-86); and EUROIMMUN was 91% (80-96) & 81% (57-93) for distinguishing neutralizing antibodies. Patients who died, were intubated, or had a cardiac injury from COVID-19 infection had significantly higher neutralizing titers relative to those with mild symptoms. Conclusion COVID-19 patients generate an antibody response to multiple viral proteins such that the calibrator ratios on the Roche, Abbott, and EUROIMMUN assays are all associated with SARS-CoV-2 neutralization. Nevertheless, commercial serological assays have poor NPA for SARS-CoV-2 neutralization, making them imperfect proxies for neutralization.

positive: Clinical evaluation of an immunochromatographic IgM/IgG antibody assay and chest computed tomography for the diagnosis of COVID-19 Abstract Background We evaluated the clinical performance of an immunochromatographic (IC) IgM/IgG antibody assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) and chest computed tomography (CT) for the diagnosis of Coronavirus disease 2019 (COVID-19). Methods We examined 139 serum specimens collected from 112 patients with COVID-19 and 48 serum specimens collected from 48 non-COVID-19 patients. The presence of IgM/IgG antibody for SARS-CoV2 was determined using the One Step Novel Coronavirus (COVID-19) IgM/IgG Antibody Test. Chest CT was performed in COVID-19 patients on admission. Findings Of the139 COVID-19 serum specimens, IgM was detected in 27.8%, 48.0%, and 95.8% of the specimens collected within 1 week, 1-2 weeks, and >2 weeks after symptom onset and IgG was detected in 3.3%, 8.0%, and 62.5%, respectively. Among the 48 non-COVID-19 serum specimens, 1 generated a false-positive result for IgM. Thirty-eight of the 112 COVID-19 patients were asymptomatic, of whom 15 were positive for IgM, and 74 were symptomatic, of whom 22 were positive for IgM and 7 were positive for IgG. The diagnostic sensitivity of CT scan alone and in combination with the IC assay was 57.9 % (22/38) and 68.4% (26/38) for the asymptomatic patients and 74.3% (55/74) and 82.4% (61/74) for the symptomatic patients, respectively. Conclusion The IC assay had low sensitivity during the early phase of infection, and thus IC assay alone is not recommended for initial diagnostic testing for COVID-19. If RT-qPCR is not available, the combination of chest CT and IC assay may be useful for diagnosing COVID-19.

positive: Investigation of COVID-19 cases and use of serological tests

positive: Antibody Tests in Detecting SARS-CoV-2 Infection: A Meta-Analysis The emergence of Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 made imperative the need for diagnostic tests that can identify the infection. Although Nucleic Acid Test (NAT) is considered to be the gold standard, serological tests based on antibodies could be very helpful. However, individual studies are usually inconclusive, thus, a comparison of different tests is needed. We performed a systematic review and meta-analysis in PubMed, medRxiv and bioRxiv. We used the bivariate method for meta-analysis of diagnostic tests pooling sensitivities and specificities. We evaluated IgM and IgG tests based on Enzyme-linked immunosorbent assay (ELISA), Chemiluminescence Enzyme Immunoassays (CLIA), Fluorescence Immunoassays (FIA), and the Lateral Flow Immunoassays (LFIA). We identified 38 studies containing data from 7848 individuals. Tests using the S antigen are more sensitive than N antigen-based tests. IgG tests perform better compared to IgM ones and show better sensitivity when the samples were taken longer after the onset of symptoms. Moreover, a combined IgG/IgM test seems to be a better choice in terms of sensitivity than measuring either antibody alone. All methods yield high specificity with some of them (ELISA and LFIA) reaching levels around 99%. ELISA- and CLIA-based methods perform better in terms of sensitivity (90%–94%) followed by LFIA and FIA with sensitivities ranging from 80% to 89%. ELISA tests could be a safer choice at this stage of the pandemic. LFIA tests are more attractive for large seroprevalence studies but show lower sensitivity, and this should be taken into account when designing and performing seroprevalence studies.

positive: Detection of IgM and IgG antibodies against SARS-CoV-2 in patients with autoimmune diseases

positive: Testing for SARS-CoV-2 (COVID-19): a systematic review and clinical guide to molecular and serological in-vitro diagnostic assays The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its associated coronavirus disease 2019 (COVID-19) pandemic has demanded rapid upscaling of in-vitro diagnostic assays to enable mass screening and testing of high-risk groups, and simultaneous ascertainment of robust data on past SARS-CoV-2 exposure at an individual and a population level. To meet the exponential demand in testing, there has been an accelerated development of both molecular and serological assays across a plethora of platforms. The present review discusses the current literature on these modalities, including nucleic acid amplification tests, direct viral antigen tests and the rapidly expanding laboratory-based and point of care serological tests. This suite of complementary tests will inform crucial decisions by healthcare providers and policy makers, and understanding their strengths and limitations will be critical to their judicious application for the development of algorithmic approaches to treatment and public health strategies.

positive: Detection of Nucleocapsid Antibody to SARS-CoV-2 is More Sensitive than Antibody to Spike Protein in COVID-19 Patients Background: SARS-CoV-2, the cause of coronavirus disease 2019 (COVID-19), is associated with respiratory-related morbidity and mortality. Assays to detect virus-specific antibodies are important to understand the prevalence of infection and the course of the immune response. Methodology: Quantitative measurements of plasma or serum antibodies by luciferase immunoprecipitation assay systems (LIPS) to the nucleocapsid and spike proteins were analyzed in 100 cross-sectional or longitudinal samples from SARS-CoV-2-infected patients. A subset of samples was tested with and without heat inactivation. Results: Fifteen or more days after symptom onset, antibodies against SARS-CoV-2 nucleocapsid protein showed 100% sensitivity and 100% specificity, while antibodies to spike protein were detected with 91% sensitivity and 100% specificity. Neither antibody levels nor the rate of seropositivity were significantly reduced by heat inactivation of samples. Analysis of daily samples from six patients with COVID-19 showed anti-nucleocapsid and spike antibodies appearing between day 8 to day 14 after initial symptoms. Immunocompromised patients generally had a delayed antibody response to SARS-CoV-2 compared to immunocompetent patients. Conclusions: Antibody to the nucleocapsid protein of SARS-CoV-2 is more sensitive than spike protein antibody for detecting early infection. Analyzing heat-inactivated samples by LIPS is a safe and sensitive method for detecting SARS-CoV-2 antibodies.

positive: Establishment of serological test to detect antibody against ferret coronavirus Since there is no available serological methods to detect antibodies to ferret coronavirus (FRCoV), an enzyme-linked immunosorbent assay (ELISA) using recombinant partial nucleocapsid (N) proteins of the ferret coronavirus (FRCoV) Yamaguchi-1 strain was developed to establish a serological method for detection of FRCoV infection. Many serum samples collected from ferrets recognized both a.a. 1–179 and a.a. 180–374 of the N protein, but two serum samples did not a.a. 180–374 of the N protein. This different reactivity was also confirmed by immunoblot analysis using the serum from the ferret.Therefore, the a.a. 1–179 of the N protein was used as an ELISA antigen. Serological test was carried out using sera or plasma of ferrets in Japan. Surprisingly, 89% ferrets in Japan had been infected with FRCoV. These results indicated that our established ELISA using a.a. 1–179 of the N protein is useful for detection of antibody to FRCoV for diagnosis and seroepidemiology of FRCoV infection.

positive: Clinical validation and performance evaluation of the automated Vitros Total Anti-SARS-CoV-2 Antibodies assay for screening of serostatus in COVID-19 Objectives: Evaluation of serostatus against SARS-CoV-2 has emerged as an important tool in identification of exposure to COVID-19. We report on the validation of the Vitros Anti-SARS-CoV-2 Total (CoV2T) assay for qualitative serological testing of SARS-CoV-2 antibodies. Methods: We performed validation studies according to COLA guidelines, using samples previously tested for SARS-CoV-2 by RT-PCR. We evaluated precision, analytical interferences, and cross-reactivity with other viral infections. We also evaluated concordance with molecular and other serological testing, and evaluated seroconversion. Results: The Vitros CoV2T assay exhibited acceptable precision, was resistant to analytical interference, and did not exhibit cross-reactivity with samples positive for other respiratory viruses. The CoV2T assay exhibited 100% negative predictive agreement (56/56) and 71% positive predictive agreement (56/79) with RT-PCR across all patient samples, and was concordant with other serological assays. Concordance with RT-PCR was 97% > 7 days after symptom onset. Conclusions: The Vitros CoV2T assay was successfully validated in our laboratory. We anticipate it will be a useful tool in screening for exposure to SARS-CoV-2, however, the use of the CoV2T and other serological assays in clinical management of COVID-19 patients is yet unknown, and must be evaluated in future studies.

positive: The COVID-19 Serology Studies Workshop: Recommendations and Challenges Summary The development, validation and appropriate application of serological assays to detect antibodies to SARS-CoV-2 are essential to determining seroprevalence of this virus in the United States and globally and in guiding government leadership and the private sector on back-to-work policies. An interagency working group of the U.S. Department of Health and Human Services convened a virtual workshop to identify knowledge gaps and key outstanding scientific issues and to develop strategies to fill them. Key outcomes of the Workshop included recommendations for: 1) advancing serology assays as a tool to better understand SARS-CoV-2 infection; and 2) conducting crucial serology field studies to advance an understanding of immunity to SARS-CoV-2 leading to protection and duration of protection, including the correlation between serological test results and risk of reinfection.

positive: Emergence of novel coronavirus and progress toward treatment and vaccine In late December 2019, a group of patients was observed with pneumonia‐like symptoms that were linked with a wet market in Wuhan, China. The patients were found to have a novel coronavirus genetically related to a bat coronavirus that was termed SARS‐CoV‐2. The virus gradually spread worldwide and was declared a pandemic by WHO. Scientists have started trials on potential preventive and treatment options. Currently, there is no specific approved treatment for SARS‐CoV‐2, and various clinical trials are underway to explore better treatments. Some previously approved antiviral and other drugs have shown some in vitro activity. Here we summarize the fight against this novel coronavirus with particular focus on the different treatment options and clinical trials exploring treatment as well as work done toward development of vaccines.

positive: Estimation of seroprevalence of novel coronavirus disease (COVID-19) using preserved serum at an outpatient setting in Kobe, Japan: A cross-sectional study. Summary Background Coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 has been affecting many people on earth and our society. Japan is known to have relatively less number of infections as well as deaths among developed nations. However, accurate prevalence of COVID-19 in Japan remains unknown. Therefore, we conducted a cross-sectional study to estimate seroprevalence of SARS-CoV-2 infection. Methods We conducted a cross-sectional serologic testing for SARS-CoV-2 antibody using 1,000 samples from patients at outpatient settings who visited the clinic from March 31 to April 7, 2020, stratified by decade of age and sex. Results There were 33 positive IgG among 1,000 serum samples (3.3%, 95%CI: 2.3-4.6%). By applying this figure to the census of Kobe City (poplation: 1,518,870), it is estimated that the number of people with positive IgG be 50,123 (95%CI: 34,934-69,868). Age and sex adjusted prevalence of positivity was 2.7% (95%CI 1.8-3.9%), and the estimated number of people with positive IgG was 40,999 (95%CI: 27,333-59,221). These numbers were 396 to 858 fold more than confirmed cases with PCR testing in Kobe City. Conclusions Our cross-sectional serological study suggests that the number of people with seropositive for SARS-CoV-2 infection in Kobe, Japan is far more than the confirmed cases by PCR testing.

positive: Development and Evaluation of a Multiplexed Immunoassay for Simultaneous Detection of Serum IgG Antibodies to Six Human Coronaviruses Known human coronaviruses (hCoV) usually cause mild to moderate upper-respiratory tract illnesses, except SARS-CoV and MERS-CoV, which, in addition to mild illness can also be associated with severe respiratory diseases and high mortality rates. Well-characterized multiplexed serologic assays are needed to aid in rapid detection and surveillance of hCoVs. The present study describes development and evaluation of a multiplexed magnetic microsphere immunoassay (MMIA) to simultaneously detect immunoglobulin G (IgG) antibodies specific for recombinant nucleocapsid proteins (recN) from hCoVs 229E, NL63, OC43, HKU1, SARS-CoV, and MERS-CoV. We used paired human sera to screen for IgG with reactivity against six hCoVs to determine assay sensitivity, specificity and reproducibility. We found no signal interference between monoplex and multiplex assay formats (R(2) range = 0.87–0.97). Screening of paired human sera using MMIA, resulted in 92 of 106 (sensitivity: 86%) as positive and 68 of 80 (specificity: 84%) as negative. This study serves as a proof of concept that it is feasible to develop and use a multiplexed microsphere immunoassay as a next generation screening tool for use in large scale seroprevalence studies of hCoVs.

positive: Prevalence of IgG and IgM antibodies to SARS-CoV-2 among clinic staff and patients The coronavirus disease 2019 (COVID-19) is now a pandemic with devastating social and economic consequences. The extent of the spread of COVID-19 within populations is uncertain since diagnostic tests have not been carried out on all eligible persons and doing such diagnostic tests on everyone is much less feasible in developing countries such as Nigeria. Tests for antibodies to SARS-CoV-2, the virus that causes COVID-19, are more affordable, readily available, and require minimal training than current diagnostic tests. Employing a seroepidemiological strategy, serological tests were conducted on 66 volunteering staff and patients at the University of Calabar Teaching Hospital (UCTH), a Federal Government owned tertiary healthcare facility, to determine the extent of exposure to SARS-CoV-2, from 17th to 25th June 2020. Using a COVID-19 IgG/IgM Rapid Test Cassette with emergency use authorization (EUA) from the Food and Drug Administration (FDA) of the United States, it was observed that of the 66 samples tested, 5 (7.6%) were both IgG and IgM positive and 17 (26%) were IgG positive. Moreover, for 44 of the 66 participants, simultaneous tests were carried out using a rapid test kit from a different manufacturer but without FDA-EUA and all the results completely matched with the FDA-EUA kit, except one case where the FDA-EUA kit showed positive for both IgG and IgM while the other kit was positive only for IgM. The 26% positive IgG indicates a high exposure rate for the hospital staff and patients and points to community transmission where the facility is situated. Hence, immediate activation of WHO guidelines for controlling community transmission is called for. These results can further serve as a pilot study to guide public health policies in response to COVID-19 pandemic in both the general population and in healthcare settings.

positive: Clinical And Analytical Performance Of An Automated Serological Test That Identifies S1/S2 Neutralizing IgG In COVID-19 Patients Semiquantitatively. BACKGROUND In the COVID-19 pandemic, highly selective serological testing is essential to define exposure to SARS-CoV-2 virus. Many tests have been developed, yet with variable speed to first result, and of unknown quality, particularly when considering the prediction of neutralizing capacity. OBJECTIVES/METHODS The LIAISON® SARS-CoV-2 S1/S2 IgG assay was designed to measure antibodies against the SARS-CoV-2 native S1/S2 proteins in a standardized automated chemiluminescent assay. Clinical and analytical performance of the test were validated in an observational study using residual samples (>1500) with positive or negative COVID-19 diagnosis. RESULTS The LIAISON® SARS-CoV-2 S1/S2 IgG assay proved to be highly selective and specific, and offers semiquantitative measures of serum or plasma levels of anti-S1/S2 IgG with neutralizing activity. The assay's diagnostic sensitivity was 91.3% and 95.7% at >5 or ≥15 days from diagnosis, respectively, and 100% when assessed against a neutralizing assay. The assay's specificity ranged between 97% and 98.5%. The average imprecision of the assay was <5 % coefficient of variation. Assay performance at 2 different cut-offs was evaluated to optimize predictive values. CONCLUSIONS The automated LIAISON® SARS-CoV-2 S1/S2 IgG assay brings efficient, sensitive, specific, and precise serological testing to the laboratory, with the capacity to test large amounts of samples per day: first results are available within 35 minutes with a throughput of 170 tests/hour. The semiquantitative results provided by the test also associate with the presence of neutralizing antibodies, and may provide a useful tool for the large scale screening of convalescent plasma for safe therapeutic use.

positive: Current laboratory diagnostics of coronavirus disease 2019 (COVID-19) Laboratory medicine provides an almost irreplaceable contribution to the diagnostic reasoning and managed care of most human pathologies. The novel coronavirus disease 2019 (COVID-19) is not an exception to this paradigm. Although the relatively recent emergence does not allow to draw definitive conclusions on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostics, some standpoints can be conveyed. First and foremost, it seems now clear that we will be living together with this virus for quite a long time, so that our vigilance and responsiveness against the emergence of new local outbreaks shall be maintained at the highest possible levels. The etiological diagnosis of COVID-19 is, and will remain for the foreseeable future, deeply based on direct identification of viral RNA by means of molecular biology techniques in biological materials, especially upper and lower respiratory tract specimens. Whether other materials, such as blood, urine, stools, saliva and throat washing, will become valid alternatives has not been unequivocally defined so far. As concerns serological testing, promising information can be garnered from preliminary investigations, showing that the vast majority of COVID-19 patients seem to develop a sustained immune response against the virus, characterized especially by emergence of anti-SARS-CoV-2 IgG and IgA, 1 to 2 weeks after the onset of fever and/or respiratory symptoms. Whether these antibodies will have persistent neutralizing activity against the virus is still to be elucidated on individual and general basis. The availability of rapid tests for detecting either viral antigens or anti-SARS-CoV-2 antibodies are a potentially viable opportunity for purposes of epidemiologic surveillance, though more information is needed on accuracy and reliability of these portable immunoassays.

positive: Laboratory Testing Methods for Novel Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) Following the first reports of coronavirus disease-19 (COVID-19) by China to the World Health Organization (WHO) on 31st December 2019, more than 4,302,774 novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) cases have been reported by authorities in 212 countries and territories by 12th May 2020. The outbreak and spread of COVID-19 worldwide, highlights the critical need for developing rapid and accurate diagnostic testing methods for emerging human coronavirus (CoV) infections. Testing is crucial to track the spread of disease during a pandemic, and to swiftly permit public health interventions including isolation, quarantine, and appropriate clinical management of afflicted individuals. The key components of viral diagnostic tests are (1) collection of the appropriate sample (blood, nasal swab, and throat swab), (2) availability of the genetic and proteomic sequences of the novel virus for analysis, and (3) rapid and accurate laboratory testing methods. The current gold standard for the molecular diagnosis of SARS-CoV-2 infection is the real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for the qualitative and quantitative detection of viral nucleic acids. Other relevant laboratory methods include enzyme-linked immunoassays (EIA) for viral antibody and antigen detection, and serum viral neutralization (SVN) assays for antibody neutralization determination. The challenges faced in developing a diagnostic test for a novel pathogen are the ability to measure low viral loads for early detection, to provide low or no cross-reactivity with other viral strains and to deliver results rapidly. Several point-of-care molecular devices are currently being integrated for fast and accurate diagnosis of SARS-CoV-2 infections. This review discusses the current laboratory methods available to test for coronaviruses by focusing on the present COVID-19 outbreak.

positive: Validation of a SARS-CoV-2 spike protein ELISA for use in contact investigations and sero-surveillance Since emergence of SARS-CoV-2 in late 2019, there has been a critical need to understand prevalence, transmission patterns, to calculate the burden of disease and case fatality rates. Molecular diagnostics, the gold standard for identifying viremic cases, are not ideal for determining true case counts and rates of asymptomatic infection. Serological detection of SARS-CoV-2 specific antibodies can contribute to filling these knowledge gaps. In this study, we describe optimization and validation of a SARS-CoV-2-specific-enzyme linked immunosorbent assay (ELISA) using the prefusion-stabilized form of the spike protein [1]. We performed receiver operator characteristic (ROC) analyses to define the specificities and sensitivities of the optimized assay and examined cross reactivity with immune sera from persons confirmed to have had infections with other coronaviruses. These assays will be used to perform contact investigations and to conduct large-scale, cross sectional surveillance to define disease burden in the population.

positive: Analysis of the diagnostic value of serum specific antibody testing for coronavirus disease 2019 The coronavirus disease 2019 (COVID-19) pandemic has spread to various regions worldwide. As of 27 April 2020, according to real-time statistics released by the World Health Organization, there have been 84,341 confirmed cases and 4,643 deaths in China, with more than 2,979,484 confirmed cases and 206,450 deaths outside China. The detection of antibodies produced during the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has become an important laboratory method for the diagnosis of COVID-19. However, at present, little research on these specific antibodies has been conducted. In this study, retrospective analysis was used to explore the dynamic changes of serum IgM and IgG antibody and factors affecting diagnostic efficacy, so as to provide a theoretical basis for clinical diagnosis and treatment. This article is protected by copyright. All rights reserved.

positive: Developing antibody tests for SARS-CoV-2

positive: Clinical And Analytical Performance Of An Automated Serological Test That Identifies S1/S2 Neutralizing IgG In Covid-19 Patients Semiquantitatively BACKGROUND In the Covid-19 pandemic, highly selective serological testing is essential to define exposure to SARS-CoV-2 virus. Many tests have been developed, yet with variable speed to first result, and of unknown quality, particularly when considering the prediction of neutralizing capacity. OBJECTIVES/METHODS The LIAISON® SARS-CoV-2 S1/S2 IgG assay was designed to measure antibodies against the SARS-CoV-2 native S1/S2 proteins in a standardized automated chemiluminescent assay. Clinical and analytical performance of the test were validated in an observational study using residual samples (>1500) with positive or negative Covid-19 diagnosis. RESULTS The LIAISON® SARS-CoV-2 S1/S2 IgG assay proved highly selective and specific, and offers semiquantitative measures of serum or plasma levels of anti-S1/S2 IgG with neutralizing activity. The diagnostic sensitivity was 91.3% and 95.7% at >5 or ≥15 days from diagnosis respectively, and 100% when assessed against a neutralizing assay. The specificity ranged between 97% and 98.5%. The average imprecision of the assay was <5 % coefficient of variation. Assay performance at 2 different cut-offs was evaluated to optimize predictive values in settings with different % disease prevalence. CONCLUSIONS. The automated LIAISON® SARS-CoV-2 S1/S2 IgG assay brings efficient, sensitive, specific, and precise serological testing to the laboratory, with the capacity to test large amounts of samples per day: first results are available within 35 minutes with a throughput of 170 tests/hour. The test also provides a semiquantitative measure to identify samples with neutralizing antibodies, useful also for a large scale screening of convalescent plasma for safe therapeutic use. IMPORTANCE With the worldwide advance of the COVID-19 pandemic, efficient, reliable and accessible diagnostic tools are needed to support public health officials and healthcare providers in their efforts to deliver optimal medical care, and articulate sound demographic policy. DiaSorin has developed an automated serology based assay for the measurement of IgG specific to SARS CoV-2 Spike protein, and tested its clinical performance in collaboration with Italian health care professionals who provided access to large numbers of samples from infected and non-infected individuals. The assay delivers excellent sensitivity and specificity, and is able to identify samples with high levels of neutralizing antibodies. This will provide guidance in assessing the true immune status of subjects, as well as meeting the pressing need to screen donors for high titer convalescent sera for subsequent therapeutic and prophylactic use.

positive: Diagnostic performances and thresholds: the key to harmonization in serological SARS-CoV-2 assays? BACKGROUND: The evaluation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific antibody (Ab) assay performances is of the utmost importance in establishing and monitoring virus spread in the community. In this study focusing on IgG antibodies, we compare reliability of three chemiluminescent (CLIA) and two enzyme linked immunosorbent (ELISA) assays. METHODS: Sera from a total of 271 subjects, including 64 reverse transcription-polymerase chain reaction (RT-PCR) confirmed SARS-CoV-2 patients were tested for specific Ab using Maglumi (Snibe), Liaison (Diasorin), iFlash (Yhlo), Euroimmun (Medizinische Labordiagnostika AG) and Wantai (Wantai Biological Pharmacy) assays. Diagnostic sensitivity and specificity, positive and negative likelihood ratios were evaluated using manufacturers’ and optimized thresholds. RESULTS: Optimized thresholds (Maglumi 2 kAU/L, Liaison 6.2 kAU/L and iFlash 15.0 kAU/L) allowed us to achieve a negative likelihood ratio and an accuracy of: 0.06 and 93.5% for Maglumi; 0.03 and 93.1% for Liaison; 0.03 and 91% for iFlash. Diagnostic sensitivities and specificities were above 93.8% and 85.9%, respectively for all CLIA assays. Overall agreement was 90.3% (Cohen’s kappa = 0.805 and SE = 0.041) for CLIA, and 98.4% (Cohen’s kappa = 0.962 and SE = 0.126) for ELISA. CONCLUSIONS: The results obtained indicate that, for CLIA assays, it might be possible to define thresholds that improve the negative likelihood ratio. Thus, a negative test result enables the identification of subjects at risk of being infected, who should then be closely monitored over time with a view to preventing further viral spread. Redefined thresholds, in addition, improved the overall inter-assay agreement, paving the way to a better harmonization of serologic tests.

positive: Case series of coronavirus (SARS-CoV-2) in a military recruit school: clinical, sanitary and logistical implications INTRODUCTION: A new coronavirus, called Severe Acute Respiratory Syndrome-CoronaVirus-2 (SARS-CoV-2), has emerged from China in late 2019 and has now caused a worldwide pandemic. The impact of COVID-19 has not been described so far in a military setting. We therefore report a case series of infected patients in a recruit school in Switzerland and the herein associated challenges. METHODS: Retrospective review of COVID-19 cases among Swiss Armed Forces recruits in the early weeks of SARS-CoV-2 pandemic in the canton of Ticino, the southernmost canton of Switzerland. Positive cases were defined with two positive PCR testing for SARS-CoV-2 from nasopharyngeal swabs. Serological testing was performed with a commercially available kit according to manufacturers’ instructions. RESULTS: The first case was likely contaminated while skiing during weekend permission. He became symptomatic 4 days later, tested positive for SARS-CoV-2 and was put into isolation. He showed complete symptom resolution after 48 hours. Quarantine was ordered for all recruits with close contact in the past 2 days, a total of 55 persons out of 140 in the company. Seven out of nine recruits in one particular quarantine room became mildly symptomatic. SARS-CoV-2 PCR was positive in one of them. Seven days after initial diagnosis, the index patient and the other one from the quarantine retested positive for SARS-CoV-2, although they had been completely asymptomatic for over 96 hours. Serological testing revealed positive for both patients. All others showed negative IgM and IgG. CONCLUSIONS: Young healthy recruits often showed a mild course of COVID-19 with rapid symptom decline but were persistent SARS-CoV-2 carriers. This illustrates how asymptomatic patients may be responsible for covert viral transmission. An early and prolonged establishment of isolation and quarantine for patients and close contacts is essential to slow down the spread of SARS-CoV-2, especially in the confined space of a military environment.

positive: Antikörpertests bei COVID-19 - Was uns die Ergebnisse sagen./ [Antibody tests for COVID-19: What the results tell us] INTRODUCTION: In the context of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the detection of virus-specific antibodies (AB) will play an increasing role. The presence or absence of such antibodies can potentially lead to considerations regarding immunity and infection. ISSUE: How reliable are inferences from positive or negative test results regarding the actual presence of SARS-CoV-2 specific antibodies? METHODS: Calculation of the probability that, depending on the pretest probability (prevalence of SARS-CoV-2 infection) and test properties, antibodies are present or absent in the case of positive or negative test results. RESULTS: Sensitivity and specificity of different SARS-CoV-2 AB test systems vary between 53 % and 94 % and between 91 % and 99.5 %, respectively. When using a test with high test quality, the positive predictive value (PPV) is 42 % and 7 9%, respectively, with a pre-test probability of 1 % to 5 %, as can currently be assumed for the general population in Austria or Germany. For persons with an increased pre-test probability of 20 %, e. g. persons from high-risk professions, the PPW is 95 %, with a pre-test probability of 80 % the PPW is almost 100 %. The negative predictive value (NPV) is at least 99.7 % for persons with a low pre-test probability of up to 5 % and 79.1 % for persons with a pre-test probability of 80 %. When using test systems with lower sensitivity and specificity, the reliability of the results decreases considerably. The PPV is 5.9 % with a pre-test probability of 1 %. CONCLUSIONS: A sufficiently high sensitivity and specificity are prerequisites for the application of antibody test systems. Positive test results are often false if the pre-test probability is low. Depending on the assumed prevalence of a SARS-CoV-2 infection, there are substantial differences in the significance of a concrete test result for the respective affected persons.

positive: Test, test, test for COVID-19 antibodies: the importance of sensitivity, specificity and predictive powers Abstract SARS-CoV-2 antibody tests of varying specificity and sensitivity are now available. For informing individuals whether they have had COVID-19, they need to be very accurate. For measuring population prevalence of past infection, the numbers of false positives and negatives need to be roughly equal. With a series of worked examples for a notional population of 100,000 people, we show that even test systems with a high specificity can yield a large number of false positive results, especially where the population prevalence is low. For example, at a true population prevalence of 5%, using a test with 99% sensitivity and specificity, 16% of positive results will be false and thus 950 people will be incorrectly informed they have had the infection. Further confirmatory testing may be needed. Giving false reassurance upon which personal or societal decisions might be based could be harmful for individuals, undermine public confidence and foster further outbreaks.

positive: Antibody tests for identification of current and past infection with SARS-CoV-2. BACKGROUND The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus and resulting COVID-19 pandemic present important diagnostic challenges. Several diagnostic strategies are available to identify current infection, rule out infection, identify people in need of care escalation, or to test for past infection and immune response. Serology tests to detect the presence of antibodies to SARS-CoV-2 aim to identify previous SARS-CoV-2 infection, and may help to confirm the presence of current infection. OBJECTIVES To assess the diagnostic accuracy of antibody tests to determine if a person presenting in the community or in primary or secondary care has SARS-CoV-2 infection, or has previously had SARS-CoV-2 infection, and the accuracy of antibody tests for use in seroprevalence surveys. SEARCH METHODS We undertook electronic searches in the Cochrane COVID-19 Study Register and the COVID-19 Living Evidence Database from the University of Bern, which is updated daily with published articles from PubMed and Embase and with preprints from medRxiv and bioRxiv. In addition, we checked repositories of COVID-19 publications. We did not apply any language restrictions. We conducted searches for this review iteration up to 27 April 2020. SELECTION CRITERIA We included test accuracy studies of any design that evaluated antibody tests (including enzyme-linked immunosorbent assays, chemiluminescence immunoassays, and lateral flow assays) in people suspected of current or previous SARS-CoV-2 infection, or where tests were used to screen for infection. We also included studies of people either known to have, or not to have SARS-CoV-2 infection. We included all reference standards to define the presence or absence of SARS-CoV-2 (including reverse transcription polymerase chain reaction tests (RT-PCR) and clinical diagnostic criteria). DATA COLLECTION AND ANALYSIS We assessed possible bias and applicability of the studies using the QUADAS-2 tool. We extracted 2x2 contingency table data and present sensitivity and specificity for each antibody (or combination of antibodies) using paired forest plots. We pooled data using random-effects logistic regression where appropriate, stratifying by time since post-symptom onset. We tabulated available data by test manufacturer. We have presented uncertainty in estimates of sensitivity and specificity using 95% confidence intervals (CIs). MAIN RESULTS We included 57 publications reporting on a total of 54 study cohorts with 15,976 samples, of which 8526 were from cases of SARS-CoV-2 infection. Studies were conducted in Asia (n = 38), Europe (n = 15), and the USA and China (n = 1). We identified data from 25 commercial tests and numerous in-house assays, a small fraction of the 279 antibody assays listed by the Foundation for Innovative Diagnostics. More than half (n = 28) of the studies included were only available as preprints. We had concerns about risk of bias and applicability. Common issues were use of multi-group designs (n = 29), inclusion of only COVID-19 cases (n = 19), lack of blinding of the index test (n = 49) and reference standard (n = 29), differential verification (n = 22), and the lack of clarity about participant numbers, characteristics and study exclusions (n = 47). Most studies (n = 44) only included people hospitalised due to suspected or confirmed COVID-19 infection. There were no studies exclusively in asymptomatic participants. Two-thirds of the studies (n = 33) defined COVID-19 cases based on RT-PCR results alone, ignoring the potential for false-negative RT-PCR results. We observed evidence of selective publication of study findings through omission of the identity of tests (n = 5). We observed substantial heterogeneity in sensitivities of IgA, IgM and IgG antibodies, or combinations thereof, for results aggregated across different time periods post-symptom onset (range 0% to 100% for all target antibodies). We thus based the main results of the review on the 38 studies that stratified results by time since symptom onset. The numbers of individuals contributing data within each study each week are small and are usually not based on tracking the same groups of patients over time. Pooled results for IgG, IgM, IgA, total antibodies and IgG/IgM all showed low sensitivity during the first week since onset of symptoms (all less than 30.1%), rising in the second week and reaching their highest values in the third week. The combination of IgG/IgM had a sensitivity of 30.1% (95% CI 21.4 to 40.7) for 1 to 7 days, 72.2% (95% CI 63.5 to 79.5) for 8 to 14 days, 91.4% (95% CI 87.0 to 94.4) for 15 to 21 days. Estimates of accuracy beyond three weeks are based on smaller sample sizes and fewer studies. For 21 to 35 days, pooled sensitivities for IgG/IgM were 96.0% (95% CI 90.6 to 98.3). There are insufficient studies to estimate sensitivity of tests beyond 35 days post-symptom onset. Summary specificities (provided in 35 studies) exceeded 98% for all target antibodies with confidence intervals no more than 2 percentage points wide. False-positive results were more common where COVID-19 had been suspected and ruled out, but numbers were small and the difference was within the range expected by chance. Assuming a prevalence of 50%, a value considered possible in healthcare workers who have suffered respiratory symptoms, we would anticipate that 43 (28 to 65) would be missed and 7 (3 to 14) would be falsely positive in 1000 people undergoing IgG/IgM testing at days 15 to 21 post-symptom onset. At a prevalence of 20%, a likely value in surveys in high-risk settings, 17 (11 to 26) would be missed per 1000 people tested and 10 (5 to 22) would be falsely positive. At a lower prevalence of 5%, a likely value in national surveys, 4 (3 to 7) would be missed per 1000 tested, and 12 (6 to 27) would be falsely positive. Analyses showed small differences in sensitivity between assay type, but methodological concerns and sparse data prevent comparisons between test brands. AUTHORS' CONCLUSIONS The sensitivity of antibody tests is too low in the first week since symptom onset to have a primary role for the diagnosis of COVID-19, but they may still have a role complementing other testing in individuals presenting later, when RT-PCR tests are negative, or are not done. Antibody tests are likely to have a useful role for detecting previous SARS-CoV-2 infection if used 15 or more days after the onset of symptoms. However, the duration of antibody rises is currently unknown, and we found very little data beyond 35 days post-symptom onset. We are therefore uncertain about the utility of these tests for seroprevalence surveys for public health management purposes. Concerns about high risk of bias and applicability make it likely that the accuracy of tests when used in clinical care will be lower than reported in the included studies. Sensitivity has mainly been evaluated in hospitalised patients, so it is unclear whether the tests are able to detect lower antibody levels likely seen with milder and asymptomatic COVID-19 disease. The design, execution and reporting of studies of the accuracy of COVID-19 tests requires considerable improvement. Studies must report data on sensitivity disaggregated by time since onset of symptoms. COVID-19-positive cases who are RT-PCR-negative should be included as well as those confirmed RT-PCR, in accordance with the World Health Organization (WHO) and China National Health Commission of the People's Republic of China (CDC) case definitions. We were only able to obtain data from a small proportion of available tests, and action is needed to ensure that all results of test evaluations are available in the public domain to prevent selective reporting. This is a fast-moving field and we plan ongoing updates of this living systematic review.

positive: The receptor binding domain of the viral spike protein is an immunodominant and highly specific target of antibodies in SARS-CoV-2 patients The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that first emerged in late 2019 is responsible for a pandemic of severe respiratory illness. People infected with this highly contagious virus can present with clinically inapparent, mild, or severe disease. Currently, the virus infection in individuals and at the population level is being monitored by PCR testing of symptomatic patients for the presence of viral RNA. There is an urgent need for SARS-CoV-2 serologic tests to identify all infected individuals, irrespective of clinical symptoms, to conduct surveillance and implement strategies to contain spread. As the receptor binding domain (RBD) of the spike protein is poorly conserved between SARS-CoVs and other pathogenic human coronaviruses, the RBD represents a promising antigen for detecting CoV-specific antibodies in people. Here we use a large panel of human sera (63 SARS-CoV-2 patients and 71 control subjects) and hyperimmune sera from animals exposed to zoonotic CoVs to evaluate RBD's performance as an antigen for reliable detection of SARS-CoV-2-specific antibodies. By day 9 after the onset of symptoms, the recombinant SARS-CoV-2 RBD antigen was highly sensitive (98%) and specific (100%) for antibodies induced by SARS-CoVs. We observed a strong correlation between levels of RBD binding antibodies and SARS-CoV-2 neutralizing antibodies in patients. Our results, which reveal the early kinetics of SARS-CoV-2 antibody responses, support using the RBD antigen in serological diagnostic assays and RBD-specific antibody levels as a correlate of SARS-CoV-2 neutralizing antibodies in people.

positive: COVID-19 diagnosis and study of serum SARS-CoV-2 specific IgA, IgM and IgG by a quantitative and sensitive immunoassay Background The current pandemic of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has caused a great loss in lives and economy. Detecting viral RNAs on nasopharyngeal and throat swabs is the standard approach for SARS-CoV-2 diagnosis with variable success. Currently, there are only a few studies describing the serological diagnostic methods that involve the detection of SARS-CoV-2-specific IgM and IgG. Here, we aimed to develop a more quantitative and sensitive serological test for COVID-19 diagnosis, monitoring and clinical investigation, based on the detection of antigen-specific IgA as well as IgM and IgG in blood in response to SARS-CoV-2 infection. Methods In this investigation, we report the development of a set of validated diagnostic kits for detecting serum IgA, IgM, and IgG specific to SARS-CoV-2 nucleocapsid protein (NP) and receptor-binding domain (RBD) of the spike protein by chemi-luminescence immuno-analysis. The kits were tested with a cohort of 216 sera from 87 laboratory-confirmed COVID-19 patients, and 483 sera from SARS-CoV-2 negative or healthy individuals as negative controls. A standard receiver operating characteristic (ROC) analysis was conducted to evaluate the diagnostic accuracy. Using the kits, serum levels of IgA, IgM, and IgG were analyzed, in response to SARS-CoV-2 infection and COVID-19 pathogenesis. Findings The diagnostic kits based on the RBD antigen outperformed those based on the NP. RBD-specific IgA, IgM, and IgG detection kits showed sensitivities of 98.6%, 96.8%, and 96.8%, and specificities of 98.1%, 92.3%, and 99.8%, respectively. In addition, using purified RBD-specific immunoglobulins from a serum pool of COVID-19 patients as standards, the serum concentrations of RBD-specific IgA, IgM, and IgG proteins were determined. The concentrations varied widely among different patients. Median concentration of IgA and IgM reached peaks at 16-20 days after illness onset at 8.84 μg/mL and 7.25 μg/mL, respectively, while median concentration of IgG peaked during 21-25 days after illness onset at 16.47 μg/mL. Furthermore, the serum IgA level positively correlates with COVID-19 severity. Interpretation Our immunoassay of measuring SARS-CoV-2 specific antibodies IgA, IgM, and IgG in serum provides a better serological testing with improved sensitivity and specificity. Data of IgA, IgM, and IgG responses in blood of COVID-19 patients may provide novel insight for the monitoring and treatments of COVID-19. The kits are also suitable for epidemiological studies and vaccine validations.

positive: Performance of six SARS-CoV-2 immunoassays in comparison with microneutralisation There is an urgent need for reliable high-throughput serological assays for the management of the ongoing COVID-19 pandemic. Preferably, the performance of serological tests for a novel virus should be determined with clinical specimens against a gold standard, i.e. virus neutralisation. We compared the performance of six commercial immunoassays for the detection of SARS-COV-2 IgG, IgA and IgM antibodies, including four automated assays [Abbott SARS-COV-2 IgG (CE marked), Diasorin Liaison® SARS-COV-2 S1/S2 IgG (research use only, RUO), and Euroimmun SARS-COV-2 IgG and IgA (CE marked)], and two rapid lateral flow (immunocromatographic) tests [Acro Biotech 2019-nCoV IgG/IgM (CE marked) and Xiamen Biotime Biotechnology SARS-COV-2 IgG/IgM (CE marked)] with a microneutralisation test (MNT). Two specimen panels from serum samples sent to Helsinki University Hospital Laboratory (HUSLAB) were compiled: the patient panel (N=70) included sera from PCR confirmed COVID-19 patients, and the negative panel (N=81) included sera sent for screening of autoimmune diseases and respiratory virus antibodies in 2018 and 2019. The MNT was carried out for all COVID-19 samples (70 serum samples, 62 individuals) and for 53 samples from the negative panel. Forty-one out of 62 COVID-19 patients showed neutralising antibodies.The specificity and sensitivity values of the commercial tests against MNT, respectively, were as follows: 95.1 %/80.5 % (Abbott Architect SARS-CoV-2 IgG), 94.9 %/43.8 % (Diasorin Liaison SARS-CoV-2 IgG; RUO), 68.3 %/87.8 % (Euroimmun SARS-CoV-2 IgA), 86.6 %/70.7 % (Euroimmun SARS-CoV-2 IgG), 74.4 %/56.1 % (Acro 2019-nCoV IgG), 69.5 %/46.3 % (Acro 2019-nCoV IgM), 97.5 %/71.9 % (Xiamen Biotime SARS-CoV-2 IgG), and 88.8 %/81.3 % (Xiamen Biotime SARS-CoV-2 IgM). This study shows variable performance values. Laboratories should carefully consider their testing process, such as a two-tier approach, in order to optimize the overall performance of SARS- CoV-2 serodiagnostics.

positive: Use of antibody avidity assays for diagnosis of severe acute respiratory syndrome coronavirus infection. An indirect immunofluorescent assay (Euroimmun AG, Luebeck, Germany) was used to investigate the avidity of immunoglobulin G (IgG), IgM, IgA, and total Ig (IgGAM) antibody responses to severe acute respiratory syndrome coronavirus (SARS CoV) infections. Serial serum samples from eight patients collected during the first, third, and ninth months after the onset of infection were evaluated. It was found that low-avidity IgG antibodies were detected in 15/15 (100%), 1/5 (20%), and 0/8 (0%) serum samples collected during the first, third, and ninth months after the onset of symptoms, respectively. Low-avidity antibodies of IgA and IgM subclasses were detected in 14/14 (100%) and 3/14 (21%) serum samples, respectively, collected in the first month after the onset of infection. However, IgA antibodies remained low in avidity in a proportion of patients even during late convalescence. As a consequence, IgG antibody avidity assays gave better discrimination between acute-phase and late-convalescent-phase serum samples than IgM, IgA, or IgGAM assays. In two of these patients, sequential serum samples were also tested for IgG avidity against human CoV strains OC43 and 229E in parallel. While SARS CoV infections induced an anamnestic IgG antibody response to the 229E and OC43 viruses, these cross-reactive antibodies remained of high avidity from early (the first month) postinfection. The results showed that assays to detect low-avidity antibody may be useful for discriminating early from late antibody responses and also for distinguishing anamnestic cross-reactive antibody responses from primary specific responses. This may be useful in some clinical situations.

positive: Correlation of ELISA based with random access serologic immunoassays for identifying adaptive immune response to SARS-CoV-2 Public health emergency of SARS-CoV-2 has facilitated diagnostic testing as a related medical countermeasure against COVID-19 outbreak. Numerous serologic antibody tests have become available through an expedited federal emergency use only process. This paper highlights the analytical characteristic of an ELISA based assay by AnshLabs and three random access immunoassay (RAIA) by DiaSorin, Roche, and Abbott that have been approved for emergency use authorization (EUA), at a tertiary academic center in a low disease-prevalence area. The AnshLabs gave higher estimates of sero-prevalence, over the three RAIA methods. For positive results, AnshLabs had 93.3% and 100% concordance with DiaSorin or Abbott and Roche respectively. For negative results, AnshLabs had 69.7% and 73.0% concordance with DiaSorin and Roche or Abbott respectively. All discrepant samples that were positive by AnshLabs and negative by RAIA tested positive by all-in-one step SARS-CoV-2 Total (COV2T) assay performed on the automated Siemens Advia Centaur XPT analyzer. None of these methods, however, are useful in early diagnosis of SARSCoV- 2.

positive: Molecular, serological, and biochemical diagnosis and monitoring of COVID-19: IFCC taskforce evaluation of the latest evidence. The global coronavirus disease 2019 (COVID-19) has presented major challenges for clinical laboratories, from initial diagnosis to patient monitoring and treatment. Initial response to this pandemic involved the development, production, and distribution of diagnostic molecular assays at an unprecedented rate, leading to minimal validation requirements and concerns regarding their diagnostic accuracy in clinical settings. In addition to molecular testing, serological assays to detect antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are now becoming available from numerous diagnostic manufacturers. In both cases, the lack of peer-reviewed data and regulatory oversight, combined with general misconceptions regarding their appropriate use, have highlighted the importance of laboratory professionals in robustly validating and evaluating these assays for appropriate clinical use. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Task Force on COVID-19 has been established to synthesize up-to-date information on the epidemiology, pathogenesis, and laboratory diagnosis and monitoring of COVID-19, as well as to develop practical recommendations on the use of molecular, serological, and biochemical tests in disease diagnosis and management. This review summarizes the latest evidence and status of molecular, serological, and biochemical testing in COVID-19 and highlights some key considerations for clinical laboratories operating to support the global fight against this ongoing pandemic. Confidently this consolidated information provides a useful resource to laboratories and a reminder of the laboratory's critical role as the world battles this unprecedented crisis.

positive: The Importance of Diagnostic Testing during a Viral Pandemic: Early Lessons from Novel Coronavirus Disease (COVID-19) The Importance of Diagnostic Testing during a Viral Pandemic: Early Lessons from Novel Coronavirus Disease (COVID-19).

positive: Detection of SARS Coronavirus in Patients with Suspected SARS Cases of severe acute respiratory syndrome (SARS) were investigated for SARS coronavirus (SARS-CoV) through RNA tests, serologic response, and viral culture. Of 537 specimens from patients in whom SARS was clinically diagnosed, 332 (60%) had SARS-CoV RNA in one or more clinical specimens, compared with 1 (0.3%) of 332 samples from controls. Of 417 patients with clinical SARS from whom paired serum samples were available, 92% had an antibody response. Rates of viral RNA positivity increased progressively and peaked at day 11 after onset of illness. Although viral RNA remained detectable in respiratory secretions and stool and urine specimens for >30 days in some patients, virus could not be cultured after week 3 of illness. Nasopharyngeal aspirates, throat swabs, or sputum samples were the most useful clinical specimens in the first 5 days of illness, but later in the illness viral RNA could be detected more readily in stool specimens.

positive: Diagnosing COVID-19: The Disease and Tools for Detection [Image: see text] COVID-19 has spread globally since its discovery in Hubei province, China in December 2019. A combination of computed tomography imaging, whole genome sequencing, and electron microscopy were initially used to screen and identify SARS-CoV-2, the viral etiology of COVID-19. The aim of this review article is to inform the audience of diagnostic and surveillance technologies for SARS-CoV-2 and their performance characteristics. We describe point-of-care diagnostics that are on the horizon and encourage academics to advance their technologies beyond conception. Developing plug-and-play diagnostics to manage the SARS-CoV-2 outbreak would be useful in preventing future epidemics.

positive: The early antibody response to SARS-Cov-2 infection.

positive: Diagnostic performance of immunochromatography assay for rapid detection of IgM and IgG in coronavirus disease 2019 Serologic assays have been developed to detect infection with coronavirus disease 2019 (COVID‐19). This study was conducted to evaluate the diagnostic performance of an immunochromatography‐based assay of human serum for COVID‐19. The present study enrolled 149 subjects who had been tested by real‐time reverse transcription‐polymerase chain reaction (RT‐PCR) for COVID‐19 and were classified into two groups: 70 who were positive for COVID‐19 and 79 who were negative for COVID‐19 based on RT‐PCR. An immunochromatography‐based COVID‐19 immunoglobulin G (IgG)/immunoglobulin M (IgM) rapid test on the sera of the study population was applied to measure the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and receiver operating characteristic (ROC) curve compared to RT‐PCR, with a 95% confidence interval (CI). IgM or IgG antibodies were detected in 65 subjects (92.9%) classified as positive for COVID‐19 and in three subjects (3.8%) classified as negative for COVID‐19. The sensitivity and specificity percentages for IgM or IgG antibodies were 92.9% (95% CI: 84.1‐97.6) and 96.2% (95% CI: 89.3‐99.2), respectively, with 95.6% PPV and 93.8% NPV. The PPV rapidly improved with increasing disease prevalence from 19.8% to 96.1% in the presence of either IgM or IgG, while the NPV remained high with a change from 99.9% to 93.1%. The area under the ROC curve was 0.945 (95% CI: 0.903‐0.988) for subjects with either IgM or IgG positivity. In conclusion, the immunochromatography‐based COVID‐19 IgG/IgM rapid test is a useful and practical diagnostic assay for detection of COVID‐19, especially in the presence of IgM or IgG antibodies.

positive: [Serological investigation on close contacts to patients with severe acute respiratory syndrome in an SARS outbreak]. OBJECTIVE To study the evidence of severe acute respiratory syndrome (SARS) infection among close contacts to SARS patients and the level of sera IgG antibody in SARS cases. METHODS Specific IgG antibody against SARS-CoV in serum samples from contacts to patients, five months before an SARS outbreak in Beijing. Neutralized test, ELISA and immunity adherence test were studied. Samples were collected after clinical onset of patients or close contacts to patients, for 22 - 24 weeks. 19 close contacts and 13 cases were included in the study. RESULTS In close contacts, all tests were negative on three methods. All SARS cases were positive except one by immunity adherence test. The neutralized antibody levels were from 1:16 to 1:203, with medium level of 1:43. CONCLUSION According to our survey, there was no latent infection among close contacts. IgG antibody in sera continued to be at higher levels among SARS cases 22 - 24 weeks after onset.

positive: Negative SARS-CoV-2 antibody testing following COVID-19 infection in Two MS patients treated with ocrelizumab BACKGROUND: It is unknown whether MS disease modifying therapies impact ability to mount an antibody response to SARS-CoV-2. METHODS: Case series and literature review. We report a series of two MS patients who developed COVID-19 while on Ocrelizumab therapy and subsequently exhibited negative SARS-CoV-2 serology. RESULTS: A 42-year-old man and 39-year-old woman with MS developed COVID-19 while on Ocrelizumab therapy. Neither patient required hospitalization. The man exhibited negative serology at 7- and 9-weeks post-infection. The woman exhibited negative serology at 6- and 12-weeks post-infection. CONCLUSIONS: Large studies are essential to determine whether certain DMTs may blunt SARS-CoV-2 antibody production.

positive: Covid-19: Antibody tests will not be rolled out in UK until at least May, MPs hear.

positive: Diagnostic value and dynamic variance of serum antibody in coronavirus disease 2019 OBJECTIVE: To investigate the diagnostic value of serological testing and dynamic variance of serum antibody in coronavirus disease 2019 (COVID-19). METHODS: This study retrospectively included 43 patients with a laboratory-confirmed infection and 33 patients with a suspected infection, in whom the disease was eventually excluded. The IgM/IgG titer of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was measured by chemiluminescence immunoassay analysis. RESULTS: Compared to molecular detection, the sensitivities of serum IgM and IgG antibodies to diagnose COVID-19 were 48.1% and 88.9%, and the specificities were 100% and 90.9%, respectively.In the COVID-19 group, the IgM-positive rate increased slightly at first and then decreased over time; in contrast, the IgG-positive rate increased to 100% and was higher than IgM at all times. The IgM-positive rate and titer were not significantly different before and after conversion to virus-negative. The IgG-positive rate was up to 90% and not significantly different before and after conversion to virus-negative. However, the median IgG titer after conversion to virus-negative was double that before, and the difference was significant. CONCLUSIONS: Viral serological testing is an effective means of diagnosis for SARS-CoV-2 infection. The positive rate and titer variance of IgG are higher than those of IgM in COVID-19.

positive: Anti-SARS-CoV-2 virus antibody levels in convalescent plasma of six donors who have recovered from COVID-19 Background: Anti-SARS-CoV-2 virus antibody levels in convalescent plasma (CP), which may be useful in severe Anti-SARS-CoV-2 virus infections, have been rarely reported. Results: A total of eight donors were considered for enrollment; two of them were excluded because of ineligible routine check. Of the six remaining participants, five samples were tested weakly positive by the IgM ELISA. Meanwhile, high titers of IgG were observed in five samples. The patient treated with CP did not require mechanical ventilation 11 days after plasma transfusion, and was then transferred to a general ward. Conclusions: Our serological findings in convalescent plasma from recovered patients may help facilitate understanding of the SARS-CoV-2 infection and establish CP donor screening protocol in COVID-19 outbreak. Methods: Anti-SARS-CoV-2 antibodies including IgM and IgG were measured by two enzyme-linked immunosorbent assays (ELISA) in convalescent plasma from six donors who have recovered from coronavirus disease 2019 (COVID-19) in Nanjing, China. CP was also utilized for the treatment of one severe COVID-19 patient.

positive: The early antibody response to SARS-Cov-2 infection

positive: The role of serology for COVID-19 control: Population, kinetics and test performance do matter

positive: Joint Detection of Serum IgM/IgG Antibody is An Important Key to Clinical Diagnosis of SARS-COV-2 Infection Background: This study was aimed to investigate the application of SARS- COV-2 IgM and IgG antibodies in diagnosis of COVID-19 infection. Method: This study enrolled a total of 178 patients at Huangshi Central Hospital from January to February, 2020. Among them, 68 patients were SARS-COV-2 infected confirmed with nucleic acid test (NAT) and CT imaging. 9 patients were in the suspected group (NAT negative) with fever and other respiratory symptoms. 101 patients were in the control group with other diseases and negative to SARS-COV-2 infection. After serum samples were collected, SARS-COV-2 IgG and IgM antibodies were tested by chemiluminescence immunoassay (CLIA) for all patients. Results: The specificity of serum IgM and IgG antibodies to SARS-COV-2 were 99.01% (100/101) and 96.04% (97/101) respectively, and the sensitivity were 88.24% (60/68) and 97.06% (66/68) respectively. The combined detection rate of SARS-COV-2 IgM and IgG antibodies were 98.53% (67/68). Conclusion: Combined detection of serum SARS-COV-2 IgM and IgG antibodies had better sensitivity compared with single IgM or IgG test, which can be used as an important diagnostic tool for SARS-COV-2 infection and a screening tool of potential SARS-COV-2 carriers in clinics, hospitals and accredited scientific laboratory.

positive: Profile of IgG and IgM antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) We profiled the serological responses to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) nucleocapsid (N) protein and spike (S) glycoprotein. The majority of the patients developed robust antibody responses between 17 and 23 days after illness onset. Delayed, but stronger antibody responses were observed in critical patients.

positive: Development and validation of different indirect ELISAs for MERS-CoV serological testing Abstract Since 2012, MERS-CoV has caused up to 2220 cases and 790 deaths in 27 countries with Saudi Arabia being the most affected country with ~83.1% of the cases and ~38.8% local death rate. Current serological assays such as microneutralization (MN), plaque reduction neutralization, immunofluorescence, protein microarray or pseudoparticle neutralization assays rely on handling of live MERS-CoV in high containment laboratories or need for expensive and special equipment and reagents and highly trained personnel which represent a technical hurdle for most laboratories in resource-limited MERS-CoV endemic countries. Here, we developed, compared and evaluated three different indirect ELISAs based on MERS-CoV nucleocapsid protein (N), spike (S) ectodomain (amino acids 1–1297) and S1 subunit (amino acids 1–725) and compared them with MN assay. The developed ELISAs were evaluated using large number of confirmed seropositive (79 samples) and seronegative (274 samples) MERS-CoV human serum samples. Both rS1- and rS-ELISAs maintained high sensitivity and specificity (≥90%) across a wider range of OD values compared to rN-ELISA. Moreover, rS1- and rS-based ELISAs showed better agreement and correlation with MN assay in contrast to rN-ELISA. Collectively, our data demonstrate that rS1-ELISA and rS-ELISA are more reliable than rN-ELISA and represent a suitable choice for seroepidemiological testing and surveillance in MERS-CoV endemic regions.

positive: Development and application of an indirect ELISA for the detection of antibodies to porcine epidemic diarrhea virus based on a recombinant spike protein BACKGROUND: As the major causative agent of swine viral diarrhea, porcine epidemic diarrhea virus (PEDV) has caused massive losses to the economies of swine raising countries. Accordingly, the serological detection of corresponding antibodies would be beneficial to diagnose PEDV indirectly to control the disease. In this study, an indirect enzyme-linked immunosorbent assay (ELISA) based on the recombinant truncated spike (S) protein of PEDV was developed and validated. RESULTS: The reaction conditions of the developed indirect ELISA were optimized. This indirect ELISA was compared to indirect immunoinfluscent assay (IFA), and the overall coincidence rate was 96.74% based on testing 368 clinical serum samples with different PEDV antibody levels. No cross-reactivity with other common swine pathogens was detected for the developed S1 indirect ELISA. Finally, the S1 indirect ELISA was applied to detect serum antibodies of 3304 field samples collected from different pig farms in eastern China, and it presented an overall substantial agreement on the PEDV infection status. CONCLUSIONS: This established S1 indirect ELISA is capable of detecting serum antibodies against PEDV, and due to its high sensitivity and specificity, it could be applied for serological evaluation and indirect diagnosis of PEDV infection.

positive: Different longitudinal patterns of nucleic acid and serology testing results based on disease severity of COVID-19 patients Effective strategy to mitigate the ongoing pandemic of 2019 novel coronavirus (COVID-19) require a comprehensive understanding of humoral responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the emerging virus causing COVID-19. The dynamic profile of viral replication and shedding along with viral antigen specific antibody responses among COVID-19 patients started to be reported but there is no consensus on their patterns. Here, we conducted a serial investigation on 21 individuals infected with SARS-CoV-2 in two medical centres from Jiangsu Province, including 11 non-severe COVID-19 patients, and 5 severe COVID-19 patients and 5 asymptomatic carriers based on nucleic acid test and clinical symptoms. The longitudinal swab samples and sera were collected from these people for viral RNA testing and antibody responses, respectively. Our data revealed different pattern of seroconversion among these groups. All 11 non-severe COVID-19 patients and 5 severe COVID-19 patients were seroconverted during hospitalization or follow-up period, suggesting that serological testing is a complementary assay to nucleic acid test for those symptomatic COVID-19 patients. Of note, immediate antibody responses were identified among severe cases, compared to non-severe cases. On the other hand, only one were seroconverted for asymptomatic carriers. The SARS-CoV-2 specific antibody responses were well-maintained during the observation period. Such information is of immediate relevance and would assist COVID-19 clinical diagnosis, prognosis and vaccine design.

positive: Evaluations of serological test in the diagnosis of 2019 novel coronavirus (SARS-CoV-2) infections during the COVID-19 outbreak The ongoing SARS-CoV-2 outbreak has killed over twenty-one thousand and sickened over four hundred thousand people worldwide, posing a great challenge to global public health. A sensitive and accurate diagnosis method will substantially help to control disease expansion. Here, we developed a chemiluminescence-immunoassay method based on the recombinant nucleocapsid antigen and the magnetic beads for diagnosis of SARS-CoV-2 infections and surveillance of antibody changing pattern. Serums from 29 healthy individuals, 51 tuberculosis patients, and 79 SARS-CoV-2 confirmed patients were employed to evaluate the performance of this approach. Compared to the IgM testing, the IgG testing was more reliable in which it identified 65 SARS-CoV-2 infections from the 79 confirmed patients and only two false-positive cases from the 80 control group with a sensitivity and specificity reaching 82.28% and 97.5%, respectively. However, only a slight difference (not statistically significant) in the detected cases of SARS-CoV-2 infections was observed between the IgM and IgG testing manner in patients at a different time of onset of disease. A performance comparison between an ELISA kit using the same nucleocapsid antigen and our chemiluminescence method was undertaken. The same false-positive cases were seen in both methods from the paired control group, while ELISA kit can only detect half of the SARS-CoV-2 infections from paired SARS-CoV-2 confirmed patients group than that of the chemiluminescence method, indicating a higher performance for the chemiluminescence-immunoassay approach. Together, our studies provide a useful and valuable serological testing tool for the diagnosis of SARS-CoV-2 infections in the community.

positive: A preliminary study on serological assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 238 admitted hospital patients In this study, we aimed to evaluate the diagnostic value of serological assay for SARS-CoV-2. A newly-developed ELISA assay for IgM and IgG antibodies against N protein of SARS-CoV-2 was used to screen the serums of 238 admitted hospital patients between February 6 and February 14, 2020 with confirmed or suspected SARS-CoV-2. SARS-CoV-2 RNA was detected on pharyngeal swab specimens using real time RT-PCR. 194 (81.5%) of the serums were detected to be antibody (IgM and/or IgG) positive, significantly higher than the positive rate of viral RNA (64.3%). There was no difference in the positive rate of antibodies between the confirmed patients (83.0%, 127/153) and the suspected patients (78.8%, 67/85), whose nucleic acid tests were negative. The antibody positive rates were very low in the first five days after initial onset of symptoms, and then rapidly increased as the disease progressed. After 10 days, the antibody positive rates jumped from below 50% to over 80%. However, the positive rates of viral RNA maintained above 60% in the first 11 days after initial onset of symptoms, and then rapidly decreased. Overall, the suspected patients were most likely infected by SARS-CoV-2. Before the 11th day after initial onset of symptoms, nucleic acid test is key for confirmation of viral infection. The combination of serological assay can greatly improve the diagnostic efficacy. After the 11th day post-disease onset, the diagnosis for viral infection should be majorly dependent on serological assay.

positive: Performance of VivaDiag COVID‐19 IgM/IgG Rapid Test is inadequate for diagnosis of COVID‐19 in acute patients referring to emergency room department From late December 2019 COVID-19 (Coronavirus infectious disease 19) epidemics spread from Wuhan, China, to all over the world, including Italy. This article is protected by copyright. All rights reserved.

positive: Development of a Western blot assay for detection of antibodies against coronavirus causing severe acute respiratory syndrome. To identify a major antigenic determinant for use in the development of a rapid serological diagnostic test for severe acute respiratory syndrome (SARS) coronavirus infection and to study the immune response during SARS coronavirus infection in humans, we cloned the full length and six truncated fragments of the nucleocapsid gene, expressed them, and purified them as glutathione S-transferase-tagged recombinant proteins. The reactivities of the recombinant proteins to a panel of antibodies containing 33 SARS coronavirus-positive sera and 66 negative sera and to antibodies against other animal coronaviruses were screened. A truncated 195-amino-acid fragment from the C terminus of the nucleocapsid protein (N195) was identified that had a strong ability to detect antibodies against SARS coronavirus. No cross-reaction was found between the N195 protein and antibodies against chicken, pig, and canine coronaviruses. The N195 protein was used to develop a Western blot assay to detect antibodies against SARS coronavirus in 274 clinically blinded samples. The specificity and sensitivity of this test were 98.3 and 90.9%, respectively. The correlation between our Western blotting assay and an immunofluorescence assay (IFA) was also analyzed. The results of our Western blot assay and IFA for the detection of SARS coronavirus-positive sera were the same. Thus, the N195 protein was identified as a suitable protein to be used as an antigen in Western blot and other possible assays for the detection of SARS coronavirus infection.

positive: Navigating the Pandemic Response Life Cycle: Molecular Diagnostics and Immunoassays in the Context of COVID-19 Management. Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To counter COVID-19 spreading, an infrastructure to provide rapid and thorough molecular diagnostics and serology testing is the cornerstone of outbreak and pandemic management. We hereby review the clinical insights with regard to using molecular tests and immunoassays in the context of COVID-19 management life cycle: the preventive phase, the preparedness phase, the response phase and the recovery phase. The spatial and temporal distribution of viral RNA, antigens and antibodies during human infection is summarized to provide a biological foundation for accurate detection of the disease. We shared the lessons learned and the obstacles encountered during real world high-volume screening programs. Clinical needs are discussed to identify existing technology gaps in these tests. Leverage technologies, such as engineered polymerases, isothermal amplification, and direct amplification from complex matrices may improve the productivity of current infrastructure, while emerging technologies like CRISPR diagnostics, visual end point detection, and PCR free methods for nucleic acid sensing may lead to at-home tests. The lessons learned, and innovations spurred from the COVID-19 pandemic could upgrade our global public health infrastructure to better combat potential outbreaks in the future.

positive: Reactivity of antibodies in human serum with antigens of an enteropathogenic bovine coronavirus Antibodies in human serum against an enteropathogenic bovine coronavirus were detected by double immunodiffusion (DID), neutralization of infectivity, indirect immunofluorescence, and immune electron microscopy. Human sera reacting in the DID test neutralized the infectivity of the bovine coronaviruses to indices of 2.5 to > 5. Nineteen of 40 DID-negative, heat-inactivated sera had neutralizing indices of 1 to 3.0. Human serum with neutralizing and DID antibodies produced juxtanuclear and cytoplasmic fluorescence identical to that of bovine immune serum in cells infected with the bovine coronavirus. Antibodies in human and bovine sera interacted with the peplomeres of the bovine coronavirus, matting and bridging them, when present in excess, and facilitated formation of large viral aggregates when present in equivalent concentrations. Complement added to the virus-antibody complexes did not alter specifically the morphology of single, antibody-laden viral particles or viral particles in aggregates. Evidence of the transmission of coronavirus from experimentally inoculated calves to man, with ensuing gastroenteritis, was found by electron microscopic tracing of the coronavirus and its virus-antibody complexes.

positive: Sensitivity in Detection of Antibodies to Nucleocapsid and Spike Proteins of Severe Acute Respiratory Syndrome Coronavirus 2 in Patients With Coronavirus Disease 2019 BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), is associated with respiratory-related disease and death. Assays to detect virus-specific antibodies are important to understand the prevalence of infection and the course of the immune response. METHODS: Quantitative measurements of plasma or serum antibodies to the nucleocapsid and spike proteins were analyzed using luciferase immunoprecipitation system assays in 100 cross-sectional or longitudinal samples from patients with SARS-CoV-2 infection. A subset of samples was tested both with and without heat inactivation. RESULTS: At >14 days after symptom onset, antibodies against SARS-CoV-2 nucleocapsid protein showed 100% sensitivity and 100% specificity, whereas antibodies to spike protein were detected with 91% sensitivity and 100% specificity. Neither antibody levels nor the rate of seropositivity were significantly reduced by heat inactivation of samples. Analysis of daily samples from 6 patients with COVID-19 showed anti-nucleocapsid and spike protein antibodies appearing between days 8 and 14 after initial symptoms. Immunocompromised patients generally had a delayed antibody response to SARS-CoV-2, compared with immunocompetent patients. CONCLUSIONS: Antibody to the nucleocapsid protein of SARS-CoV-2 is more sensitive than spike protein antibody for detecting early infection. Analyzing heat-inactivated samples with a luciferase immunoprecipitation system assay is a safe and sensitive method for detecting SARS-CoV-2 antibodies.

positive: Four point-of-care lateral flow immunoassays for diagnosis of COVID-19 and for assessing dynamics of antibody responses to SARS-CoV-2 OBJECTIVES: We aimed to evaluate the role of rapid serological tests in the management of coronavirus disease 2019 (COVID-19) patients. METHODS: This retrospective study enrolled 16 real-time reverse transcription polymerase chain reaction-confirmed symptomatic patients with COVID-19 and 58 COVID-19 negative patients at a medical center in Taiwan over a 3-month period. Serial serum samples were collected and tested for antibody response using four point-of-care (POC) lateral flow immunoassays (LFIA) (ALLTEST 2019-nCoV IgG/IgM Rapid Test, Dynamiker 2019-nCoV IgG/IgM Rapid Test, ASK COVID-19 IgG/IgM Rapid Test, and Wondfo SARS-CoV-2 Antibody Test). Time-dependent detection sensitivity and timeliness of seroconversion were determined and compared between the four POC rapid tests. RESULTS: The overall sensitivity and specificity of the four tests for detecting anti-SARS-CoV-2 antibodies after 3 weeks of symptom onset were 100% and 100%, respectively. There was no significant difference between the rapid tests used for detection of IgM and IgG separately and those used for detection of combined total antibody (mainly IgM/IgG). There was no significant difference between the four POC rapid tests in terms of time required for determining seroconversion of COVID-19. Patients with COVID-19 with pneumonia demonstrated shorter seroconversion time than those without pneumonia. CONCLUSION: Though the POC antibody rapid tests based on LFIA showed reliable performance in the detection of SARS-CoV-2-specific antibodies, the results of these tests should be interpreted and applied appropriately in the context of antibody dynamic of COVID-19 infection. COVID-19 patients complicated with pneumonia exhibited earlier anti-SARS-CoV-2 antibody response than COVID-19 patients without pneumonia.

positive: Review of Current Advances in Serologic Testing for COVID-19 OBJECTIVES: To examine and summarize the current literature on serologic methods for the detection of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: A literature review was performed using searches in databases including PubMed, medRxiv, and bioRxiv. Thirty-two peer-reviewed papers and 23 preprints were examined. RESULTS: The studies included lateral flow immunoassay, enzyme-linked immunosorbent assay, chemiluminescence immunoassay, and neutralizing antibody assays. The use of all major SARS-CoV-2 antigens was demonstrated to have diagnostic value. Assays measuring total antibody reactivity had the highest sensitivity. In addition, all the methods provided opportunities to characterize the humoral immune response by isotype. The combined use of IgM and IgG detection resulted in a higher sensitivity than that observed when detecting either isotype alone. Although IgA was rarely studied, it was also demonstrated to be a sensitive marker of infection, and levels correlated with disease severity and neutralizing activity. CONCLUSIONS: The use of serologic testing, in conjunction with reverse transcription polymerase chain reaction testing, was demonstrated to significantly increase the sensitivity of detection of patients infected with SARS-CoV-2. There was conflicting evidence regarding whether antibody titers correlated with clinical severity. However, preliminary investigations indicated some immunoassays may be a surrogate for the prediction of neutralizing antibody titers and the selection of recovered patients for convalescent serum donation.

positive: Specific serology for emerging human coronaviruses by protein microarray. We present a serological assay for the specific detection of IgM and IgG antibodies against the emerging human coronavirus hCoV-EMC and the SARS-CoV based on protein microarray technology. The assay uses the S1 receptor-binding subunit of the spike protein of hCoV-EMC and SARS-CoV as antigens. The assay has been validated extensively using putative cross-reacting sera of patient cohorts exposed to the four common hCoVs and sera from convalescent patients infected with hCoV-EMC or SARS-CoV.

positive: Covid-19: Antibody tests will not be rolled out in UK until at least May, MPs hear

positive: Evaluation of recombinant nucleocapsid and spike proteins for serological diagnosis of novel coronavirus disease 2019 (COVID-19) Background: The colloidal gold immunochromatography assay (GICA) is a rapid diagnostic tool for novel coronavirus disease 2019 (COVID-19) infections. However, with significant numbers of false negatives, improvements to GICA are needed. Methods: Six recombinant HCoV-19 nucleocapsid and spike proteins were prepared and evaluated. The optimal proteins were employed to develop a sandwich-format GICA strip to detect total antibodies (IgM and IgG) against HCoV-19. GICA performance was assessed with comparison of viral RNA detection. Results: Recombinant HCoV-19 proteins were obtained, including three prokaryotically expressed rN, rN1, rN2 nucleocapsid proteins, and three eukaryotically expressed rS1, rS-RBD, rS-RBD-mFc spike proteins. The recombinant proteins with the highest ELISA titers (rS1 and rS-RBD-mFc) against coronavirus-specific IgM and IgG were chosen for GICA development. The GICA has a sensitivity and specificity of 86.89% (106/122) and 99.39% (656/660), respectively. Furthermore, 65.63% (21/32) of the clinically confirmed but RT-PCR negative samples were GICA positive. Conclusions: The eukaryotically-expressed spike proteins (rS1and rS-RBD-mFc) are more suitable than the prokaryotically expressed nucleocapsid proteins for HCoV-19 serological diagnosis. The GICA sandwich used to detect total antibodies is a powerful complement to the current standard RNA-based tests.

positive: Laboratory diagnosis of SARS. The emergence of new viral infections of man requires the development of robust diagnostic tests that can be applied in the differential diagnosis of acute illness, or to determine past exposure, so as to establish the true burden of disease. Since the recognition in April 2003 of the severe acute respiratory syndrome coronavirus (SARS-CoV) as the causative agent of severe acute respiratory syndrome (SARS), enormous efforts have been applied to develop molecular and serological tests for SARS which can assist rapid detection of cases, accurate diagnosis of illness and the application of control measures. International progress in the laboratory diagnosis of SARS-CoV infection during acute illness has led to internationally agreed World Health Organization criteria for the confirmation of SARS. Developments in the dissection of the human immune response to SARS indicate that serological tests on convalescent sera are essential to confirm SARS infection, given the sub-optimal predictive value of molecular detection tests performed during acute SARS illness.

positive: Development and evaluation of an ELISA using recombinant fusion protein to detect the presence of host antibody to equine arteritis virus A recombinant glutathione-S-transferase fusion protein expressing amino acids 55–98 of equine arteritis virus (EAV) G(L) (rG(L)55–98) was tested in an ELISA for its ability to detect serum antibodies to EAV. Host antibodies induced following EAV infection bound the recombinant antigen by ELISA. The ELISA specificity and sensitivity were determined with a panel of equine sera including postinfection and postvaccination samples. A good correlation existed between EAV neutralizing antibody titers and ELISA absorbance values (r = 0.827). The sensitivity and specificity of the ELISA were 99.6 and 90.1%, respectively, compared with the EAV neutralization test and the recombinant antigen did not crossreact in ELISA with equine sera directed against other common equine respiratory viruses. Three post-EAV infection equine sera raised against different EAV isolates reacted strongly in the ELISA, as did two equine sera raised against EAV vaccines, indicating that the viral epitope was conserved between the viruses tested. Following vaccination with an inactivated whole virus vaccine, antibody detected with the recombinant antigen ELISA preceded the development of a virus-neutralizing response. The study demonstrates the potential application of rG(L)55–98 as a diagnostic antigen.

positive: Comparison of four new commercial serologic assays for determination of SARS-CoV-2 IgG BACKGROUND: Facing the ongoing pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there is an urgent need for serological assays identifying individuals with past coronavirus disease 2019 (COVID-19). STUDY DESIGN: Our study is the first to compare four new commercially available assays using 75 sera from patients tested positive or negative by SARS-CoV-2 PCR: the anti SARS-CoV-2 ELISA (IgG) (Euroimmun, Germany), the EDI New Coronavirus COVID-19 IgG ELISA, (Epitope diagnostics (EDI), USA), the recomWell SARS-CoV-2 IgG ELISA (Mikrogen, Germany), and the SARS-CoV-2 Virachip IgG (Viramed, Germany). RESULTS: We found a sensitivity of 86.4 %, 100 %, 86.4 %, and 77.3 % and a specificity of 96,2 %, 88,7 %, 100 %, and 100 % for the Euroimmun assay, the EDI assay, the Mikrogen assay, and the Viramed assay, respectively. CONCLUSIONS: Commercially available SARS-CoV-2 IgG assays have a sufficient specificity and sensitivity for identifying individuals with past SARS-CoV-2 infection.

positive: SARS‐CoV‐2 Seroconversion in Humans: A Detailed Protocol for a Serological Assay, Antigen Production, and Test Setup In late 2019, cases of atypical pneumonia were detected in China. The etiological agent was quickly identified as a betacoronavirus (named SARS‐CoV‐2), which has since caused a pandemic. Several methods allowing for the specific detection of viral nucleic acids have been established, but these only allow detection of the virus during a short period of time, generally during acute infection. Serological assays are urgently needed to conduct serosurveys, to understand the antibody responses mounted in response to the virus, and to identify individuals who are potentially immune to re‐infection. Here we describe a detailed protocol for expression of antigens derived from the spike protein of SARS‐CoV‐2 that can serve as a substrate for immunological assays, as well as a two‐stage serological enzyme‐linked immunosorbent assay (ELISA). These assays can be used for research studies and for testing in clinical laboratories. © 2020 The Authors. Current Protocols in Microbiology published by Wiley Periodicals LLC. Basic Protocol 1: Mammalian cell transfection and protein purification Basic Protocol 2: A two‐stage ELISA for high‐throughput screening of human serum samples for antibodies binding to the spike protein of SARS‐CoV‐2

positive: Evaluation of Nucleocapsid and Spike Protein-Based Enzyme-Linked Immunosorbent Assays for Detecting Antibodies against SARS-CoV-2 At present, PCR-based nucleic acid detection cannot meet the demands for coronavirus infectious disease (COVID-19) diagnosis. Two hundred fourteen confirmed COVID-19 patients who were hospitalized in the General Hospital of Central Theater Command of the People's Liberation Army between 18 January and 26 February 2020 were recruited. Two enzyme-linked immunosorbent assay (ELISA) kits based on recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (rN) and spike protein (rS) were used for detecting IgM and IgG antibodies, and their diagnostic feasibility was evaluated. Among the 214 patients, 146 (68.2%) and 150 (70.1%) were successfully diagnosed with the rN-based IgM and IgG ELISAs, respectively; 165 (77.1%) and 159 (74.3%) were successfully diagnosed with the rS-based IgM and IgG ELISAs, respectively. The positive rates of the rN-based and rS-based ELISAs for antibody (IgM and/or IgG) detection were 80.4% and 82.2%, respectively. The sensitivity of the rS-based ELISA for IgM detection was significantly higher than that of the rN-based ELISA. We observed an increase in the positive rate for IgM and IgG with an increasing number of days post-disease onset (d.p.o.), but the positive rate of IgM dropped after 35 d.p.o. The positive rate of rN-based and rS-based IgM and IgG ELISAs was less than 60% during the early stage of the illness, 0 to 10 d.p.o., and that of IgM and IgG was obviously increased after 10 d.p.o. ELISA has a high sensitivity, especially for the detection of serum samples from patients after 10 d.p.o., so it could be an important supplementary method for COVID-19 diagnosis.

positive: SARS-CoV-2-specific T cells without antibodies

positive: Quantification of SARS-CoV-2 antibodies with eight commercially available immunoassays Since the emergence of SARS-CoV-2 numerous antibody assays have become available, demonstrating different performance characteristics. This study focused on a quantitative correlation between different commercial assays and a neutralization test (NT). Comparative data is needed as a basis for the production of convalescent plasma and potential interpretations COVID-19 immunity. Sera of 100 SARS-CoV-2 convalescent plasma donors were collected and SARS-CoV-2 antibodies were characterized using three different IgG-ELISAs EUROIMMUN IgG and NCP-IgG ELISA, Wantai ELISA), two CLIA (Elecsys, LIAISON) and two lateral flow tests (MEDsan IgM/IgG-Rapid-Test, Wantai Rapid Test) and subsequently correlated to neutralization titers. The Wantai ELISA and the Elecsys provide the highest sensitivities in this sample (98 and 95 percent respectively). Titers with the best overall quantitative correlation to the NT titer were obtained with the Euroimmun IgG ELISA assay (Rho=0.759) and the Wantai ELISA assay (Rho=0.729). An infection without fever and negative or weakly positive reactions in the Wantai Rapid test were negative predictive factors for NT titers >1:200 (negative predictive value of 92% and 92% respectively, combination of both 100%). The Wantai ELISA titer could be a suitable substitute for NT. An adequate pooling strategy of plasma units additionally could compensate deviations of individual antibody titers.

positive: Estimating Force of Infection from Serologic Surveys with Imperfect Tests The force of infection, or the rate at which susceptible individuals become infected, is an important public health measure for assessing the extent of outbreaks and the impact of control programs. Here we present methods for estimating force of infection from serological surveys of infections which produce lasting immunity, taking into account imperfections in the test used, and uncertainty in such imperfections. The methods cover both single serological surveys, in which age is a proxy for time at risk, and repeat surveys in the same people, in which the force of infection is estimated more directly. Fixed values can be used for the sensitivity and specificity of the tests, or existing methods for belief elicitation can be used to include uncertainty in these values. The latter may be applicable, for example, when the specificity of a test depends on co-circulating pathogens, which may not have been well characterized in the setting of interest. We illustrate the methods using data from two published serological studies of dengue.

positive: Evaluation of two automated and three rapid lateral flow immunoassays for the detection of anti-SARS-CoV-2 antibodies INTRODUCTION: Several SARS-CoV-2 immunoassays have been developed recently. The purpose of this study was to assess the performance of five immunoassays for the detection of SARS-CoV-2 antibodies. METHODS: Two quantitative automated immunoassays (Maglumi™2019-n-Cov IgG and IgM and Euroimmun Anti-SARS-CoV-2 IgG and IgA assays) and three lateral flow rapid tests were performed. This retrospective study included 200 residual sera from patients and healthy volunteers. Case serum samples (n = 128) were obtained from COVID-19 patients confirmed by RT-qPCR and CT-scan. Days since onset of symptoms was collected from their medical records. Control non-SARS-CoV-2 samples (n = 72) were obtained from anonymous stored residual serum samples. RESULTS: Maglumi™ IgG/IgM tests showed overall less sensitivity than Euroimmun IgG/IgA test (84.4 % versus 64.3 %). Both tests showed similar specificities of IgG at 99 % and 100 %, respectively. The results from the lateral flow assays were easily interpretable with unambiguous coloured reading bands. The overall sensitivity of the three tests was similar (around 70 %) without any significant differences. The sensitivity of the three lateral flow assays and also of the serological quantitative assays increased during the second week after symptom onset and all reached similar values (91 %-94 %) after 14 days. CONCLUSION: This study shows accurate and equivalent performance of the five serological antibody assays (ELISA, CLIA and three lateral flow tests) in detecting SARS-CoV-2 antibodies 14 days after the onset of COVID-19 symptoms. This is compatible with their application in specific clinical contexts and in determining epidemiological strategies for the COVID-19 pandemic.

positive: Development and potential usefulness of the COVID-19 Ag Respi-Strip diagnostic assay in a pandemic context. Introduction: COVID-19 Ag Respi-Strip, an immunochromatographic (ICT) assay for the rapid detection of SARS-CoV-2 antigen on nasopharyngeal specimen, has been developed to identify positive COVID-19 patients allowing prompt clinical and quarantine decisions. In this Original Research article, we describe the conception, the analytical and clinical performances as well as the risk management of implementing the COVID-19 Ag Respi-Strip in a diagnostic decision algorithm. Materials and Methods: Development of the COVID-19 Ag Respi-Strip resulted in a ready-to-use ICT assay based on a membrane technology with colloidal gold nanoparticles using monoclonal antibodies directed against the SARS-CoV and SARS-CoV-2 highly conserved nucleoprotein antigen. Four hundred observations were recorded for the analytical performance study and thirty tests were analysed for the cross-reactivity study. The clinical performance study was performed in a retrospective multi-centric evaluation on aliquots of 328 nasopharyngeal samples. COVID-19 Ag Respi-Strip results were compared with qRT-PCR as golden standard for COVID-19 diagnostics. Results: In the analytical performance study, the reproducibility showed a between-observer disagreement of 1.7%, a robustness of 98%, an overall satisfying user friendliness and no cross-reactivity with other virus-infected nasopharyngeal samples. In the clinical performance study performed in three different clinical laboratories we found an overall sensitivity and specificity of 57.6% and 99.5% respectively with an accuracy of 82.6%. The cut-off of the assay was found at Ct<22. User-friendliness analysis and risk management assessment through Ishikawa diagram demonstrate that COVID-19 Ag Respi-Strip may be implemented in clinical laboratories according to biosafety recommendations. Conclusion: The COVID-19 Ag Respi-Strip represents a promising rapid SARS-CoV-2 antigen assay for the first-line diagnosis of COVID-19 in 15 minutes. Its role in the proposed diagnostic algorithm is complementary to the currently-used molecular techniques.

positive: Characteristics and assessment of the usefulness of serological tests in the diagnostic of infections caused by coronavirus SARS-CoV-2 on the basis of available manufacturer's data and literature review. Recognized in 2019 in Wuhan, China, the new SARS-CoV-2 coronavirus is responsible for the occurrence of a global pandemic disease called COVID-19. So far, confirmation of infection is based on the detection of virus RNA in a sample taken from a person meeting the suspected case definition. However, in the laboratory diagnosis of SARS-CoV-2 infections, in addition to genetic tests, serological methods can also be used to detect specific antibodies of the IgM, IgG and IgA class produced after contact with antigens or to detect viral antigen. Currently, a number of rapid immunochromatographic, chemiluminescent and ELISA immunoassay tests developed by different manufacturers for the diagnosis of COVID-19 are available on the market. Despite this fact, so far there is no WHO or ECDC recommendations or even reliable research regarding the usefulness of serological investigations in the laboratory diagnosis of infections caused by SARS-CoV-2.

positive: Severe Acute Respiratory Syndrome Coronavirus 2-Specific Antibody Responses in Coronavirus Disease Patients A new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has recently emerged to cause a human pandemic. Although molecular diagnostic tests were rapidly developed, serologic assays are still lacking, yet urgently needed. Validated serologic assays are needed for contact tracing, identifying the viral reservoir, and epidemiologic studies. We developed serologic assays for detection of SARS-CoV-2 neutralizing, spike protein-specific, and nucleocapsid-specific antibodies. Using serum samples from patients with PCR-confirmed SARS-CoV-2 infections, other coronaviruses, or other respiratory pathogenic infections, we validated and tested various antigens in different in-house and commercial ELISAs. We demonstrated that most PCR-confirmed SARS-CoV-2-infected persons seroconverted by 2 weeks after disease onset. We found that commercial S1 IgG or IgA ELISAs were of lower specificity, and sensitivity varied between the 2 assays; the IgA ELISA showed higher sensitivity. Overall, the validated assays described can be instrumental for detection of SARS-CoV-2-specific antibodies for diagnostic, seroepidemiologic, and vaccine evaluation studies.

positive: Test performance evaluation of SARS-CoV-2 serological assays BACKGROUND: Serological tests are crucial tools for assessments of SARS-CoV-2 exposure, infection and potential immunity. Their appropriate use and interpretation require accurate assay performance data. METHOD: We conducted an evaluation of 10 lateral flow assays (LFAs) and two ELISAs to detect anti-SARS-CoV-2 antibodies. The specimen set comprised 128 plasma or serum samples from 79 symptomatic SARS-CoV-2 RT-PCR-positive individuals; 108 pre-COVID-19 negative controls; and 52 recent samples from individuals who underwent respiratory viral testing but were not diagnosed with Coronavirus Disease 2019 (COVID-19). Samples were blinded and LFA results were interpreted by two independent readers, using a standardized intensity scoring system. RESULTS: Among specimens from SARS-CoV-2 RT-PCR-positive individuals, the percent seropositive increased with time interval, peaking at 81.8–100.0% in samples taken >20 days after symptom onset. Test specificity ranged from 84.3–100.0% in pre-COVID-19 specimens. Specificity was higher when weak LFA bands were considered negative, but this decreased sensitivity. IgM detection was more variable than IgG, and detection was highest when IgM and IgG results were combined. Agreement between ELISAs and LFAs ranged from 75.7–94.8%. No consistent cross-reactivity was observed. CONCLUSION: Our evaluation showed heterogeneous assay performance. Reader training is key to reliable LFA performance, and can be tailored for survey goals. Informed use of serology will require evaluations covering the full spectrum of SARS-CoV-2 infections, from asymptomatic and mild infection to severe disease, and later convalescence. Well-designed studies to elucidate the mechanisms and serological correlates of protective immunity will be crucial to guide rational clinical and public health policies.

positive: Rapid and Sensitive Detection of anti-SARS-CoV-2 IgG, Using Lanthanide-Doped Nanoparticles-Based Lateral Flow Immunoassay [Image: see text] The outbreak of 2019 coronavirus disease (COVID-19) has been a challenge for hospital laboratories because of the huge number of samples that must be tested for the presence of the causative pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Simple and rapid immunodiagnostic methods are urgently needed to identify positive cases. Here we report the development of a rapid and sensitive lateral flow immunoassay (LFIA) that uses lanthanide-doped polysterene nanoparticles (LNPs) to detect anti-SARV-CoV-2 IgG in human serum. A recombinant nucleocapsid phosphoprotein of SARS-CoV-2 was dispensed onto a nitrocellulose membrane to capture specific IgG. Mouse anti-human IgG antibody was labeled with self-assembled LNPs that served as a fluorescent reporter. A 100-μL aliquot of serum samples (1:1000 dilution) was used for this assay and the whole detection process took 10 min. The results of the validation experiment met the requirements for clinical diagnostic reagents. A value of 0.0666 was defined as the cutoff value by assaying 51 normal samples. We tested 7 samples that were positive by reverse-transcription (RT-)PCR and 12 that were negative but clinically suspicious for the presence of anti-SARS-CoV-2 IgG. One of the negative samples was determined to be SARS-CoV-2 IgG positive, while the results for the other samples were consistent with those obtained by RT-PCR. Thus, this assay can achieve rapid and sensitive detection of anti-SARS-CoV-2 IgG in human serum and allow positive identification in suspicious cases; it can also be useful for monitoring the progression COVID-19 and evaluating patients’ response to treatment.

positive: Evaluation of nine commercial SARS-CoV-2 immunoassays Due to urgency and demand, numerous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoassays are rapidly being developed and placed on the market with limited validation on clinical samples. Thorough validation of serological tests are required to facilitate their use in the accurate diagnosis of SARS-CoV-2 infection, confirmation of molecular results, contact tracing, and epidemiological studies. This study evaluated the sensitivity and specificity of nine commercially available serological tests. These included three enzyme-linked immunosorbent assays (ELISAs) and six point-of-care (POC) lateral flow tests. The assays were validated using serum samples from: i) SARS-CoV-2 PCR-positive patients with a documented first day of disease; ii) archived sera obtained from healthy individuals before the emergence of SARS-CoV-2 in China; iii) sera from patients with acute viral respiratory tract infections caused by other coronaviruses or non-coronaviruses; and iv) sera from patients positive for dengue virus, cytomegalovirus and Epstein Barr virus. The results showed 100% specificity for the Wantai SARS-CoV-2 Total Antibody ELISA, 93% for the Euroimmun IgA ELISA, and 96% for the Euroimmun IgG ELISA with sensitivities of 90%, 90%, and 65%, respectively. The overall performance of the POC tests according to manufacturer were in the rank order of AutoBio Diagnostics > Dynamiker Biotechnology = CTK Biotech > Artron Laboratories > Acro Biotech ≥ Hangzhou Alltest Biotech. Overall, these findings will facilitate selection of serological assays for the detection SARS-CoV-2-specific antibodies towards diagnosis as well as sero-epidemiological and vaccine development studies.

positive: Serology for SARS-CoV-2: Apprehensions, opportunities, and the path forward Serological testing for SARS-CoV-2 has enormous potential to contribute to COVID-19 pandemic response efforts. However, the required performance characteristics of antibody tests will critically depend on the use case (individual-level vs. population-level).

positive: Monoclonal antibody-based antigen capture enzyme-linked immunosorbent assay reveals high sensitivity of the nucleocapsid protein in acute-phase sera of severe acute respiratory syndrome patients. Accurate and timely diagnosis of severe acute respiratory syndrome coronavirus (SARS-CoV) infection is a critical step in preventing another global outbreak. In this study, 829 serum specimens were collected from 643 patients initially reported to be infected with SARS-CoV. The sera were tested for the N protein of SARS-CoV by using an antigen capture enzyme-linked immunosorbent assay (ELISA) based on monoclonal antibodies against the N protein of SARS-CoV and compared to 197 control serum samples from healthy donors and non-SARS febrile patients. The results of the N protein detection analysis were directly related to the serological analysis data. From 27 SARS patients who tested positive with the neutralization test, 100% of the 24 sera collected from 1 to 10 days after the onset of symptoms were positive for the N protein. N protein was not detected beyond day 11 in this group. The positive rates of N protein for sera collected at 1 to 5, 6 to 10, 11 to 15, and 16 to 20 days after the onset of symptoms for 414 samples from 298 serologically confirmed patients were 92.9, 69.8, 36.4, and 21.1%, respectively. For 294 sera from 248 serological test-negative patients, the rates were 25.6, 16.7, 9.3, and 0%, respectively. The N protein was not detected in 66 patients with cases of what was initially suspected to be SARS but serologically proven to be negative for SARS and in 197 serum samples from healthy donors and non-SARS febrile patients. The specificity of the assay was 100%. Furthermore, of 16 sera collected from four patients during the SARS recurrence in Guangzhou, 5 sera collected from 7 to 9 days after the onset of symptoms were positive for the N protein. N protein detection exhibited a high positive rate, 96 to 100%, between day 3 and day 5 after the onset of symptoms for 27 neutralization test-positive SARS patients and 298 serologically confirmed patients. The N protein detection rate continually decreased beginning with day 10, and N protein was not detected beyond day 19 after the onset of symptoms. In conclusion, an antigen capture ELISA reveals a high N protein detection rate in acute-phase sera of patients with SARS, which makes it useful for early diagnosis of SARS.

positive: Indication for SARS-CoV-2 serology: first month follow-up SARS-CoV-2 detection is mainly performed by RT-PCR but recently serological tests were made available. A first one month follow-up of the SARS-CoV-2 serology records was performed in our laboratory to precise the diversity and proportion of the SARS-CoV-2 serology test indications and to identify new valid indications (meningoencephalitis, vasculitis, etc)

positive: Comparison of serologic assays for measurement of antibody response to coronavirus in cats. Serologic virus neutralization tests, indirect immunofluorescence tests, and ELISA, using tissue culture-adapted feline infectious peritonitis virus (FIPV) or feline enteric coronavirus (FECV) were compared for their ability to distinguish specific virus exposure in cats. Sera of specific-pathogen-free cats inoculated with virulent or modified FIPV or FECV were used to compare the sensitivity and specificity of the homologous assays to a heterologous assay that measures antibody reactivity with transmissible gastroenteritis virus of swine. The geometric means of the serologic titers in FIPV and FECV assays were higher for FIPV- or FECV-infected specific-pathogen-free cats than the geometric means of the transmissible gastroenteritis virus assays for most groups. None of the assays was specific enough to discern the virus to which a cat had been exposed. However, the FIPV virus neutralization test appeared to be more sensitive for detection of an early response to FIPV infection than did the FIPV immunofluorescence test or FIPV-ELISA.

positive: Potential Rapid Diagnostics, Vaccine and Therapeutics for 2019 Novel Coronavirus (2019-nCoV): A Systematic Review Rapid diagnostics, vaccines and therapeutics are important interventions for the management of the 2019 novel coronavirus (2019-nCoV) outbreak. It is timely to systematically review the potential of these interventions, including those for Middle East respiratory syndrome-Coronavirus (MERS-CoV) and severe acute respiratory syndrome (SARS)-CoV, to guide policymakers globally on their prioritization of resources for research and development. A systematic search was carried out in three major electronic databases (PubMed, Embase and Cochrane Library) to identify published studies in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Supplementary strategies through Google Search and personal communications were used. A total of 27 studies fulfilled the criteria for review. Several laboratory protocols for confirmation of suspected 2019-nCoV cases using real-time reverse transcription polymerase chain reaction (RT-PCR) have been published. A commercial RT-PCR kit developed by the Beijing Genomic Institute is currently widely used in China and likely in Asia. However, serological assays as well as point-of-care testing kits have not been developed but are likely in the near future. Several vaccine candidates are in the pipeline. The likely earliest Phase 1 vaccine trial is a synthetic DNA-based candidate. A number of novel compounds as well as therapeutics licensed for other conditions appear to have in vitro efficacy against the 2019-nCoV. Some are being tested in clinical trials against MERS-CoV and SARS-CoV, while others have been listed for clinical trials against 2019-nCoV. However, there are currently no effective specific antivirals or drug combinations supported by high-level evidence.

positive: COVID-19 Special Column: Principles Behind the Technology for Detecting SARS-CoV-2, the Cause of COVID-19. Nationwide shortages of tests that detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and diagnose coronavirus disease 2019 (COVID-19) have led the US Food and Drug Administration (FDA) to significantly relax regulations regarding COVID-19 diagnostic testing. To date the FDA has given emergency use authorization (EUA) to 48 COVID-19 in vitro diagnostic tests and 21 high complexity molecular-based laboratory developed tests, as well as implemented policies that give broad authority to clinical laboratories and commercial manufacturers in the development, distribution, and use of COVID-19 diagnostic tests. Currently, there are 2 types of diagnostic tests available for the detection of SARS-CoV-2: (1) molecular and (2) serological tests. Molecular detection of nucleic acid (RNA or DNA) sequences relating to the suspected pathogen is indicative of an active infection with the suspected pathogen. Serological tests detect antibodies against the suspected pathogen, which are produced by an individual's immune system. A positive serological test result indicates recent exposure to the suspected pathogen but cannot be used to determine if the individual is actively infected with the pathogen or immune to reinfection. In this article, the SARS-CoV-2 diagnostic tests currently approved by the FDA under EUA are reviewed, and other diagnostic tests that researchers are developing to detect SARS-CoV-2 infection are discussed.

positive: Role of serology in the COVID-19 pandemic

positive: Understanding Antibody Testing for COVID-19 The orthopedic community has seen the COVID-19 pandemic decimate elective surgical volumes in most geographies. Patients and essential workers, such as health care providers, remain rightfully concerned about how to appropriately begin to return to work and community activity in a safe and responsible manner. Many believe that testing for the presence of antibodies on a widespread scale could help drive evidence-based decision-making, both on an individual and societal scale. Much information, and an equal amount of misinformation, has been produced on antibody testing. Education about the role and science of such testing is critically important for programs to be effectively understood and managed.

positive: Serological Analysis of New York City COVID19 Convalescent Plasma Donors BACKGROUND: The development of neutralizing antibodies (NAbs) against SARS-CoV-2, following infection or vaccination, is likely to be critical for the development of sufficient population immunity to drive cessation of the COVID19 pandemic. A large number of serologic tests, platforms and methodologies are being employed to determine seroprevalence in populations to select convalescent plasmas for therapeutic trials, and to guide policies about reopening. However, these tests have substantially variable sensitivity and specificity, and their ability to quantitatively predict levels of NAbs is unknown. METHODS: We determined levels of antibodies in convalescent plasma using commercially available SARS-CoV-2 detection tests and in-house ELISA assays and correlated those measurements with neutralization activity measured using pseudotyped virus particles, which offer the most informative assessment of antiviral activity of patient sera against viral infection. FINDINGS: Our data show that a large proportion of convalescent plasma samples have modest antibody levels and that commercially available tests have varying degrees of accuracy in predicting neutralizing activity. Nevertheless, we found particular commercially available tests are capable of accurately measuring levels of antibodies that strongly correlate with neutralization assays. INTERPRETATION: Our findings imply that SARS-CoV-2 convalescent plasma donors have a wide range of antibody concentrations. At present it is unclear how antibody acquisition, particularly for low titer individuals, might afford future immunity to SARS-CoV-2. Further research will be required to determine the minimum threshold of antibody and neutralization activity necessary to accurately predict immunity. Correlation of clinical antibody tests with neutralization activity in this study could serve as a valuable ‘roadmap’ to guide the choice and interpretation of serological tests for SARS-CoV-2.

positive: Serological assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), March 2020 BACKGROUND: The ongoing coronavirus disease (COVID-19) pandemic has major impacts on health systems, the economy and society. Assessing infection attack rates in the population is critical for estimating disease severity and herd immunity which is needed to calibrate public health interventions. We have previously shown that it is possible to achieve this in real time to impact public health decision making. AIM: Our objective was to develop and evaluate serological assays applicable in large-scale sero-epidemiological studies. METHODS: We developed an ELISA to detect IgG and IgM antibodies to the receptor-binding domain (RBD) of the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluated its sensitivity and specificity in combination with confirmatory microneutralisation (MN) and 90% plaque reduction neutralisation tests (PRNT(90)) in 51 sera from 24 patients with virologically confirmed COVID-19 and in age-stratified sera from 200 healthy controls. RESULTS: IgG and IgM RBD ELISA, MN and PRNT(90) were reliably positive after 29 days from illness onset with no detectable cross-reactivity in age-stratified controls. We found that PRNT(90) tests were more sensitive in detecting antibody than MN tests carried out with the conventional 100 tissue culture infectious dose challenge. Heparinised plasma appeared to reduce the infectivity of the virus challenge dose and may confound interpretation of neutralisation test. CONCLUSION: Using IgG ELISA based on the RBD of the spike protein to screen sera for SARS-CoV-2 antibody, followed by confirmation using PRNT(90), is a valid approach for large-scale sero-epidemiology studies.

positive: Evaluation the auxiliary diagnosis value of antibodies assays for detection of novel coronavirus (SARS-Cov-2) causing an outbreak of pneumonia (COVID-19) Background: The spread of an novel coronavirus (SARS-CoV-2, previously named 2019-nCoV) has already taken on pandemic proportions, affecting over 100 countries in a matter of weeks. Elucidating the diagnostic value of different methods, especially the auxiliary diagnosis value of antibodies assays for SARS-CoV-2 infection is helpful for improving the sensitivities of pathogenic-diagnosis, providing timely treatment, and differentiating the infected cases from the healthy, thus preventing further epidemics. Methods: Medical records from 38 patients with confirmed SARS-CoV-2 infection in the Second People's Hospital of Fuyang from January 22, 2020 to February 28, 2020 were collected and retrospectively analyzed. Specimens including throat swabs, sputum and serum were collected during the hospitalization period, viral RNAs and serum IgM-IgG antibodies to SARS-CoV-2 were measured respectively. The detectability of different methods as well as the auxiliary diagnosis value of antibodies test for SARS-CoV-2 infection were analyzed. Results: Among 38 patients, the total seropositive rate for IgM and IgG was 50.0% and 92.1%, respectively. Two patients remained seronegative throughout the course of illness. In the early phase of illness, the RNA test for sputum specimens possessed the highest detectability(92.3%), followed by the the RNA test for throat swabs (69.2%), and the antibodies assays presented lower positive rates(IgM, 23.0%, IgG, 53.8%). While, the sensitivity of antibodies assays overtook that of RNA test since day 8 after onset (IgM, 50.0%; IgG, 87.5%). Of note, the positive rate of throat swabs was only 13.0% for cases in later phase(≥15 d.a.o), and the sensitivities of IgM and IgG rose to 52.2% and 91.3%, respectively. Combined use of antibodies assay and qRT-PCR at the same time was able to improve the sensitivities of pathogenic-diagnosis, especially for the throat swabs group at the later stage of illness. Moreover, most of these cases with undetectable viral RNA in throat swabs specimens at the early stage of illness were able to be IgM/IgG seropositive after 7 days. Conclusions: The antibodies detection against SARS-CoV-2 offers vital clinical information for physicians, and could be used as an effective supplementary indicator for suspected cases of negative viral nucleic acid detection or in conjunction with nucleic acid detection in the diagnosis of suspected cases.

positive: Antibody Profiling and Prevalence in the US population during the SARS-CoV2 Pandemic ABSTRACT Background: Antibody diagnostics play an important role in disease detection and can potentially aid in monitoring of the immune responses to see if an individual has developed immunity. Developing high throughput diagnostics which does not involve handling of infectious material becomes imperative in the case of pandemics such as the recent outbreak of SARS-CoV2. Methods: A protein microarray technology was used to detect the plurality of antibody response to four novel antigens namely S1 glycoprotein, Receptor binding domain (RBD), S2 glycoprotein and Nucleoprotein of the novel coronavirus named SARS-CoV2 using serum samples. A DBS card was additionally used to compare its performance with a venipuncture-based serum separator tube (SST) draw. Results: The three main subclasses of antibodies IgM, IgA and IgG were analyzed to see the variations in immune responses in the affected population and compared to their microbial RT-PCR based NP swab results. The clinical sensitivity and specificity were determined to be 98.1% and 98.6%. In the matrix comparison study, which would enable patients to test without risk of transmitting the virus, DBS matched with higher than 98% accuracy to a venipuncture-based SST collection. Conclusion: Multiplex testing enables higher sensitivity and specificity which is essential while establishing exposure on a population scale. This flexible platform along with a discrete collection methodology would be crucial and broadly useful to scale up testing in current and future pandemics. Minimum sample volume that can be collected using DBS cards can be processed in this multiplex pillar plate format enabling the capacity to provide the reliability of high throughput analyzers while having the ease of collection similar to rapid tests. Keywords: COVID19, SARS-CoV2, Antibody, Multiplex, serology, biomarker, immune modulation, prevalence, high sensitivity, high specificity, Dried blood spot, pandemic, venipuncture

positive: Recombinant protein-based enzyme-linked immunosorbent assay and immunochromatographic tests for detection of immunoglobulin G antibodies to severe acute respiratory syndrome (SARS) coronavirus in SARS patients. An enzyme-linked immunosorbent assay (ELISA) and a rapid immunochromatographic test for detection of immunoglobulin G (IgG) antibodies in severe acute respiratory syndrome (SARS) patients were developed by utilizing the well-characterized recombinant proteins Gst-N and Gst-U274. The ELISA detected IgG antibodies to SARS-CoV in all 74 convalescent-phase samples from SARS patients while weakly cross-reacting to only 1 of the 210 control sera from healthy donors. This finding thus led to a kit sensitivity, specificity, and accuracy of 100, 99.5, and 99.6%, respectively. The test thus provided a positive predictive value (PPV) of 98.7% and a negative predictive value (NPV) of 100%. In addition, the ELISA gave a positive delta of 5.4 and a negative delta of 3.6, indicating an excellent differentiation between positives and negatives. The same recombinant proteins were also applied to a newly developed platform for the development of a 15-min rapid test. The resulting rapid test has an excellent agreement of 99.6%, with a kappa value of 1.00, with the ELISA. Again, this rapid test was able to detect 100% of the samples tested (n = 42) while maintaining a specificity of 99.0% (n = 210). The PPV and NPV for the rapid test thus reached 95.3 and 100%, respectively.

positive: Testing for SARS-CoV-2 (COVID-19): a systematic review and clinical guide to molecular and serological in-vitro diagnostic assays The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its associated Coronavirus disease 2019 (COVID-19) pandemic has demanded rapid upscaling of in-vitro diagnostic assays to enable mass screening and testing of high-risk groups, and simultaneous ascertainment of robust data on past SARS-CoV-2 exposure at an individual and population level. To meet the exponential demand in testing, there has been an accelerated development of both molecular and serological assays across a plethora of platforms. In the present review, we discuss the current literature on these modalities including the nucleic acid amplification tests, direct viral antigen tests and the rapidly expanding laboratory based and point of care serological tests. This suite of complementary tests will inform crucial decisions by healthcare providers and policy makers and understanding their strengths and limitations will be critical to their judicious application for the development of algorithmic approaches to treatment and public health strategies.

positive: Comparison of the Elecsys® Anti-SARS-CoV-2 immunoassay with the EDI(TM) enzyme linked immunosorbent assays for the detection of SARS-CoV-2 antibodies in human plasma BACKGROUND: Here, we report on a head-to-head comparison of the fully-automated Elecsys® Anti-SARS-CoV-2 immunoassay with the EDI(TM) enzyme linked immunosorbent assays (ELISA) for the detection of SARS-CoV-2 antibodies in human plasma. METHODS: SARS-CoV-2 antibodies were measured with the Elecsys® assay and the EDI(TM) ELISAs (IgM and IgG) in 64 SARS-CoV-2 RT-PCR confirmed COVID-19 patients with serial blood samples (n=104) collected at different time points from symptom onset. Blood samples from 200 healthy blood donors and 256 intensive care unit (ICU) patients collected before the COVID-19 outbreak were also used. RESULTS: In COVID-19 patients, the percentage of positive results rose with time from symptom onset, peaking to positivity rates after 15-22 days of 100% for the Elecsys® assay, of 94% for the EDI(TM) IgM-ELISA and of 100% for the EDI(TM) IgG ELISA. In the 104 blood samples, the agreement between positive/negative classifications of the Elecsys® assay and the EDI(TM) ELISAs (IgM or IgG) was 90%. The false positivity rates in the healthy blood donors and the ICU patients were <1% for the Elecsys® assay and <3% for the EDI(TM) ELISAs. CONCLUSIONS: Our results indicate a high sensitivity and specificity for the Elecsys® assay and an acceptable agreement with the EDI(TM) ELISAs.

positive: [Rapid point-of-care serology testing for sars-cov-2]. Increasing evidence indicates immunity against severe acute respiratory syndrome coronavirus 2 (sars-cov-2) after covid-19, but it remains unclear for how long the protection remains. Serology testing seems to have a higher sensitivity than molecular diagnostics from 8 days after onset of symtoms, and should be part of risk assessment and epidemiological studies of COVID-19. The performance of commercial serological point-of-care (POC) lateral flow tests are highly manufacturer-dependant. Low sensitivity increases the risk of false negative results and could result in unnecessary quarantine of test persons with developed antibodies. Low specificity increases the risk of false positive results and could lead to false assumptions of immunity. Carefully selected serological POC tests for sars-cov-2 can be used in large scale testing but should only be used by licensed medical staff able to understand their limitations and interpret the results.

positive: Seroepidemiologic Study Designs for Determining SARS-COV-2 Transmission and Immunity. Serologic studies are crucial for clarifying dynamics of the coronavirus disease pandemic. Past work on serologic studies (e.g., during influenza pandemics) has made relevant contributions, but specific conditions of the current situation require adaptation. Although detection of antibodies to measure exposure, immunity, or both seems straightforward conceptually, numerous challenges exist in terms of sample collection, what the presence of antibodies actually means, and appropriate analysis and interpretation to account for test accuracy and sampling biases. Successful deployment of serologic studies depends on type and performance of serologic tests, population studied, use of adequate study designs, and appropriate analysis and interpretation of data. We highlight key questions that serologic studies can help answer at different times, review strengths and limitations of different assay types and study designs, and discuss methods for rapid sharing and analysis of serologic data to determine global transmission of severe acute respiratory syndrome coronavirus 2.

positive: In vitro diagnostics of coronavirus disease 2019: technologies and application Abstract Laboratory-based diagnostic measures including virological and serological tests are essential for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Real-time reverse transcription-polymerase chain reactions (rRT-PCR) can detect SARS-COV-2 by targeting open reading frame-1 antibodies (ORF1ab), envelope protein, nucleocapsid protein, RNA-dependent RNA polymerase genes, and the N1, N2, and N3 (3N) target genes. Therefore, rRT-PCR remains the primary method of diagnosing SARS-CoV-2 despite being limited by false-negative results, long turnaround, complex protocols, and a need for skilled personnel. Serological diagnosis of coronavirus disease 2019 (COVID-19) is simple and does not require complex techniques and equipment, rendering it suitable for rapid detection and massive screening. However, serological tests cannot confirm SARS-CoV-2, and results will be false-negative when antibody concentrations fall below detection limits. Balancing the increased use of laboratory tests, risk of testing errors, need for tests, burden on healthcare systems, benefits of early diagnosis, and risk of unnecessary exposure is a significant and persistent challenge in diagnosing COVID-19.

positive: A Sequence Homology and Bioinformatic Approach Can Predict Candidate Targets for Immune Responses to SARS-CoV-2 Effective countermeasures against the recent emergence and rapid expansion of the 2019 novel coronavirus (SARS-CoV-2) require the development of data and tools to understand and monitor its spread and immune responses to it. However, little information is available about the targets of immune responses to SARS-CoV-2. We used the Immune Epitope Database and Analysis Resource (IEDB) to catalog available data related to other coronaviruses. This includes SARS-CoV, which has high sequence similarity to SARS-CoV-2 and is the best-characterized coronavirus in terms of epitope responses. We identified multiple specific regions in SARS-CoV-2 that have high homology to the SARS-CoV virus. Parallel bioinformatic predictions identified a priori potential B and T cell epitopes for SARS-CoV-2. The independent identification of the same regions using two approaches reflects the high probability that these regions are promising targets for immune recognition of SARS-CoV-2. These predictions can facilitate effective vaccine design against this virus of high priority.

positive: SARS-CoV-2 specific antibody responses in COVID-19 patients A new coronavirus, SARS-CoV-2, has recently emerged to cause a human pandemic. Whereas molecular diagnostic tests were rapidly developed, serologic assays are still lacking, yet urgently needed. Validated serologic assays are important for contact tracing, identifying the viral reservoir and epidemiological studies. Here, we developed serological assays for the detection of SARS-CoV-2 neutralizing, spike- and nucleocapsid-specific antibodies. Using serum samples from patients with PCR-confirmed infections of SARS-CoV-2, other coronaviruses, or other respiratory pathogenic infections, we validated and tested various antigens in different in-house and commercial ELISAs. We demonstrate that most PCR-confirmed SARS-CoV-2 infected individuals seroconverted, as revealed by sensitive and specific in-house ELISAs. We found that commercial S1 IgG or IgA ELISAs were of lower specificity while sensitivity varied between the two, with IgA showing higher sensitivity. Overall, the validated assays described here can be instrumental for the detection of SARS-CoV-2-specific antibodies for diagnostic, seroepidemiological and vaccine evaluation studies.

positive: Production of specific antibodies against SARS-coronavirus nucleocapsid protein without cross reactivity with human coronaviruses 229E and OC43 Severe acute respiratory syndrome (SARS) is a life-threatening disease for which accurate diagnosis is essential. Although many tools have been developed for the diagnosis of SARS, false-positive reactions in negative sera may occur because of cross-reactivity with other coronaviruses. We have raised polyclonal and monoclonal antibodies (Abs) using a recombinant form of the SARS virus nucleocapsid protein. Cross-reactivity of these anti-SARS Abs against human coronavirus (HCoV) 229E and HCoV OC43 were determined by Western blotting. The Abs produced reacted with recombinant SARS virus nucleocapsid protein, but not with HCoV 229E or HCoV OC43.

positive: Meta-analysis of diagnostic performance of serological tests for SARS-CoV-2 antibodies up to 25 April 2020 and public health implications. We reviewed the diagnostic accuracy of SARS-CoV-2 serological tests. Random-effects models yielded a summary sensitivity of 82% for IgM, and 85% for IgG and total antibodies. For specificity, the pooled estimate were 98% for IgM and 99% for IgG and total antibodies. In populations with ≤ 5% of seroconverted individuals, unless the assays have perfect (i.e. 100%) specificity, the positive predictive value would be ≤ 88%. Serological tests should be used for prevalence surveys only in hard-hit areas.

positive: Diagnostic strategies for SARS-CoV-2 infection and interpretation of microbiological results BACKGROUND: To face the current COVID-19 pandemic, diagnostic tools are essential. It is recommended to use real-time RT-PCR for RNA viruses in order (i) to perform a rapid and accurate diagnostic, (ii) to guide patient care and management and (iii) to guide epidemiological strategies. Further studies are warranted to define the role of serological diagnosis and a possible correlation between serological response and prognosis. OBJECTIVES: To guide clinical microbiologists in the use of these diagnostic tests and clinicians in the interpretation of their results. SOURCES: A research of literature was performed through PubMed and Google Scholar using the keywords SARS-CoV-2, SARS-CoV-2 molecular diagnosis, SARS-CoV-2 immune response, SARS-CoV-2 serology/antibody testing, coronavirus diagnosis. CONTENT: The present review discusses performances, limitations and use of current and future diagnostic tests for SARS-CoV-2. IMPLICATIONS: Real-time RT-PCR remains the reference method for diagnosis of SARS-CoV-2 infection. On the other hand, notwithstanding its varying sensitivity according to the time of infection, serology represents a valid asset (i) to try to solve possible discrepancies between a highly suggestive clinical and radiological presentation and negative RT-PCR, (ii) to solve discrepancies between different PCR assays, and (iii) for epidemiological purposes.

positive: A Peptide-based Magnetic Chemiluminescence Enzyme Immunoassay for Serological Diagnosis of Coronavirus Disease 2019 (COVID-19) SARS-CoV-2, a novel ß-coronavirus, cause severe pneumonia and has spread throughout the globe rapidly. The disease associated with SARS-CoV-2 infection is named COVID-19. To date, real-time RT-PCR is the only test able to confirm this infection. However, the accuracy of RT-PCR depends on several factors; variations in these factors might significantly lower the sensitivity of detection. Here, we developed a peptide-based luminescent immunoassay that detected immunoglobulin G (IgG) and IgM. The assay cut-off value was determined by evaluating the sera from healthy and infected patients for pathogens other than SARS-CoV-2. To evaluate assay performance, we detected IgG and IgM in the sera from confirmed patients. The positive rate of IgG and IgM was 71.4% and 57.2%, respectively. Therefore, combining our immunoassay with real-time RT-PCR might enhance the diagnostic accuracy of COVID-19.

positive: A HIGH THROUGH-PUT ASSAY FOR CIRCULATING ANTIBODIES DIRECTED AGAINST THE S PROTEIN OF SEVERE ACUTE RESPIRATORY SYNDROME CORONAVIRUS 2 (SARS-CoV-2) BACKGROUND. More than one million infections with the severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) have been confirmed. While PCR-based assays are used for diagnosis, high through-put serologic methods are needed to detect antibodies for seroserveillance and for identification of seroconversion, potential plasma donors, and the nature of the immune response to this pathogen. METHODS. A Luminex binding assay was used to assess the presence of antibodies in human sera from COVID-19-infected and -uninfected individuals specific for two recombinant proteins of SARS-CoV-2. FINDINGS. Fluorochrome-labeled beads were coated with a recombinant soluble stabilized trimeric SARS-CoV-2 S protein ectodomain or its central portion, the receptor binding domain (RBD). Coated beads were incubated with sera, followed by incubation with biotinylated anti-human total Ig antibodies and phycoerythrin (PE)-labeled streptavidin. Readout using a Luminex analyzer clearly differentiated between sera of the infected and uninfected subjects, delineating a wide range of serum antibody levels in infected subjects. INTERPRETATION. Antibody assays of sera can identify individuals who are infected with SARS-CoV-2 and have seroconverted, as well as subjects who have been infected and recovered. The use of the Luminex binding Ab assay has the advantage that it can be run in approximately 2.5 hours, uses very little antigen, and permits a high through-put of samples/day. FUNDING. NIAID contracts and grants, Department of Veterans Affairs’ grants, the Microbiology Laboratory Clinical Services, Translational Science Hub, and Personalized Virology Initiative, and Department of Medicine of Mount Sinai Health System and Icahn School of Medicine at Mount Sinai.

positive: Performance Characteristics of the Abbott Architect SARS-CoV-2 IgG Assay and Seroprevalence in Boise, Idaho Coronavirus disease-19 (COVID19), the novel respiratory illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with severe morbidity and mortality. The rollout of diagnostic testing in the United States was slow, leading to numerous cases that were not tested for SARS-CoV-2 in February and March 2020, necessitating the use of serological testing to determine past infections. Here, we evaluated the Abbott SARS-CoV-2 IgG test for detection of anti-SARS-CoV-2 IgG antibodies by testing 3 distinct patient populations. We tested 1,020 serum specimens collected prior to SARS-CoV-2 circulation in the United States and found one false positive, indicating a specificity of 99.90%. We tested 125 patients who tested RT-PCR positive for SARS-CoV-2 for which 689 excess serum specimens were available and found sensitivity reached 100% at day 17 after symptom onset and day 13 after PCR positivity. Alternative index value thresholds for positivity resulted in 100% sensitivity and 100% specificity in this cohort. We tested 4,856 individuals from Boise, Idaho collected over one week in April 2020 as part of the Crush the Curve initiative and detected 87 positives for a positivity rate of 1.79%. These data demonstrate excellent analytical performance of the Abbott SARS-CoV-2 IgG test as well as the limited circulation of the virus in the western United States. We expect the availability of high-quality serological testing will be a key tool in the fight against SARS-CoV-2.

positive: Performance Characteristics of Four High-Throughput Immunoassays for Detection of IgG Antibodies against SARS-CoV-2. The role of serologic testing for SARS-CoV-2, both in the clinical and public health settings, will continue to evolve as we gain increasing insight into our immune response to the virus. Here, we evaluated four high throughput serologic tests for detection of anti-SARS-CoV-2 IgG antibodies, including assays from Abbott Laboratories (Abbott Park, IL), Epitope Diagnostics Inc. (San Diego, CA), Euroimmun (Lubeck, Germany), and Ortho-Clinical Diagnostics (Rochester, NY), using a panel of serially collected serum samples (N=224) from 56 patients with confirmed COVID-19, healthy donor sera from 2018 and a cross-reactivity serum panel collected in early 2020. Sensitivity of the Abbott, Epitope, Euroimmun and Ortho-Clinical IgG assays in convalescent serum samples collected more than 14 days post symptom onset or initial positive RT-PCR result was 92.9% (78/84), 88.1% (74/84), 97.6% (82/84) and 98.8% (83/84), respectively. Among unique convalescent patients, sensitivity of the Abbott, Epitope, Euroimmun and Ortho-Clinical anti-SARS-CoV-2 IgG assays was 97.3% (36/37), 73% (27/37), 94.6% (35/37) and 97.3% (36/37), respectively. Overall assay specificity and positive predictive values based on a 5% prevalence rate are 99.6%/92.8%, 99.6%/90.6%, 98.0%/71.2% and 99.6%/92.5%, respectively, for the Abbott, Epitope, Euroimmun and Ortho-Clinical IgG assays. In conclusion, we show high sensitivity in convalescent sera and high specificity for the Abbott, Euroimmun and Ortho-Clinical anti-SARS-CoV-2 IgG assays. With the unprecedented influx of commercially available serologic tests for detection of antibodies against SARS-CoV-2, it remains imperative that laboratories thoroughly evaluate such assays for accuracy prior to implementation.

positive: Clinical performance of different SARS‐CoV‐2 IgG antibody tests SARS‐CoV‐2 serological assays are urgently needed for rapid diagnosis, contact tracing and for epidemiological studies. So far, there is limited data on how commercially available tests perform with real patient samples and if positive tested samples show neutralizing abilities. Focusing on IgG antibodies, we demonstrate the performance of two ELISA assays (Euroimmun SARS‐CoV‐2 IgG and Vircell COVID‐19 ELISA IgG) in comparison to one lateral flow assay ((LFA) FaStep COVID‐19 IgG/IgM Rapid Test Device) and two in‐house developed assays (immunofluorescence assay (IFA) and plaque reduction neutralization test (PRNT)). We tested follow up serum/plasma samples of individuals PCR‐diagnosed with COVID‐19. Most of the SARS‐CoV‐2 samples were from individuals with moderate to severe clinical course, who required an in‐patient hospital stay. For all examined assays, the sensitivity ranged from 58.8 to 76.5% for the early phase of infection (days 5‐9) and from 93.8 to 100% for the later period (days 10‐18). With exception of one sample, all positive tested COVID‐19 follow up‐samples, using the commercially available assays examined (including the in‐house developed IFA), demonstrated neutralizing properties in the PRNT. Regarding specificity, some samples of endemic coronavirus (HCoV‐OC43, HCoV‐229E) and Epstein Barr virus (EBV) infected individuals cross‐reacted in the ELISA assays and IFA, in one case generating a false positive result. This article is protected by copyright. All rights reserved.

positive: Highly sensitive and specific multiplex antibody assays to quantify immunoglobulins M, A and G against SARS-CoV-2 antigens Reliable serological tests are required to determine the prevalence of antibodies against SARS-CoV-2 antigens and to characterise immunity to the disease in order to address key knowledge gaps in the context of the COVID-19 pandemic. Quantitative suspension array technology (qSAT) assays based on the xMAP Luminex platform overcome the limitations of rapid diagnostic tests and ELISA with their higher precision, dynamic range, throughput, miniaturization, cost-efficacy and multiplexing capacity. We developed three qSAT assays to detect IgM, IgA and IgG to a panel of eight SARS-CoV-2 antigens including spike (S), nucleoprotein (N) and membrane (M) protein constructs. The assays were optimized to minimize processing time and maximize signal to noise ratio. We evaluated the performance of the assays using 128 plasmas obtained before the COVID-19 pandemic (negative controls) and 115 plasmas from individuals with SARS-CoV-2 diagnosis (positive controls), of whom 8 were asymptomatic, 58 had mild symptoms and 49 were hospitalized. Pre-existing IgG antibodies recognizing N, M and S2 proteins were detected in negative controls suggestive of cross-reactive to common cold coronaviruses. The best performing antibody isotype/antigen signatures had specificities of 100% and sensitivities of 94.94% at ≥14 days since the onset of symptoms and 96.08% at ≥21 days since the onset of symptoms, with AUC of 0.992 and 0.999, respectively. Combining multiple antibody markers as assessed by qSAT assays has the highest efficiency, breadth and versatility to accurately detect low-level antibody responses for obtaining reliable data on prevalence of exposure to novel pathogens in a population. Our assays will allow gaining insights into antibody correlates of immunity required for vaccine development to combat pandemics like the COVID-19.

positive: SARS-CoV-2 serological analysis of COVID-19 hospitalized patients, pauci-symptomatic individuals and blood donors. It is of paramount importance to evaluate the prevalence of both asymptomatic and symptomatic cases of SARS-CoV-2 infection and their antibody response profile. Here, we performed a pilot study to assess the levels of anti-SARS-CoV-2 antibodies in samples taken from 491 pre- epidemic individuals, 51 patients from Hopital Bichat (Paris), 209 pauci-symptomatic individuals in the French Oise region and 200 contemporary Oise blood donors. Two in-house ELISA assays, that recognize the full-length nucleoprotein (N) or trimeric Spike (S) ectodomain were implemented. We also developed two novel assays: the S-Flow assay, which is based on the recognition of S at the cell surface by flow-cytometry, and the LIPS assay that recognizes diverse antigens (including S1 or N C- terminal domain) by immunoprecipitation. Overall, the results obtained with the four assays were similar, with differences in sensitivity that can be attributed to the technique and the antigen in use. High antibody titers were associated with neutralisation activity, assessed using infectious SARS-CoV- 2 or lentiviral-S pseudotypes. In hospitalized patients, seroconversion and neutralisation occurred on 5-14 days post symptom onset, confirming previous studies. Seropositivity was detected in 29% of pauci-symptomatic individuals within 15 days post-symptoms and 3 % of blood of healthy donors collected in the area of a cluster of COVID cases. Altogether, our assays allow for a broad evaluation of SARS-CoV2 seroprevalence and antibody profiling in different population subsets.

positive: Serological differentiation between COVID-19 and SARS infections In response to the coronavirus disease 2019 (COVID-19) outbreak, caused by SARS-CoV-2, multiple diagnostic tests are required for acute disease diagnosis, contact tracing, monitoring asymptomatic infection rates and assessing herd immunity. While PCR remains the frontline test of choice in the acute diagnostic setting, serological tests are urgently needed. Unlike PCR tests which are highly specific, cross-reactivity is a major challenge for COVID-19 antibody tests considering there are six other coronaviruses known to infect humans. SARS-CoV is genetically related to SARS-CoV-2 sharing approximately 80% sequence identity and both belong to the species SARS related coronavirus in the genus Betacoronavirus of family Coronaviridae. We developed and compared the performance of four different serological tests to comprehensively assess the cross-reactivity between COVID-19 and SARS patient sera. There is significant cross-reactivity when N protein of either virus is used. The S1 or RBD regions from the spike (S) protein offers better specificity. Amongst the different platforms, capture ELISA performed best. We found that SARS survivors all have significant levels of antibodies remaining in their blood 17 years after infection. Anti-N antibodies waned more than anti-RBD antibodies, and the latter is known to play a more important role in providing protective immunity.

positive: Development and Validation of a S1 Protein-Based ELISA for the Specific Detection of Antibodies against Equine Coronavirus Equine coronavirus (ECoV) is considered to be involved in enteric diseases in foals. Recently, several outbreaks of ECoV infection have also been reported in adult horses from the USA, France and Japan. Epidemiological studies of ECoV infection are still limited, and the seroprevalence of ECoV infection in Europe is unknown. In this study, an indirect enzyme-linked immunosorbent assay (ELISA) method utilizing ECoV spike S1 protein was developed in two formats, and further validated by analyzing 27 paired serum samples (acute and convalescent sera) from horses involved in an ECoV outbreak and 1084 sera of horses with unknown ECoV exposure. Both formats showed high diagnostic accuracy compared to virus neutralization (VN) assay. Receiver-operating characteristic (ROC) analyses were performed to determine the best cut-off values for both ELISA formats, assuming a test specificity of 99%. Employing the developed ELISA method, we detected seroconversion in 70.4% of horses from an ECoV outbreak. Among the 1084 horse sera, seropositivity varied from 25.9% (young horses) to 82.8% (adult horses) in Dutch horse populations. Further, sera of Icelandic horses were included in this study and a significant number of sera (62%) were found to be positive. Overall, the results demonstrated that the ECoV S1-based ELISA has reliable diagnostic performance compared to the VN assay and is a useful assay to support seroconversion in horses involved with ECoV outbreaks and to estimate ECoV seroprevalence in populations of horses.

positive: Heg.IA: An intelligent system to support diagnosis of Covid-19 based on blood tests A new kind of coronavirus, the SARS-Cov2, started the biggest pandemic of the century. It has already killed more than 250,000 people. Because of this, it is necessary quick and precise diagnosis test. The current gold standard is the RT-PCR with DNA sequencing and identification, but its results takes too long to be available. Tests base on IgM/IgG antibodies have been used, but their sensitivity and specificity may be very low. Many studies have been demonstrating the Covid-19 impact in hematological parameters. This work proposes an intelligent system to support Covid-19 diagnosis based on blood testing. We tested several machine learning methods, and we achieved high classification performance: 95.159% +- 0.693 of overall accuracy, kappa index of 0.903 +- 0.014, sensitivity of 0.968 +- 0.007, precision of 0.938 +- 0.010 and specificity of 0.936 +- 0.011. These results were achieved using classical and low computational cost classifiers, with Bayes Network being the best of them. In addition, only 24 blood tests were needed. This points to the possibility of a new rapid test with low cost. The desktop version of the system is fully functional and available for free use.

positive: Diagnostic performance of 7 rapid IgG/IgM antibody tests and the Euroimmun IgA/IgG ELISA in COVID-19 patients OBJECTIVES: To evaluate the diagnostic performance of 7 rapid IgG/IgM tests and the Euroimmun IgA/IgG ELISA for antibodies against SARS-CoV-2 in COVID-19 patients. METHODS: Specificity was evaluated in 103 samples collected before January 2020. Sensitivity and time to seropositivity was evaluated in samples from 94 patients with COVID-19 confirmed with PCR on nasopharyngeal swab. RESULTS: Specificity [confidence interval] of lateral flow assays (LFA) was ≥ 91.3% [84.0-95.5] for IgM, ≥ 90.3% [82.9-94.8] for IgG, and ≥ 85.4% [77.2-91.1] for the combination IgM OR IgG. Specificity of the ELISA was 96.1% [90.1-98.8] for IgG and only 73.8% [64.5-81.4] for IgA. Sensitivity 14-25 days after onset of symptoms was ≥ 92.1% [78.5-98.0] to 100% [95.7-100] for IgG LFA compared to 89.5% [75.3-96.4] for IgG ELISA. Positivity of IgM OR IgG for LFA resulted in a decrease in specificity compared to IgG alone without a gain in diagnostic performance except for VivaDiag. The results for IgM varied significantly between the LFA with an average overall agreement of only 70% compared to 89% for IgG. The average dynamic trend to seropositivity for IgM was not shorter than for IgG. At time of admission to the hospital, the sensitivity of LFA was <60%. CONCLUSIONS: Sensitivity for the detection IgG antibodies 14-25 days after onset of symptoms was ≥ 92.1% for all 7 LFA compared to 89.5% for the IgG ELISA. The results for IgM varied significantly and including IgM antibodies in addition to IgG for the interpretation of LFA did not improve the diagnostic performance.

positive: Development and clinical application of a rapid IgM‐IgG combined antibody test for SARS‐CoV‐2 infection diagnosis The outbreak of the novel coronavirus disease (COVID‐19) quickly spread all over China and to more than 20 other countries. Although the virus (severe acute respiratory syndrome coronavirus [SARS‐Cov‐2]) nucleic acid real‐time polymerase chain reaction (PCR) test has become the standard method for diagnosis of SARS‐CoV‐2 infection, these real‐time PCR test kits have many limitations. In addition, high false‐negative rates were reported. There is an urgent need for an accurate and rapid test method to quickly identify a large number of infected patients and asymptomatic carriers to prevent virus transmission and assure timely treatment of patients. We have developed a rapid and simple point‐of‐care lateral flow immunoassay that can detect immunoglobulin M (IgM) and IgG antibodies simultaneously against SARS‐CoV‐2 virus in human blood within 15 minutes which can detect patients at different infection stages. With this test kit, we carried out clinical studies to validate its clinical efficacy uses. The clinical detection sensitivity and specificity of this test were measured using blood samples collected from 397 PCR confirmed COVID‐19 patients and 128 negative patients at eight different clinical sites. The overall testing sensitivity was 88.66% and specificity was 90.63%. In addition, we evaluated clinical diagnosis results obtained from different types of venous and fingerstick blood samples. The results indicated great detection consistency among samples from fingerstick blood, serum and plasma of venous blood. The IgM‐IgG combined assay has better utility and sensitivity compared with a single IgM or IgG test. It can be used for the rapid screening of SARS‐CoV‐2 carriers, symptomatic or asymptomatic, in hospitals, clinics, and test laboratories.

positive: Multiplex Evaluation of Influenza Neutralizing Antibodies with Potential Applicability to In-Field Serological Studies The increased number of outbreaks of H5 and H7 LPAI and HPAI viruses in poultry has major public and animal health implications. The continuous rapid evolution of these subtypes and the emergence of new variants influence the ability to undertake effective surveillance. Retroviral pseudotypes bearing influenza haemagglutinin (HA) and neuraminidase (NA) envelope glycoproteins represent a flexible platform for sensitive, readily standardized influenza serological assays. We describe a multiplex assay for the study of neutralizing antibodies that are directed against both influenza H5 and H7 HA. This assay permits the measurement of neutralizing antibody responses against two antigenically distinct HAs in the same serum/plasma sample thus increasing the amount and quality of serological data that can be acquired from valuable sera. Sera obtained from chickens vaccinated with a monovalent H5N2 vaccine, chickens vaccinated with a bivalent H7N1/H5N9 vaccine, or turkeys naturally infected with an H7N3 virus were evaluated in this assay and the results correlated strongly with data obtained by HI assay. We show that pseudotypes are highly stable under basic cold-chain storage conditions and following multiple rounds of freeze-thaw. We propose that this robust assay may have practical utility for in-field serosurveillance and vaccine studies in resource-limited regions worldwide.

positive: COVID-19 Special Column: Principles Behind the Technology for Detecting SARS-CoV-2, the Cause of COVID-19 Nationwide shortages of tests that detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and diagnose coronavirus disease 2019 (COVID-19) have led the US Food and Drug Administration (FDA) to significantly relax regulations regarding COVID-19 diagnostic testing. To date the FDA has given emergency use authorization (EUA) to 48 COVID-19 in vitro diagnostic tests and 21 high complexity molecular-based laboratory developed tests, as well as implemented policies that give broad authority to clinical laboratories and commercial manufacturers in the development, distribution, and use of COVID-19 diagnostic tests. Currently, there are 2 types of diagnostic tests available for the detection of SARS-CoV-2: (1) molecular and (2) serological tests. Molecular detection of nucleic acid (RNA or DNA) sequences relating to the suspected pathogen is indicative of an active infection with the suspected pathogen. Serological tests detect antibodies against the suspected pathogen, which are produced by an individual's immune system. A positive serological test result indicates recent exposure to the suspected pathogen but cannot be used to determine if the individual is actively infected with the pathogen or immune to reinfection. In this article, the SARS-CoV-2 diagnostic tests currently approved by the FDA under EUA are reviewed, and other diagnostic tests that researchers are developing to detect SARS-CoV-2 infection are discussed.

positive: Side by side comparison of three fully automated SARS-CoV-2 antibody assays with a focus on specificity Background: In the context of the COVID-19 pandemic, numerous new serological test systems for the detection of anti-SARS-CoV-2 antibodies have become available quickly. However, the clinical performance of many of them is still insufficiently described. Therefore we compared three commercial, CE-marked, SARS-CoV-2 antibody assays side by side. Methods: We included a total of 1,154 specimens from pre-COVID-19 times and 65 samples from COVID-19 patients ([≥]14 days after symptom onset) to evaluate the test performance of SARS-CoV-2 serological assays by Abbott, Roche, and DiaSorin. Results: All three assays presented with high specificities: 99.2% (98.6-99.7) for Abbott, 99.7% (99.2-100.0) for Roche, and 98.3% (97.3-98.9) for DiaSorin. In contrast to the manufacturers' specifications, sensitivities only ranged from 83.1% to 89.2%. Although the three methods were in good agreement (Cohen's Kappa 0.71-0.87), McNemar's test revealed significant differences between results obtained from Roche and DiaSorin. However, at low seroprevalences, the minor differences in specificity resulted in profound discrepancies of positive predictability at 1% seroprevalence: 52.3% (36.2-67.9), 77.6% (52.8-91.5), and 32.6% (23.6-43.1) for Roche, Abbott, and DiaSorin, respectively. Conclusion: We find diagnostically relevant differences in specificities for the anti-SARS-CoV-2 antibody assays by Abbott, Roche, and DiaSorin that have a significant impact on the positive predictability of these tests.

positive: Recurrent positive SARS‐CoV‐2: Immune certificate may not be valid Currently, coronavirus disease in 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)1 has become a global pandemic. The presence of SARS-CoV-2 in COVID-19 patients is usually confirmed using real-time reverse-transcriptase polymerase chain reaction (RT-PCR) method.2 This article is protected by copyright. All rights reserved.

positive: Analysis of SARS-CoV-2 Antibodies in COVID-19 Convalescent Plasma using a Coronavirus Antigen Microarray The current practice for diagnosis of COVID-19, based on SARS-CoV-2 PCR testing of pharyngeal or respiratory specimens in a symptomatic patient at high epidemiologic risk, likely underestimates the true prevalence of infection. Serologic methods can more accurately estimate the disease burden by detecting infections missed by the limited testing performed to date. Here, we describe the validation of a coronavirus antigen microarray containing immunologically significant antigens from SARS-CoV-2, in addition to SARS-CoV, MERS-CoV, common human coronavirus strains, and other common respiratory viruses. A comparison of antibody profiles detected on the array from control sera collected prior to the SARS-CoV-2 pandemic versus convalescent blood specimens from virologically confirmed COVID-19 cases demonstrates complete discrimination of these two groups. This array can be used as a diagnostic tool, as an epidemiologic tool to more accurately estimate the disease burden of COVID-19, and as a research tool to correlate antibody responses with clinical outcomes.

positive: Detection of specific antibodies to severe acute respiratory syndrome (SARS) coronavirus nucleocapsid protein for serodiagnosis of SARS coronavirus pneumonia. We report the evaluation of recombinant severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) nucleocapsid protein enzyme-linked immunosorbent assay (ELISA)-based antibody tests for serodiagnosis of SARS-CoV pneumonia and compare the sensitivities and specificities of this ELISA for detection of immunoglobulin G (IgG), IgM, IgA, and their combinations with serum samples from 149 healthy blood donors who donated blood 3 years ago as controls and 106 SARS-CoV pneumonia patients in Hong Kong. The specificities of the ELISA for IgG, IgM, and IgA detection were 95.3, 96.6, and 96.6%, respectively, with corresponding sensitivities of 94.3, 59.4, and 60.4%, respectively. The present ELISA appears to be a sensitive test for serodiagnosis of SARS-CoV pneumonia, is much more economical and less labor-intensive than the indirect immunofluorescence assay, and does not require cultivation of SARS-CoV.

positive: Will antibody tests for the coronavirus really change everything?

positive: COVID-19: towards controlling of a pandemic

positive: Evolving status of the 2019 novel coronavirus infection: Proposal of conventional serologic assays for disease diagnosis and infection monitoring

positive: Seroprevalence of antibodies against SARS-CoV-2 among public community and health-care workers in Alzintan City of Libya Abstract A study was conducted to determine the seroprevalence of antibodies against SARS-CoV-2 among public community and health care workers in Alzintan City, Libya. During the period from 2/4/2020 to 18/5/2020, a total of 219 blood samples were collected and analyzed for the presence of antibodies against SARS-CoV-2. Collection of samples were divided in two categories; random samples from public community and samples from health care workers belong to two Governmental hospitals and one private clinic. One Step Novel Coronavirus (COVID-19) IgM/IgG Antibody Test was used. Out of the 219 samples tested, 6 (2.74%) samples were seropositive for SARS-CoV-2. All health-care workers were tested negative. All positive cases were females and 5 of them aged between 44 to 75 years and one aged 32 years. The prevalence in young females ([≤]40 years) was 1.4% in total young females tested in the study and 1.75% in young females taken from public community. The prevalence in older females aged ( 40 years), was 11.1% in total females tested and 13.9% in females taken from public community. In conclusion, the preliminary investigation of SARS-CoV-2 revealed considerable prevalence in Alzintan City although the disease seems to be in its mild form. Active surveillance studies with high number of samples using both virological and serological tests are in urgent need.

positive: Molecular Targets for the Testing of COVID‐19 The pandemic outbreaks of coronavirus disease 2019 (COVID‐19), caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), spread all over the world in a short period of time. Efficient identification of the infection by SARS‐CoV‐2 has been one of the most important tasks to facilitate all the following counter measurements in dealing with the infectious disease. In Taiwan, a COVID‐19 Open Science Platform adheres to the spirit of open science: sharing sources, data, and methods to promote progress in academic research while corroborating findings from various disciplines has established in mid‐February 2020, for collaborative research in support of the development of detection methods, therapeutics, and a vaccine for COVID‐19. Research priorities include infection control, epidemiology, clinical characterization and management, detection methods (including viral RNA detection, viral antigen detection, and serum antibody detection), therapeutics (neutralizing antibody and small molecule drugs), vaccines, and SARS‐CoV‐2 pathogenesis. In addition, research on social ethics and the law are included to take full account of the impact of the COVID‐19 virus.

positive: Validation of a commercially available SARS-CoV-2 serological immunoassay OBJECTIVES: To validate the diagnostic accuracy of a Euroimmun SARS-CoV-2 IgG and IgA immunoassay for COVID-19. METHODS: In this unmatched (1:2) case-control validation study, we used sera of 181 laboratory-confirmed SARS-CoV-2 cases and 326 controls collected before SARS-CoV-2 emergence. Diagnostic accuracy of the immunoassay was assessed against a whole spike protein-based recombinant immunofluorescence assay (rIFA) by receiver operating characteristic (ROC) analyses. Discrepant cases between ELISA and rIFA were further tested by pseudo-neutralization assay. RESULTS: COVID-19 patients were more likely to be male and older than controls, and 50.3% were hospitalized. ROC curve analyses indicated that IgG and IgA had high diagnostic accuracies with AUCs of 0.990 (95% Confidence Interval [95%CI]: 0.983-0.996) and 0.978 (95%CI: 0.967-0.989), respectively. IgG assays outperformed IgA assays (p=0.01). Taking an assessed 15% inter-assay imprecision into account, an optimized IgG ratio cut-off > 2.5 displayed a 100% specificity (95%CI: 99-100) and a 100% positive predictive value (95%CI: 96-100). A 0.8 cut-off displayed a 94% sensitivity (95%CI: 88-97) and a 97% negative predictive value (95%CI: 95-99). Substituting the upper threshold for the manufacturer's, improved assay performance, leaving 8.9% of IgG ratios indeterminate between 0.8-2.5. CONCLUSIONS: The Euroimmun assay displays a nearly optimal diagnostic accuracy using IgG against SARS-CoV-2 in patient samples, with no obvious gains from IgA serology. The optimized cut-offs are fit for rule-in and rule-out purposes, allowing determination of whether individuals in our study population have been exposed to SARS-CoV-2 or not. IgG serology should however not be considered as a surrogate of protection at this stage.

positive: Clinical performance of SARS-CoV-2 IgG antibody tests and potential protective immunity As the current SARS-CoV-2 pandemic continues, serological assays are urgently needed for rapid diagnosis, contact tracing and for epidemiological studies. So far, there is little data on how commercially available tests perform with real patient samples and if detected IgG antibodies provide protective immunity. Focusing on IgG antibodies, we demonstrate the performance of two ELISA assays (Euroimmun SARS-CoV-2 IgG & Vircell COVID-19 ELISA IgG) in comparison to one lateral flow assay ((LFA) FaStep COVID-19 IgG/IgM Rapid Test Device) and two in-house developed assays (immunofluorescence assay (IFA) and plaque reduction neutralization test (PRNT)). We tested follow up serum/plasma samples of individuals PCR-diagnosed with COVID-19. Most of the SARS-CoV-2 samples were from individuals with moderate to severe clinical course, who required an in-patient hospital stay. For all examined assays, the sensitivity ranged from 58.8 to 76.5% for the early phase of infection (days 5-9) and from 93.8 to 100% for the later period (days 10-18) after PCR-diagnosed with COVID-19. With exception of one sample, all positive tested samples in the analysed cohort, using the commercially available assays examined (including the in-house developed IFA), demonstrated neutralizing (protective) properties in the PRNT, indicating a potential protective immunity to SARS-CoV-2. Regarding specificity, there was evidence that samples of endemic coronavirus (HCoV-OC43, HCoV-229E) and Epstein Barr virus (EBV) infected individuals cross-reacted in the ELISA assays and IFA, in one case generating a false positive result (may giving a false sense of security). This need to be further investigated.

positive: A preliminary study on analytical performance of serological assay for SARS-CoV-2 IgM/IgG and application in clinical practice Objective: To investigate the performance of serological test and dynamics of serum antibody with the progress of SARS-CoV-2 infections. Methods: A total of 419 patients were enrolled including 19 confirmed cases and 400 patients from fever clinics. Their serial serum samples collected during the hospitalization were menstruated for IgM and IgG against SARS-CoV-2 using gold immunochromatographic assay and chemiluminescence immunoassay. We investigated whether thermal inactivation could affect the results of antibody detection. The dynamics of antibodies with the disease progress and false positive factors for antibody testing were also analyzed. Results: The positive rate of IgG detection was 91.67% and 83.33% using two CLIA, respectively. However, the IgM positive rate was dramatically declined might due to the lack of blood samples at early stages of the disease. The chemiluminescence immunoassay had a favorable but narrow linear range. Our work showed increased IgG values in serums from virus-negative patients and four negative samples were IgG weak-positive after thermal incubation. Our data showed the specificity of viral N+S proteins was higher than single antigen. Unlike generally thought that IgM appeared earlier than IgG, there is no certain chronological order of IgM and IgG seroconversion in COVID-19 patients. It was difficult to detect antibodies in asymptomatic patients suggesting that their low viral loads were not enough to cause immune response. Analysis of common interferent in three IgG false-positive patients, such as rheumatoid factor, proved that false positives were not caused by these interfering substances and antigenic cross-reaction. Conclusions: Viral serological test is an effective means for SARS-CoV-2 infect detection using both chemiluminescence immunoassay and gold immunochromatographic assay. Chemiluminescence immunoassay against multi-antigens has obvious advantages but still need improve in reducing false positives.

positive: Comparison of test performance of commercial anti-SARS-CoV-2 immunoassays in serum and plasma samples BACKGROUND: For epidemiologic, social and economic reasons, assessment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection prevalence and immunity are important to adapt decisions to current demands. Hence, immunoassays for detection of anti-SARS-CoV-2 antibodies are introduced rapidly without requiring FDA emergency use authorization approval. Thus, evaluation of test performance predominantly relies on laboratories. This study aimed to evaluate the test performance of recently launched commercial immunoassays in serum and plasma samples. METHODS: 51 serum samples from 26 patients with confirmed SARS-CoV-2 infection after end of quarantine and 25 control patients were analyzed using anti-SARS-CoV-2 IgG immunoassays from Roche, Euroimmun and Epitope to assess diagnostic sensitivity and specificity. 20 matching pairs of serum and plasma samples were included to analyze comparability between different specimens. RESULTS: Overall, a diagnostic sensitivity of 92.3%, 96.2-100% and 100% with a respective diagnostic specificity of 100%, 100% and 84-86% for the immunoassays from Roche, Euroimmun and Epitope were determined. In total, 84-96 % of samples were correctly classified as negative and 92.3-95.2% as positive. The level of concordance between plasma- and serum-based testing diverged between the assays (Epitope r2=0.97; Euroimmun r2=0.91; Roche r2=0.76). CONCLUSIONS: The immunoassays from Euroimmun and Roche revealed a higher specificity than the Epitope assay without a substantial drop of diagnostic sensitivity. Significant differences between plasma- and serum-based testing highlights the need for determination of appropriate cut-offs per specimen type. Hence, there is an urgent need for test harmonization and establishment of quality standards for an appropriate use of COVID-19 serological tests.

positive: Seroprevalence of Antibodies to SARS-CoV-2 in Healthcare Workers in Non-epidemic Region: A Report from Iwate Prefecture in Japan Background: As of June 8, 2020, Iwate is the only one of 47 prefectures in Japan with no confirmed coronavirus disease 2019 (COVID-19) cases. Serological survey for COVID-19 antibodies is crucial in area with low prevalence as well as epidemic area when addressing health and social issues caused by COVID-19. Rapid, accurate and easy-to-use antibody tests as well laboratory-based antibody tests are necessary for confirming immunity in a given community. Methods:Serum samples from healthcare workers (n = 1,000, mean 40 {+/-} 11 years) of Iwate Prefectural Central Hospital, Iwate, Japan were tested for the prevalence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. Two laboratory-based quantitative tests (Abbott Architect SARS-CoV-2 IgG and Roche Elecsys Anti-SARS-CoV-2 assays) and one point-of-care (POC) qualitative test (Alfa Instant-view plus COVID-19 Test) were performed simultaneously. Sensitivity and specificity were 100%, 99.6% in Abbott assay; 100%, 99.8% in Roche assay; 97.8%, 94.6% in Alfa POC test, respectively. Results:The laboratory-based quantitative tests showed positive in 4 of 1,000 samples (0.4%) (95% CI: 0.01 to 0.79): 4/1,000 (0.4%) (95% CI: 0.01 to 0.79) in Abbott; 0/1,000 (0%) in Roche. Positive samples were not detected for both Abbott and Roche assays. The POC qualitative test showed positive in 33 of 1,000 samples (3.3%) (95% CI: 2.19 to 4.41), showing higher rates than those of the laboratory-based quantitative tests. There were no samples with simultaneous positive reaction for two quantitative tests and a POC test. Conclusions: Infected COVID-2 cases were not confirmed by a retrospective serological study in healthcare workers of our hospital. The POC qualitative tests with lower specificity have the potential for higher false positive reactions than the laboratory-based quantitative tests in areas with very low prevalence of COVID-19.

positive: Use of viral lysate antigen combined with recombinant protein in Western immunoblot assay as confirmatory test for serodiagnosis of severe acute respiratory syndrome. A Western immunoblot assay for confirmatory serodiagnosis of severe acute respiratory syndrome (SARS) was developed utilizing viral lysate antigens combined with a recombinant nucleocapsid protein, GST-N (glutathione S-transferase-nucleocapsid) of the SARS coronavirus (SARS-CoV). The viral lysate antigens were separated by electrophoresis and transblotted onto nitrocellulose membranes. The resultant membrane was subsequently added with the GST-N recombinant protein at a specific location. The positions of bands corresponding to some of the structural proteins immobilized on the membrane were then located and verified with mouse or rabbit antisera specific to the respective proteins. The Western immunoblot assay was able to detect antibodies to SARS-CoV in all 40 serum specimens from SARS patients and differentiate the SARS-positive samples from those of the healthy donor or non-SARS patient controls (150 samples) when set criteria were followed. In addition, when the immunoblot was used to test samples considered falsely positive by an in-house-developed SARS-specific enzyme-linked immunosorbent assay, band patterns different from those with samples from SARS patients were obtained.

positive: First external quality assurance of antibody diagnostic for SARS-new coronavirus Abstract To confirm an infection with the new coronavirus (SARS-CoV) causing the severe acute respiratory syndrome (SARS) diagnostic assays for detection of SARS-CoV specific antibody are necessary. To evaluate the diagnostic performance of laboratories an external quality assurance (EQA) study was performed in 2004. Participating laboratories (9/20) correctly detected anti-SARS antibodies in serum samples without false positive results in an immunofluorescence assay. In contrast, only 4/13 laboratories detected most of the anti-SARS antibody positive samples without false positive results using enzyme immunoassays (EIA) and/or immunoblot. The overall results clearly demonstrate that serological diagnosis of SARS-CoV remains at an early stage of development, with further technical improvements required, particularly with respect to the use of SARS specific EIAs.

positive: [Effect of heat inactivation of blood samples on the efficacy of three detection methods of SARS-CoV-2 antibodies] OBJECTIVE: To evaluate the effects of heat inactivation of blood samples at 56â for 30 min on the results of SARS-CoV-2 antibody detection using different methods. METHODS: This retrospective study was conducted in 11 patients with established diagnosis of COVID-19 and 10 patients with diseases other than COVID- 19 in our hospital. We collected samples of serum, plasma and whole blood from each patient between February, 12 and 18, 2020, and with a double- blind design, the samples were examined for SARS-CoV-2 antibodies before and after heat inactivation at 56 â for 30 min. In all the samples, the total SARS-CoV-2 antibodies were detected using immunochromatography, and the IgM antibodies were detected using fluorescence immunochromatography; the IgM and IgG antibodies in the serum and plasma samples detected with chemiluminescence immunoassay. We compared the detection results and analyzed the correlation of semi-quantitative detection results of IgM and IgG antibodies before and after heat inactivation of the samples. RESULTS: With immuno-chromatography, the coincidence rate of the total SARS-CoV-2 antibody detection before and after heat inactivation of the serum and plasma samples was 90.0% in COVID-19 cases and 100.0% in the negative cases, resulting in a total coincidence rate 95.2%; for the whole blood samples, the total coincidence rates of the total SARS-CoV-2 antibodies were 100.0%. For detection of IgM antibodies in the serum, plasma and whole blood samples using fluorescence immunochromatography, the coincidence rates in SARS-CoV-2-positive and negative cases and the total coincidence rate before and after inactivation were 100.0%, 0 and 47.6%, respectively. For detection of serum IgM and IgG antibodies and plasma IgG antibodies with chemiluminescence immunoassay, the coincidence rates in SARS-CoV-2-positive and negative cases and the total coincidence rate before and after inactivation were all 100.0%, and the total coincidence rate of plasma IgM antibodies was 95.2%. Pearson correlation analysis of the semi-quantitative results of IgM and IgG detection in the serum and plasma samples showed a correlation coefficient of 0.9999 (95%CI: 0.9998-1.000, P < 0.001) between the results before and after sample inactivation. CONCLUSIONS: Heat inactivation of blood samples at 56 â for 30 min does not obviously affect the results of immunochromatography and chemiluminescent immunoassay for detection of SARS-COV-2 antibodies but can reduce the risk of infection for the operators. Heat-inactivated samples can not be used in fluorescence immunochromatography for SARS-CoV-2 antibody detection.

positive: Comparative assessment of multiple COVID-19 serological technologies supports continued evaluation of point-of-care lateral flow assays in hospital and community healthcare settings There is a clear requirement for an accurate SARS-CoV-2 antibody test, both as a complement to existing diagnostic capabilities and for determining community seroprevalence. We therefore evaluated the performance of a variety of antibody testing technologies and their potential as diagnostic tools. A highly specific in-house ELISA was developed for the detection of anti-spike (S), -receptor binding domain (RBD) and -nucleocapsid (N) antibodies and used for the cross-comparison of ten commercial serological assays - a chemiluminescence-based platform, two ELISAs and seven colloidal gold lateral flow immunoassays (LFIAs) - on an identical panel of 110 SARS-CoV-2-positive samples and 50 pre-pandemic negatives. There was a wide variation in the performance of the different platforms, with specificity ranging from 82% to 100%, and overall sensitivity from 60.9% to 87.3%. However, the head to head comparison of multiple serodiagnostic assays on identical sample sets revealed that performance is highly dependent on the time of sampling, with sensitivities of over 95% seen in several tests when assessing samples from more than 20 days post onset of symptoms. Furthermore, these analyses identified clear outlying samples that were negative in all tests, but were later shown to be from individuals with mildest disease presentation. Rigorous comparison of antibody testing platforms will inform the deployment of point of care technologies in healthcare settings and their use in the monitoring of SARS-CoV-2 infections.

positive: Evaluation of a safe and sensitive Spike protein-based immunofluorescence assay for the detection of antibody responses to SARS-CoV Abstract Previously, we have identified a truncated antigenic fragment named protein C [441 to 700 amino acids (a.a.)] as the immunodominant fragment of Spike (S) protein of severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV). We have now successfully expressed protein C using the baculovirus system in S. frugiperda (Sf-9) cells. This recombinant baculovirus expressing protein C was first characterized using five SARS convalescent human sera and five normal human sera. The results showed that protein C is an authentic antigen against SARS-CoV antibody. Our Spike protein-based immunoflourescence assay (IFA) based on this recombinant baculovirus-Sf-9 system was further assessed with a panel of 163 clinical samples collected during the SARS epidemic in Singapore, which include samples from 21 clinically confirmed SARS, 42 non-SARS patient sera, and 100 normal sera. The results were compared to a commercial SARS IFA kit (EUROIMMUN, Germany) and a conventional IFA test performed in Singapore General Hospital. All of the 21 SARS-positive serum samples could be recognized by our IFA, giving a specificity and sensitivity of 100%, which was compatible with both whole virus-based IFA assays. No cross-reactivity with serum samples against infectious bronchitis virus (IBV) and transmissible gastroenteritis virus (TGEV) were detected in our assays. Thus, our Spike protein-based IFA could offer a safer procedure which can be performed in a BSL-2 laboratory as it could mimic the whole virus based-IFA without any loss of sensitivity and specificity. It is also more user-friendly and cost-effective than the whole virus-based IFA.

positive: Characteristics of patients with coronavirus disease (COVID‐19) confirmed using an IgM‐IgG antibody test Coronavirus disease (COVID‐19), caused by a novel betacoronavirus, severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has rapidly developed into a pandemic since it was first reported in December 2019. Nucleic acid testing is the standard method for the diagnosis of viral infections. However, this method reportedly has a low positivity rate. To increase the sensitivity of COVID‐19 diagnoses, we developed an IgM‐IgG combined assay and tested it in patients with suspected SARS‐CoV‐2 infection. In total, 56 patients were enrolled in this study and SARS‐CoV‐2 was detected by using both IgM‐IgG antibody and nucleic acid tests. Clinical and laboratory data were collected and analyzed. Our findings suggest that patients who develop severe illness might experience longer virus exposure times and develop a more severe inflammatory response. The IgM‐IgG test is an accurate and sensitive diagnostic method. A combination of nucleic acid and IgM‐IgG testing is a more sensitive and accurate approach for diagnosis and early treatment of COVID‐19.

positive: Laboratory Diagnosis of COVID-19: Current Issues and Challenges The COVID-19 outbreak has had a major impact on clinical microbiology laboratories in the past several months. This commentary covers current issues and challenges for the laboratory diagnosis of infections caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In the preanalytical stage, collecting the proper respiratory tract specimen at the right time from the right anatomic site is essential for a prompt and accurate molecular diagnosis of COVID-19. Appropriate measures are required to keep laboratory staff safe while producing reliable test results. In the analytic stage, real-time reverse transcription-PCR (RT-PCR) assays remain the molecular test of choice for the etiologic diagnosis of SARS-CoV-2 infection while antibody-based techniques are being introduced as supplemental tools. In the postanalytical stage, testing results should be carefully interpreted using both molecular and serological findings. Finally, random-access, integrated devices available at the point of care with scalable capacities will facilitate the rapid and accurate diagnosis and monitoring of SARS-CoV-2 infections and greatly assist in the control of this outbreak.

positive: Evaluation of Nucleocapsid and Spike Protein-Based Enzyme-Linked Immunosorbent Assays for Detecting Antibodies against SARS-CoV-2 At present, PCR-based nucleic acid detection cannot meet the demands for coronavirus infectious disease (COVID-19) diagnosis. Two hundred fourteen confirmed COVID-19 patients who were hospitalized in the General Hospital of Central Theater Command of the People’s Liberation Army between 18 January and 26 February 2020 were recruited. Two enzyme-linked immunosorbent assay (ELISA) kits based on recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (rN) and spike protein (rS) were used for detecting IgM and IgG antibodies, and their diagnostic feasibility was evaluated. Among the 214 patients, 146 (68.2%) and 150 (70.1%) were successfully diagnosed with the rN-based IgM and IgG ELISAs, respectively; 165 (77.1%) and 159 (74.3%) were successfully diagnosed with the rS-based IgM and IgG ELISAs, respectively. The positive rates of the rN-based and rS-based ELISAs for antibody (IgM and/or IgG) detection were 80.4% and 82.2%, respectively. The sensitivity of the rS-based ELISA for IgM detection was significantly higher than that of the rN-based ELISA. We observed an increase in the positive rate for IgM and IgG with an increasing number of days post-disease onset (d.p.o.), but the positive rate of IgM dropped after 35 d.p.o. The positive rate of rN-based and rS-based IgM and IgG ELISAs was less than 60% during the early stage of the illness, 0 to 10 d.p.o., and that of IgM and IgG was obviously increased after 10 d.p.o. ELISA has a high sensitivity, especially for the detection of serum samples from patients after 10 d.p.o., so it could be an important supplementary method for COVID-19 diagnosis.

positive: Antibody Detection and Dynamic Characteristics in Patients with COVID-19 BACKGROUND: The corona virus disease 2019 (COVID-19) caused by the corona virus 2 (SARS-CoV-2) has been rapidly spreading nationwide and abroad. A serologic test to identify antibody dynamics and response to SARS-CoV-2 was developed. METHODS: The antibodies against SARS-CoV-2 were detected by an enzyme-linked immunosorbent assay (ELISA) based on the recombinant nucleocapsid protein of SARS-CoV-2 in patients with confirmed or suspected COVID-19 at 3-40 days after symptom onset. The gold standard for COVID-19 diagnosis was nucleic acid testing for SARS-CoV-2 by RT-PCR. The serodiagnostic power of the specific IgM and IgG antibodies against SARS-CoV-2 was investigated in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and consistency rate. RESULTS: The seroconversion of specific IgM and IgG antibodies were observed as early as the 4th day after symptom onset. In the confirmed patients with COVID-19, sensitivity, specificity, PPV, NPV, and consistency rate of IgM were 77.3% (51/66), 100%, 100%, 80.0%, and 88.1%, and those of IgG were 83.3.3% (55/66), 95.0%, 94.8%, 83.8%, and 88.9 %. In patients with suspected COVID-19, sensitivity, specificity, PPV, NPV, and consistency rate of IgM were 87.5% (21/24), 100%, 100%, 95.2%, and 96.4%, and those of IgG were 70.8% (17/24), 96.6%, 85.0%, 89.1%, and 88.1%. Both antibodies performed well in serodiagnosis for COVID-19 rely on great specificity. CONCLUSIONS: The antibodies against SARS-CoV-2 can be detected in the middle and later stage of the illness. Antibody detection may play an important role in the diagnosis of COVID-19 as complement approach for viral nucleid acid assays.

positive: Evaluation of the performance of SARS-CoV-2 serological tools and their positioning in COVID-19 diagnostic strategies Rapid and accurate diagnosis is crucial for successful outbreak containment. During the current coronavirus disease 2019 (COVID-19) public health emergency, the gold standard for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection diagnosis is the detection of viral RNA by reverse transcription (RT)-PCR. Additional diagnostic methods enabling the detection of current or past SARS-CoV-2 infection would be highly beneficial to ensure the timely diagnosis of all infected and recovered patients. Here, we investigated several serological tools, i.e., two immunochromatographic lateral flow assays (LFA-1 (Biosynex COVID-19 BSS) and LFA-2 (COVID-19 Sign IgM/IgG)) and two enzyme-linked immunosorbent assays (ELISAs) detecting IgA (ELISA-1 Euroimmun), IgM (ELISA-2 EDI) and/or IgG (ELISA-1 and ELISA-2) based on well-characterized panels of serum samples from patients and healthcare workers with PCR-confirmed COVID-19 and from SARS-CoV-2-negative patients. A total of 272 serum samples were used, including 62 serum samples from hospitalized patients (panel 1 and panel 3), 143 serum samples from healthcare workers (panel 2) diagnosed with COVID-19 and 67 serum samples from negative controls. Diagnostic performances of each assay were assessed according to days after symptom onset (dso) and the antigenic format used by manufacturers. We found overall sensitivities ranging from 69% to 93% on panels 1 and 2 and specificities ranging from 83% to 98%. The clinical sensitivity varied greatly according to the panel tested and the dso. The assays we tested showed poor mutual agreement. A thorough selection of serological assays for the detection of ongoing or past infections is advisable.

positive: [Sensitivity, specificity, predictive values in serological Covid-19 tests].

positive: SARS-CoV-2 infection serology: a useful tool to overcome lockdown? The outbreak of 2019 novel coronavirus disease (Covid-19) caused by SARS-CoV-2 has spread rapidly, inducing a progressive growth in infected patients number. Social isolation (lockdown) has been assessed to prevent and control virus diffusion, leading to a worldwide financial and political crisis. Currently, SARS-CoV-2 RNA detection in nasopharyngeal swab takes place by real-time PCR (RT-qPCR). However, molecular tests can give some false-negative results. In this context, serological assays can be useful to detect IgG/IgM antibodies, to assess the degree of immunization, to trace the contacts, and to support the decision to re-admit people at work. A lot of serological diagnostic kits have been proposed on the market but validation studies have not been published for many of them. The aim of our work was to compare and to evaluate different assays analytical performances (two different immunochromatographic cards, an immunofluorescence chromatographic card, and a chemiluminescence-automated immunoassay) on 43 positive samples with RT-qPCR-confirmed SARS-CoV-2 infection and 40 negative control subjects. Our data display excellent IgG/IgM specificities for all the immunocromatographic card tests (100% IgG and 100% IgM) and for the chemiluminescence-automated assay (100% IgG and 94% IgM); IgG/IgM sensitivities are moderately lower for all methods, probably due to the assay viral antigen’s nature and/or to the detection time of nasopharyngeal swab RT-qPCR, with respect to symptoms onset. Given that sensitivities (around 94% and 84% for IgG and IgM, respectively) implicate false-negative cases and given the lack of effective vaccines or treatments, the only currently available procedure to reduce SARS-CoV-2 transmission is to identify and isolate persons who are contagious. For this reason, we would like to submit a flowchart in which serological tests, integrated with nasopharyngeal swab RT-qPCR, are included to help social and work activities implementation after the pandemic acute phase and to overcome lockdown.

positive: An evaluation of COVID-19 serological assays informs future diagnostics and exposure assessment The world is entering a new era of the COVID-19 pandemic in which there is an increasing call for reliable antibody testing. To support decision making on the deployment of serology for either population screening or diagnostics, we present a detailed comparison of serological COVID-19 assays. We show that among the selected assays there is a wide diversity in assay performance in different scenarios and when correlated to virus neutralizing antibodies. The Wantai ELISA detecting total immunoglobulins against the receptor binding domain of SARS CoV-2, has the best overall characteristics to detect functional antibodies in different stages and severity of disease, including the potential to set a cut-off indicating the presence of protective antibodies. The large variety of available serological assays requires proper assay validation before deciding on deployment of assays for specific applications.

positive: Detection of coronavirus 229E antibody by indirect hemagglutination. Tannic-acid treated sheep erythrocytes (fresh or glutaraldehyde preserved) were sensitized with 229E antigens from human embryonic lung (RU-1) cell cultures. Indirect hemagglutination (IHA) antigen titers in 229E-infected cell cultures paralleled virus infectivity and complement fixation (CF) antigen titers. The identity of the IHA antigen was confirmed by testing extracts from inoculated and control cell cultures for ability to inhibit IHA. Also, significant increases in IHA antibody were demonstrated with acute and convalescent serum pairs from patients with proven 229E infections. A comparison of IHA, neutralization and CF titers for 229E antibodies was made on human sera drawn from different populations. The IHA and neutralization results were in agreement on 93% of the 129 sera found to be positive by at least one of three tests. The number of antibody titers detected by the CF test was insufficient to permit comparison. Hyperimmune sera from animals immunized with OC 43 did not react with 229E by IHA. Also no increase in IHA antibody was demonstrated with acute and convalescent serum pairs from patients with seroconversions to OC 43. These findings suggest that the IHA test provides (i) a rapid and sensitive method for serodiagnosis of 229E infections and (ii) a simple and inexpensive method for seroepidemiological studies.

positive: Serologic testing of coronaviruses from MERS-CoV to SARS-CoV-2: Learning from the past and anticipating the future

positive: Detection of SARS-CoV-2 antibodies using commercial assays and seroconversion patterns in hospitalized patients OBJECTIVES: SARS-CoV-2 antibody assays are needed for serological surveys and as a complement to molecular tests to confirm COVID-19. However, the kinetics of the humoral response against SARS-CoV-2 remains poorly described and relies on the performance of the different serological tests. METHODS: In this study, we evaluated the performance of six CE-marked point-of-care tests (POC) and three ELISA assays for the diagnosis of COVID-19 by exploring seroconversions in hospitalized patients who tested positive for SARS-CoV-2 RNA. RESULTS: Both the ELISA and POC tests were able to detect SARS-CoV-2 antibodies in at least half of the samples collected seven days or more after the onset of symptoms. After 15 days, the rate of detection rose to over 80% but without reaching 100%, irrespective of the test used. More than 90% of the samples collected after 15 days tested positive using the iSIA and Accu-Tell® POC tests and the ID.Vet IgG ELISA assay. Seroconversion was observed 5 to 12 days after the onset of symptoms. Three assays suffer from a specificity below 90% (EUROIMMUN IgG and IgA, UNscience, Zhuhai Livzon). CONCLUSIONS: The second week of COVID-19 seems to be the best period for assessing the sensitivity of commercial serological assays. To achieve an early diagnosis of COVID-19 based on antibody detection, a dual challenge must be met: the immunodiagnostic window period must be shortened and an optimal specificity must be conserved.

positive: Diagnostic accuracy of serological tests for covid-19: systematic review and meta-analysis OBJECTIVE: To determine the diagnostic accuracy of serological tests for coronavirus disease-2019 (covid-19). DESIGN: Systematic review and meta-analysis. DATA SOURCES: Medline, bioRxiv, and medRxiv from 1 January to 30 April 2020, using subject headings or subheadings combined with text words for the concepts of covid-19 and serological tests for covid-19. ELIGIBILITY CRITERIA AND DATA ANALYSIS: Eligible studies measured sensitivity or specificity, or both of a covid-19 serological test compared with a reference standard of viral culture or reverse transcriptase polymerase chain reaction. Studies were excluded with fewer than five participants or samples. Risk of bias was assessed using quality assessment of diagnostic accuracy studies 2 (QUADAS-2). Pooled sensitivity and specificity were estimated using random effects bivariate meta-analyses. MAIN OUTCOME MEASURES: The primary outcome was overall sensitivity and specificity, stratified by method of serological testing (enzyme linked immunosorbent assays (ELISAs), lateral flow immunoassays (LFIAs), or chemiluminescent immunoassays (CLIAs)) and immunoglobulin class (IgG, IgM, or both). Secondary outcomes were stratum specific sensitivity and specificity within subgroups defined by study or participant characteristics, including time since symptom onset. RESULTS: 5016 references were identified and 40 studies included. 49 risk of bias assessments were carried out (one for each population and method evaluated). High risk of patient selection bias was found in 98% (48/49) of assessments and high or unclear risk of bias from performance or interpretation of the serological test in 73% (36/49). Only 10% (4/40) of studies included outpatients. Only two studies evaluated tests at the point of care. For each method of testing, pooled sensitivity and specificity were not associated with the immunoglobulin class measured. The pooled sensitivity of ELISAs measuring IgG or IgM was 84.3% (95% confidence interval 75.6% to 90.9%), of LFIAs was 66.0% (49.3% to 79.3%), and of CLIAs was 97.8% (46.2% to 100%). In all analyses, pooled sensitivity was lower for LFIAs, the potential point-of-care method. Pooled specificities ranged from 96.6% to 99.7%. Of the samples used for estimating specificity, 83% (10 465/12 547) were from populations tested before the epidemic or not suspected of having covid-19. Among LFIAs, pooled sensitivity of commercial kits (65.0%, 49.0% to 78.2%) was lower than that of non-commercial tests (88.2%, 83.6% to 91.3%). Heterogeneity was seen in all analyses. Sensitivity was higher at least three weeks after symptom onset (ranging from 69.9% to 98.9%) compared with within the first week (from 13.4% to 50.3%). CONCLUSION: Higher quality clinical studies assessing the diagnostic accuracy of serological tests for covid-19 are urgently needed. Currently, available evidence does not support the continued use of existing point-of-care serological tests. STUDY REGISTRATION: PROSPERO CRD42020179452.

positive: Prevalence of SARS-CoV-2 in Spain (ENE-COVID): a nationwide, population-based seroepidemiological study BACKGROUND: Spain is one of the European countries most affected by the COVID-19 pandemic. Serological surveys are a valuable tool to assess the extent of the epidemic, given the existence of asymptomatic cases and little access to diagnostic tests. This nationwide population-based study aims to estimate the seroprevalence of SARS-CoV-2 infection in Spain at national and regional level. METHODS: 35â883 households were selected from municipal rolls using two-stage random sampling stratified by province and municipality size, with all residents invited to participate. From April 27 to May 11, 2020, 61â075 participants (75·1% of all contacted individuals within selected households) answered a questionnaire on history of symptoms compatible with COVID-19 and risk factors, received a point-of-care antibody test, and, if agreed, donated a blood sample for additional testing with a chemiluminescent microparticle immunoassay. Prevalences of IgG antibodies were adjusted using sampling weights and post-stratification to allow for differences in non-response rates based on age group, sex, and census-tract income. Using results for both tests, we calculated a seroprevalence range maximising either specificity (positive for both tests) or sensitivity (positive for either test). FINDINGS: Seroprevalence was 5·0% (95% CI 4·7-5·4) by the point-of-care test and 4·6% (4·3-5·0) by immunoassay, with a specificity-sensitivity range of 3·7% (3·3-4·0; both tests positive) to 6·2% (5·8-6·6; either test positive), with no differences by sex and lower seroprevalence in children younger than 10 years (<3·1% by the point-of-care test). There was substantial geographical variability, with higher prevalence around Madrid (>10%) and lower in coastal areas (<3%). Seroprevalence among 195 participants with positive PCR more than 14 days before the study visit ranged from 87·6% (81·1-92·1; both tests positive) to 91·8% (86·3-95·3; either test positive). In 7273 individuals with anosmia or at least three symptoms, seroprevalence ranged from 15·3% (13·8-16·8) to 19·3% (17·7-21·0). Around a third of seropositive participants were asymptomatic, ranging from 21·9% (19·1-24·9) to 35·8% (33·1-38·5). Only 19·5% (16·3-23·2) of symptomatic participants who were seropositive by both the point-of-care test and immunoassay reported a previous PCR test. INTERPRETATION: The majority of the Spanish population is seronegative to SARS-CoV-2 infection, even in hotspot areas. Most PCR-confirmed cases have detectable antibodies, but a substantial proportion of people with symptoms compatible with COVID-19 did not have a PCR test and at least a third of infections determined by serology were asymptomatic. These results emphasise the need for maintaining public health measures to avoid a new epidemic wave. FUNDING: Spanish Ministry of Health, Institute of Health Carlos III, and Spanish National Health System.

positive: Antibody responses to SARS-CoV-2 in COVID-19 patients: the perspective application of serological tests in clinical practice Background We aim to investigate the profile of acute antibody response in COVID-19 patients, and provide proposals for the usage of antibody test in clinical practice. Methods A multi-center cross-section study (285 patients) and a single-center follow-up study (63 patients) were performed to investigate the feature of acute antibody response to SARS-CoV-2. A cohort of 52 COVID-19 suspects and 64 close contacts were enrolled to evaluate the potentiality of the antibody test. Results The positive rate for IgG reached 100% around 20 days after symptoms onset. The median day of serocon-version for both lgG and IgM was 13 days after symptoms onset. Seroconversion of IgM occurred at the same time, or earlier, or later than that of IgG. IgG levels in 100% patients (19/19) entered a platform within 6 days after seroconversion. The criteria of IgG seroconversion and ≥ 4-fold increase in the IgG titers in sequential samples together diagnosed 82.9% (34/41) of the patients. Antibody test aided to confirm 4 patients with COVID-19 from 52 suspects who failed to be confirmed by RT-PCR and 7 patients from 148 close contacts with negative RT-PCR. Conclusion IgM and IgG should be detected simultaneously at the early phase of infection. The serological diagnosis criterion of seroconversion or ≥ 4-fold increase in the IgG titer is suitable for a majority of COVID-19 patients. Serologic test is helpful for the diagnosis of SARS-CoV-2 infection in suspects and close contacts.

positive: Characterization of anti-viral immunity in recovered individuals infected by SARS-CoV-2 The WHO has declared SARS-CoV-2 outbreak a public health emergency of international concern. However, to date, there was hardly any study in characterizing the immune responses, especially adaptive immune responses to SARS-CoV-2 infection. In this study, we collected blood from COVID-19 patients who have recently become virus-free and therefore were discharged, and analyzed their SARS-CoV-2-specific antibody and T cell responses. We observed SARS-CoV-2-specific humoral and cellular immunity in the patients. Both were detected in newly discharged patients, suggesting both participate in immune-mediated protection to viral infection. However, follow-up patients (2 weeks post discharge) exhibited high titers of IgG antibodies, but with low levels of virus-specific T cells, suggesting that they may enter a quiescent state. Our work has thus provided a basis for further analysis of protective immunity to SARS-CoV-2, and understanding the pathogenesis of COVID-19, especially in the severe cases. It has also implications in designing an effective vaccine to protect and treat SARS-CoV-2 infection.

positive: Serological immunochromatographic approach in diagnosis with SARS-CoV-2 infected COVID-19 patients An outbreak of new coronavirus SARS-CoV-2 was occurred in Wuhan, China and rapidly spread to other cities and nations. The standard diagnostic approach that widely adopted in the clinic is nucleic acid detection by real-time RT-PCR. However, the false-negative rate of the technique is unneglectable and serological methods are urgently warranted. Here, we presented the colloidal gold-based immunochromatographic (ICG) strip targeting viral IgM or IgG antibody and compared it with real-time RT-PCR. The sensitivity of ICG assay with IgM and IgG combinatorial detection in nucleic acid confirmed cases were 11.1%, 92.9% and 96.8% at the early stage (1-7 days after onset), intermediate stage (8-14 days after onset), and late stage (more than 15 days), respectively. The ICG detection capacity in nucleic acid-negative suspected cases was 43.6%. In addition, the concordance of whole blood samples and plasma showed Cohen's kappa value of 0.93, which represented the almost perfect agreement between two types of samples. In conclusion, serological ICG strip assay in detecting SARS-CoV-2 infection is both sensitive and consistent, which is considered as an excellent supplementary approach in clinical application.

positive: Assessment of SARS-CoV-2 serological tests for the diagnosis of COVID-19 through the evaluation of three immunoassays: Two automated immunoassays (Euroimmun and Abbott) and one rapid lateral flow immunoassay (NG Biotech) BACKGROUND: The emergence of new SARS-CoV-2 has promoted the development of new serological tests that could be complementary to RT-PCR. Nevertheless, the assessment of clinical performances of available tests is urgently required as their use has just been initiated for diagnose. OBJECTIVES: The aim of this study was to assess the performance of three immunoassays for the detection of SARS-CoV-2 antibodies. METHODS: Two automated immunoassays (Abbott SARS-CoV-2 CLIA IgG and Euroimmun Anti-SARS-CoV-2 ELISA IgG/IgA assays) and one lateral flow immunoassay (LFIA NG-Test® IgG-IgM COVID-19) were tested. 293 specimens were analyzed from patients with a positive RT-PCR response, from patients with symptoms consistent with COVID-19 but exhibiting a negative response to the RT-PCR detection test, and from control group specimens. Days since symptoms onset were collected from clinical information sheet associated with respiratory tract samples. RESULTS: Overall sensitivity for IgG was equivalent (around 80 %) for CLIA, ELISA and LFIA. Sensitivity for IgG detection, >14 days after onset of symptoms, was 100.0 % for all assays. Overall specificity for IgG was greater for CLIA and LFIA (more than 98 %) compared to ELISA (95.8 %). Specificity was significantly different between IgA ELISA (78.9 %) and IgM LFIA (95.8 %) (pâ¯<â¯0.05). The best agreement was observed between CLIA and LFIA assays (97 %; kâ¯=â¯0.936). CONCLUSION: Excellent sensitivity for IgG detection was obtained >14 days after onset of symptoms for all immunoassays. Specificity was also excellent for IgG CLIA and IgG LFIA. Our study shows that NG-Test® is reliable and accurate for routine use in clinical laboratories.

positive: Alltest rapid lateral flow immunoassays is reliable in diagnosing SARS-CoV-2 infection from 14 days after symptom onset: a prospective single-center study OBJECTIVES: SARS-CoV-2 infection diagnosis is challenging in patients from 2-3 weeks after the onset of symptoms, due to the low positivity rate of the PCR. Serologic tests could be complementary to PCR in these situations. The aim of our study was to analyze the diagnostic performance of one serologic rapid test in COVID-19 patients. METHODS: We evaluated a lateral flow immunoassay (AllTest COVID-19 IgG/IgM) which detects IgG and IgM antibodies. We validated the serologic test using serum samples from 100 negative patients (group 1) and 90 patients with COVID-19 confirmed by PCR (group 2). Then, we prospectively evaluated the test in 61 patients with clinical diagnosis of pneumonia of unknown etiology that were negative for SARS-CoV-2 by PCR (group 3). RESULTS: All 100 patients from group 1 were negative for the serologic test (specificity = 100%). Regarding group 2 (PCR-positive), the median time from their symptom onset until testing was 17 days. For these 90 group-2 patients, the test was positive for either IgM or IgG in 58 (overall sensitivity = 64.4%), and in patients tested 14 days or more after the onset of symptoms, the sensitivity was 88.0%. Regarding the 61 group-3 patients, median time after symptom onset was also 17 days, and the test was positive in 54 (88.5% positivity). CONCLUSIONS: Our study shows that serologic lateral flow immunoassays are reliable as a complement of PCR to diagnose SARS-CoV-2 infection after 14 days from the onset of symptoms and in patients with pneumonia and negative PCR for SARS-CoV-2.

positive: A new and rapid approach for detecting COVID-19 based on S1 protein fragments The pandemic of novel coronavirus disease 2019 (COVID-19) seriously threatened the public health all over the world. A colloidal gold immunochromatography assay for IgM/IgG antibodies against the receptor-binding domain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) S1 protein was established to assess its rapid diagnostic value. We first designed and manufactured all contents of the test cassette of SARS-CoV-2 rapid test kit: the colloidal gold-labeled mouse-antihuman lgM/lgG antibody, the recombinant SARS-CoV-2 antigen, the nitrocellulose membrane control line, and specimen diluents. Furthermore, reverse transcription-polymerase chain reaction (RT-PCR) assay, colloidal gold immunochromatography assay, serological validation of cross reaction with other common viruses, and clinical validation were performed. The kit was finally evaluated by 75 serum/plasma samples of SARS-CoV-2 infection cases and 139 healthy samples as control, with the result of that the sensitivity, specificity, and accuracy for IgM were 90.67%, 97.84%, and 95.33%, whereas for IgG were 69.33%, 99.28%, and 88.79%, respectively; the combination of IgM and IgG could improve the value: 92.00%, 97.12%, and 95.33%, respectively. Therefore, the rapid detection kit has high sensitivity and specificity, especially for IgM&IgG, showing a critical value in clinical application and epidemic control of COVID-19.

positive: Perspectives of Immune Therapy in Coronavirus Disease 2019 The global fight against coronavirus disease 2019 (COVID-19) is largely based on strategies to boost immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and prevent its severe course and complications. The human defence may include antibodies which interact with SARS-CoV-2 and neutralize its aggressive actions on multiple organ systems. Protective cross-reactivity of antibodies against measles and other known viral infections has been postulated, primarily as a result of the initial observations of asymptomatic and mild COVID-19 in children. Uncontrolled case series have demonstrated virus-neutralizing effect of convalescent plasma, supporting its efficiency at early stages of contracting SARS-CoV-2. Given the variability of the virus structure, the utility of convalescent plasma is limited to the geographic area of its preparation, and for a short period of time. Intravenous immunoglobulin may also be protective in view of its nonspecific antiviral and immunomodulatory effects. Finally, human monoclonal antibodies may interact with some SARS-CoV-2 proteins, inhibiting the virus-receptor interaction and prevent tissue injury. The improved understanding of the host antiviral responses may help develop safe and effective immunotherapeutic strategies against COVID-19 in the foreseeable future.

positive: Serological Approaches for COVID-19: Epidemiologic Perspective on Surveillance and Control Since December 2019, the novel coronavirus, SARS-CoV-2, has garnered global attention due to its rapid transmission, which has infected more than two million people worldwide. Early detection of SARS-CoV-2 is one of the crucial interventions to control virus spread and dissemination. Molecular assays have been the gold standard to directly detect for the presence of viral genetic material in infected individuals. However, insufficient viral RNA at the point of detection may lead to false negative results. As such, it is important to also employ immune-based assays to determine one's exposure to SARS-CoV-2, as well as to assist in the surveillance of individuals with prior exposure to SARS-CoV-2. Within a span of 4 months, extensive studies have been done to develop serological systems to characterize the antibody profiles, as well as to identify and generate potentially neutralizing antibodies during SARS-CoV-2 infection. The vast diversity of novel findings has added value to coronavirus research, and a strategic consolidation is crucial to encompass the latest advances and developments. This review aims to provide a concise yet extensive collation of current immunoassays for SARS-CoV-2, while discussing the strengths, limitations and applications of antibody detection in SARS-CoV-2 research and control.

positive: Performance Characteristics of the Abbott Architect SARS-CoV-2 IgG Assay and Seroprevalence Testing in Idaho Coronavirus disease-19 (COVID19), the novel respiratory illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with severe morbidity and mortality. The rollout of diagnostic testing in the United States was slow, leading to numerous cases that were not tested for SARS-CoV-2 in February and March 2020, necessitating the use of serological testing to determine past infections. Here, we evaluated the Abbott SARS-CoV-2 IgG test for detection of anti-SARS-CoV-2 IgG antibodies by testing 3 distinct patient populations. We tested 1,020 serum specimens collected prior to SARS-CoV-2 circulation in the United States and found one false positive, indicating a specificity of 99.90%. We tested 125 patients who tested RT-PCR positive for SARS-CoV-2 for which 689 excess serum specimens were available and found sensitivity reached 100% at day 17 after symptom onset and day 13 after PCR positivity. Alternative index value thresholds for positivity resulted in 100% sensitivity and 100% specificity. We then tested 4,856 individuals from Boise, Idaho collected over one week in April 2020 as part of the Crush the Curve initiative and detected 87 positives for a positivity rate of 1.79%. These data demonstrate excellent analytical performance of the Abbott SARS-CoV-2 IgG test as well as the limited circulation of the virus on the West Coast. We expect the availability of high-quality serological testing will be a key tool in the fight against SARS-CoV-2.

positive: Serological Screening for Coronavirus Infections in Cats Coronaviruses (CoVs) are widespread among mammals and birds and known for their potential for cross-species transmission. In cats, infections with feline coronaviruses (FCoVs) are common. Several non-feline coronaviruses have been reported to infect feline cells as well as cats after experimental infection, supported by their ability to engage the feline receptor ortholog for cell entry. However, whether cats might become naturally infected with CoVs of other species is unknown. We analyzed coronavirus infections in cats by serological monitoring. In total 137 cat serum samples and 25 FCoV type 1 or type 2-specific antisera were screened for the presence of antibodies against the S1 receptor binding subunit of the CoV spike protein, which is immunogenic and possesses low amino acid sequence identity among coronavirus species. Seventy-eight sera were positive for antibodies that recognized one or more coronavirus S1s whereas 1 serum exclusively reacted with human coronavirus 229E (HCoV-229E) and two sera exclusively reacted with porcine delta coronavirus (PDCoV). We observed antigenic cross-reactivity between S1s of type 1 and type 2 FCoVs, and between FCoV type 1 and porcine epidemic diarrhea virus (PEDV). Domain mapping of antibody epitopes indicated the presence of conserved epitope(s) particularly in the CD domains of S1. The cross-reactivity of FCoV type 1 and PEDV was also observed at the level of virus neutralization. To conclude, we provide the first evidence of antigenic cross-reactivity among S1 proteins of coronaviruses, which should be considered in the development of serological diagnoses. In addition, the potential role of cats in cross-species transmission of coronaviruses cannot be excluded.

positive: COVID-19 SCREENING AND MONITORING OF ASYMPTOMATIC HEALTH WORKERS WITH A RAPID SEROLOGICAL TEST Background Health workers are at high risk for SARS-CoV-2 infection and, if asymptomatic, for transmitting the virus on to fragile cancer patients. Materials and method We monitored health care workers (HCW) of our Cancer Institute with the rapid serological test Viva-DiagTM analyzing COVID-19 associated-IgG/IgM. Test were performed at time 0 and after 14 days; Rt-PCR and CLIA assays were also perfoRmed in positive Viva-DiagTM cases. 606 and 393 HCW had blood sample taken at time 0 and 14, respectively. Results Overall, 9 HCW (1.5%) resulted not-negative at Viva-DiagTM and one of them was confirmed positive for SARS-COV2 infection at RT-PCR oropharingeal swab. At time 0, all 9 cases showed some IgM expression and only one IgG; after 14 days IgM persisted in all cases while IgG became evident in 4 ones. A parallel CLIA test was performed in 23 quaratined subjetcs and in all Viva-Diag not negative cases. CLIA confirmed a positive level of IgM in 5/13 positive Viva-Diag cases; conversely, IgG was confirmed positive at CLIA in 4/5 cases positive at Viva-Diag. These results pose the question of different performances of the two tests. Conclusions Our study suggest that Viva-Diag assay can be of help in individualizing SARS_COV2 infected people fisrt of all in cohorts of subjetcs with high prevalence. Different performances of serological colorimetric and CLIA tools remain to be ascertained.

positive: [Effect of heat inactivation of blood samples on the efficacy of three detection methods of SARS-CoV-2 antibodies]. OBJECTIVE To evaluate the effects of heat inactivation of blood samples at 56℃ for 30 min on the results of SARS-CoV-2 antibody detection using different methods. METHODS This retrospective study was conducted in 11 patients with established diagnosis of COVID-19 and 10 patients with diseases other than COVID- 19 in our hospital. We collected samples of serum, plasma and whole blood from each patient between February, 12 and 18, 2020, and with a double- blind design, the samples were examined for SARS-CoV-2 antibodies before and after heat inactivation at 56 ℃ for 30 min. In all the samples, the total SARS-CoV-2 antibodies were detected using immunochromatography, and the IgM antibodies were detected using fluorescence immunochromatography; the IgM and IgG antibodies in the serum and plasma samples detected with chemiluminescence immunoassay. We compared the detection results and analyzed the correlation of semi-quantitative detection results of IgM and IgG antibodies before and after heat inactivation of the samples. RESULTS With immuno-chromatography, the coincidence rate of the total SARS-CoV-2 antibody detection before and after heat inactivation of the serum and plasma samples was 90.0% in COVID-19 cases and 100.0% in the negative cases, resulting in a total coincidence rate 95.2%; for the whole blood samples, the total coincidence rates of the total SARS-CoV-2 antibodies were 100.0%. For detection of IgM antibodies in the serum, plasma and whole blood samples using fluorescence immunochromatography, the coincidence rates in SARS-CoV-2-positive and negative cases and the total coincidence rate before and after inactivation were 100.0%, 0 and 47.6%, respectively. For detection of serum IgM and IgG antibodies and plasma IgG antibodies with chemiluminescence immunoassay, the coincidence rates in SARS-CoV-2-positive and negative cases and the total coincidence rate before and after inactivation were all 100.0%, and the total coincidence rate of plasma IgM antibodies was 95.2%. Pearson correlation analysis of the semi-quantitative results of IgM and IgG detection in the serum and plasma samples showed a correlation coefficient of 0.9999 (95%CI: 0.9998-1.000, P < 0.001) between the results before and after sample inactivation. CONCLUSIONS Heat inactivation of blood samples at 56 ℃ for 30 min does not obviously affect the results of immunochromatography and chemiluminescent immunoassay for detection of SARS-COV-2 antibodies but can reduce the risk of infection for the operators. Heat-inactivated samples can not be used in fluorescence immunochromatography for SARS-CoV-2 antibody detection.

positive: Intrafamilial Exposure to SARS-CoV-2 Induces Cellular Immune Response without Seroconversion Background. In the background of the current COVID-19 pandemic, serological tests are being used to assess past infection and immunity against SARS-CoV-2. This knowledge is paramount to determine the transmission dynamics of SARS-CoV-2 through the post pandemic period. Several individuals belonging to households with an index COVID-19 patient, reported symptoms of COVID-19 but discrepant serology results. Methods. Here we investigated the humoral and cellular immune responses against SARS-CoV-2 in seven families, including nine index patients and eight contacts, who had evidence of serological discordances within the households. Ten unexposed healthy donors were enrolled as controls. Results. All index patients recovered from a mild COVID-19. They all developed anti-SARS-CoV-2 antibodies and a significant T cell response detectable up to 69 days after symptom onset. Six of the eight contacts reported COVID-19 symptoms within 1 to 7 days after the index patients but all were SARS-CoV-2 seronegative. Six out of eight contacts developed a SARS-CoV-2-specific T cell response against structural and/or accessory proteins that lasts up to 80 days post symptom onset suggesting a past SARS-CoV-2 infection. Conclusion. Exposure to SARS-CoV-2 can induce virus-specific T cell responses without seroconversion. T cell responses may be more sensitive indicators of SARS-Co-V-2 exposure than antibodies. Our results indicate that epidemiological data relying only on the detection of SARS-CoV-2 antibodies may lead to a substantial underestimation of prior exposure to the virus

positive: COVID-19 epidemic phases: criteria, challenges and issues for the future*

positive: Recombinant nucleocapsid protein-based IgG enzyme-linked immunosorbent assay for the serological diagnosis of SARS Abstract The recombinant nucleocapsid protein (rNP) of severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) was expressed in a baculovirus system. The purified SARS-CoV rNP was used as an antigen for detection of SARS-CoV antibodies in IgG enzyme-linked immunosorbent assay (ELISA). The ELISA was evaluated in comparison with neutralizing antibody assay and the authentic SARS-CoV antigen-based IgG ELISA. Two-hundred and seventy-six serum samples were collected from health care workers in a hospital in which a nosocomial SARS outbreak took place and used for evaluation. The SARS-CoV rNP-based IgG ELISA has 92% of sensitivity and specificity compared with the neutralizing antibody assay and 94% sensitivity and specificity compared with the authentic SARS-CoV antigen-based IgG ELISA. The results suggest that the newly developed SARS-CoV rNP-based IgG ELISA is a valuable tool for the diagnosis and seroepidemiological study of SARS. The SARS-CoV rNP-based IgG ELISA has an advantage over the conventional IgG ELISA in that the antigen can be prepared by laboratory workers without the risk of infection.

positive: Double-antigen sandwich ELISA for detection of antibodies to SARS-associated coronavirus in human serum The study presented here was conducted to evaluate the performance of a double-antigen sandwich ELISA to detect antibodies in human serum against the coronavirus associated with severe acute respiratory syndrome (SARS). A recombinant partial nucleocapsid protein of SARS-associated coronavirus was used as a serodiagnostic antigen in the ELISA. A total of 2892 clinical serum samples were tested with the ELISA kit, which positively identified 25 of 35 (71.4%) samples of patients with confirmed SARS infection, 286 of 407 (70%) samples of patients suspected of having SARS, 229 of 302 (75.8%) samples of convalescent SARS patients, and 0 of 544 samples obtained from healthcare workers; only 1 of 1604 clinical samples obtained from patients with other diseases demonstrated a weakly positive result. These results indicate that the double-antigen sandwich ELISA is an effective screening method for the serodiagnosis of SARS-associated coronavirus.

positive: Antibody epitope repertoire analysis enables rapid antigen discovery and multiplex serology The detection of pathogen-specific antibodies remains a cornerstone of clinical diagnostics. Yet, many test exhibit undesirable performance or are completely lacking. Given this, we developed serum epitope repertoire analysis (SERA), a method to rapidly discover conserved, pathogen-specific antigens and their epitopes, and applied it to develop an assay for Chagas disease caused by the protozoan parasite Trypanosoma cruzi. Antibody binding peptide motifs were identified from 28 Chagas repertoires using a bacterial display random 12-mer peptide library and next-generation sequencing (NGS). Thirty-three motifs were selected and mapped to candidate Chagas antigens. In a blinded validation set (n = 72), 30/30 Chagas were positive, 30/30 non-Chagas were negative, and 1/12 Leishmania sp. was positive. After unblinding, a Leishmania cross-reactive epitope was identified and removed from the panel. The Chagas assay exhibited 100% sensitivity (30/30) and specificity (90/90) in a second blinded validation set including individuals with other parasitic infections. Amongst additional epitope repertoires with unknown Chagas serostatus, assay specificity was 99.8% (998/1000). Thus, the Chagas assay achieved a combined sensitivity and specificity equivalent or superior to diagnostic algorithms that rely on three separate tests to achieve high specificity. NGS-based serology via SERA provides an effective approach to discover antigenic epitopes and develop high performance multiplex serological assays.

positive: An Outbreak of Human Coronavirus OC43 Infection and Serological Cross-reactivity with SARS Coronavirus. BACKGROUND In summer 2003, a respiratory outbreak was investigated in British Columbia, during which nucleic acid tests and serology unexpectedly indicated reactivity for severe acute respiratory syndrome coronavirus (SARS-CoV). METHODS Cases at a care facility were epidemiologically characterized and sequentially investigated for conventional agents of respiratory infection, SARS-CoV and other human CoVs. Serological cross-reactivity between SARS-CoV and human CoV-OC43 (HCoV-OC43) was investigated by peptide spot assay. RESULTS Ninety-five of 142 residents (67%) and 53 of 160 staff members (33%) experienced symptoms of respiratory infection. Symptomatic residents experienced cough (66%), fever (21%) and pneumonia (12%). Eight residents died, six with pneumonia. No staff members developed pneumonia. Findings on reverse transcriptase-polymerase chain reaction assays for SARS-CoV at a national reference laboratory were suspected to represent false positives, but this was confounded by concurrent identification of antibody to N protein on serology. Subsequent testing by reverse transcriptase-polymerase chain reaction confirmed HCoV-OC43 infection. Convalescent serology ruled out SARS. Notably, sera demonstrated cross-reactivity against nucleocapsid peptide sequences common to HCoV-OC43 and SARS-CoV. CONCLUSIONS These findings underscore the virulence of human CoV-OC43 in elderly populations and confirm that cross-reactivity to antibody against nucleocapsid proteins from these viruses must be considered when interpreting serological tests for SARS-CoV.

positive: Evolving status of the 2019 novel coronavirus infection: Proposal of conventional serologic assays for disease diagnosis and infection monitoring The novel coronavirus (nCoV-2019) outbreak in Wuhan, China has spread rapidly nationwide, with some cases occurring in other parts of the world. Although most patients present with mild febrile illness with patchy pulmonary inflammation, a significant portion develop severe acute respiratory distress syndrome (ARDS), with a current case fatality of 2.3-3%. Diagnosis is based on clinical history and laboratory and chest radiographic findings, but confirmation currently relies on nucleic acid-based assays. The latter are playing an important role in facilitating patient isolation, treatment and assessment of infectious activities. However, due to their limited capacity to handle an epidemic of the current scale and insufficient supply of assay kits, only a portion of suspected cases can be tested, leading to incompleteness and inaccuracy in updating new cases, as well as delayed diagnosis. Furthermore, there has not been enough time to assess specificity and sensitivity. Conventional serological assays, such as enzyme-linked immunoassay (ELISA) for specific IgM and IgG antibodies, should offer a high-throughput alternative, which allows for uniform tests for all suspected patients, and can facilitate more complete identification of infected cases and avoidance of unnecessary cross infection among unselected patients. This article is protected by copyright. All rights reserved.

positive: Laboratory Tests for COVID-19: A Review of Peer-Reviewed Publications and Implications for Clinical UIse. Diagnostic tests for the coronavirus infection 2019 (COVID-19) are critical for prompt diagnosis, treatment and isolation to break the cycle of transmission. A positive real-time reverse-transcriptase polymerase chain reaction (RT-PCR), in conjunction with clinical and epidemiologic data, is the current standard for diagnosis, but several challenges still exist. Serological assays help to understand epidemiology better and to evaluate vaccine responses but they are unreliable for diagnosis in the acute phase of illness or assuming protective immunity. Serology is gaining attention, mainly because of convalescent plasma gaining importance as treatment for clinically worsening COVID-19 patients. We provide a narrative review of peer-reviewed research studies on RT-PCR, serology and antigen immune-assays for COVID-19, briefly describe their lab methods and discuss their limitations for clinical practice.

positive: A rapid, point of care red blood cell agglutination assay for detecting antibodies against SARS-CoV-2 The COVID-19 pandemic has brought the world to a halt, with cases observed around the globe causing significant mortality. There is an urgent need for serological tests to detect antibodies against SARS-CoV-2, which could be used to assess the prevalence of infection, as well as ascertain individuals who may be protected from future infection. Current serological tests developed for SARS-CoV-2 rely on traditional technologies such as enzyme-linked immunosorbent assays (ELISA) and lateral flow assays, which may lack scalability to meet the demand of hundreds of millions of antibody tests in the coming year. Herein, we present an alternative method of antibody testing that just depends on one protein reagent being added to patient serum/plasma or whole blood and a short five-minute assay time. A novel fusion protein was designed that binds red blood cells (RBC) via a single-chain variable fragment (scFv) against the H antigen and displays the receptor-binding domain (RBD) of SARS-CoV-2 spike protein on the surface of RBCs. Upon mixing of the fusion protein, RBD-scFv with recovered COVID-19 patient serum and RBCs, we observed agglutination of RBCs, indicating the patient developed antibodies against SARS-CoV-2 RBD. Given that the test uses methods routinely used in hospital clinical labs across the world, we anticipate the test can be rapidly deployed with only the protein reagent required at projected manufacturing cost at U.S. cents per test. We anticipate our agglutination assay may find extensive use in low-resource settings for detecting SARS-CoV-2 antibodies.

positive: Assessment of SARS-CoV-2 serological tests for the diagnosis of COVID-19 through the evaluation of three immunoassays: two automated immunoassays (Euroimmun and Abbott) and one rapid lateral flow immunoassay (NG Biotech) BACKGROUND: The emergence of new SARS-CoV-2 has promoted the development of new serological tests that could be complementary to RT-PCR. Nevertheless, the assessment of clinical performances of available tests is urgently required as their use has just been initiated for diagnose. OBJECTIVES: The aim of this study was to assess the performance of three immunoassays for the detection of SARS-CoV-2 antibodies. METHODS: Two automated immunoassays (Abbott SARS-CoV-2 CLIA IgG and Euroimmun Anti-SARS-CoV-2 ELISA IgG/IgA assays) and one lateral flow immunoassay (LFIA NG-Test® IgG-IgM COVID-19) were tested. 293 specimens were analyzed from patients with a positive RT-PCR response, from patients with symptoms consistent with COVID-19 but exhibiting a negative response to the RT-PCR detection test, and from control group specimens. Days since symptoms onset were collected from clinical information sheet associated with respiratory tract samples. RESULTS: Overall sensitivity for IgG was equivalent (around 80%) for CLIA, ELISA and LFIA. Sensitivity for IgG detection, >14 days after onset of symptoms, was 100.0% for all assays. Overall specificity for IgG was greater for CLIA and LFIA (more than 98%) compared to ELISA (95.8%). Specificity was significantly different between IgA ELISA (78.9%) and IgM LFIA (95.8%) (p < 0.05). The best agreement was observed between CLIA and LFIA assays (97%; k = 0.936). CONCLUSION: Excellent sensitivity for IgG detection was obtained >14 days after onset of symptoms for all immunoassays. Specificity was also excellent for IgG CLIA and IgG LFIA. Our study shows that NG-Test® is reliable and accurate for routine use in clinical laboratories.

positive: Concordance of "rapid" serological tests and IgG and IgM chemiluminescence for SARS-COV-2 Background The COVID-19 serological tests for IgG and IgM have been developed with several methodologies: Immunoenzymatic Assay (ELISA), Chemiluminescence, Electro Chemiluminescence, Fluorescent Lateral Flow Immunoassays and Immunochromatography. None of these tests should be used for the diagnosis or population screening of the disease, considering that the antibodies appear only on the 8th - 14th day of the disease onset. The present study evaluates a sample of immunofluorescent and immunochromatographic rapid tests to show their agreement in relation to Chemiluminescence. Methods A diagnostic test evaluation assay was performed to establish the performance of five rapid tests (4 immunochromatographic and 1 immunofluorescent tests) for IgG and IgM serology for SARS-CoV-2 using a panel of 30 serum samples from patients received in the laboratory analysis routine. For the evaluation of clinical performance, the qualitative results of the rapid tests were compared against those obtained by chemiluminescence, dichotomized as positives (>>10 AU / mL) or negative (<10 UA / mL). Findings The best agreement is seen in the immunofluorescent assay, for the IgG contrast, with a particularly good kappa index (0.85), without positive disagreements and a negative disagreement of about 15%. In the immunochromatographic methods Kappa index was 0.61 at best, with disagreements in negative findings of {approx}35% and in positive cases of up to {approx}70%. The IgM concordance behavior, on the other hand, reflects a weak to moderate Kappa concordance value (Kappa 0.2 to 0.6), with negative disagreements reaching up to 55% and positives of up to 84%, without any evaluated test reaching Kappa performance equal to or greater than 0.8. Interpretation Serological studies should be used in the clinical and epidemiological context and of other diagnostic tests. Given the high demand and supply in the market of "rapid serological tests", its evaluation against panels of serologically positive or negative samples established by Chemiluminescence or Electro chemiluminescence is essential to authorize its extensive use in populations Funding None

positive: Reliability of serological tests for COVID-19: Comparison of three immunochromatography test kits for SARS-CoV-2 antibodies. Background: Several immunochromatographic serological test kits have been developed to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific antibodies, but their relative performance and potential clinical utility is unclear. Methods: Three commercially available serological test kits were evaluated using 99 serum samples collected from 29 patients diagnosed with coronavirus disease 2019 (COVID-19). Results: The IgM antibody-positive rates of the three serological test kits for samples taken at the early stage of the disease (0-6 days after onset) were 19.0%, 23.8%, and 19.0%, respectively. The IgM antibody-positive rates over the entire period were 21.2%, 60.6%, and 15.2%, respectively. The IgG antibody-positive rates for samples taken after 13 days of onset were 100.0%, 97.6%, and 97.6%, respectively. Conclusion: There were large differences among the results of the three test kits. Only few cases showed positive results for IgM in the early stage of disease and the IgM antibody-positive rates over the entire period were low, suggesting that the kits used in this study were unsuitable for diagnosis of COVID-19. The IgG antibody was positive in almost all samples after 13 days of onset, suggesting that it may be useful for determining infections in the recent past.

positive: Antibodies to SARS Coronavirus in Civets Using three different assays, we examined 103 serum samples collected from different civet farms and a market in China in June 2003 and January 2004. While civets on farms were largely free from SARS-CoV infection, ≈80% of the animals from one animal market in Guangzhou contained significant levels of antibody to SARS-CoV, which suggests no widespread infection among civets resident on farms, and the infection of civets in the market might be associated with trading activities under the conditions of overcrowding and mixing of various animal species.

positive: Detection of asymptomatic SARS-CoV-2 exposed individuals by a sensitive S-based ELISA. To assess the current coronavirus pandemic, there is a pressing need to determine the exposure and seroconversion to SARS-CoV-2 on a local and global level. Here, we demonstrate a sensitive and specific S-protein based assay that is well suited for detection of weak SARS- CoV-2-directed IgG responses, and that could identify exposed individuals with asymptomatic infection without the requirement of PCR diagnostics. Our results raise the possibility that on- going population-based studies using less sensitive state-of-the-art serological assays may significantly underestimate the frequency of exposure and seroconversion to SARS-CoV-2.

positive: Diagnostic strategies for SARS-CoV-2 infection and interpretation of microbiological results BACKGROUND: To face the current COVID-19 pandemic, diagnostic tools are essential. It is recommended to use real-time RT-PCR for RNA viruses in order (a) to perform a rapid and accurate diagnostic, (b) to guide patient care and management and (c) to guide epidemiological strategies. Further studies are warranted to define the role of serological diagnosis and a possible correlation between serological response and prognosis. OBJECTIVES: The aim was to guide clinical microbiologists in the use of these diagnostic tests and clinicians in the interpretation of their results. SOURCES: A search of literature was performed through PubMed and Google Scholar using the keywords SARS-CoV-2, SARS-CoV-2 molecular diagnosis, SARS-CoV-2 immune response, SARS-CoV-2 serology/antibody testing, coronavirus diagnosis. CONTENT: The present review discusses performances, limitations and use of current and future diagnostic tests for SARS-CoV-2. IMPLICATIONS: Real-time RT-PCR remains the reference method for diagnosis of SARS-CoV-2 infection. On the other hand, notwithstanding its varying sensitivity according to the time of infection, serology represents a valid asset (a) to try to solve possible discrepancies between a highly suggestive clinical and radiological presentation and negative RT-PCR, (b) to solve discrepancies between different PCR assays and (c) for epidemiological purposes.

positive: Clinical Sensitivity and Interpretation of PCR and Serological COVID-19 Diagnostics for Patients Presenting to the Hospital Introduction: The diagnosis of COVID-19 requires integration of clinical and laboratory data. SARS-CoV-2 diagnostic assays play a central role in diagnosis and have fixed technical performance metrics. Interpretation becomes challenging because the clinical sensitivity changes as the virus clears and the immune response emerges. Our goal was to examine the clinical sensitivity of two most common SARS-CoV-2 diagnostic test modalities, polymerase chain reaction (PCR) and serology, over the disease course to provide insight into their clinical interpretation in patients presenting to the hospital. Methods: A single-center, retrospective study. To derive clinical sensitivity of PCR, we identified 209 PCR-positive SARS-CoV-2 patients with multiple PCR test results (624 total PCR tests) and calculated daily sensitivity from date of symptom onset or first positive test. To calculate daily clinical sensitivity by serology, we utilized 157 PCR-positive patients with a total of 197 specimens tested by enzyme-linked immunosorbent assay for IgM, IgG, and IgA anti-SARS-CoV-2 antibodies. Results: Clinical sensitivity of PCR decreased with days post symptom onset with >90% clinical sensitivity during the first 5 days after symptom onset, 70-71% from days 9-11, and 30% at day 21. In contrast, serological sensitivity increased with days post symptom onset with >50% of patients seropositive by at least one antibody isotype after day 7, >80% after day 12, and 100% by day 21. Conclusion: PCR and serology are complimentary modalities that require time-dependent interpretation. Superimposition of sensitivities over time indicate that serology can function as a reliable diagnostic aid indicating recent or prior infection.

positive: Comparison of the Elecsys® Anti-SARS-CoV-2 immunoassay with the EDI™ enzyme linked immunosorbent assays for the detection of SARS-CoV-2 antibodies in human plasma BACKGROUND: Here, we report on a head-to-head comparison of the fully-automated Elecsys® Anti-SARS-CoV-2 immunoassay with the EDITM enzyme linked immunosorbent assays (ELISA) for the detection of SARS-CoV-2 antibodies in human plasma. METHODS: SARS-CoV-2 antibodies were measured with the Elecsys® assay and the EDITM ELISAs (IgM and IgG) in 64 SARS-CoV-2 RT-PCR confirmed COVID-19 patients with serial blood samples (n = 104) collected at different time points from symptom onset. Blood samples from 200 healthy blood donors and 256 intensive care unit (ICU) patients collected before the COVID-19 outbreak were also used. RESULTS: In COVID-19 patients, the percentage of positive results rose with time from symptom onset, peaking to positivity rates after 15-22 days of 100% for the Elecsys® assay, of 94% for the EDITM IgM-ELISA and of 100% for the EDITM IgG ELISA. In the 104 blood samples, the agreement between positive/negative classifications of the Elecsys® assay and the EDITM ELISAs (IgM or IgG) was 90%. The false positivity rates in the healthy blood donors and the ICU patients were < 1% for the Elecsys® assay and < 3% for the EDITM ELISAs. CONCLUSIONS: Our results indicate a high sensitivity and specificity for the Elecsys® assay and an acceptable agreement with the EDITM ELISAs.

positive: Efficacy of Serology Testing in Predicting Reinfection in Patients with SARS-CoV-2. In many parts of the United States, SARS-CoV-2 cases have reached peak infection rates, prompting administrators to create protocols to resume elective cases. As elective procedures and surgeries get scheduled, ASCs must implement some form of widespread testing in order to ensure the safety of both the ASC staff as well as the patients being seen. The CDC recently announced the approval of new serological testing for SARS-CoV-2, a test that can indicate the presence of IgM and IgG antibodies in the serum against viral particles. However, the possibility for reinfection raises questions about the utility of this new serological test, as the presence of IgG may not correspond to long-term immunity. The coronavirus has been known to form escape mutations, which may correspond to reduction in immunoglobulin binding capacity. Patients who develop more robust immune responses with formation of memory CD8+ T-cells and helper CD4+ T-cells will be the most equipped if exposed to the virus, but unfortunately the serology test will not help us in distinguishing those individuals. Given the inherent disadvantages of serological testing, antibody testing alone should not be used when deciding patient care and should be combined with PCR testing.

positive: Analytical performance of lateral flow immunoassay for SARS-CoV-2 exposure screening on venous and capillary blood samples Objectives: Numerous serologic immunoassays have been launched to detect antibodies to SARS-CoV-2, including rapid tests. Here, we validate use of a lateral flow immunoassay (LFI) intended for rapid screening and qualitative detection of anti-SARS-CoV-2 IgM and IgG in serum, plasma, and whole blood, and compare results with ELISA. We also seek to establish the value of LFI testing on blood obtained from a capillary blood sample. Methods: Samples collected by venous blood draw and capillary finger stick were obtained from patients with SARS-CoV-2 detected by RT-qPCR and control patients negative for SARS-CoV-2. Samples were tested with the 2019-nCoV IgG/IgM Detection Kit (Colloidal Gold) lateral flow immunoassay, and antibody calls were compared with results obtained by ELISA. Results: The Biolidics LFI kit shows clinical sensitivity of 92% at 7 days after PCR diagnosis of SARS-CoV-2 on venous blood. Test specificity was 92% for IgM and 100% for IgG. There was no significant difference in detecting IgM and IgG with Biolidics LFI and ELISA at D0 and D7 (p=1.00), except for detection of IgM at D7 (p=0.04). Finger stick whole blood of SARS-CoV-2 patients showed 93% sensitivity for antibody detection. Conclusions: Clinical performance of Biolidics 2019-nCoV IgG/IgM Detection Kit (Colloidal Gold) is comparable to ELISA and showed consistent results across different sample types. Furthermore, we show that capillary blood obtained by finger stick shows similar sensitivity for detecting anti-SARS-CoV-2 IgM and IgG antibodies as venous blood samples. This provides an opportunity for decentralized rapid testing in the community and may allow point-of-care and longitudinal self-testing for the presence of anti-SARS-CoV-2 antibodies.

positive: IgA-Ab response to spike glycoprotein of SARS-CoV-2 in patients with COVID-19: A longitudinal study Validation studies of serological antibody tests must be properly designed for clinical, epidemiological and Public Health objectives such as confirmation of suspected COVID-19 cases, certification of seroconversion after infection, and epidemiological surveillance. We evaluated the kinetics of IgM, IgA and IgG SARS-CoV-2 antibodies in COVID-19 patients with confirmed (rRT-PCR) infection. We found that the IgA response appears and grows early, peaks at week 3, and it is stronger and more persistent than the IgM response. Further longitudinal investigations of virus-specific antibodies functions and of their protective efficacy over time are needed.

positive: Detection of human coronavirus 229E-specific antibodies using recombinant fusion proteins Abstract Human coronaviruses are known to be a common cause of respiratory infections in man. However, the diagnosis of human coronavirus infections is not carried out routinely, primarily because the isolation and propagation of these viruses in tissue culture is difficult and time consuming. The aim of this study was to evaluate the use of recombinant, bacterial expressed proteins in the serodiagnosis of coronavirus infections. Two proteins were examined: the human coronavirus 229E nucleocapsid protein (N), expressed as a fusion protein in the vector pUR and the coronavirus 229E surface glycoprotein (S), expressed as a fusion protein in the vector pROS. The recombinant proteins were used as antigens in Western blot (WB) assays to detect the 229E-specific IgG antibodies and the results were compared with a standard serological method, indirect immunofluorescence. Serum samples of 51 paediatric patients, suffering from acute respiratory illness, and 10 adults, voluntarily infected with human coronavirus, were tested. The serum samples of the adult group had coronavirus-specific IgG antibodies in both test systems. In contrast, only 8 51 sera of the paediatric group were positive for coronavirus-specific IgG by both WB and IF and 20 51 sera were positive by WB, but not by IF. The overall incidence of human coronavirus infections in the paediatric age group was 55% evaluated by WB analysis and 16% evaluated by IF. This study shows that recombinant human coronavirus 229E proteins are suitable reagents for the epidemiological screening of coronavirus 229E infections.

positive: Diagnostic efficacy of anti‐SARS‐CoV‐2 IgG/IgM test for COVID‐19: A meta‐analysis The serological testing of anti‐SARS‐CoV‐2 immunoglobulin G (IgG) and/or IgM is widely used in the diagnosis of COVID‐19. However, its diagnostic efficacy remains unclear. In this study, we searched for diagnostic studies from the Web of Science, PubMed, Embase, CNKI, and Wanfang databases to calculate the pooled diagnostic accuracy measures using bivariate random‐effects model meta‐analysis. As a result, 22 from a total of 1613 articles, including 2282 patients with SARS‐CoV‐2 and 1485 healthy persons or patients without SARS‐CoV‐2, were selected for a meta‐analysis. Pooled sensitivity, specificity, and area under curve of the summary receiver operator curve (SROC) were: (a) 0.85 (95% confidence interval [CI]: 0.79‐0.90), 0.99 (95% CI: 0.98‐1.00), and 0.99 (95% CI: 0.97‐0.99) for anti‐SARS‐CoV‐2 IgG and (b) 0.74 (95% CI: 0.65‐0.81), 0.99 (95% CI: 0.97‐1.00), and 0.95 (95% CI: 0.93‐0.97) for IgM. A subgroup analysis among detection methods indicated the sensitivity of IgG and IgM using enzyme‐linked immunosorbent assay were slightly lower than those using gold immunochromatography assay (GICA) and chemiluminescence immunoassay (P > .05). These results showed that the detection of anti‐SARS‐CoV‐2 IgG and IgM had high diagnostic efficiency to assist the diagnosis of SARS‐CoV‐2 infection. And, GICA might be used as the preferred method for its accuracy and simplicity.

positive: Serological signatures of SARS-CoV-2 infection: Implications for antibody-based diagnostics Background The antibody response generated following infection with SARS-CoV-2 is expected to decline over time. This may cause individuals with confirmed SARS-CoV-2 infection to test negative according to serological diagnostic tests in the months and years following symptom onset. Methods A multiplex serological assay was developed to measure IgG and IgM antibody responses to four SARS-CoV-2 Spike (S) antigens: spike trimeric ectodomain (Stri), its receptor-binding domain (RBD), spike subunit 1 (S1), and spike subunit 2 (S2). Antibody responses were measured in serum samples from patients in French hospitals with RT-qPCR confirmed infection (n = 259), and negative control serum samples collected before the start of the SARS-CoV-2 epidemic in 2019 (n = 335). The multiplex antibody data was used to train a random forests algorithm for classifying individuals with previous SARS-CoV-2 infection. A mathematical model of antibody kinetics informed by prior information from other coronaviruses was used to estimate time-varying antibody responses and assess the potential sensitivity and classification performance of serological diagnostics during the first year following symptom onset. Results IgG antibody responses to one S antigen identified individuals with previous RT-qPCR confirmed SARS-CoV-2 infection with 90.3% sensitivity (95% confidence interval (CI); 86.1%, 93.4%) and 99.1% specificity (95% CI; 97.4%, 99.7%). Using a serological signature of IgG to four antigens, it was possible to identify infected individuals with 96.1% sensitivity (95% CI; 93.0%, 97.9%) and 99.1% specificity (95% CI; 97.4%, 99.7%). Antibody responses to SARS-CoV-2 increase rapidly 1-2 weeks after symptom onset, with antibody responses predicted to peak within 2-4 weeks. Informed by prior data from other coronaviruses, one year following symptom onset antibody responses are predicted to decay by approximately 60% from the peak response. Depending on the selection of sero-positivity cutoff, we estimate that the sensitivity of serological diagnostics may reduce to 56%-97% after six months, and to 49%-93% after one year. Conclusion Serological signatures based on antibody responses to multiple antigens can provide more accurate and robust serological classification of individuals with previous SARS-CoV-2 infection. Changes in antibody levels over time may cause reductions in the sensitivity of serological diagnostics leading to an underestimation of sero-prevalence. It is essential that data continue to be collected to evaluate this potential risk.

positive: Longitudinal Monitoring of SARS-CoV-2 IgM and IgG Seropositivity to Detect COVID-19 BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a novel beta-coronavirus that has recently emerged as the cause of the 2019 coronavirus pandemic (COVID-19). Polymerase chain reaction (PCR) based tests are optimal and recommended for the diagnosis of an acute SARS-CoV-2 infection. Serology tests for viral antibodies provide an important tool to diagnose previous exposure to the virus. Here we evaluate the analytical performance parameters of the Diazyme SARS-CoV-2 IgM/IgG serology assays and describe the kinetics of IgM and IgG seroconversion observed in patients with PCR confirmed COVID-19 who were admitted to our hospital. METHODS: We validated the performance of the Diazyme assay in 235 subjects to determine specificity. Subsequently, we evaluated the SARS-CoV-2 IgM and IgG seroconversion of 54 PCR confirmed COVID-19 patients and determined sensitivity of the assay at three different timeframes. RESULT: Sensitivity and specificity for detecting seropositivity at ≥ 15 days following a positive SARS-CoV-2 PCR result, was 100.0% and 98.7% when assaying for the panel of IgM and IgG. The median time to seropositivity observed for a reactive IgM and IgG result from the date of a positive PCR was 5 days (IQR: 2.75-9 days) and 4 days (IQR: 2.75-6.75 days), respectively. CONCLUSIONS: Our data demonstrates that the Diazyme IgM/IgG assays are suited for the purpose of detecting SARS-CoV-2 IgG and IgM in patients with suspected SARS-CoV-2 infections. For the first time, we report longitudinal data showing the evolution of seroconversion for both IgG and IgM in a cohort of acutely ill patients in the United States. We also demonstrate a low false positive rate in patients who were presumed to be disease free.

positive: Applying lessons from SARS to a newly identified coronavirus

positive: Optimize Clinical Laboratory Diagnosis of COVID-19 from Suspect Cases by Likelihood Ratio of SARS-CoV-2 IgM and IgG antibody Objective: To optimize clinical laboratory diagnosis of COVID-19 from suspect cases by Likelihood Ratio of SARS-CoV-2 IgM and IgG antibody. Methods: By reinterpreting the data in the article "Diagnostic Value of Combined Detection of Serum 2019 novel coronavirus IgM and IgG Antibodies in novel coronavirusin Infection", the positive likelihood ratio of IgM and IgG antibody in diagnosis of COVID-19 (nucleic acid positive patients) was calculated, and the posterior probability of IgM and IgG antibodies and their tandem detection to diagnose was finally calculated. Results: The positive likelihood ratios of single IgM and IgG antibody were 18.50 and 12.65 respectively, and the posterior probabilities were 90.18% and 86.26% respectively. However, the posterior probability of the two antibodies tandem detection is 99.15%, which can give clinicians quantitative confidence in the diagnosis of COVID-19 from suspected cases. According to the results of this study, combining the advantages and disadvantages of nucleic acid detection and antibody detection, the clinical pathway for clinicians to diagnose COVID-19 is found. Conclusion: For suspected cases, IgM and IgG antibody tests should be firstly done at the same time. If the antibody tests are all positive, COVID-19 can be confirmed. If not, nucleic acid detection (one or more times) is performed, and in extreme cases, high-throughput viral genome sequencing is performed.

positive: Sensitive and specific monoclonal antibody-based capture enzyme immunoassay for detection of nucleocapsid antigen in sera from patients with severe acute respiratory syndrome. A rapid antigen test for the diagnosis of severe acute respiratory syndrome (SARS) is essential for control of this disease at the point of management. The nucleocapsid (N) protein of SARS-associated coronavirus (SARS-CoV) is abundantly expressed in infected-cell culture filtrate as demonstrable by Western blotting using convalescent-phase sera from patients with SARS. We used monoclonal antibodies specifically directed against N protein to establish a sensitive antigen capture sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of SARS-CoV. The assay employed a mixture of three monoclonal antibodies for capture and rabbit polyclonal antibodies for detection of serum antigen in 32 cases of clinically probable SARS as defined by the World Health Organization during the epidemic in Guangzhou, China. Recombinant N protein was used as a standard to establish a detection sensitivity of approximated 50 pg/ml. The linear range of detection in clinical specimens was from 100 pg/ml to 3.2 ng/ml. Using a panel of sera collected at different points in time, the amount of circulating N antigen was found to peak 6 to 10 days after the onset of symptoms. The sensitivity of the assay was 84.6% in 13 serologically confirmed SARS patients with blood taken during the first 10 days after the onset of symptoms (11 of 13). The specificity of the assay was 98.5% in 1,272 healthy individuals (1,253 of 1,272). There was no cross-reaction with other human and animal coronaviruses in this assay. In conclusion, a sensitive and quantitative antigen capture ELISA was established for the early diagnosis and disease monitoring of SARS-CoV infection.

positive: The spectrum of severe acute respiratory syndrome-associated coronavirus infection. BACKGROUND Whether subclinical or atypical presentations of severe acute respiratory syndrome (SARS) occur and whether clinical judgment is accurate in detecting SARS are unknown. OBJECTIVES To describe the spectrum of SARS coronavirus infection in a large outbreak and to compare diagnoses based on clinical judgment with the SARS coronavirus test. DESIGN Secondary analysis of prospectively collected clinical data and archived serum. SETTING A SARS screening clinic of a university hospital in the New Territories of Hong Kong. PATIENTS 1221 patients attending the clinic between 12 March 2003 and 12 May 2003. MEASUREMENTS SARS coronavirus serology. RESULTS 145 of 553 (26%) patients had serologic evidence of SARS coronavirus infection. Of 910 patients who were managed without hospitalization, only 6 had serologic evidence of SARS. Five of the six patients had normal chest radiographs, and four had symptoms such as myalgia, chills, coughing, and feeling feverish. With the SARS coronavirus serologic test as the gold standard, the clinical diagnosis of probable SARS at hospitalization had a sensitivity of 0.96 (95% CI, 0.91 to 0.98) and a specificity of 0.96 (CI, 0.92 to 0.97). LIMITATIONS Follow-up serologic samples were not obtained from almost half of the patients because they declined further testing. Some people living in the community who were infected but who had minor or no symptoms might not have visited the clinic. CONCLUSIONS There is little evidence of widespread subclinical or mild forms of SARS coronavirus infection. Clinical diagnoses during the outbreak were reasonable and resulted in appropriate triaging.

positive: Development and application of an enzyme immunoassay for coronavirus OC43 antibody in acute respiratory illness. Study of coronavirus OC43 infections has been limited because of the lack of sensitive cell culture systems and serologic assays. To improve this circumstance, we developed an indirect enzyme immunoassay (EIA) to detect serum antibody to OC43. Antigen (100 ng) prepared by polyethylene glycol precipitation provided optimal results without a postcoat procedure. Evaluation of intraplate variation indicated that a > or = 2.5-fold increase in serum titer was significant. Sixteen of 18 (89%) paired serum samples with previously identified, reproducible increases in the level of hemagglutination inhibition (HAI) antibody to OC43 also showed significant increases as detected by EIA. Specificity for the EIA was established with paired sera obtained from persons given influenza immunizations or experiencing a respiratory infection. No rise in antibody titers occurred among 33 persons with documented coronavirus 229E infection. EIA was then performed on each of 419 paired serum samples from ambulatory chronic obstructive pulmonary disease patients and healthy older adults, from asthmatic adults presenting for emergency room treatment, and from persons hospitalized with acute respiratory symptoms. Twenty-three antibody rises to OC43 were detected; only nine of these were detected by the HAI test, and the HAI test did not detect any increases in antibody titers that were not detected by EIA. Nineteen of 25 coronavirus OC43 infections for which a month of infection could be assigned occurred between November and February. Overall, 4.4% of acute respiratory illnesses in the studied populations were associated with a coronavirus OC43 infection.

positive: Seroprevalence and epidemiological characteristics of immunoglobulin M and G antibodies against SARS-CoV-2 in asymptomatic people in Wuhan, China Background The seroprevalence of immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may be a more reliable approach to detect true infected population, particularly in asymptomatic persons. Few studies focus on the diagnosis of COVID-19 patients using serological tests. To detect and assess asymptomatic infections of COVID-19 among people in Wuhan, the epicenter of the COVID-19 pandemic in China, and provide evidence for planning adequate public health measures, we collected and analyzed the clinical data in the Wuhan General Hospital mandatory for 16- to 64-year-old asymptomatic people. This retrospective study estimated the seroprevalence of IgM and IgG and compared the epidemiological characteristics of asymptomatic SARS-CoV-2-infected population. Methods Demographical and radiological data were collected from the Wuhan General Hospital between March 26 and April 28, 2020. Serological tests for IgM and IgG antibodies against SARS-CoV-2 were conducted with a colloidal gold method. Nucleic acid sequences of viruses were detected with RT-PCR. Statistical analyses were carried out using SPSS 20.0 software. Findings Between March 26 and April 28, 2020, 18,391 asymptomatic back-to-work participants were enrolled. Among them, 89 had positivity for IgM (0.48%, 95% confidence interval (CI): 0.38-0.58%); 620 cases had IgG positivity (3.37%, 95% CI: 3.11-3.64%), and 650 cases had either IgG positivity or IgM positivity (3.53%, 95% CI: 3.26-3.80%). After standardizing for the genders and ages in the population of Wuhan, the overall standardized seroprevalence of IgG was 3.33% (95% CI: 3.07-3.59%) and the standardized seroprevalence of IgG was 3.01% (95% CI: 2.69-3.33%) among males and 3.66% (95 % CI: 3.23-4.09%) among females. The standardized seroprevalence of IgG was higher in women than in men with a significant difference ({chi}2 = 2,060.3, p < 0.01). By a detection method adjustment, the seroprevalence of IgG was 1.57% (95% CI: 1.39-1.75%) in all medical records, of which males were 1.96% (95% CI: 1.64-2.28%), and females were 1.19% (95% CI: 0.99-1.39%). The assay-adjusted seroprevalence of IgG was higher in women than in men, and the difference was significant ({chi}2 = 5,871.0, p < 0.01). The differences were significant for the seroprevalence of IgG among people who went back to work in different categories of workplace ({chi}2 = 198.44, p < 0.01). The differences in seroprevalence for IgG positivity or IgM positivity among people who went back to work in different urban and rural areas was also significant ({chi}2 = 45.110, p < 0.01). Calculated as IgG and/or IgM antibody positivity, the number of new infections was reduced by 64.8% from March 26 to April 28, 2020. Based on the census population aged 16-64 years in Wuhan in 2017, we estimated that 172,340 (95% CI: 157,568-187,112) asymptomatic people aged 16-64 years were infected with SARS-CoV-2 in Wuhan between March 25 and April 28, 2020. This estimate was 3.4-times higher than the officially reported 50,333 infections on April 28. Interpretation The seropositivity rate in Wuhan indicated that RT-PCR-confirmed patients only represented a small part of the total number of cases. Seropositivity progressively decreased in the Wuhan population from March 26 to April 28, 2020, comparable to Japan and Denmark, but well below the level reported in New York, Iran, Italy, and Germany. The prevalence of asymptomatic infection was higher in women than in men among people who went back to work in Wuhan. The low seroprevalence suggests that most of the population remains susceptible to COVID-19. Funding The Emergency Management Project of the National Natural Science Foundation of China (81842035) and Advisory Research Project of the Chinese Academy of Engineering in 2019 (2019-XZ-70).

positive: Comparison of diagnostic accuracies of rapid serological tests and ELISA to molecular diagnostics in patients with suspected COVID-19 presenting to the hospital OBJECTIVES: To assess the diagnostic performance of rapid lateral flow immunochromatographic assays (LFAs) compared to an enzyme-linked immunosorbent assay (ELISA) and nucleic acid amplification tests (NATs) in suspected coronavirus disease 2019 (COVID-19) patients. METHODS: Patients presenting to a Dutch teaching hospital were eligible between March 17 and April 10, 2020, when they had respiratory symptoms that were suspected for COVID-19. The performances of six different LFAs were evaluated in plasma samples obtained on corresponding respiratory sample dates of NATs testing. Subsequently, the best performing LFA was evaluated in 228 patients and in 50 sera of a historical patient control group. RESULTS: In the pilot analysis sensitivity characteristics of LFA were heterogenous ranging from 2/20 (10%; 95% confidence interval (CI) 0-23) to 11/20 (55%; 95% CI 33-77). In the total cohort, Orient Gene Biotech COVID-19 IgG/IgM Rapid Test LFA had a sensitivity of 43/99 (43%; 95% CI 34-53) and specificity of 126/129 (98%; 95% CI 95-100). Sensitivity increased to 31/52 (60%; 95% CI 46-73) in patients with at least seven days of symptoms, and to 21/33 (64%; 95% CI 47-80) in patients with C-reactive protein (CRP) >100 mg/L. Sensitivity and specificity of Wantai SARS-CoV-2 Ab ELISA was 59/95 (62%; 95% CI 52-72) and 125/128 (98%; 95% CI 95-100) in all patients, respectively, but sensitivity increased to 38/48 (79%; 95% CI 68-91) in patients with at least seven days of symptoms. CONCLUSIONS: There is large variability in diagnostic test performance between rapid LFAs, but overall limited sensitivity and high specificity in acutely admitted patients. Sensitivity improved in patients with longer existing symptoms or high CRP. LFAs should only be considered as additional triage tools when these may lead to the improvement of hospital logistics.

positive: Diagnostic efficacy of anti-SARS-CoV-2 IgG/IgM test for COVID-19: A meta-analysis The serological testing of anti-SARS-CoV-2 immunoglobulin G (IgG) and/or IgM is widely used in the diagnosis of COVID-19. However, its diagnostic efficacy remains unclear. In this study, we searched for diagnostic studies from the Web of Science, PubMed, Embase, CNKI, and Wanfang databases to calculate the pooled diagnostic accuracy measures using bivariate random-effects model meta-analysis. As a result, 22 from a total of 1613 articles, including 2282 patients with SARS-CoV-2 and 1485 healthy persons or patients without SARS-CoV-2, were selected for a meta-analysis. Pooled sensitivity, specificity, and area under curve of the summary receiver operator curve (SROC) were: (a) 0.85 (95% confidence interval [CI]: 0.79-0.90), 0.99 (95% CI: 0.98-1.00), and 0.99 (95% CI: 0.97-0.99) for anti-SARS-CoV-2 IgG and (b) 0.74 (95% CI: 0.65-0.81), 0.99 (95% CI: 0.97-1.00), and 0.95 (95% CI: 0.93-0.97) for IgM. A subgroup analysis among detection methods indicated the sensitivity of IgG and IgM using enzyme-linked immunosorbent assay were slightly lower than those using gold immunochromatography assay (GICA) and chemiluminescence immunoassay (P > .05). These results showed that the detection of anti-SARS-CoV-2 IgG and IgM had high diagnostic efficiency to assist the diagnosis of SARS-CoV-2 infection. And, GICA might be used as the preferred method for its accuracy and simplicity.

positive: Performance of six SARS-CoV-2 immunoassays in comparison with microneutralisation There is an urgent need for reliable high-throughput serological assays for the management of the ongoing COVID-19 pandemic. Preferably, the performance of serological tests for a novel virus should be determined with clinical specimens against a gold standard, i.e. virus neutralisation. We evaluated specificity and sensitivity of six commercial immunoassays for the detection of SARS-CoV-2 IgG, IgA and IgM antibodies, including four automated assays [Abbott SARS-COV-2 IgG (CE marked), Diasorin Liaison SARS-CoV-2 S1/S2 IgG (research use only), and Euroimmun SARS-CoV-2 IgG and IgA (CE marked)], and two rapid lateral flow (immunocromatographic) tests [Acro Biotech 2019-nCoV IgG/IgM (CE marked) and Xiamen Biotime Biotechnology SARS-CoV-2 IgG/IgM (CE marked)] in comparison with a microneutralisation test (MNT). Two specimen panels from serum samples sent to Helsinki University Hospital Laboratory (HUSLAB) were compiled: the patient panel included sera from PCR confirmed COVID-19 patients, and the negative panel included sera sent for screening of autoimmune diseases and respiratory virus antibodies in 2018 and 2019. The MNT was carried out for all COVID-19 samples (70 serum samples, 62 individuals) and for 53 samples from the negative panel. Forty-one out of 62 COVID-19 patients showed neutralising antibodies with median of 11 days (range 3-51) after onset of symptoms. The specificity and sensitivity values of the commercial tests against MNT, respectively, were as follows: 95.1%/80.5% (Abbott Architect SARS-CoV-2 IgG), 94.9%/43.8% (Diasorin Liaison SARS-CoV-2 IgG), 68.3%/87.8% (Euroimmun SARS-CoV-2 IgA), 86.6%/70.7% (Euroimmun SARS-CoV-2 IgG), 74.4%/56.1% (Acro 2019-nCoV IgG), 69.5%/46.3% (Acro 2019-nCoV IgM), 97.5%/71.9% (Xiamen Biotime SARS-CoV-2 IgG), and 88.8%/81.3% (Xiamen Biotime SARS-CoV-2 IgM). This study shows variable performance values. Laboratories should carefully consider their testing process, such as a two-tier approach, in order to optimize the overall performance of SARS-CoV-2 serodiagnostics.

positive: Performance of six SARS-CoV-2 immunoassays in comparison with microneutralisation There is an urgent need for reliable high-throughput serological assays for the management of the ongoing COVID-19 pandemic. Preferably, the performance of serological tests for a novel virus should be determined with clinical specimens against a gold standard, i.e. virus neutralisation. We compared the performance of six commercial immunoassays for the detection of SARS-CoV-2 IgG, IgA and IgM antibodies, including four automated assays [Abbott SARS-COV-2 IgG (CE marked), Diasorin Liaison® SARS-CoV-2 S1/S2 IgG (research use only, RUO), and Euroimmun SARS-CoV-2 IgG and IgA (CE marked)], and two rapid lateral flow (immunocromatographic) tests [Acro Biotech 2019-nCoV IgG/IgM (CE marked) and Xiamen Biotime Biotechnology SARS-CoV-2 IgG/IgM (CE marked)] with a microneutralisation test (MNT). Two specimen panels from serum samples sent to Helsinki University Hospital Laboratory (HUSLAB) were compiled: the patient panel (N=70) included sera from PCR confirmed COVID-19 patients, and the negative panel (N=81) included sera sent for screening of autoimmune diseases and respiratory virus antibodies in 2018 and 2019. The MNT was carried out for all COVID-19 samples (70 serum samples, 62 individuals) and for 53 samples from the negative panel. Forty-one out of 62 COVID-19 patients showed neutralising antibodies.The specificity and sensitivity values of the commercial tests against MNT, respectively, were as follows: 95.1%/80.5% (Abbott Architect SARS-CoV-2 IgG), 94.9%/43.8% (Diasorin Liaison SARS-CoV-2 IgG; RUO), 68.3%/87.8% (Euroimmun SARS-CoV-2 IgA), 86.6%/70.7% (Euroimmun SARS-CoV-2 IgG), 74.4%/56.1% (Acro 2019-nCoV IgG), 69.5%/46.3% (Acro 2019-nCoV IgM), 97.5%/71.9% (Xiamen Biotime SARS-CoV-2 IgG), and 88.8%/81.3% (Xiamen Biotime SARS-CoV-2 IgM). This study shows variable performance values. Laboratories should carefully consider their testing process, such as a two-tier approach, in order to optimize the overall performance of SARS- CoV-2 serodiagnostics.

positive: Seroconversion rate and diagnostic accuracy of serological tests for COVID-19

positive: Serological immunochromatographic approach in diagnosis with SARS-CoV-2 infected COVID-19 patients Abstract An outbreak of new coronavirus SARS-CoV-2 was occurred in Wuhan, China and rapidly spread to other cities and nations. The standard diagnostic approach that widely adopted in the clinic is nucleic acid detection by real-time RT-PCR. However, the false-negative rate of the technique is unneglectable and serological methods are urgently warranted. Here, we presented the colloidal gold-based immunochromatographic (ICG) strip targeting viral IgM or IgG antibody and compared it with real-time RT-PCR. The sensitivity of ICG assay with IgM and IgG combinatorial detection in nucleic acid confirmed cases were 11.1%, 92.9% and 96.8% at the early stage (1–7 days after onset), intermediate stage (8–14 days after onset), and late stage (more than 15 days), respectively. The ICG detection capacity in nucleic acid-negative suspected cases was 43.6%. In addition, the concordance of whole blood samples and plasma showed Cohen's kappa value of 0.93, which represented the almost perfect agreement between two types of samples. In conclusion, serological ICG strip assay in detecting SARS-CoV-2 infection is both sensitive and consistent, which is considered as an excellent supplementary approach in clinical application.

positive: Laboratory Tests for COVID-19: A Review of Peer-Reviewed Publications and Implications for Clinical UIse Diagnostic tests for the coronavirus infection 2019 (COVID-19) are critical for prompt diagnosis, treatment and isolation to break the cycle of transmission A positive real-time reverse-transcriptase polymerase chain reaction (RT-PCR), in conjunction with clinical and epidemiologic data, is the current standard for diagnosis, but several challenges still exist Serological assays help to understand epidemiology better and to evaluate vaccine responses but they are unreliable for diagnosis in the acute phase of illness or assuming protective immunity Serology is gaining attention, mainly because of convalescent plasma gaining importance as treatment for clinically worsening COVID-19 patients We provide a narrative review of peer-reviewed research studies on RT-PCR, serology and antigen immune-assays for COVID-19, briefly describe their lab methods and discuss their limitations for clinical practice

positive: Serology characteristics of SARS-CoV-2 infection since exposure and post symptom onset. BACKGROUND Timely diagnosis of SARS-CoV-2 infection is a prerequisite for treatment and prevention. The serology characteristics and complement diagnosis value of the antibody test to RNA test need to be demonstrated. METHOD Serial sera of 80 patients with PCR-confirmed COVID-19 were collected at the First Affiliated Hospital of Zhejiang University, China. Total antibody (Ab), IgM and IgG antibodies against SARS-CoV-2 were detected, and the antibody dynamics during the infection were described. RESULTS The seroconversion rates for Ab, IgM and IgG were 98.8%, 93.8% and 93.8%, respectively. The first detectible serology marker was Ab, followed by IgM and IgG, with a median seroconversion time of 15, 18 and 20 days post exposure (d.p.e) or 9, 10 and 12 days post onset (d.p.o), respectively. The antibody levels increased rapidly beginning at 6 d.p.o. and were accompanied by a decline in viral load. For patients in the early stage of illness (0-7 d.p.o), Ab showed the highest sensitivity (64.1%) compared to IgM and IgG (33.3% for both, p<0.001). The sensitivities of Ab, IgM and IgG increased to 100%, 96.7% and 93.3% 2 weeks later, respectively. When the same antibody type was detected, no significant difference was observed between enzyme-linked immunosorbent assays and other forms of immunoassays. CONCLUSIONS A typical acute antibody response is induced during SARS-CoV-2 infection. Serology testing provides an important complement to RNA testing in the later stages of illness for pathogenic specific diagnosis and helpful information to evaluate the adapted immunity status of patients.

positive: Diagnostic Indexes of a Rapid IgG/IgM Combined Antibody Test for SARS-CoV-2 [Abstract]Objective Coronavirus disease 2019 has become pandemic in the world. The need for IgG/IgM combined antibody test is booming, but data on diagnostic indexes evaluation was inadequate. The aim of this study was to evaluate diagnostic indexes of a rapid IgG/IgM combined antibody test for SARS-CoV-2. Methods A total of 179 patients were enrolled. Serum were collected for IgG-IgM combined antibody test and corresponding nasal and pharyngeal swab specimens were collected for SARS-CoV-2 RT-PCR. According to SARS-CoV-2 RT-PCR results, patients under study were categorized as PCR positive group in 90 patients and PCR negative group in 89 patients. Results 1. Of the 90 PCR positive samples, 77 were tested positive by SARS-CoV-2 IgG-IgM test kit, yielding a sensitivity of 85.6%. Meanwhile, of the 89 PCR negative sample, 8 samples were detected positive, resulting in a specificity of 91%. Positive predictive value, negative predictive value and accuracy of this test kit was 95.1%, 82.7%, and 88.3%, respectively. Kappa efficiency between IgG/IgM test kit and RT-PCR were 0.75. 2. Accuracy in mild/common and severe/critical subgroup were 73.9% and 97.7%, respectively. Accuracy in clinical confirmed, suspected cases and other disease subgroups were 70%, 60%, and 100%, respectively. 3. Patients were further divided into 0-7, 8-15 and >= 16 groups according to the time from illness onset to sample collection. Sensitivity, specificity and accuracy in these three groups were 18.8%, 77.8% and 40%; 100%, 50% and 87.5%; 100%, 64.3%, and 93.9, respectively. Conclusion The sensitivity and specificity of this ease-of-use IgG/IgM combined test kit were adequate, plus short turnaround time, no specific requirements for additional equipment or skilled technicians, all of these collectively contributed to its competence for mass testing. At the current stage, it cannot take the place of SARA-CoV-2 nucleic acid RT-PCR, but can be served as a complementary option for RT-PCR. The combination of RT-PCR and IgG-IgM combined test kit could provide further insight into SARS-CoV-2 infection diagnosis.

positive: Alltest rapid lateral flow immunoassays is reliable in diagnosing SARS-CoV-2 infection from 14 days after symptom onset: A prospective single-center study OBJECTIVES: SARS-CoV-2 infection diagnosis is challenging in patients from 2 to 3 weeks after the onset of symptoms, due to the low positivity rate of the PCR. Serologic tests could be complementary to PCR in these situations. The aim of our study was to analyze the diagnostic performance of one serologic rapid test in COVID-19 patients. METHODS: We evaluated a lateral flow immunoassay (AllTest COVID-19 IgG/IgM) which detects IgG and IgM antibodies. We validated the serologic test using serum samples from 100 negative patients (group 1) and 90 patients with COVID-19 confirmed by PCR (group 2). Then, we prospectively evaluated the test in 61 patients with clinical diagnosis of pneumonia of unknown etiology that were negative for SARS-CoV-2 by PCR (group 3). RESULTS: All 100 patients from group 1 were negative for the serologic test (specificity = 100 %). Regarding group 2 (PCR-positive), the median time from their symptom onset until testing was 17 days. For these 90 group-2 patients, the test was positive for either IgM or IgG in 58 (overall sensitivity = 64.4 %), and in patients tested 14 days or more after the onset of symptoms, the sensitivity was 88.0 %. Regarding the 61 group-3 patients, median time after symptom onset was also 17 days, and the test was positive in 54 (88.5 % positivity). CONCLUSIONS: Our study shows that Alltest lateral flow immunoassay is reliable as a complement of PCR to diagnose SARS-CoV-2 infection after 14 days from the onset of symptoms and in patients with pneumonia and negative PCR for SARS-CoV-2.

positive: Serological tests facilitate identification of asymptomatic SARS‐CoV‐2 infection in Wuhan, China The Wuhan City has ended the lockdown and people have been allowed to resume working since April 8 if meeting a set of COVID‐19‐associated tests including SARS‐CoV‐2 nucleic acid test (NAT) of nasopharyngeal swabs, chest CT scan or a SARS‐CoV‐2‐specific serological test. Here, we reported the positive rate of COVID‐19 tests based on NAT, chest CT scan and a serological SARS‐CoV‐2 test, from April 3 to 15 in one hospital in Qingshan Destrict, Wuhan. We observed a ~10% SARS‐CoV‐2‐specific IgG positive rate from 1,402 tests. Combination of SARS‐CoV‐2 NAT and a specific serological test might facilitate the detection of COVID‐19 infection, or the asymptomatic SARS‐CoV‐2‐infected subjects. Large‐scale investigation is required to evaluate the herd immunity of the city, for the resuming people and for the re‐opened city. This article is protected by copyright. All rights reserved.

positive: Detection of SARS-CoV-2 neutralizing antibodies with a cell-free PCR assay Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to more than 4 million confirmed infections worldwide and over 300,000 deaths. While Remdesivir has recently received FDA emergency use authorization for treatment of SARS-CoV-2 infection, convalescent plasma (CP) with high titers of SARS-CoV-2 neutralizing antibodies (NAbs) from recovered donors remains a promising and widely accessible method to mitigate severe disease symptoms. Here, we describe the development and validation of a cell-free neutralization PCR assay using SARS-CoV-2 spike protein S1 and human ACE2 receptor-DNA conjugates. By comparing with samples collected prior to the outbreak, we confirmed that NAbs were specifically detected in COVID-19 cases. Using our unique assay, the NAb signals are detectable as early as 10 days after onset of symptoms and continue to rise, plateauing after 18 days. Notably, we showed that the use of a licensed pathogen reduction technology to inactivate potentially contaminating infectious pathogens in CP did not alter NAb signals, paving a path to safely administer effective CP therapies. The described neutralization PCR assay can serve as a qualification tool to easily identify suitable CP donors of a potentially lifesaving therapy. In addition, this assay tool is readily deployable in standard laboratories with biosafety level 2 capability, and can yield results within 2–3 hrs. This advancement can facilitate research on factors driving diverse COVID-19 disease manifestations, help evaluate the impact of various CP processing protocols on CP therapeutic efficacy and assist in accelerating vaccine efficacy assessment.

positive: Serology in the Digital Age: Using Long Synthetic Peptides Created from Nucleic Acid Sequences as Antigens in Microarrays Background: Antibodies to microbes, or to autoantigens, are important markers of disease. Antibody detection (serology) can reveal both past and recent infections. There is a great need for development of rational ways of detecting and quantifying antibodies, both for humans and animals. Traditionally, serology using synthetic antigens covers linear epitopes using up to 30 amino acid peptides. Methods: We here report that peptides of 100 amino acids or longer (“megapeptides”), designed and synthesized for optimal serological performance, can successfully be used as detection antigens in a suspension multiplex immunoassay (SMIA). Megapeptides can quickly be created just from pathogen sequences. A combination of rational sequencing and bioinformatic routines for definition of diagnostically-relevant antigens can, thus, rapidly yield efficient serological diagnostic tools for an emerging infectious pathogen. Results: We designed megapeptides using bioinformatics and viral genome sequences. These long peptides were tested as antigens for the presence of antibodies in human serum to the filo-, herpes-, and polyoma virus families in a multiplex microarray system. All of these virus families contain recently discovered or emerging infectious viruses. Conclusion: Long synthetic peptides can be useful as serological diagnostic antigens, serving as biomarkers, in suspension microarrays.

positive: Evaluation of inapparent nosocomial severe acute respiratory syndrome coronavirus infection in Vietnam by use of highly specific recombinant truncated nucleocapsid protein-based enzyme-linked immunosorbent assay. Severe acute respiratory syndrome (SARS) is a recently emerged human disease associated with pneumonia. Inapparent infection with SARS coronavirus (CoV) is not well characterized. To develop a safe, simple, and reliable screening method for SARS diagnosis and epidemiological study, two recombinant SARS-CoV nucleocapsid proteins (N' protein and (N)Delta(121) protein) were expressed in Escherichia coli, purified by affinity chromatography, and used as antigens for indirect, immunoglobulin G enzyme-linked immunosorbent assays (ELISA). Serum samples collected from healthy volunteers and SARS patients in Vietnam were used to evaluate the newly developed methods. The N' protein-based ELISA showed a highly nonspecific reaction. The (N)Delta(121) protein-based ELISA, with a nonspecific reaction drastically reduced compared to that of the nearly-whole-length N' protein-based ELISA, resulted in higher rates of positive reactions, higher titers, and earlier detection than the SARS-CoV-infected cell lysate-based ELISA. These results indicate that our newly developed SARS-CoV (N)Delta(121) protein-based ELISA is not only safe but also a more specific and more sensitive method to diagnose SARS-CoV infection and hence a useful tool for large-scale epidemiological studies. To identify inapparent SARS-CoV infections, serum samples collected from health care workers (HCWs) in Vietnam were screened by the (N)Delta(121) protein-based ELISA, and positive samples were confirmed by a virus neutralization test. Four out of 149 HCWs were identified to have inapparent SARS-CoV infection in Vietnam, indicating that subclinical SARS-CoV infection in Vietnam is rare but does exist.

positive: Diagnostic performance of COVID-19 serology assays. INTRODUCTION The World Health Organization (WHO) declared COVID-19 outbreak as a world pandemic on 12th March 2020. Diagnosis of suspected cases is confirmed by nucleic acid assays with real-time PCR, using respiratory samples. Serology tests are comparatively easier to perform, but their utility may be limited by the performance and the fact that antibodies appear later during the disease course. We aimed to describe the performance data on serological assays for COVID-19. MATERIALS AND METHODS A review of multiple reports and kit inserts on the diagnostic performance of rapid tests from various manufacturers that are commercially available were performed. Only preliminary data are available currently. RESULTS From a total of nine rapid detection test (RDT) kits, three kits offer total antibody detection, while six kits offer combination SARS-CoV-2 IgM and IgG detection in two separate test lines. All kits are based on colloidal gold-labeled immunochromatography principle and one-step method with results obtained within 15 minutes, using whole blood, serum or plasma samples. The sensitivity for both IgM and IgG tests ranges between 72.7% and 100%, while specificity ranges between 98.7% to 100%. Two immunochromatography using nasopharyngeal or throat swab for detection of COVID-19 specific antigen are also reviewed. CONCLUSIONS There is much to determine regarding the value of serological testing in COVID-19 diagnosis and monitoring. More comprehensive evaluations of their performance are rapidly underway. The use of serology methods requires appropriate interpretations of the results and understanding the strengths and limitations of such tests.

positive: The Role of Antibody Testing for SARS-CoV-2: Is There One? The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) brought with it rapid development of both molecular and serologic assays for identification of COVID-19 infections. While Food and Drug Administration (FDA) emergency use authorization (EUA) is required for clinical application of SARS-CoV-2 molecular tests, submission for EUA is currently a voluntary process for manufacturers of serologic assays. The absence of FDA oversight of serologic tests is concerning, given that the commercially available serologic assays are highly variable, differing in their format, the antibody class detected, the targeted antigen and the acceptable specimen types. An added complication is the lack of a clear understanding for how such assays should be utilized and what the reported results ultimately indicate, or perhaps more importantly, what they do not indicate. Here, we provide a brief summary of the performance of a number of serologic assays reported in the literature, comment on what we do and do not know regarding our immune response to SARS-CoV-2, and provide a number of scenarios for which serologic testing will play a role in during our global response to this pandemic.

positive: Clinical meanings of rapid serological assay in patients tested for SARS-Co2 RT-PCR Background RT-PCR test for identifiction of viral nucleic acid is the current standard diagnostic method for the diagnosis of COVID-19 disease but technical reasons limit the utilization of this assay on large scale screenings. Method We verified in a consecutive series of 191 symptomatic patients the clinical information that new rapid serological colorimetric test qualitatively analyzing IgM/IgG expression can provide with respect to standard assay and with respect to clinical outcome of patients. Results Rapid serological test showed a sensitivity of 30% and a specificity of 89% with respect to the standard assay but, interestingly, these performances improve after 8 days of symptoms appearance. After 10 days of symptoms the predictive value of rapid serological test is higher than that of standard assay. When the behaviour of the two immunoglobulins was evaluated with respect to time length of symptoms appearance, no significant difference in immunoglobulins behaviour was shown. Conclusions The rapid serological test analyzed in the present study is candidate to provide information on immunoreaction of the subject to COVID-19 exposure.

positive: Sensitive detection of SARS-CoV-2-specific-antibodies in dried blood spot samples Abstract Importance: Population-wide serological testing is an essential component in understanding the COVID-19 pandemic. The logistical challenges of undertaking widespread serological testing could be eased through use of a reliable dried blood spot (DBS) sampling method. Objective: To validate the use of dried blood spot sampling for the detection of SARS-CoV-2-specific antibodies. Design, setting and participants: Eighty-seven matched DBS and serum samples were obtained from eighty individuals, including thirty-one who were previously PCR-positive for SARS-CoV-2. DBS eluates and sera were used in an ELISA to detect antibodies to the viral spike protein. Results: Specific anti-SARS-Cov-2 spike glycoprotein antibodies were detectable in both serum and DBS eluate and there was a significant correlation between the antibody levels detected in matched samples (r = 0.96, p<0.0001). Using serum as the gold standard in the assay, matched DBS samples achieved a Cohens kappa coefficient of 0.975 (near-perfect agreement), a sensitivity of 98.1% and specificity of 100%, for detecting anti-spike glycoprotein antibodies. Conclusions and relevance: Eluates from DBS samples are a reliable and reproducible source of antibodies to be used for the detection of SARS-CoV-2-specific antibodies. The use of DBS sampling could complement the use of venepuncture in the immunosurveillance of COVID-19 in both low and high income settings.

positive: Diagnostic value and dynamic variance of serum antibody in coronavirus disease 2019 Abstract Objective To investigate the diagnostic value of serological testing and dynamic variance of serum antibody in coronavirus disease 2019 (COVID-19). Methods This study retrospectively included 43 patients with a laboratory-confirmed infection and 33 patients with a suspected infection, in whom the disease was eventually excluded. The IgM/IgG titer of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was measured by chemiluminescence immunoassay analysis. Results Compared to molecular detection, the sensitivities of serum IgM and IgG antibodies to diagnose COVID-19 were 48.1% and 88.9%, and the specificities were 100% and 90.9%, respectively.In the COVID-19 group, the IgM-positive rate increased slightly at first and then decreased over time; in contrast, the IgG-positive rate increased to 100% and was higher than IgM at all times. The IgM-positive rate and titer were not significantly different before and after conversion to virus-negative. The IgG-positive rate was up to 90% and not significantly different before and after conversion to virus-negative. However, the median IgG titer after conversion to virus-negative was double that before, and the difference was significant. Conclusions Viral serological testing is an effective means of diagnosis for SARS-CoV-2 infection. The positive rate and titer variance of IgG are higher than those of IgM in COVID-19.

positive: Commercial Serology Assays Predict Neutralization Activity Against SARS-CoV-2 Background. Currently it is unknown whether a positive serology results correlates with protective immunity against SARS-CoV-2. There are also concerns regarding the low positive predictive value of SARS-CoV-2 serology tests, especially when testing populations with low disease prevalence. Methods. A neutralization assay was validated in a set of PCR confirmed positive specimens and in a negative cohort. 9,530 specimens were screened using the Diazyme SARS-CoV-2 IgG serology assay and all positive results (N=164) were reanalyzed using the neutralization assay, the Roche total immunoglobin assay, and the Abbott IgG assay. The relationship between the magnitude of a positive SARS-CoV-2 serology result and the levels of neutralizing antibodies detected was correlated. Neutralizing antibody titers (ID50) were also longitudinally monitored in SARS-CoV-2 PCR confirmed patients. Results. The SARS-CoV-2 neutralization assay had a PPA of 96.6% with a SARS-CoV-2 PCR test and a NPA of 98.0% across 100 negative controls. ID50 neutralization titers positively correlated with all three clinical serology platforms. Longitudinal monitoring of hospitalized PCR confirmed COVID-19 patients demonstrates they made high neutralization titers against SARS-CoV-2. PPA between the Diazyme IgG assay alone and the neutralization assay was 50.6%, while combining the Diazyme IgG assay with either the Roche or Abbott platforms increased the PPA to 79.2% and 78.4%, respectively. Conclusions. For the first time, we demonstrate that three widely available clinical serology assays positively correlate with SARS-CoV-2 neutralization activity observed in COVID-19 patients. When a two-platform screen and confirm approach was used for SARS-CoV-2 serology, nearly 80% of two-platform positive specimens had neutralization titers (ID50 >50).

positive: Evaluating COVID-19 screening strategies based on serological tests Background. Facing the SARS-CoV-2 epidemic requires intensive testing on the population to early identify and isolate infected subjects. Although RT-PCR is the most reliable technique to detect ongoing infections, serological tests are frequently proposed as tools in heterogeneous screening strategies. We analyze the performance of a screening strategy proposed in Tuscany (Italy), which first uses qualitative rapid tests for antibody detection, and then RT-PCR tests on the positive subjects. Methods. We simulate the number of RT-PCR tests required by the screening strategy and the undetected ongoing infections in a pseudo-population of 500000 subjects, under different prevalence scenarios and assuming a sensitivity of the serological test ranging from 0.50 to 0.80 (specificity=0.98). A compartmental model is used to predict the number of new infections generated by the false negatives two months after the screening, under different values of the infection reproduction number. Results. Assuming a sensitivity equal to 0.80 and a prevalence of 0.3%, the screening procedure would require on average 11167.6 RT-PCR tests and would produce 300 false negatives, responsible after two months of a number of contagions ranging from 526 to 1132, under the optimistic scenario of a reproduction number between 0.5 to 1. Costs and false negatives increase with the prevalence. Conclusions. The analyzed screening procedure should be avoided unless the prevalence and the rate of contagion are very low. The cost and effectiveness of the screening strategies should be evaluated in the actual context of the epidemic, accounting for the fact that it may change over time.

positive: Prevalence of Sars-Cov-2 Infection in Health Workers (HWs) and Diagnostic Test Performance: The Experience of a Teaching Hospital in Central Italy (1) Background: Health workers (HWs) are at high risk of acquiring SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) infections. Therefore, health authorities further recommend screening strategies for SARS-CoV-2 infection in exposed or high-risk HWs. Nevertheless, to date, the best/optimal method to screen HWs for SARS-CoV-2 infection is still under debate, and data on the prevalence of SARS-CoV-2 infection in HWs are still scarce. The present study aims to assess the SARS-CoV-2 infection rate amongst HWs in a teaching hospital in Central Italy and the diagnostic performance of SARS-CoV-2 serology (index test) in comparison with the SARS-CoV-2 RNA PCR assay (reference standard). (2) Methods: A cross-sectional study on the retrospective data of HWs tested for SARS-CoV-2 by RNA-RT-PCR on nasopharyngeal swabs and by an IgM/IgG serology assay on venous blood samples, irrespective of exposure and/or symptoms, was carried out. (3) Results: A total of 2057 HWs (median age 46, 19–69 years, females 60.2%) were assessed by the RNA RT-PCR assay and 58 (2.7%) tested positive for SARS-CoV-2 infection. Compared with negative HWs, SARS-CoV-2-positives were younger (mean age 41.7 versus 45.2, p < 0.01; 50% versus 31% under or equal to 40 years old, p < 0.002) and had a shorter duration of employment (64 versus 125 months, p = 0.02). Exposure to SARS-CoV-2 was more frequent in positive HWs than in negatives (55.2% versus 27.5%, p < 0.0001). In 44.8% of positive HWs, no exposure was traced. None of the positive HWs had a fatal outcome, none of them had acute respiratory distress syndrome, and only one required hospitalization for mild/moderate pneumonia. In 1084 (51.2%) HWs, nasopharyngeal swabs and an IgM/IgG serology assay were performed. With regard to IgM serology, sensitivity was 0% at a specificity of 98.99% (positive predictive value, PPV 0%, negative predictive value, NPV 99.2%). Concerning IgG serology and irrespective of the time interval between nasopharyngeal swab and serology, sensitivity was 50% at a specificity of 99.1% (PPV 28.6%, NPV 99.6%). IgG serology showed a higher diagnostic performance when performed at least two weeks after testing SARS-CoV-2-positive at the RNA RT-PCR assay by a nasopharyngeal swab. (4) Conclusions: Our experience in Central Italy demonstrated a low prevalence of SARS-CoV-2 infection amongst HWs, but higher than in the general population. Nearly half of the positive HWs reported no previous exposure to SARS-CoV-2-infected subjects and were diagnosed thanks to the proactive screening strategy implemented. IgG serology seems useful when performed at least two weeks after an RNA RT-PCR assay. IgM serology does not seem to be a useful test for the diagnosis of active SARS-CoV-2 infection. High awareness of SARS-CoV-2 infection is mandatory for all people, but especially for HWs, irrespective of symptoms, to safeguard their health and that of patients.

positive: Serology characteristics of SARS-CoV-2 infection since exposure and post symptom onset BACKGROUND: Timely diagnosis of SARS-CoV-2 infection is a prerequisite for treatment and prevention. The serology characteristics and complement diagnosis value of the antibody test to RNA test need to be demonstrated. METHOD: Serial sera of 80 patients with PCR-confirmed COVID-19 were collected at the First Affiliated Hospital of Zhejiang University, China. Total antibody (Ab), IgM and IgG antibodies against SARS-CoV-2 were detected, and the antibody dynamics during the infection were described. RESULTS: The seroconversion rates for Ab, IgM and IgG were 98.8%, 93.8% and 93.8%, respectively. The first detectible serology marker was Ab, followed by IgM and IgG, with a median seroconversion time of 15, 18 and 20â days post exposure (d.p.e) or 9, 10 and 12â days post onset (d.p.o), respectively. The antibody levels increased rapidly beginning at 6â d.p.o. and were accompanied by a decline in viral load. For patients in the early stage of illness (0-7â d.p.o), Ab showed the highest sensitivity (64.1%) compared to IgM and IgG (33.3% for both, p<0.001). The sensitivities of Ab, IgM and IgG increased to 100%, 96.7% and 93.3% 2â weeks later, respectively. When the same antibody type was detected, no significant difference was observed between enzyme-linked immunosorbent assays and other forms of immunoassays. CONCLUSIONS: A typical acute antibody response is induced during SARS-CoV-2 infection. Serology testing provides an important complement to RNA testing in the later stages of illness for pathogenic specific diagnosis and helpful information to evaluate the adapted immunity status of patients.

positive: SARS-CoV-2 proteome microarray for mapping COVID-19 antibody interactions at amino acid resolution COVID-19 has quickly become a worldwide pandemic, which has significantly impacted the economy, education, and social interactions. Understanding the humoral antibody response to SARS-CoV-2 proteins may help identify biomarkers that can be used to detect and treat COVID-19 infection. However, no immuno-proteomics platform exists that can perform such proteome-wide analysis. To address this need, we created a SARS-CoV-2 proteome microarray to analyze antibody interactions at amino acid resolution by spotting peptides 15 amino acids long with 5-amino acid offsets representing full-length SARS-CoV-2 proteins. Moreover, the array processing time is short (1.5 hours), the dynamic range is ~2 orders of magnitude, and the lowest limit of detection is 94 pg/mL. Here, the SARS-CoV-2 proteome array reveals that antibodies commercially available for SARS-CoV-1 proteins can also target SARS-CoV-2 proteins. These readily available reagents could be used immediately in COVID-19 research. Second, IgM and IgG immunogenic epitopes of SARS-CoV-2 proteins were profiled in the serum of ten COVID-19 patients. Such epitope biomarkers provide insight into the immune response to COVID-19 and are potential targets for COVID-19 diagnosis and vaccine development. Finally, serological antibodies that may neutralize viral entry into host cells via the ACE2 receptor were identified. Further investigation into whether these antibodies can inhibit the propagation of SARS-CoV-2 is warranted. Antibody and epitope profiling in response to COVID-19 is possible with our peptide-based SARS-COV-2 proteome microarray. The data gleaned from the array could provide invaluable information to the scientific community to understand, detect, and treat COVID-19.

positive: Diagnostic Techniques: Serological and Molecular Approaches Virus laboratory diagnostics has an increasingly important role in modern patient care. Virological methods are needed to investigate the etiology of acute viral infection or the reactivation of a latent infection, as well as to follow virus load in antiviral treatments. Serological assays are also used for screening of blood products for the risk of certain chronic infections, evaluation of the immune status, and need for prophylatic treatments in connection with organ transplantations. For diagnostic purposes the following approaches can be used: demonstration of presence of infectious virus or its structural components directly from a patient's specimens or investigation of specific antibody response in serum specimes. Virus isolation is used to demonstrate infectious virus in a patient's specimens, whereas nucleic acid amplification techniques, like polymerase chain reaction (PCR), are widely used to detect virus nucleic acids. Virus antigens are investigated by antigen detection assays. Serological diagnosis is based on either the demonstration of the presence of virus-specific IgM antibodies or a significant increase in the levels of specific IgG antibodies. Immunoassays are the most commonly used serological assays. Point-of-care tests (POC tests), both for antigens and antibodies, are also becoming more and more common in diagnostic use. In order to reach the best diagnostic efficiency for each patient it is important to select the most suitable method using the right sample collected at the right time.

positive: COVID-19: Understanding the science of antibody testing and lessons from the HIV epidemic Abstract Potential pitfalls in the development, deployment and interpretation of antibody tests for COVID-19 are discussed. Lessons learned from the experience with the introduction of antibody tests for HIV are highlighted.

positive: Serology assays to manage COVID-19. Measurement of antibodies to SARS-CoV-2 will improve disease management if used correctly.

positive: Early detection of SARS-CoV-2 antibodies in COVID-19 patients as a serologic marker of infection BACKGROUND: Thousands of medical staff had been infected with SARS-CoV-2 virus with hundreds of deaths reported. Such loss could be prevented if there is a serologic assay for SARS-CoV-2-specific antibodies for serological surveillance of its infection at the early stage of disease. METHODS: Using CHO cell expressed full length SARS-CoV-2 S1 protein as capturing antigen, a COVID-19/SARS-CoV-2 S1 serology ELISA kit was developed and validated with negative samples collected prior to the outbreaks or during the outbreak, and positive samples from patients confirmed with COVID-19. RESULTS: The specificity of the ELISA kit was 97.5%, as examined against total 412 normal human samples. The sensitivity was 97.1% by testing against 69 samples from hospitalized and/or recovered COVID-19 patients. The overall accuracy rate reached 97.3%. The assay was able to detect SARS-CoV-2 antibody on day one after the onset of COVID-19 disease. The average antibody levels increased during the hospitalization and after been discharged for two weeks. SARS-CoV-2 antibodies were detected in 28 out of 276 asymptomatic medical staff and one out of five nucleic acid test-negative “Close contacts” of COVID-19 patient. CONCLUSION: With the assays developed here, we can screen medical staff, in-coming patients, passengers and people who are in close contact with the confirmed patients to identify the “innocent viral spreaders”, protect the medical staff and stop the further spreading of the virus.

positive: Monitoring antibody response following SARS-CoV-2 infection: Diagnostic efficiency of four automated immunoassays INTRODUCTION: SARS-CoV-2 seroconversion is important for epidemiological studies as well as contact tracing. MATERIAL AND METHODS: The antibody response against SARS-CoV-2 was examined in 111 patients with a positive qRT-PCR. Seroconversion was assessed using the Elecsys from Roche, the Liaison S1/S2 IgG from Diasorin, the IgG and IgA from Euroimmun as well as the VIDAS IgG and IgM. Specificity was estimated based on the measurement of SARS-CoV-2 antibodies in 96 residual samples collected during a non-pandemic period. RESULTS: The highest overall sensitivity for detecting seroconversion was obtained using the Elecsys (81.1%), the Euroimmun with a combined detection of IgG/IgA (86.5%) and the VIDAS with a simultaneous measurement of IgG/IgM (78.4%).The Elecsys and the VIDAS IgG/IgM demonstrated a specificity as well as a positive predictive value of 100%. CONCLUSIONS: The Elecsys and the VIDAS methods with a combination of IgG/IgM measurement demonstrated a high sensitivity with no false positive results.

positive: Evaluation of the EUROIMMUN Anti-SARS-CoV-2 ELISA Assay for detection of IgA and IgG antibodies As the Coronavirus 2019 (COVID-19) pandemic evolves, the development of immunoassays to help determine exposure and potentially predict immunity has become a pressing priority. In this report we present the performance of the EUROIMMUN enzyme-linked immunosorbent assay (ELISA) for semi-quantitative detection of IgA and IgG antibodies in serum and plasma samples using recombinant S1 domain of the SARS-CoV-2 spike protein as antigen. Specimens from patients, with and without COVID-19 infection, were tested at the University of Chicago Clinical Microbiology and Immunology Laboratory. Of 57 samples from COVID-19 PCR-negative patients, including 28 samples positive for common human coronavirus strains, 53 tested negative and 4 tested positive for IgA (93.0% agreement) while 56 tested negative and 1 tested positive for IgG (98.2% agreement). For COVID-19 PCR-positive patients, 29 of 30 (96.7%) samples collected ≥3 days after positive PCR were positive for IgA, and 28 of 28 samples collected ≥4 days after positive PCR were positive for IgG. The EUROIMMUN Anti-SARS-CoV-2 ELISA Assay demonstrates excellent sensitivity for detection of IgA and IgG antibodies from samples collected ≥3 days and ≥4 days, respectively, after COVID-19 diagnosis by PCR. This assay did not demonstrate cross reaction in any of the 28 samples from patients with common human coronaviruses, including types HKU1, NL63, CV229E, and OC43.

positive: Sensitivity of commercial Anti-SARS-CoV-2 serological assays in a high-prevalence setting We analysed SARS-CoV-2 specific antibody responses in 42 social and working contacts of a super-spreader from the Heinsberg area in Germany. Consistent with a high-prevalence setting 26 individuals had SARS-CoV-2 antibodies determined by in-house neutralisation testing. These results were compared with four commercial assays, suggesting limited sensitivity of the assays in such a high-prevalence setting. Although SARS-CoV-2 nucleocapsid restricted tests showed a better sensitivity, spike based assays had a stronger correlation with neutralisation capacity.

positive: COVID-19: Current Trends in Invitro Diagnostics The novel coronavirus SARS-CoV-2 is the seventh known species of coronavirus, infectious to human beings. The pandemic COVID-19 spread all over the world with an unprecedented spreading rate after its first appearance in Wuhan, China. As a novel viral disease there in no antiviral treatment or vaccine for the COVID-19. At present, the early detection and the quarantine of infected patients are the ways to stop the spreading of the disease. This review will discuss about the current invitro diagnostic methods used worldwide for the early and accurate diagnosis of COVID-19. Currently the nucleic acid based polymerase chain reaction is used as the reliable diagnostic platform and antigen/antibody detection immunoassays are playing the role of screening tests for early detection and prognosis in COVID-19 treatment.

positive: Are antibodies tests accurate? Understanding predictive values and uncertainty of serology tests for the novel coronavirus. Antibodies testing in the coronavirus era is frequently promoted, but the underlying statistics behind their validation has come under more scrutiny in recent weeks. We provide calculations, interpretations, and plots of positive and negative predictive values under a variety of scenarios. Prevalence, sensitivity, and specificity are estimated within ranges of values from researchers and antibodies manufacturers. Illustrative examples are highlighted, and interactive plots are provided in the Supplementary Material. Implications are discussed for society overall and across diverse locations with different levels of disease burden. Specifically, the proportion of positive serology tests that are false can differ drastically from up to 3% to 88% for people from different places with different proportions of infected people in the populations while the false negative rate is typically under 10%.

positive: Clinical evaluation of serological IgG antibody response on the Abbott Architect for established SARS-CoV-2 infection OBJECTIVE: This study aimed to evaluated the diagnostic performance of the Abbott Architect SARS-CoV-2 IgG assay in COVID-19 patients. METHODS: Residual sera from 177 symptomatic COVID-19 positive patients, and 163 non-COVID-19 patients were tested for antibody with the Abbott SARS-CoV-2 IgG assay (Abbott Diagnostics, Chicago, US). Clinical records for COVID-19 patients were reviewed to determine the time from onset of clinical illness to testing. RESULTS: Specificity of the assay was 100.0% (95% CI: 97.1 – 100.0%). The clinical sensitivity of the assay varied depending on time from onset of symptoms, increasing with longer periods since onset of clinical illness. The clinical sensitivity at ≤6 days was 8.6% (7/81; 95% CI: 3.8 – 17.5%), 7-13 days: 43.6% (17/39; 95% CI: 28.2 – 60.2%), 14-20 days: 84.0% (21/25; 95% CI: 63.1 – 94.7%), and ≥21 days: 84.4% (27/32; 95% CI: 66.5 – 94.1%). Clinical sensitivity was higher in the ≥14 days group compared to <14. There were no differences between the 14-20 days and ≥21 days group; the combined clinical sensitivity for these groups (≥14 days) was 84.2% (49/57; 71.6 – 92.1%). CONCLUSION: The Abbott SARS-CoV-2 IgG test has high specificity. Clinical sensitivity was limited in early stages of disease but improved from 14 days after onset of clinical infection.

positive: Use of recombinant nucleocapsid proteins for serological diagnosis of feline coronavirus infection by three immunochromatographic tests Abstract Three types of immunochromatographic assays (ICAs) were designed to detect anti-feline coronavirus (FCoV) antibodies. Recombinant FCoV nucleocapsid protein (rNP) was used as a conjugate or test line in all 3 ICA kits (CJIgG/TNP, CJNP/TNP, and CJNP/TPA). All three ICA kits were capable of detecting anti-FCoV antibodies; however, non-specific positive reactions of anti-FCoV antibody-negative plasma samples with the test line were observed in 2 ICA kits (CJIgG/TNP and CJNP/TNP), in which rNP was used as the test line. On the other hand, the specific detection of anti-FCoV antibodies was possible in all plasma, serum, whole blood, and ascitic fluid samples using the ICA kit with protein A blotted as the test line (CJNP/TPA). In addition, the specificity and sensitivity of ICA (CJNP/TPA) were equivalent to those of the reference ELISA. The development of simple antibody test methods using the principle of ICA (CJNP/TPA) for other coronavirus and feline viral infections is expected in the future.

positive: Evaluation of Diagnostic Performance of Three Indirect Enzyme-Linked Immunosorbent Assays for the Detection of IgG Antibodies to Ebola Virus in Human Sera Filovirus serological diagnosis and epidemiological investigations are hampered due to the unavailability of validated immunoassays. Diagnostic performance of three indirect enzyme-linked immunosorbent assays (I-ELISA) was evaluated for the detection of IgG antibody to Ebola virus (EBOV) in human sera. One I-ELISA was based on a whole EBOV antigen (WAg) and two utilized recombinant nucleocapsid (NP) and glycoproteins (GP), respectively. Validation data sets derived from individual sera collected in South Africa (SA), representing an EBOV non-endemic country, and from sera collected during an Ebola disease (EBOD) outbreak in Sierra Leone (SL), were categorized according to the compounded results of the three I-ELISAs and real time reverse-transcription polymerase chain reaction (RT-PCR). At the cut-off values selected at 95% accuracy level by the two-graph receiver operating characteristic analysis, specificity in the SA EBOV negative serum panel (n = 273) ranged from 98.17% (GP ELISA) to 99.27% (WAg ELISA). Diagnostic specificity in the SL EBOV negative panel (n = 676) was 100% by the three ELISAs. The diagnostic sensitivity in 423 RT-PCR confirmed EBOD patients was dependent on the time when the serum was collected after onset of disease. It significantly increased 2 weeks post-onset, reaching 100% sensitivity by WAg and NP and 98.1% by GP I-ELISA.

positive: Double-Edged Spike: Are SARS-CoV-2 Serologic Tests Safe Right Now?

positive: Evaluation of a COVID-19 IgM and IgG rapid test; an efficient tool for assessment of past exposure to SARS-CoV-2 COVID-19 is the most rapidly growing pandemic in modern time, and the need for serological testing is most urgent. Although the diagnostics of acute patients by RT-PCR is both efficient and specific, we are also crucially in need of serological tools for investigating antibody responses and assessing individual and potential herd immunity. We evaluated a commercially available test developed for rapid (within 15 minutes) detection of SARS-CoV-2-specific IgM and IgG by 29 PCR-confirmed COVID-19 cases and 124 negative controls. The results revealed a sensitivity of 69% and 93.1% for IgM and IgG, respectively, based solely on PCR-positivity due to the absence of a serological gold standard. The assay specificities were shown to be 100% for IgM and 99.2% for IgG. This indicates that the test is suitable for assessing previous virus exposure, although negative results may be unreliable during the first weeks after infection. More detailed studies on antibody responses during and post infection are urgently needed.

positive: Covid-19: Antibody test that claims to be 99% accurate is certified by EU.

positive: Serological diagnostic kit of SARS-CoV-2 antibodies using CHO-expressed full-length SARS-CoV-2 S1 proteins WHO has declared COVID-19 a pandemic with more than 300,000 confirmed cases and more than 14,000 deaths. There is urgent need for accurate and rapid diagnostic kits. Here we report the development and validation of a COVID-19/SARS-CoV-2 S1 serology ELISA kit for the detection of total anti-virus antibody (IgG+IgM) titers in sera from either the general population or patients suspected to be infected. For indirect ELISA, CHO-expressed recombinant full length SARS-CoV-2-S1 protein with 6*His tag was used as the coating antigen to capture the SARS-CoV-2-S1 antibodies specifically. The specificity of the ELISA kit was determined to be 97.5%, as examined against total 412 normal human sera including 257 samples collected prior to the outbreak and 155 collected during the outbreak. The sensitivity of the ELISA kit was determined to be 97.5% by testing against 69 samples from hospitalized and/or recovered COVID-19 patients. The overall accuracy rate reached 97.3%. Most importantly, in one case study, the ELISA test kit was able to identify an infected person who had previously been quarantined for 14 days after coming into contact with a confirmed COVID-19 patient, and discharged after testing negative twice by nucleic acid test. With the assays developed here, we can screen millions of medical staffs in the hospitals and people in residential complex, schools, public transportations, and business parks in the epidemic centers of the outbreaks to fish out the "innocent viral spreaders", and help to stop the further spreading of the virus.

positive: Longitudinal Monitoring of SARS-CoV-2 IgM and IgG Seropositivity to Detect COVID-19 BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a novel beta-coronavirus that has recently emerged as the cause of the 2019 coronavirus pandemic (COVID-19). Polymerase chain reaction (PCR) based tests are optimal and recommended for the diagnosis of an acute SARS-CoV-2 infection. Serology tests for viral antibodies provide an important tool to diagnose previous exposure to the virus. Here we evaluate the analytical performance parameters of the Diazyme SARS-CoV-2 IgM/IgG serology assays and describe the kinetics of IgM and IgG seroconversion observed in patients with PCR confirmed COVID-19 who were admitted to our hospital. METHODS: We validated the performance of the Diazyme assay in 235 subjects to determine specificity. Subsequently, we evaluated the SARS-CoV-2 IgM and IgG seroconversion of 54 PCR confirmed COVID-19 patients and determined sensitivity of the assay at three different timeframes. RESULT: Sensitivity and specificity for detecting seropositivity at ≥ 15 days following a positive SARS-CoV-2 PCR result, was 100.0% and 98.7% when assaying for the panel of IgM and IgG. The median time to seropositivity observed for a reactive IgM and IgG result from the date of a positive PCR was 5 days (IQR: 2.75-9 days) and 4 days (IQR: 2.75-6.75 days), respectively. CONCLUSIONS: Our data demonstrates that the Diazyme IgM/IgG assays are suited for the purpose of detecting SARS-CoV-2 IgG and IgM in patients with suspected SARS-CoV-2 infections. For the first time, we report longitudinal data showing the evolution of seroconversion for both IgG and IgM in a cohort of acutely ill patients in the United States. We also demonstrate a low false positive rate in patients who were presumed to be disease free.

positive: Evaluation of a computer-assisted, kinetics-based enzyme-linked immunosorbent assay for detection of coronavirus antibodies in cats. A computer-assisted, kinetics-based enzyme-linked immunosorbent assay was adapted for the detection of coronavirus antibodies in feline serum. An alkaline antigen diluent (carbonate-bicarbonate buffer, pH 9.6) used in initial experiments produced diffuse, nonspecific color reactions in both viral and control antigen cuvettes which were correlated, paradoxically, with coronavirus antibody levels in test sera. These interfering reactions were minimized by use of lower-pH antigen diluents such as water and phosphate-buffered saline. Background kinetics-based enzyme-linked immunosorbent assay reactivity directed against a noncoronaviral component of antigen tissue culture fluids could then detected in numerous sera, particularly in samples with lower titers. Much of this reactivity was shown to be associated with bovine gamma globulins in cell culture fluid. It was not serum lot or species specific, since a variety of bovine serum lots as well as individual lots of serum from other mammalian and avian species reacted. Reactivity was markedly reduced when cells for antigen preparation were grown in gamma globulin-free bovine serum. Generation of corrected slope values from the kinetics-based enzyme-linked immunosorbent assay made it possible to correct for residual background reactivity in individual test sera and thus eliminate a potentially major source of false-positive reactions. Collectively, these studies indicated that the control of nonspecific reactivity in feline coronavirus serology is absolutely essential to obtain useful estimates of specific antibody responses.

positive: On the importance of population-based serological surveys of SARS-CoV-2 without overlooking their inherent uncertainties Abstract The SARS-CoV-2 epidemic has caused an unprecedented public health situation and more than ever it is important to be well informed on methods to monitor and analyse the progression of the epidemic. This brief note aims to explain the scope in conducting large-scale serological surveys of SARS-CoV-2 to define the landscape of population immunity, without overlooking the inherent uncertainty steaming from sampling design and diagnostic validity. The note completes with a succinct appendix of simple statistical methods for estimating prevalence from random population samples using imperfect diagnostic tests.

positive: Comparison of ELISA with electro-chemiluminescence technology for the qualitative and quantitative assessment of serological responses to vaccination BACKGROUND: Profiling immune responses induced by either infection or vaccination can provide insight into identification of correlates of protection. Furthermore, profiling of serological responses can be used to identify biomarkers indicative of exposure to pathogens. Conducting such immune surveillance requires readout methods that are high-throughput, robust, and require small sample volumes. While the enzyme-linked immunosorbent assay (ELISA) is the classical readout method for assessing serological responses, the advent of multiplex assays has significantly increased the throughput and capacity for immunoprofiling. This report describes the development and assay performance (sensitivity, linearity of detection, requirement for multiple dilutions for each sample, intra- and inter-assay variability) of an electro-chemiluminescence (ECLIA)-based multiplex assay. METHODS: The current study describes the development of a multiplex ECLIA-based assay and characterizes the sensitivity, linear range, and inter- and intra-assay variability of the ECLIA platform and its agreement with the traditional ELISA. Special emphasis was placed on potential antigenic competition when testing closely related antigens in the multiplex format. RESULTS: Multiplexing of antigens in ECLIA provides significant practical benefits in terms of reducing sample volume requirements and experimental time. Beyond the practical advantages of multiplexing, the ECLIA provides superior assay performance when compared to the ELISA. Not only does ECLIA show good agreement with the ELISA assay, but the linear range of ECLIA is also sufficiently wide to permit single-dilution measurements of concentration without the need to do serial dilutions. The lack of antigenic competition allows the simultaneous testing of closely related antigens, such as plate antigens representing different alleles of the same protein, which can inform about cross-reactivities—or lack thereof—of serological responses. CONCLUSION: The advantages of the newly developed tool for assessing the antigen profiles of serological responses may ultimately lead to the identification of biomarkers associated with various disease stages and or protection against disease.

positive: IgA-Ab response to spike glycoprotein of SARS-CoV-2 in patients with COVID-19: A longitudinal study Abstract Validation studies of serological antibody tests must be properly designed for clinical, epidemiological and Public Health objectives such as confirmation of suspected COVID-19 cases, certification of seroconversion after infection, and epidemiological surveillance. We evaluated the kinetics of IgM, IgA and IgG SARS-CoV-2 antibodies in COVID-19 patients with confirmed (rRT-PCR) infection. We found that the IgA response appears and grows early, peaks at week 3, and it is stronger and more persistent than the IgM response. Further longitudinal investigations of virus-specific antibodies functions and of their protective efficacy over time are needed.

positive: Long period dynamics of viral load and antibodies for SARS-CoV-2 infection: an observational cohort study ABSTRACT OBJECTIVE To investigate the dynamics of viral RNA, IgM, and IgG and their relationships in patients with SARS-CoV-2 pneumonia over an 8-week period. DESIGN Retrospective, observational case series. SETTING Wenzhou Sixth Peoples Hospital PARTICIPANTS Thirty-three patients with laboratory confirmed SARS-CoV-2 pneumonia admitted to hospital. Data were collected from January 27 to April 10, 2020. MAIN OUTCOME MEASURES Throat swabs, sputum, stool, and blood samples were collected, and viral load was measured by reverse transcription PCR (RT-PCR). Specific IgM and IgG against spike protein (S), spike protein receptor binding domain (RBD), and nucleocapsid (N) were analyzed. RESULTS At the early stages of symptom onset, SARS-CoV-2 viral load is higher in throat swabs and sputum, but lower in stool. The median (IQR) time of undetectable viral RNA in throat swab, sputum, and stool was 18.5 (13.25-22) days, 22 (18.5-27.5) days, and 17 (11.5-32) days, respectively. In sputum, 17 patients (51.5%) had undetectable viral RNA within 22 days (short persistence), and 16 (48.5%) had persistent viral RNA more than 22 days (long persistence). Three patients (9.1%) had a detectable relapse of viral RNA in sputum within two weeks of their discharge from the hospital. One patient had persistent viral RNA for 59 days or longer. The median (IQR) seroconversion time of anti-S IgM, anti-RBD IgM, and anti-N IgM was 10.5 (7.75-15.5) days, 14 (9-24) days, and 10 (7-14) days, respectively. The median (IQR) seroconversion time of anti-S IgG, anti-RBD IgG, and anti-N IgG was 10 (7.25-16.5) days, 13 (9-17) days, and 10 (7-14) days, respectively. By week 8 after symptom onset, IgM were negative in many of the previously positive patients, and IgG levels remained less than 50% of the peak levels in more than 20% of the patients. In about 40% of the patients, anti-RBD IgG levels were 4-times higher in convalescence than in acute phase. SARS-CoV-2 RNA coexisted with antibodies for more than 50 days. Anti-RBD IgM and IgG levels, including anti-RBD IgM levels at presentation and peak time, were significantly higher in viral RNA short persistence patients than in long persistence patients. CONCLUSION This study adds important new information about the features of viral load and antibody dynamics of SARS-CoV-2. It is clear from these results that the viral RNA persists in sputum and stool specimens for a relatively long time in many patients. Anti-RBD may also serve as a potential protective antibody against SARS-CoV-2 infection, as viral persistence appears to be related to anti-RBD levels. Earlier treatment intervention also appears to be a factor in viral persistence.

positive: [Study on the response of specific antibodies against SARS-CoV in patients infected with SARS]. OBJECTIVE To study the response of specific antibodies against severe acute respiratory syndrome (SARS)-CoV in patients infected with SARS. METHODS IgM-capture, indirect and antigen-sandwiched enzyme linked immunosorbent assay (ELISA) were used to detect the SARS-CoV specific IgM, IgG and total antibodies in sera of clinical SARS patients or non-SARS individuals. RESULTS The positive rates of IgM, IgG and total antibodies to SARS-CoV in 146 sera of SARS patients collected in different phases of the disease were 61.64%, 53.43% and 69.86%, respectively. The earliest detectable days after onset of the disease for IgM and IgG to SRAS-CoV were 7 and 12 days, respectively. The specific IgM disappeared as early as 42 days after the onset of SARS. Of 70 sera from hepatitis A patients, 2 showed false positive results, while 127 sera from other patients were all negative, detected by the 3 methods. Serum from one medical worker who had been close contact to SARS patients was positive for anti-SARS-CoV IgG and total antibodies. These 3 methods used for detection were all not influenced by rheumatoid factor (RF). CONCLUSION All of the three methods were specific and sensitive for the detection of specific antibodies to SARS-CoV, and useful for epidemiological research and clinical diagnosis, but not for early diagnosis of SARS.

positive: Comparison of SARS-CoV-2 serological tests with different antigen targets Background These last months, dozens of SARS-CoV-2 serological tests have become available with varying performances. A major effort was completed to compare 17 serological tests. Methods In a preliminary phase, we compared 17 IgG, IgM, IgA and pan Ig serological tests including ELISA, LFA, CLIA and ECLIA on a panel of 182 sera, comprising 113 sera from hospitalized patients with a positive RT-PCR, and 69 sampled before 1st November 2019, expected to give a positive and negative results, respectively. In a second phase, the five best performing and most available tests were further evaluated on a total of 582 sera (178 and 404 expected positive and negative, respectively), allowing the assessment of 20 possible cross-reactions with other virus. Results In the preliminary phase, among eight IgG/pan-Ig ELISA or CLIA/ECLIA tests, four had a sensitivity and specificity above 90% and 98% respectively, and on six IgM/IgA tests, only one was acceptable. Only one LFA test on three showed good performances for both IgG and IgM. For all the tests IgM and IgG aroused concomitantly. In the second phase, no tests showed particular cross-reaction. We observed an important heterogeneity in the development of the antibody response, and that anti-nucleocapside (anti-N) antibodies appeared earlier than the anti-spike (anti-S) proteins. Conclusions The identified SARS-CoV-2 serology tests may be used for the diagnostic of CoviD-19 for negative RT-PCR patients presenting severe to mild suggestive symptoms or particular clinical presentation. Detection of both anti-N and anti-S could be complementary to increase the sensitivity of the analysis.

positive: A serological assay to detect SARS-CoV-2 antibodies in at-home collected finger-prick dried blood spots Accurate surveillance of coronavirus disease 2019 (COVID-19) incidence requires large-scale testing of the population. Current testing methods require in-person collection of biospecimens by a healthcare worker, limiting access of individuals who do not have access to testing facilities while placing both the patient and healthcare worker at risk of exposure to infection. We report the development and validation of a at-home finger-prick dried blood spot collection kit and an analysis method. We demonstrated 100% sensitivity and specificity using at-home collected specimens across the US. Such methods may facilitate the conduct of unbiased serosurveys within hard to reach populations and help reduce the sample collection burden of serological testing on both health care systems and individuals alike.

positive: Antibody responses to SARS-CoV-2 in patients of novel coronavirus disease 2019 Summary Background The novel coronavirus SARS-CoV-2 is a newly emerging virus. The antibody response in infected patient remains largely unknown, and the clinical values of antibody testing have not been fully demonstrated. Methods A total of 173 patients with confirmed SARS-CoV-2 infection were enrolled. Their serial plasma samples (n = 535) collected during the hospitalization period were tested for total antibodies (Ab), IgM and IgG against SARS-CoV-2 using immunoassays. The dynamics of antibodies with the progress and severity of disease was analyzed. Findings Among 173 patients, the seroconversion rate for Ab, IgM and IgG was 93.1% (161/173), 82.7% (143/173) and 64.7% (112/173), respectively. Twelve patients who had not seroconverted were those only blood samples at the early stage of illness were collected. The seroconversion sequentially appeared for Ab, IgM and then IgG, with a median time of 11, 12 and 14 days, respectively. The presence of antibodies was < 40% among patients in the first 7 days of illness, and then rapidly increased to 100.0%, 94.3% and 79.8% for Ab, IgM and IgG respectively since day 15 after onset. In contrast, the positive rate of RNA decreased from 66.7% (58/87) in samples collected before day 7 to 45.5% (25/55) during days 15 to 39. Combining RNA and antibody detections significantly improved the sensitivity of pathogenic diagnosis for COVID-19 patients (p < 0.001), even in early phase of 1-week since onset (p = 0.007). Moreover, a higher titer of Ab was independently associated with a worse clinical classification (p = 0.006). Interpretation The antibody detection offers vital clinical information during the course of SARS-CoV-2 infection. The findings provide strong empirical support for the routine application of serological testing in the diagnosis and management of COVID-19 patients.

positive: Evaluation of Nucleocapsid and Spike Protein-based ELISAs for detecting antibodies against SARS-CoV-2 Background: At present, PCR-based nucleic acid detection cannot meet the demands for coronavirus infectious disease (COVID-19) diagnosis. Methods: 214 confirmed COVID-19 patients who were hospitalized in the General Hospital of Central Theater Command of the People's Liberation Army between January 18 and February 26, 2020, were recruited. Two Enzyme-Linked Immunosorbent Assay (ELISA) kits based on recombinant SARS-CoV-2 nucleocapsid protein (rN) and spike protein (rS) were used for detecting IgM and IgG antibodies, and their diagnostic feasibility was evaluated. Results: Among the 214 patients, 146 (68.2%) and 150 (70.1%) were successfully diagnosed with the rN-based IgM and IgG ELISAs, respectively; 165 (77.1%) and 159 (74.3%) were successfully diagnosed with the rS-based IgM and IgG ELISAs, respectively. The positive rates of the rN-based and rS-based ELISAs for antibody (IgM and/or IgG) detection were 80.4% and 82.2%, respectively. The sensitivity of the rS-based ELISA for IgM detection was significantly higher than that of the rN-based ELISA. We observed an increase in the positive rate for IgM and IgG with an increasing number of days post-disease onset (d.p.o.), but the positive rate of IgM dropped after 35 d.p.o. The positive rate of rN-based and rS-based IgM and IgG ELISAs was less than 60% during the early stage of the illness 0-10 d.p.o., and that of IgM and IgG was obviously increased after 10 d.p.o. Conclusions: ELISA has a high sensitivity, especially for the detection of serum samples from patients after 10 d.p.o, it can be an important supplementary method for COVID-19 diagnosis.

positive: Evaluation of two automated and three rapid lateral flow immunoassays for the detection of anti-SARS-CoV-2 antibodies Abstract Introduction Several SARS-CoV-2 immunoassays have been developed recently. The purpose of this study was to assess the performance of five immunoassays for the detection of SARS-CoV-2 antibodies. Methods Two quantitative automated immunoassays (MaglumiTM 2019-n-Cov IgG and IgM and Euroimmun Anti-SARS-CoV-2 IgG and IgA assays) and three lateral flow rapid tests were performed. This retrospective study included 200 residual sera from patients and healthy volunteers. Case serum samples (n = 128) were obtained from COVID-19 patients confirmed by RT-qPCR and CT-scan. Days since onset of symptoms was collected from their medical records. Control non-SARS-CoV-2 samples (n = 72) were obtained from anonymous stored residual serum samples. Results MaglumiTM IgG/IgM tests showed overall less sensitivity than Euroimmun IgG/IgA test (84.4% versus 64.3%). Both tests showed similar specificities of IgG at 99% and 100%, respectively. The two tests showed similar specificity for IgG at 99% and 100%, respectively. The results from the lateral flow assays were easily interpretable with unambiguous coloured reading bands. The overall sensitivity of the three tests was similar (around 70%) without any significant differences. The sensitivity of the three lateral flow assays and also of the serological quantitative assays increased during the second week after symptom onset and all reached similar values (91% to 94%) after 14 days. Conclusion This study shows accurate and equivalent performance of the five serological antibody assays (ELISA, CLIA and three lateral flow tests) in detecting SARS-CoV-2 antibodies 14 days after the onset of COVID-19 symptoms. This is compatible with their application in specific clinical contexts and in determining epidemiological strategies for the COVID-19 pandemic.

positive: Cross-reaction of sera from COVID-19 patients with SARS-CoV assays. Background: The SARS-CoV-2 shares 74.5% genome identity with SARS-CoV, both exhibiting a similar well conserved structure. Therefore, antibodies produced in COVID-19 and SARS patients should not be that dissimilar. We evaluated SARS-CoV test assays to detect for the presence of antibodies to SARS-CoV-2 and tried to determine the timing of appearance of these antibodies by testing serial sera from these patients. Methods: Tests were carried out using ELISA (total antibodies) and indirect immunofluorescence (IIFA) (IgM & IgG) methods on serial sera from patients confirmed with SARS-CoV-2 infection. Results: Cross-reactivity was seen in these two test assays with sera from COVID-19 patients and was detected in 6 out of 7 patients from 7 days after onset of symptoms. Five of the patients had detectable antibodies by the 3rd week into their illness and there was evidence of seroconversion in 4 patients. The IIFA method was marginally more sensitive compared to the ELISA assay, however the IIFA IgM test was not useful in the early phase of the illness with poor sensitivity. Conclusions: Existing diagnostic assays for SARS-CoV can detect antibodies in patients who were diagnosed with COVID-19. These assays maybe be utilized as an interim measure in epidemiological investigations for contact tracing and to determine the extent of community spread of this new emerging virus pending the availability of specific serology tests for SARS-CoV-2.

positive: Analysis of Serologic Cross-Reactivity Between Common Human Coronaviruses and SARS-CoV-2 Using Coronavirus Antigen Microarray The current practice for diagnosis of SARS-CoV-2 infection relies on PCR testing of nasopharyngeal or respiratory specimens in a symptomatic patient at high epidemiologic risk. This testing strategy likely underestimates the true prevalence of infection, creating the need for serologic methods to detect infections missed by the limited testing to date. Here, we describe the development of a coronavirus antigen microarray containing immunologically significant antigens from SARS-CoV-2, in addition to SARS-CoV, MERS-CoV, common human coronavirus strains, and other common respiratory viruses. A preliminary study of human sera collected prior to the SARS-CoV-2 pandemic demonstrates overall high IgG reactivity to common human coronaviruses and low IgG reactivity to epidemic coronaviruses including SARS-CoV-2, with some cross-reactivity of conserved antigenic domains including S2 domain of spike protein and nucleocapsid protein. This array can be used to answer outstanding questions regarding SARS-CoV-2 infection, including whether baseline serology for other coronaviruses impacts disease course, how the antibody response to infection develops over time, and what antigens would be optimal for vaccine development.

positive: Novel protein chip for the detection of antibodies against infectious bronchitis virus BACKGROUND: Infectious bronchitis (IB) caused by the IB virus (IBV) can cause acute damage to chickens around the world. Therefore, rapid diagnosis and immune status determination are critical for controlling IBV outbreaks. Enzyme-linked immunosorbent assays (ELISAs) have been widely used in the detection of IBV antibodies in the early infection and continuous infection of IB because they are more sensitive and quicker than other diagnostic methods. RESULTS: We have developed two indirect microarray methods to detect antibodies against IBV: a chemiluminescent immunoassay test (CIT) and a rapid diagnostic test (RDT). IBV nonstructural protein 5 (nsp5) was expressed, purified from Escherichia coli, and used to spot the initiator integrated poly(dimethylsiloxane), which can provide a near “zero” background for serological assays. Compared with the IDEXX IBV Ab Test kit, CIT and RDT have a sensitivity and specificity of at least 98.88% and 91.67%, respectively. No cross-reaction was detected with antibodies against avian influenza virus subtypes (H5, H7, and H9), Newcastle disease virus, Marek’s disease virus, infectious bursal disease virus, and chicken anemia virus. The coefficients of variation of the reproducibility of the intra- and inter-assays for CIT ranged from 0.8 to 18.63%. The reproducibility of RDT was consistent with the original results. The application of the IBV nsp5 protein microarray showed that the positive rate of the CIT was 96.77%, that of the nsp5 ELISA was 91.40%, and that of the RDT was 90.32%. Furthermore, the RDT, which was visible to the naked eye, could be completed within 15 min. Our results indicated that compared with nsp5 ELISA, the CIT was more sensitive, and the RDT had similar positive rates but was faster. Furthermore, the two proposed methods were specific and stable. CONCLUSIONS: Two microarray assays, which were rapid, specific, sensitive, and relatively simple, were developed for the detection of an antibody against IBV. These methods can be of great value for the surveillance of pathogens and monitoring the efficiency of vaccination.

positive: Serologic responses to SARS-CoV-2 infection among hospital staff with mild disease in eastern France Background: The serologic response of individuals with mild forms of SARS-CoV-2 infection is poorly characterized. Methods: Hospital staff who had recovered from mild forms of PCR-confirmed SARS-CoV-2 infection were tested for anti-SARS-CoV-2 antibodies using three assays: a LuLISA targeting the N protein (99% specificity), a rapid immunodiagnostic test (99.4% specificity), and a S- Flow assay (>99.5% specificity). The neutralizing activity of the sera was tested with a pseudovirus-based assay. Results: Of 162 hospital staff who participated in the investigation, 160 reported SARS-CoV- 2 infection that had not required hospital admission and were included in these analyses. The median time from symptom onset to blood sample collection was 24 days (IQR: 21-28, range 13-39). The LuLISA N assay detected antibodies in 129 (80.6%) of the samples, with better performance for samples collected after 28 days (45/48 = 93.8%); the rapid immunodiagnostic test in 153 (95.6%); and the S-Flow assay in 159 (99.4%), failing to detect antibodies in one sample collected 18 days after symptom onset (none of the other tests detected antibodies in that patient). Neutralizing antibodies (NAbs) were detected in 79%, 92% and 98% of samples collected 13-20, 21-27 and 28-41 days after symptom onset, respectively (P=0.02). Conclusion: Antibodies against SARS-CoV-2 were detected in virtually all hospital staff after 13 days from the COVID-19 symptom onset. This finding supports the use of serologic testing for the diagnosis of individuals who have recovered from SARS-CoV-2 infection. The neutralizing activity of the antibodies increased overtime. Future studies will help assess the persistence of the humoral response and its associated neutralization capacity in recovered patients.

positive: Kinetics of SARS-CoV-2 specific IgM and IgG responses in COVID-19 patients The emerging COVID-19 caused by SARS-CoV-2 infection poses severe challenges to global public health. Serum antibody testing is becoming one of the critical methods for the diagnosis of COVID-19 patients. We investigated IgM and IgG responses against SARS-CoV-2 nucleocapsid (N) and spike (S) protein after symptom onset in the intensive care unit (ICU) and non-ICU patients. 130 blood samples from 38 COVID-19 patients were collected. The levels of IgM and IgG specific to N and S protein were detected by ELISA. A series of blood samples were collected along the disease course from the same patient, including 11 ICU patients and 27 non-ICU patients for longitudinal analysis. N and S specific IgM and IgG (N-IgM, N-IgG, S-IgM, S-IgG) in non-ICU patients increased after symptom onset. N-IgM and S-IgM in some non-ICU patients reached a peak in the second week, while N-IgG and S-IgG continued to increase in the third week. The combined detection of N and S specific IgM and IgG could identify up to 75% of SARS-CoV-2 infected patients in the first week. S-IgG was significantly higher in non-ICU patients than in ICU patients in the third week. In contrast, N-IgG was significantly higher in ICU patients than in non-ICU patients. The increase of S-IgG positively correlated with the decrease of C-reactive protein (CRP) in non-ICU patients. N and S specific IgM and IgG increased gradually after symptom onset and can be used for detection of SARS-CoV-2 infection. Analysis of the dynamics of S-IgG may help to predict prognosis.

positive: Cross-sectional IgM and IgG profiles in SARS-CoV-2 infection BACKGROUND: Accurate serological assays can improve the early diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but few studies have compared performance characteristics between assays in symptomatic and recovered patients. METHODS: We recruited 32 patients who had 2019 coronavirus disease (COVID-19; 18 hospitalized and actively symptomatic, 14 recovered mild cases), and measured levels of IgM (against the full-length S1 or the highly homologous SARS-CoV E protein) and IgG (against S1 receptor binding domain [RBD]). We performed the same analysis in 103 pre-2020 healthy adult control (HC) participants and 13 participants who had negative molecular testing for SARS-CoV-2. RESULTS: Anti-S1-RBD IgG levels were very elevated within days of symptom onset for hospitalized patients (median 2.04 optical density [OD], vs. 0.12 in HC). People who recovered from milder COVID-19 only reached similar IgG levels 28 days after symptom onset. IgM levels were elevated early in both groups (median 1.91 and 2.12 vs. 1.14 OD in HC for anti-S1 IgM, 2.23 and 2.26 vs 1.52 in HC for anti-E IgM), with downward trends in hospitalized cases having longer disease duration. The combination of the two IgM levels showed similar sensitivity for COVID-19 as IgG but greater specificity, and identified 4/10 people (vs. 3/10 by IgG) with prior symptoms and negative molecular testing to have had COVID-19. CONCLUSIONS: Disease severity and timing both influence levels of IgM and IgG against SARS-CoV-2, with IgG better for early detection of severe cases but IgM more suited for early detection of milder cases.

positive: Combination of Serological Total Antibody and RT-PCR Test for Detection of SARS-CoV-2 Infections The purpose of this study was to investigate the feasibility of serological total antibody tests combined with RT-PCR for detection of SARS-CoV-2. We conducted a retrospective study in which 375 patients were enrolled during the outbreak of SARS-CoV-2 from 25th January to 16th March 2020. Patients were divided into a COVID-19 group (n = 141) and a control group (n = 234). Serum samples and throat swabs were collected from 375 patients for total antibody testing against SARS-CoV-2 and RT-PCR analysis, respectively. The results indicated that diagnostic sensitivity and specificity were 95.7% and 98.7%, 92.2% and 100% by total antibody tests and RT-PCR, respectively. The sensitivity and specificity of total antibody tests combined with RT-PCR were 98.6% and 98.7%. The sensitivity of the combined method was significantly higher than RT-PCR (X(2) = 5.16, P < 0.05), and similar to that of total antibody tests (X(2) = 1.15, P > 0.05). This study supported the advantage of the combined method for detection of SARS-CoV-2 with a high degree of sensitivity and specificity, as a useful tool for accurate diagnosis and timely treatment of suspected patients, epidemiological investigation, as well as monitoring ongoing outbreaks of infections with SARS-CoV-2.

positive: Double-Edged Spike—Are SARS-CoV-2 Serologic Tests Safe Right Now?

positive: Prevalence of SARS-CoV-2 in Spain (ENE-COVID): a nationwide, population-based seroepidemiological study BACKGROUND: Spain is one of the European countries most affected by the COVID-19 pandemic. Serological surveys are a valuable tool to assess the extent of the epidemic, given the existence of asymptomatic cases and little access to diagnostic tests. This nationwide population-based study aims to estimate the seroprevalence of SARS-CoV-2 infection in Spain at national and regional level. METHODS: 35 883 households were selected from municipal rolls using two-stage random sampling stratified by province and municipality size, with all residents invited to participate. From April 27 to May 11, 2020, 61 075 participants (75·1% of all contacted individuals within selected households) answered a questionnaire on history of symptoms compatible with COVID-19 and risk factors, received a point-of-care antibody test, and, if agreed, donated a blood sample for additional testing with a chemiluminescent microparticle immunoassay. Prevalences of IgG antibodies were adjusted using sampling weights and post-stratification to allow for differences in non-response rates based on age group, sex, and census-tract income. Using results for both tests, we calculated a seroprevalence range maximising either specificity (positive for both tests) or sensitivity (positive for either test). FINDINGS: Seroprevalence was 5·0% (95% CI 4·7–5·4) by the point-of-care test and 4·6% (4·3–5·0) by immunoassay, with a specificity–sensitivity range of 3·7% (3·3–4·0; both tests positive) to 6·2% (5·8–6·6; either test positive), with no differences by sex and lower seroprevalence in children younger than 10 years (<3·1% by the point-of-care test). There was substantial geographical variability, with higher prevalence around Madrid (>10%) and lower in coastal areas (<3%). Seroprevalence among 195 participants with positive PCR more than 14 days before the study visit ranged from 87·6% (81·1–92·1; both tests positive) to 91·8% (86·3–95·3; either test positive). In 7273 individuals with anosmia or at least three symptoms, seroprevalence ranged from 15·3% (13·8–16·8) to 19·3% (17·7–21·0). Around a third of seropositive participants were asymptomatic, ranging from 21·9% (19·1–24·9) to 35·8% (33·1–38·5). Only 19·5% (16·3–23·2) of symptomatic participants who were seropositive by both the point-of-care test and immunoassay reported a previous PCR test. INTERPRETATION: The majority of the Spanish population is seronegative to SARS-CoV-2 infection, even in hotspot areas. Most PCR-confirmed cases have detectable antibodies, but a substantial proportion of people with symptoms compatible with COVID-19 did not have a PCR test and at least a third of infections determined by serology were asymptomatic. These results emphasise the need for maintaining public health measures to avoid a new epidemic wave. FUNDING: Spanish Ministry of Health, Institute of Health Carlos III, and Spanish National Health System.

positive: Rapid point-of-care serology testing for sars-cov-2/ Snabbtest for covid-19-antikroppar bor utforas av utbildad personal Increasing evidence indicates immunity against severe acute respiratory syndrome coronavirus 2 (sars-cov-2) after covid-19, but it remains unclear for how long the protection remains Serology testing seems to have a higher sensitivity than molecular diagnostics from 8 days after onset of symtoms, and should be part of risk assessment and epidemiological studies of COVID-19 The performance of commercial serological point-of-care (POC) lateral flow tests are highly manufacturer-dependant Low sensitivity increases the risk of false negative results and could result in unnecessary quarantine of test persons with developed antibodies Low specificity increases the risk of false positive results and could lead to false assumptions of immunity Carefully selected serological POC tests for sars-cov-2 can be used in large scale testing but should only be used by licensed medical staff able to understand their limitations and interpret the results

positive: Efficacy of Serology Testing in Predicting Reinfection in Patients with SARS-CoV-2 In many parts of the United States, SARS-CoV-2 cases have reached peak infection rates, prompting administrators to create protocols to resume elective cases. As elective procedures and surgeries get scheduled, ASCs must implement some form of widespread testing in order to ensure the safety of both the ASC staff as well as the patients being seen. The CDC recently announced the approval of new serological testing for SARS-CoV-2, a test that can indicate the presence of IgM and IgG antibodies in the serum against viral particles. However, the possibility for reinfection raises questions about the utility of this new serological test, as the presence of IgG may not correspond to long-term immunity. The coronavirus has been known to form escape mutations, which may correspond to reduction in immunoglobulin binding capacity. Patients who develop more robust immune responses with formation of memory CD8+ T-cells and helper CD4+ T-cells will be the most equipped if exposed to the virus, but unfortunately the serology test will not help us in distinguishing those individuals. Given the inherent disadvantages of serological testing, antibody testing alone should not be used when deciding patient care and should be combined with PCR testing.

positive: Recombinant truncated nucleocapsid protein as antigen in a novel immunoglobulin M capture enzyme-linked immunosorbent assay for diagnosis of severe acute respiratory syndrome coronavirus infection. We report the development of an immunoglobulin M (IgM) antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) for severe acute respiratory syndrome coronavirus (SARS-CoV) by using recombinant truncated SARS-CoV nucleocapsid protein as the antigen. The newly developed MAC-ELISA had a specificity and sensitivity of 100% as evaluated by using sera from healthy volunteers and patients with laboratory-confirmed SARS. Using serial serum samples collected from SARS patients, the times to seroconversion were determined by IgM antibody detection after SARS-CoV infection. The median time to seroconversion detection was 8 days (range, 5 to 17 days) after disease onset, and the seroconversion rates after the onset of illness were 33% by the first week, 97% by the second week, and 100% by the third week. Compared with the results of our previous report on the detection of IgG, the median seroconversion time by IgM detection was 3 days earlier and the seroconversion rate by the second week after the illness for IgM was significantly higher than by IgG assay. Our results indicating that the IgM response appears earlier than IgG after SARS-CoV infection in consistent with those for other pathogens. Our newly developed MAC-ELISA system offers a new alternative for the confirmation of SARS-CoV infection.

positive: Dynamic profile for the detection of anti-SARS-CoV-2 antibodies using four immunochromatographic assays Abstract In order to fight the SARS-CoV-2 pandemic infection, there is a growing need and demand for diagnostic tools that are complementary and different from the RT-PCR currently in use. Multiple serological tests are or will be very soon available but need to be evaluated and validated. We have thus tested 4 immunochromatographic tests for the detection of antibodies to SARS-CoV-2. In addition, we assessed the kinetics of antibody appearance using these assays in 22 patients after they were tested positive by RT-PCR. We observed great heterogeneity in antiboy detection post-symptom onset. The median antibody detection time was between 8 and 10 days according to the manufacturers. All the tests showed a sensitivity of 60 to 80% on day 10 and 100% on day 15. In addition, a single cross-reaction was observed with other human coronavirus infections. Thus, immunochromatographic tests for the detection of anti-SARS-CoV-2 antibodies may have their place for the diagnostic panel of COVID-19.

positive: Validation and Performance Comparison of Three SARS-CoV-2 Antibody Assays Serology testing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is increasingly being used during the current pandemic of Coronavirus Disease 2019 (COVID-19). The clinical and epidemiologic utilities of antibody-based SARS-CoV-2 testing are under debate. Characterizing these assays helps to understand the disease and provides scientific basis for deciding how to best use these assays. The study assessed one chemiluminescent assay (Abbott COVID-2 IgG) and two lateral flow assays (STANDARD Q [SQ] IgM/IgG Duo and Wondfo Total Antibody Test). Validation included 113 blood samples from 71 PCR-confirmed COVID-19 patients and 1182 samples from negative controls with potential interferences/cross-reactions, including 1063 pre-pandemic samples. IgM antibodies against SARS-CoV-2 were detected as early as post-symptom onset days 3-4. IgG antibodies were first detected post-onset days 5-6 by SQ assays. The detection rates increased gradually, and SQ IgG, Abbott IgG and Wondfo Total detected antibodies from all the PCR-confirmed patients 14 days after symptom onset. Overall agreements between SQ IgM/IgG and Wondfo Total was 88.5% and between SQ IgG and Abbott IgG was 94.6% (Kappa = 0.75, 0.89). No cross-reaction with other endemic coronavirus infections were identified. Viral hepatitis and autoimmune samples were the main cross-reactions observed. However, the interferences/cross-reactions were low. The specificities were 100% for SQ IgG and Wondfo Total and 99.62% for Abbott IgG and 98.87% for SQ IgM. These findings demonstrate high sensitivity and specificity of appropriately validated antibody-based SARS-CoV-2 assays with implications for clinical use and epidemiological seroprevalence studies.

positive: IgG Antibody Response to SARS-CoV-2 Infection and Viral RNA Persistence in Patients on Maintenance Hemodialysis

positive: Study on the expression levels of antibodies against SARS-CoV-2 at different period of disease and its related factors in 192 cases of COVID-19 patients Background: In 2020 the current outbreak of Coronavirus Disease 2019(COVID-19) has constituted a global pandemic. But the question about the immune mechanism of patients with COVID-19 is unclear and cause particular concern to the world. Here, we launched a follow-up analysis of antibodies against SARS-CoV-2 of 192 COVID-19 patients, aiming to depict a kinetics profile of antibodies against SARS-CoV-2 and explore the related factors of antibodies expression against SARS-CoV-2 in COVID-19 patient. Methods: A total of 192 COVID-19 patients enrolled in the designated hospital of Guangzhou , Guangzhou Eighth People's Hospital, from January to February 2020 were selected as the study cohort. A cohort of 130 COVID-19 suspects who had been excluded from SARS-CoV-2 infected by negative RT-PCR result and 209 healthy people were enrolled in this study. Detection of IgM and IgG against SARS-CoV-2 were performed by Chemiluminescence immunoassay in different groups . Results: It has been found that the seroconversion time of IgM against SARS-CoV-2 in most patients was 5-10 days after the symptoms onset , and then rose rapidly, reaching a peak around 2 to 3 weeks, and the median peak concentration was 2.705 AU / mL. The peak of IgM maintained within one week, and then enters the descending channel. IgG seroconverted later than or synchronously with IgM, reaching peaks around 3 to 4 weeks.The median peak concentration was 33.998AU / ml,which was higher than that of IgM . IgM titers begins to gradually decrease after reaching the peak in the 4th week, after the 8th week, a majority of IgM in patient's serum started to turn negative. On the contrary, titers of IgG began to decline slightly after the fifth week, and more than 90% of results of patients were positive after 8 weeks. Additionally, the concentration of antibodies positively correlated with the severity of the disease and the duration of virus exist in host. Conclusion: We depict a kinetics profile of antibodies against SARS-CoV-2 in COVID-19 patients and found out that the levels of antibodies were related to the disease severity,age, gender and virus clearance or continuous proliferation of COVID-19 patients.

positive: Evaluation of the auxiliary diagnostic value of antibody assays for the detection of novel coronavirus (SARS‐CoV‐2) The spread of SARS‐CoV‐2 has taken on pandemic proportions, affecting over 100 countries in a matter of weeks. The goal of this study was to assess the diagnostic values of different methods of detecting and estimating the SARS‐CoV‐2 infection, and the auxiliary diagnostic potential of antibody assays. By retrospectively analyzing the data of viral RNAs and serum IgM‐IgG antibodies against SARS‐CoV‐2 from 38 cases with confirmed COVID‐19 in the Second People's Hospital of Fuyang, we found that, in the early phase of the illness, the viral RNA was most abundant in the sputum specimens, followed by that in the throat swabs, while the antibody assays identified fewer positive cases at this stage. However, the sensitivity of the antibody assays overtook that of RNA test from eighth day of disease onset. Simultaneous use of antibody assay and RT‐qPCR improved the sensitivity of the diagnoses. Moreover, we found that most of these cases with no detectable viral RNA load during the early stages were able to be seropositive after 7 days. Our findings indicate that the antibody detection could be used as an effective supplementary indicator of SARS‐CoV‐2 infection in suspected cases with no detectable viral RNA, and in conjunction with nucleic acid detection in confirming the infection. This article is protected by copyright. All rights reserved.

positive: Indirect Enzyme-Linked Immunosorbent Assay based on the nucleocapsid protein of SARS-like coronaviruses The nucleocapsid protein (N) is a major structural protein of coronaviruses. The N protein of bat SARS-like coronavirus (SL-CoV) has a high similarity with that of SARS-CoV. In this study, the SL-CoV N protein was expressed in Escherichia coli, purified and used as antigen. An Indirect Enzyme-Linked Immunosorbent Assay (indirect ELISA) was developed for detection of SARS- or SL-CoV infections in bat populations. The detection of 573 bat sera with this indirect ELISA demonstrated that SL-CoVs consistently circulate in Rhinilophus species, further supporting the proposal that bats are natural reservoirs of SL-CoVs. This method uses 1–2 μl of serum sample and can be used for preliminary screening of infections by SARS- or SL-CoV with a small amount of serum sample.

positive: Antibody tests suggest that coronavirus infections vastly exceed official counts

positive: Enzyme-linked immunosorbent assay for the detection of porcine epidemic diarrhea coronavirus antibodies in swine sera Abstract An enzyme-linked immunosorbent assay (ELISA) for detecting serum antibodies to the porcine epidemic diarrhea coronavirus (PEDV) was established by using cell culture-grown PEDV as antigen for coating. Ultracentrifugation through 20 and 45% (w/w) sucrose cushion proved to be the best antigen purification method. Examination of 1024 swine sera showed a high specificity and a greater sensitivity of the ELISA, when compared with indirect immunofluorescence. Reference sera with high antibody titers to PEDV originated from two pigs experimentally infected with PEDV. Three different antigen purification methods and the advantages of the ELISA compared with an immunofluorescence test are discussed.

positive: Early antibody response to SARS-CoV-2 Background. The role and significance of the immune response to SARS-CoV-2 infection is not yet well known. Methods. We therefore conducted a study on 46 symptomatic subjects with disease ascertained by laboratory tests to evaluate the presence of IgG and IgM antibodies in these subjects in relation to the time elapsed since the onset of symptoms. The analytical performance of the method used in the study (Maglumi 800, SNIBE, China) and the effect of two different serum and plasma matrices were also assessed. Results. IgG positivity was demonstrated in 100% of cases 15 days after the onset of the disease. IgM show lower concentrations and do not exceed 77% of cases after 15 days. The analytical performance of the method used was confirmed to be good in terms of imprecision, linearity, commutability in two blood sample matrices. Conclusion. The serological study through the search for specific IgG for SARS-CoV-2 results in our case series is sensitive and suitable for population research and can also play a role in diagnosis. The diagnostic performance of specific IgMs are lower.

positive: Severe Acute Respiratory Syndrome Coronavirus 2−Specific Antibody Responses in Coronavirus Disease Patients A new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has recently emerged to cause a human pandemic. Although molecular diagnostic tests were rapidly developed, serologic assays are still lacking, yet urgently needed. Validated serologic assays are needed for contact tracing, identifying the viral reservoir, and epidemiologic studies. We developed serologic assays for detection of SARS-CoV-2 neutralizing, spike protein–specific, and nucleocapsid-specific antibodies. Using serum samples from patients with PCR-confirmed SARS-CoV-2 infections, other coronaviruses, or other respiratory pathogenic infections, we validated and tested various antigens in different in-house and commercial ELISAs. We demonstrated that most PCR-confirmed SARS-CoV-2–infected persons seroconverted by 2 weeks after disease onset. We found that commercial S1 IgG or IgA ELISAs were of lower specificity, and sensitivity varied between the 2 assays; the IgA ELISA showed higher sensitivity. Overall, the validated assays described can be instrumental for detection of SARS-CoV-2–specific antibodies for diagnostic, seroepidemiologic, and vaccine evaluation studies.

positive: Identification of RT-PCR-Negative Asymptomatic COVID-19 Patients via Serological Testing Asymptomatic individuals with coronavirus disease (COVID-19) have been identified via nucleic acid testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); however, the epidemiologic characteristics and viral shedding pattern of asymptomatic patients remain largely unknown. In this study, serological testing was applied when identifying nine asymptomatic cases of COVID-19 who showed persistent negative RT-PCR test results for SARS-CoV-2 nucleic acid and no symptoms of COVID-19. Two asymptomatic cases were presumed to be index patients who had cleared the virus when their close contacts developed symptoms of COVID-19. Three of the asymptomatic cases were local individuals who spontaneously recovered before their presumed index patients developed symptoms of COVID-19. This report presents the epidemiologic and clinical characteristics of asymptomatic individuals with SARS-CoV-2 infection that were undetected on RT-PCR tests in previous epidemiologic investigations probably due to the transient viral shedding duration.

positive: Mental Health Care Providers Dealing With Coronavirus Disease 2019 (COVID-19): What Is the Definition of a Case, How Is That Changing, and What Kinds of Tests Are Available? The goal of this column is to inform mental health care professionals about the evolving way the diagnosis of Coronavirus Disease 2019 (COVID-19) is being made, with emphasis on tests to assist in making the diagnosis and to determine the presence of antibodies to the virus. This column also provides some general information about the disease, its relative risks, and efforts to develop effective treatments. Links to credible websites that are being continuously updated are also provided for readers who want more information and to stay current with ongoing developments.

positive: Evaluation of safety, humoral immune response and faecal shedding in horses inoculated with a modified‐live bovine coronavirus vaccination Equine coronavirus (ECoV) is considered an emerging enteric virus with reported morbidity rates ranging from 10 to 83% and fatality rates ranging from 7 to 27% in adult horses; a vaccine for ECoV is currently not available. This study investigated the safety, humoral response and viral shedding in horses inoculated with a commercially available modified‐live bovine coronavirus (BCoV) vaccine. Twelve healthy adult horses were vaccinated twice, 3 weeks apart, either orally, intranasally or intrarectally. Two healthy unvaccinated horses served as sentinel controls. Following each vaccine administration, horses were monitored daily for physical abnormalities whilst the onset and duration of BCoV shedding was determined by quantitative PCR (qPCR) in nasal secretions and faeces. Whole blood was collected every 3 weeks to determine BCoV‐specific antibody response. With the exception of transient and self‐limiting changes in faecal character observed in seven vaccinated and one control horse, no additional abnormal clinical findings were found in the study horses. Following the first and second vaccine administration, two and one horse, respectively, tested qPCR‐positive for BCoV in nasal secretions 1‐day post intranasal vaccination. No vaccinated horses tested qPCR‐positive for BCoV in faeces following each vaccine administration. One of the two horses that shed BCoV seroconverted to BCoV after the first vaccine administration and an additional two vaccinated horses (oral and intrarectal) seroconverted to BCoV after the second vaccine administration. In conclusion, the results show that the modified‐live BCoV is safe to administer to horses via various routes, causes minimal virus shedding and results in detectable antibodies to BCoV in 27% of the vaccinates.

positive: Capture ELISA systems for the detection of bovine coronavirus-specific IgA and IgM antibodies in milk and serum Abstract Isotype-capture ELISAs for BCV-specific IgA and IgM were developed and tested on milk and serum samples from Swedish cattle. The capture ELISAs showed higher sensitivity than indirect ELISAs for detection of BCV-specific IgA and IgM. In the capture ELISAs the agreement between detection in milk and serum samples was 94% for IgA and 86% for IgM. The correlation between log10 titres in milk and serum was r=0.82 (P<0.001) for IgA and 0.84 (P<0.001) for IgM. Milk seemed a better target than serum for diagnosing specific IgA at low levels. There was no variation in the isotype-specific BCV antibody titres between healthy quarters of the same udder, but subclinical mastitis was associated with higher levels of IgA antibodies and weak false IgM positive reactions in undiluted milk. Bovine IgA and IgM antibodies in milk and serum showed high stability towards freezing and thawing and storage at room temperature. The antibody responses to BCV were followed in milk and serum from six dairy cows and in serum from four calves for a period of 1 year after an outbreak of winter dysentery (WD). In this outbreak some animals became reinfected with BCV. The IgA and IgM capture ELISAs differentiated between primarily BCV infected and reinfected animals. In the primarily infected cattle, IgM antibodies were first detected in milk and serum four to nine days after the first WD symptoms observed, and were subsequently detected for at least 2–3 weeks. IgM was also detected in the reinfected cows, but mostly at lower levels and for a shorter period of time than in the primarily infected animals. In milk, however, the IgM response of the reinfected cows was detected for a longer period of time than in serum. Six months after the outbreak, IgA was still detected in both serum and milk of all six cows and also in serum of one calf. The reinfected cows showed higher and more long-lasting peak levels of IgA in milk and serum than the primarily infected cows, indicating boosting of the IgA response.

positive: SARS-CoV-2 Serology: Much Hype, Little Data

positive: [Serological tests should be related to the aim of the testing, as well as the population]. Expectations are high on serological tests for SARS-CoV-2. Further knowledge of the immunity is needed, but also evaluation of the reliability of the tests. Important for the latter is for which purpose the test is conducted and how common the outcome to be identified is (antibodies). For the determination of immunity at the individual level, the specificity of the test must be very high, preferably 100%. Even tests where the specificity is perceived as high, e.g. 95% or 99%, can lead to a large proportion of false positives, if the proportion of the population actually infected is small.

positive: Evaluation of the EUROIMMUN Anti-SARS-CoV-2 ELISA Assay for detection of IgA and IgG antibodies As the Coronavirus 2019 (COVID-19) pandemic evolves, the development of immunoassays to help determine exposure and potentially predict immunity has become a pressing priority. In this report we present the performance of the EUROIMMUN enzyme-linked immunosorbent assay (ELISA) for semi-quantitative detection of IgA and IgG antibodies in serum and plasma samples using recombinant S1 domain of the SARS-CoV-2 spike protein as antigen. Specimens from patients, with and without COVID-19 infection, were tested at the University of Chicago Clinical Microbiology and Immunology Laboratory. Of 86 samples from COVID-19 PCR-negative patients, including 28 samples positive for common human coronavirus strains, 76 tested negative and 10 tested positive for IgA (88.4% agreement, 95% CI: 79.9–93.6) while 84 tested negative and 2 tested positive for IgG (97.7% agreement, 95% CI: 91.9–99.6). Of 82 samples from COVID-19 PCR-positive patients, 14 tested negative and 68 tested positive for IgA (82.9% agreement, 95% CI: 73.4–89.5) while 27 tested negative and 55 tested positive for IgG (67.1% agreement, 95% CI: 56.3–76.3). Samples collected ≥4 days after positive PCR 38 of 42 (90.5% CI: 77.9–96.2) were positive for IgA, and 42 of 42 (100% 95% CI: 91.6–100) were positive for IgG, respectively. The EUROIMMUN Anti-SARS-CoV-2 ELISA Assay demonstrates good sensitivity for detection of IgA and excellent sensitivity for detection of IgG antibodies from samples collected ≥4 days, after COVID-19 diagnosis by PCR. This assay demonstrated only borderline cross reaction in 2 of the 28 samples from patients with common human coronaviruses infection, types NL63 and OC43.

positive: Monoclonal antibodies against bovine immunoglobulins and their use in isotype-specific ELISAs for rotavirus antibody Monoclonal antibodies (MCA) against bovine immunoglobulin (BIg) isotypes were produced and characterized. MCAs were obtained which react specifically with IgG, IgG(1), IgG(2) or IgA while MCAs against IgM showed a partial cross-reaction with affinity purified IgA. MCAs with optimal characteristics for application in ELISA were selected and used as conjugates in an indirect double antibody sandwich assay (IDAS) and as the capturing antibody in an antibody capture assay (ACA) for the isotype-specific detection of antibodies against rotavirus. Based on theoretical grounds, experimental analysis of inter- and intra-isotype competition in IDAS and ACA, respectively, and direct comparison of both tests, the IDAS was selected for the detection of IgG(1) and IgG(2) anti-rotavirus antibodies. The ACA was the test of choice for the detection of IgM and IgA anti-rotavirus antibodies. The isotype specificity of these tests relies on the specificity of the MCAs and was confirmed for each test by the observation that samples containing rotavirus antibodies of only 1 particular isotypee reacted only in the homologous assay. The MCAs against bovine Ig isotypes and isotype-specific ELISAs were found to be very useful in the study of humoral mucosal immunity in calves infected with rotavirus.

positive: Early data on the performance of a combined SARS-CoV-2 spike-nucleocapsid antibody lateral flow device compared to a nucleocapsid-only device Background There is a critical need for reliable antibody detection methods in order to study and evaluate the public health and clinical response to the ongoing COVID-19 pandemic. Lateral flow immunoassay (LFIA) devices offer the prospect of rapid point-of-care testing (POCT), but the performance of these devices must be evaluated for robustness before they can be adopted for routine clinical and public health use. Methods Plasma and serum specimens from SARS-CoV-2 RNA-positive (n = 131) and RNA-negative (n = 16) patients were taken from various time points with respect to the onset of symptoms. All 147 anonymised specimens were tested for IgM and IgG using the Hangzhou AllTest 2019-nCoV IgG/IgM Rapid Test Cassette and the Abbexa COVID-19 IgG/IgM Rapid Test Kit. Results IgM sensitivity ranged from 13% to 68%, depending on the date of symptom onset and the device. Regarding IgG, the Abbexa device outperformed the Hangzhou device at all cumulative timeline brackets, with sensitivity of 97·87% (Abbexa) versus 68·09% (Hangzhou) for samples beyond 21 days from symptom onset. Day 21 was therefore chosen as the cut-off for ascertaining test performance characteristics, beyond which the specificity was 100% for both devices and negative predictive value was 0·94 (Abbexa) versus 0·50 (Hangzhou). Discussion Based on this limited dataset, the performance characteristics of the Abbexa LFIA device were substantially better than those of the Hangzhou device. Applying a 21-day cut-off for the Abbexa device meets the minimum (98%) sensitivity and specificity thresholds set by the UK Medicine & Healthcare products Regulatory Agency. The Abbexa device captures antibodies against both SARS-CoV-2 spike and nucleocapsid proteins, as opposed to Hangzhou that targets only the nucleocapsid protein. We therefore propose that spike glycoprotein antibodies be considered as part of the standard diagnostic approach towards SARS-CoV-2 antibody profiling to improve clinical sensitivity and potentially specificity, pending follow-up studies to confirm this approach.

positive: Evaluation of the EUROIMMUN Anti-SARS-CoV-2 ELISA Assay for detection of IgA and IgG antibodies As the Coronavirus 2019 (COVID-19) pandemic evolves, the development of immunoassays to help determine exposure and potentially predict immunity has become a pressing priority. In this report we present the performance of the EUROIMMUN enzyme-linked immunosorbent assay (ELISA) for semi-quantitative detection of IgA and IgG antibodies in serum and plasma samples using recombinant S1 domain of the SARS-CoV-2 spike protein as antigen. Specimens from patients, with and without COVID-19 infection, were tested at the University of Chicago Clinical Microbiology and Immunology Laboratory. Of 86 samples from SARS-CoV-2 PCR-negative patients, including 28 samples positive for common human coronavirus strains, 76 tested negative and 10 tested positive for IgA (88.4% agreement, 95% CI: 79.9-93.6) while 84 tested negative and 2 tested positive for IgG (97.7% agreement, 95% CI: 91.9-99.6). Of 82 samples from SARS-CoV-2 PCR-positive patients, 14 tested negative and 68 tested positive for IgA (82.9% agreement, 95% CI: 73.4-89.5) while 27 tested negative and 55 tested positive for IgG (67.1% agreement, 95% CI: 56.3-76.3). Of samples collected ≥4 days after positive PCR, 38 of 42 (90.5% agreement, 95% CI: 77.9-96.2) were positive for IgA, and 42 of 42 (100% agreement, 95% CI: 91.6-100) were positive for IgG, respectively. The EUROIMMUN Anti-SARS-CoV-2 ELISA Assay demonstrated good sensitivity for detection of IgA and excellent sensitivity for detection of IgG antibodies from samples collected ≥4 days, after COVID-19 diagnosis by PCR. This assay demonstrated good specificity for IgA and excellent specificity for IgG and demonstrated only borderline cross reaction in 2 of the 28 samples from patients with common human coronaviruses infection, types NL63 and OC43.

positive: Antibody responses to individual proteins of SARS coronavirus and their neutralization activities Abstract A novel coronavirus, the severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), was identified as the causative agent of SARS. The profile of specific antibodies to individual proteins of the virus is critical to the development of vaccine and diagnostic tools. In this study, 13 recombinant proteins associated with four structural proteins (S, E, M and N) and five putative uncharacterized proteins (3a, 3b, 6, 7a and 9b) of the SARS-CoV were prepared and used for screening and monitoring their specific IgG antibodies in SARS patient sera by protein microarray. Antibodies to proteins S, 3a, N and 9b were detected in the sera from convalescent-phase SARS patients, whereas those to proteins E, M, 3b, 6 and 7a were undetected. In the detectable specific antibodies, anti-S and anti-N were dominant and could persist in the sera of SARS patients until week 30. Among the rabbit antisera to recombinant proteins S3, N, 3a and 9b, only anti-S3 serum showed significant neutralizing activity to the SARS-CoV infection in Vero E6 cells. The results suggest (1) that anti-S and anti-N antibodies are diagnostic markers and in particular that S3 is immunogenic and therefore is a good candidate as a subunit vaccine antigen; and (2) that, from a virus structure viewpoint, the presence in some human sera of antibodies reacting with two recombinant polypeptides, 3a and 9b, supports the hypothesis that they are synthesized during the virus cycle.

positive: Connecting clusters of COVID-19: an epidemiological and serological investigation BACKGROUND: Elucidation of the chain of disease transmission and identification of the source of coronavirus disease 2019 (COVID-19) infections are crucial for effective disease containment. We describe an epidemiological investigation that, with use of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological assays, established links between three clusters of COVID-19. METHODS: In Singapore, active case-finding and contact tracing were undertaken for all COVID-19 cases. Diagnosis for acute disease was confirmed with RT-PCR testing. When epidemiological information suggested that people might have been nodes of disease transmission but had recovered from illness, SARS-CoV-2 IgG serology testing was used to establish past infection. FINDINGS: Three clusters of COVID-19, comprising 28 locally transmitted cases, were identified in Singapore; these clusters were from two churches (Church A and Church B) and a family gathering. The clusters in Church A and Church B were linked by an individual from Church A (A2), who transmitted SARS-CoV-2 infection to the primary case from Church B (F1) at a family gathering they both attended on Jan 25, 2020. All cases were confirmed by RT-PCR testing because they had active disease, except for A2, who at the time of testing had recovered from their illness and tested negative. This individual was eventually diagnosed with past infection by serological testing. ELISA assays showed an optical density of more than 1·4 for SARS-CoV-2 nucleoprotein and receptor binding domain antigens in titres up to 1/400, and viral neutralisation was noted in titres up to 1/320. INTERPRETATION: Development and application of a serological assay has helped to establish connections between COVID-19 clusters in Singapore. Serological testing can have a crucial role in identifying convalescent cases or people with milder disease who might have been missed by other surveillance methods. FUNDING: National Research Foundation (Singapore), National Natural Science Foundation (China), and National Medical Research Council (Singapore).

positive: Evaluation by indirect immunofluorescent assay and enzyme linked immunosorbent assay of the dynamic changes of serum antibody responses against severe acute respiratory syndrome coronavirus. BACKGROUND Severe acute respiratory syndrome coronavirus (SARS-CoV) is a newly emerging virus that gives rise to SARS patients with high rates of infectivity and fatality. To study the humoral immune responses to SARS-CoV, the authors evaluated IgG and IgM specific antibodies in patients' sera. METHODS Two methods, enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescent assay (IFA), were used to detect specific serum IgG and IgM against SARS-CoV in 98 SARS patients and 250 controls consisting of patients with pneumonia, health-care professionals and healthy subjects. The serum antibody profiles were investigated at different times over one and a half years in 18 of the SARS patients. RESULTS The sensitivity and specificity of ELISA for detecting IgG against SARS-CoV were 100.0% and 97.2% and for IgM 89.8% and 97.6% respectively; the figures using IFA for IgG were 100.0% and 100.0% and for IgM 81.8% and 100.0% respectively. During the first seven days of the antibodies trace test, no IgG and IgM were detected, but on day 15, IgG response increased dramatically, reaching a peak on day 60, remaining high up to day 180 and decreasing gradually until day 540. On day 15, IgM was detected, rapidly reached a peak, then declined gradually until day 180 when IgM was undetectable. CONCLUSION The detection of antibodies against SARS virus is helpful in the clinical diagnosis of SARS.

positive: Determining SARS sub-clinical infection: a longitudinal seroepidemiological study in recovered SARS patients and controls after an outbreak in a general hospital. A cohort of 67 confirmed SARS patients were prospectively followed for 16 months and were compared with a control population. Serum samples taken at various times were tested for IgG and IgM; dynamic serological changes in these antibodies were described. The positive responses of IgM and IgG antibodies in sera against SARS virus from the first week to the sixth week after onset of the illness in patients with SARS were measured. The ELISA test of IgG antibody was negative in 200 community controls. The positive rate in the SARS high-risk population was 0.61% tested by ELISA and 0.21% by IFA. The high-risk population in this study was defined as those who provided health care and other services to SARS patients during the outbreak. IgG antibody in convalescent serum of patients with SARS revealed an increasing trend, peaking at the 22nd week after onset of illness followed by a slow decline. IgM appeared earlier than IgG and can be better used for early detection. IgG remained at a high level for a much longer period, serving as a good indicator for follow-up and for assessing past exposure. Our results also suggest that sub-clinical infection, if it exists, is very rare.

positive: Serological assays for emerging coronaviruses: Challenges and pitfalls Abstract More than a decade after the emergence of severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002/2003 the occurrence of a novel CoV termed Middle East respiratory syndrome (MERS) CoV challenges researchers and public health authorities. To control spread and finally contain novel viruses, rapid identification and subsequent isolation of infected individuals and their contacts is of utmost importance. Next to methods for nucleic acid detection, validated serological assays are particularly important as the timeframe for antibody detection is less restricted. During the SARS-CoV epidemic a wide variety of serological diagnostic assays were established using multiple methods as well as different viral antigens. Even though the majority of the developed assays showed high sensitivity and specificity, numerous studies reported on cross-reactive antibodies to antigens from wide-spread common cold associated CoVs. In order to improve preparedness and responsiveness during future outbreaks of novel CoVs, information and problems regarding serological diagnosis that occurred during the SARS-CoV should be acknowledged. In this review we summarize the performance of different serological assays as well as the applicability of the two main applied antigens (spike and nucleocapsid protein) used during the SARS-CoV outbreak. We highlight challenges and potential pitfalls that occur when dealing with a novel emerging coronavirus like MERS-CoV. In addition we describe problems that might occur when animal sera are tested in serological assays for the identification of putative reservoirs. Finally, we give a recommendation for a serological testing scheme and outline necessary improvements that should be implemented for a better preparedness.

positive: A serological assay to detect SARS-CoV-2 seroconversion in humans SARS-Cov-2 (severe acute respiratory disease coronavirus 2), which causes Coronavirus Disease 2019 (COVID19) was first detected in China in late 2019 and has since then caused a global pandemic. While molecular assays to directly detect the viral genetic material are available for the diagnosis of acute infection, we currently lack serological assays suitable to specifically detect SARS-CoV-2 antibodies. Here we describe serological enzyme-linked immunosorbent assays (ELISA) that we developed using recombinant antigens derived from the spike protein of SARS-CoV-2. Using negative control samples representing pre-COVID 19 background immunity in the general adult population as well as samples from COVID19 patients, we demonstrate that these assays are sensitive and specific, allowing for screening and identification of COVID19 seroconverters using human plasma/serum as early as two days post COVID19 symptoms onset. Importantly, these assays do not require handling of infectious virus, can be adjusted to detect different antibody types and are amendable to scaling. Such serological assays are of critical importance to determine seroprevalence in a given population, define previous exposure and identify highly reactive human donors for the generation of convalescent serum as therapeutic. Sensitive and specific identification of coronavirus SARS-Cov-2 antibody titers may, in the future, also support screening of health care workers to identify those who are already immune and can be deployed to care for infected patients minimizing the risk of viral spread to colleagues and other patients.

positive: Development and validation of IMMUNO-COV™: a high-throughput clinical assay for detecting antibodies that neutralize SARS-CoV-2 We here describe the development and validation of IMMUNO-COV™, a high-throughput clinical test to quantitatively measure SARS-CoV-2-neutralizing antibodies, the specific subset of anti-SARS-CoV-2 antibodies that block viral infection. The test measures the capacity of serum or purified antibodies to neutralize a recombinant Vesicular Stomatitis Virus (VSV) encoding the SARS-CoV-2 spike glycoprotein. This recombinant virus (VSV-SARS-CoV-2-S-Δ19CT) induces fusion in Vero cell monolayers, which is detected as luciferase signal using a dual split protein (DSP) reporter system. VSV-SARS-CoV-2-S-Δ19CT infection was blocked by monoclonal α-SARS-CoV-2-spike antibodies and by plasma or serum from SARS-CoV-2 convalescing individuals. The assay exhibited 100% specificity in validation tests, and across all tests zero false positives were detected. In blinded analyses of 230 serum samples, only two unexpected results were observed based on available clinical data. We observed a perfect correlation between results from our assay and 80 samples that were also assayed using a commercially available ELISA. To quantify the magnitude of the anti-viral response, we generated a calibration curve by adding stepped concentrations of α-SARS-CoV-2-spike monoclonal antibody to pooled SARS-CoV-2 seronegative serum. Using the calibration curve and a single optimal 1:100 serum test dilution, we reliably measured neutralizing antibody levels in each test sample. Virus neutralization units (VNUs) calculated from the assay correlated closely (p < 0.0001) with PRNTEC50 values determined by plaque reduction neutralization test against a clinical isolate of SARS-CoV-2. Taken together, these results demonstrate that the IMMUNO-COV™ assay accurately quantitates SARS-CoV-2 neutralizing antibodies in human sera and therefore is a potentially valuable addition to the currently available serological tests. The assay can provide vital information for comparing immune responses to the various SARS-CoV-2 vaccines that are currently in development, or for evaluating donor eligibility in convalescent plasma therapy studies.

positive: Towards the next phase: evaluation of serological assays for diagnostics and exposure assessment. The world is entering a new era of the COVID-19 pandemic in which there is an increasing call for reliable antibody testing. To support decision making on the deployment of serology for either population screening or diagnostics, we present a comprehensive comparison of serological COVID-19 assays. We show that the assay detecting total immunoglobulins against the receptor binding domain of SARS CoV-2, had optimal characteristics for antibody detection in different stages of disease.

positive: [Development and application of triple antibodies-based sandwich ELISA for detecting nucleocapsid protein of SARS-associated coronavirus]. OBJECTIVE To prepare and characterize monoclonal antibodies (mAb) and polyclonal antibodies against nucleocapsid (N) protein of severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) and to establish antibodies-based sandwich ELISA for detecting N protein of SARS-CoV, which might apply to early diagnosis of patients with SARS-CoV infection. METHODS BALB/c mice were immunized with purified recombinant N protein of SARS-CoV for producing mAbs, and New Zealand white rabbits were immunized for producing polyclonal antibodies. The identification of antibodies was performed using indirect enzyme-linked immunosorbent assay (ELISA), indirect fluorescent-antibody assay (IFA), and Western immunoblotting. Capturing and detecting antibodies were selected by pairing the mAbs and polyclonal antibodies one by one and an antibodies-based sandwich antigen capture ELISA was used for detecting N antigen of SARS-CoV. RESULTS Nine mAbs and hyperimmune rabbit polyclonal antibodies, specifically against SARS-CoV nucleocapsid protein were obtained. Using paired ELISA assay, three mAbs N1E8, N8E1 and N10E4 were selected as capturing antibody and rabbit polyclonal antibodies as detecting antibody then triple antibodies-based sandwich ELISA was established following horseradish peroxidase (HRP)-conjugated goat anti-rabbit immunoglobulin G. The recombinant N protein was used as a standard to establish a detection sensitivity of approximated 50 pg/ml with this assay. When tested with 420 serum specimens from serologically confirmed SARS patients, the positive rates of serum N protein were 90.1%, 23% and 0%, in which sera collected from 1 to 10 days, 11 to 20 days and beyond 21 days respectively after the onset of symptoms. The specificity of the assay was 99.86% in 715 control serum specimens. There was no cross-reaction with other respiratory viruses and coronaviruses. CONCLUSION Specific and high affinity mAbs and rabbit polyclonal antibodies were obtained. By paired and optimized sandwich ELISA, a sensitive and specific antigen capture ELISA was established for detecting N antigen of SARS-CoV, which might apply to early diagnosis, source tracing and epidemiological studies of SARS.

positive: Comparison of commercial lateral flow immunoassays and ELISA for SARS-CoV-2 antibody detection BACKGROUND: COVID-19 pandemic has spread worldwide since December 2019. Serological tests for SARS-CoV-2 antibody testing are needed for detection of current or past infections. A wide range of commercial tests is available. However, most of them need to be validated. STUDY DESIGN: The aim was to compare a commercial IgG and IgA ELISA (Euroimmun) with three lateral flow immunoassays (LFI): Hangzhou Alltest Biotech, Wuhan UNscience Biotechnology and Guangzhou Wondfo Biotech. Specificity was calculated with 62 available serum samples from 2018/19. The study included 152 sera from patients of which 109 were RT-PCR positive. Sensitivities for ELISA anti SARS-CoV-2 IgG and IgA were 81,5% and 93,1% and specificities 100% and 80,6%, respectively. LFI showed variable performances, overall results being better for Guangzhou Wondfo Biotech. CONCLUSIONS: Commercial serological tests are useful for detection of antibodies in patients with COVID-19. ELISA presented better results than LFI. The results allowed to incorporate the most sensitive LFI to the daily workflow, combining with ELISA. Careful validation is encouraged before clinical laboratories start using these tests.

positive: Development of a lateral flow immunoassay strip for rapid detection of IgG antibody against SARS-CoV-2 virus. The ongoing worldwide SARS-CoV-2 epidemic clearly has a tremendous influence on public health. Molecular detection based on oral swabs was used for confirmation of SARS-CoV-2 infection. However, high false negative rates were reported. We describe here the development of a point-of-care (POC) serological assay for the detection of IgG antibody against SARS-CoV-2. The principle of a lateral flow immunoassay strip (LFIAs) consists of fixing SARS-CoV-2 nucleocapsid protein to the surface of the strip and coupling anti-human IgG with colloidal gold nanoparticles (Au NPs). A series of parameters of this method were optimized, including the concentration of coating antigen, BSA blocking concentration and pH value for conjugation. The entire detection process took 15-20 min with a volume of 80 μL of the analyte solution containing 10 μL of serum and 70 μL sample diluent. The performance of the established assay was evaluated using serum samples of the clinically diagnosed cases of Coronavirus Disease 2019 (COVID-19). Our results indicated that the LFIAs for SARS-CoV-2 had satisfactory stability and reproducibility. As a result, our fast and easy LFIAs could provide a preliminary test result for physicians to make the correct diagnosis of SARS-CoV-2 infections along with alternative testing methods and clinical findings, as well as seroprevalence determination, especially in low-resource countries.

positive: Performance verification of detecting COVID-19 specific antibody by using four chemiluminescence immunoassay systems Background The purpose of current study is to evaluate the analytical performance of seven kits for detecting IgM/IgG antibody of corona virus (2019-nCoV) by using four chemiluminescence immunoassay systems. Methods 50 patients diagnosed with 2019-nCoV infection and 130 controls without corona virus infection from the people's hospital of Chongqing were enrolled in current retrospective study. Four chemiluminescence immunoassay systems including seven IgM/IgG antibody detection Kits for 2019-nCoV (A_IgM, A_IgG, B_IgM, B_IgG, C_IgM, C_IgG, D_Ab) were employed to detecting antibody concentration. Chi-square test,receiver operating characteristic (ROC) curve and Youden's index were demonstrated to verify the cutoff value of each detection system. Results The repeatability verification results of the A, B, C, and D system are all qualified. D-Ab performances best (92% sensitivity and 99.23% specificity), and B_IgM worse than other systems. Except for the system of A_IgM and C_IgG, the optimal diagnostic thresholds and cutoff value of other kits from recommendations are inconsistent with each other. B_IgM got the worst AUC and C_IgG had the best diagnostic accuracy. More importantly, B_IgG system have the highest false positive rate for testing patients with AIDS, tumor and pregnant. A_IgM system test showed highest false positive rates among elder over 90 years old. Conclusions Systems for CoVID-2019 IgM/IgG antibody test performance difference. Serum diagnosis kit of D-Ab is the most reliable detecting system for 2019-nCoV antibody, which can be used as an alternative method for nucleic acid testing.

positive: Serodiagnostics for Severe Acute Respiratory Syndrome–Related Coronavirus-2: A Narrative Review Accurate serologic tests to detect host antibodies to severe acute respiratory syndrome–related coronavirus-2 (SARS-CoV-2) will be critical for the public health response to the coronavirus disease 2019 pandemic. Many use cases are envisaged, including complementing molecular methods for diagnosis of active disease and estimating immunity for individuals. At the population level, carefully designed seroepidemiologic studies will aid in the characterization of transmission dynamics and refinement of disease burden estimates and will provide insight into the kinetics of humoral immunity. Yet, despite an explosion in the number and availability of serologic assays to test for antibodies against SARS-CoV-2, most have undergone minimal external validation to date. This hinders assay selection and implementation, as well as interpretation of study results. In addition, critical knowledge gaps remain regarding serologic correlates of protection from infection or disease, and the degree to which these assays cross-react with antibodies against related coronaviruses. This article discusses key use cases for SARS-CoV-2 antibody detection tests and their application to serologic studies, reviews currently available assays, highlights key areas of ongoing research, and proposes potential strategies for test implementation.

positive: Serological study of coronavirus antibodies in Hamburg. A serological study of coronaviruses with the OC 43 agent (HI-test) was undertaken in 1000 sera from the population of Hamburg. 32,7% of the sera showed HI=titers between 1 : 8 and 1 : 128. The geometric mean titer (GMT) for the whole group was 1 : 16. The frequency of seropositive reactions was highest in 244 individuals 15 to 24 years old (52,8% positive reactions, GMT 1 : 19) whilst in the older age groups (25-59 years and over 60 years old) the precentage of positive reactors was markedly lower (14,4% and 16,8%, respectively, GMT 1 : 12). Among 131 twelve to 17 years old youngsters, a seroconversion was demonstrated in paired sera in 6,8% with a 4- to 8-fold rise in HI-titer within 8 weeks.

positive: Longitudinal Change of SARS-Cov2 Antibodies in Patients with COVID-19 BACKGROUND: A novel coronavirus, SARS-CoV-2, has recently emerged and caused the rapid spread of COVID-19 worldwide. METHODS: We did a retrospective study and included COVID-19 patients admitted to Renmin Hospital of Wuhan University between February 1 and February 29, 2020. Antibody assay was conducted to detect COVID-19 envelope protein E and nucleocapsid protein N antigen. RESULTS: 112 patients were recruited with symptoms of fever, cough, fatigue, myalgia, and diarrhoea. All patients underwent antibody tests. Fifty-eight (51.79%) were positive for both IgM and IgG, 7 (6.25%) were negative for both antibodies, 1 (0.89%) was positive for only IgM, and 46 (41.07%) were positive for only IgG. IgM antibody appeared within a week post disease onset, and lasted for one month and gradually decreased, while IgG antibody was produced 10 days after infection, and lasted for a longer time. However, no significant difference in level of IgM and IgG antibody between positive and negative patients of nucleic acid test after treatment was found. CONCLUSIONS: Our results indicate that serological tests could be powerful approach for the early diagnosis of COVID-19.

positive: Development of a recombinant truncated nucleocapsid protein based immunoassay for detection of antibodies against human coronavirus OC43 Abstract Human coronaviruses are one of the main causes of upper respiratory tract infections in humans. While more often responsible for mild illness, they have been associated with illnesses that require hospitalization. In this study, an assay for one of the human coronaviruses, OC43, was developed using a truncated recombinant nucleocapsid (N) protein antigen in an enzyme immunosorbent assay (ELISA) and evaluated using serum collected from HCoV-OC43-infected patients, healthy adults, and patients with other respiratory virus infections. Results showed that the diagnostic sensitivity and specificity of the assay were 90.9% (10/11) and 82.9% (39/47), respectively. To evaluate the clinical utility of the ELISA, serum samples collected from patients during an outbreak of HCoV-OC43 infection and previously identified as positive by HCoV-OC43 whole N ELISA were screened resulting in 100% diagnosis agreement between the testing methods. These results suggest that this assay offers a reliable method to detect HCoV-OC43 infection and may be a useful tool in coronavirus seroepidemiological studies.

positive: A high-throughput neutralizing antibody assay for COVID-19 diagnosis and vaccine evaluation Virus neutralization remains the gold standard for determining antibody efficacy. Therefore, a high-throughput assay to measure SARS-CoV-2 neutralizing antibodies is urgently needed for COVID-19 serodiagnosis, convalescent plasma therapy, and vaccine development. Here we report on a fluorescence-based SARS-CoV-2 neutralization assay that detects SARS-CoV-2 neutralizing antibodies in COVID-19 patient specimens and yields comparable results to plaque reduction neutralizing assay, the gold standard of serological testing. Our approach offers a rapid platform that can be scaled to screen people for antibody protection from COVID-19, a key parameter necessary to safely reopen local communities.

positive: Nasopharyngeal and Oropharyngeal Swabs, And/Or Serology for SARS COVID-19: What Are We Looking For? Governments and clinicians that were fully involved in the dramatic SARS-CoV-2 outbreak during the last few weeks in Italy (and more or less all over the world) are fiercely debating the use of methods for screening this viral infection. Thus, all countries are employing a lot of resources in order to test more and more subjects. For this purpose, there are different strategies, based on either direct or indirect tests. Among the first category, the main assays used for SARS-CoV-2 are based on a real-time reverse transcriptase polymerase chain reaction (RT-PCR). Such tests can be performed on nasopharyngeal and oropharyngeal swabs for the categories of those with symptoms and those potentially exposed. In order to integrate the molecular assays in the diagnosis of SARS-CoV-2, a wide range of serology immunoassays (IAs) have also been developed. If we want to identify “immune” people in order to let them to come back to work, serology is the best (and probably the only) approach.

positive: Comparison of enzyme-linked immunosorbent assay systems using rift valley fever virus nucleocapsid protein and inactivated virus as antigens BACKGROUND: Rift Valley Fever (RVF) is a mosquito-borne viral zoonosis. To detect RVF virus (RVFV) infection, indirect immunoglobulin G (IgG) and immunoglobulin M (IgM) enzyme linked immunosorbent assays (ELISAs) which utilize recombinant RVFV nucleocapsid (RVFV-N) protein as assay antigen, have reportedly been used, however, there is still a need to develop more sensitive and specific methods of detection. METHODS: RVFV-N protein was expressed in Escherichia coli (E. coli) and purified by histidine-tag based affinity chromatography. This recombinant RVFV-N (rRVFV-N) protein was then used as antigen to develop an IgG sandwich ELISA and IgM capture ELISAs for human sera. Ninety six serum samples collected from healthy volunteers during the RVF surveillance programme in Kenya in 2013, and 93 serum samples collected from RVF-suspected patients during the 2006–2007 RVF outbreak in Kenya were used respectively, to evaluate the newly established rRVFV-N protein-based IgG sandwich ELISA and IgM capture ELISA systems in comparison with the inactivated virus-based ELISA systems. RESULTS: rRVFV-N protein-based-IgG sandwich ELISA and IgM capture ELISA for human sera were established. Both the new ELISA systems were in 100% concordance with the inactivated virus-based ELISA systems, with a sensitivity and specificity of 100%. CONCLUSIONS: Recombinant RVFV-N is a safe and affordable antigen for RVF diagnosis. Our rRVFV-N-based ELISA systems are safe and reliable tools for diagnosis of RVFV infection in humans and especially useful in large-scale epidemiological investigation and for application in developing countries.

positive: Development and application of a novel ELISA for detecting antibodies against group I fowl adenoviruses Since 2015, outbreaks of hepatitis-hydropericardium syndrome (HPS) caused by a novel genotype of fowl adenovirus 4 (FAdV-4) infection have created serious economic losses in China. Given that other serotypes of hypervirulent FAdVs have also been reported in poultry around the world, a common ELISA for all serotypes within the group I fowl adenoviruses (FAdV-I) is urgently needed, especially for clinical epidemic serotypes. In this study, we used high purity and concentration virions of FAdV-4 and developed a common ELISA for detecting antibodies against 12 FAdV-I serotypes. The developed ELISA was able to distinguish between antibodies against FAdV-I, FAdV-III, and other heterologous viruses without any cross-reaction. Furthermore, the ELISA showed higher sensitivity than the FAdV-1-based ELISA to the novel FAdV-4 found in China. Moreover, since there are no commercial vaccines against FAdVs in China, the ELISA was applied to detect sera samples from specific pathogen-free chickens inoculated with inactivated FAdV-1, FAdV-4, and FAdV-8a. The assay showed high sensitivities for all three detected serotypes within FAdV-I. In conclusion, a novel, common ELISA for FAdV-I was developed in this study and could be a powerful tool for seroepidemiological investigations and FAdVs vaccine development.

positive: Development of a lateral flow immunoassay strip for rapid detection of IgG antibody against SARS-CoV-2 virus The ongoing worldwide SARS-CoV-2 epidemic clearly has a tremendous influence on public health. Molecular detection based on oral swabs was used for confirmation of SARS-CoV-2 infection. However, high false negative rates were reported. We describe here the development of a point-of-care (POC) serological assay for the detection of IgG antibody against SARS-CoV-2. The principle of a lateral flow immunoassay strip (LFIAs) consists of fixing SARS-CoV-2 nucleocapsid protein to the surface of the strip and coupling anti-human IgG with colloidal gold nanoparticles (Au NPs). A series of parameters of this method were optimized, including the concentration of coating antigen, BSA blocking concentration and pH value for conjugation. The entire detection process took 15-20 min with a volume of 80 µL of the analyte solution containing 10 µL of serum and 70 µL sample diluent. The performance of the established assay was evaluated using serum samples of the clinically diagnosed cases of Coronavirus Disease 2019 (COVID-19). Our results indicated that the LFIAs for SARS-CoV-2 had satisfactory stability and reproducibility. As a result, our fast and easy LFIAs could provide a preliminary test result for physicians to make the correct diagnosis of SARS-CoV-2 infections along with alternative testing methods and clinical findings, as well as seroprevalence determination, especially in low-resource countries.

positive: SARS-CoV-2 neutralizing serum antibodies in cats: a serological investigation Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in Wuhan, China, and rapidly spread worldwide. Previous studies suggested cat could be a potential susceptible animal of SARS-CoV-2. Here, we investigated the infection of SARS-CoV-2 in cats by detecting specific serum antibodies. A cohort of serum samples were collected from cats in Wuhan, including 102 sampled after COVID-19 outbreak, and 39 prior to the outbreak. 15 of 102 (14.7%) cat sera collected after the outbreak were positive for the receptor binding domain (RBD) of SARS-CoV-2 by indirect enzyme linked immunosorbent assay (ELISA). Among the positive samples, 11 had SARS-CoV-2 neutralizing antibodies with a titer ranging from 1/20 to 1/1080. No serological cross-reactivity was detected between the SARS-CoV-2 and type I or II feline infectious peritonitis virus (FIPV). Our data demonstrates that SARS-CoV-2 has infected cat population in Wuhan during the outbreak.

positive: What policy makers need to know about COVID-19 protective immunity

positive: The COVID-19 Serology Studies Workshop: Recommendations and Challenges The development, validation, and appropriate application of serological assays to detect antibodies to SARS-CoV-2 are essential to determining seroprevalence of this virus in the United States and globally and in guiding government leadership and the private sector on back-to-work policies. An interagency working group of the US Department of Health and Human Services convened a virtual workshop to identify knowledge gaps and key outstanding scientific issues and to develop strategies to fill them. Key outcomes of the workshop included recommendations for (1) advancing serology assays as a tool to better understand SARS-CoV-2 infection and (2) conducting crucial serology field studies to advance an understanding of immunity to SARS-CoV-2, leading to protection and duration of protection, including the correlation between serological test results and risk of reinfection.

positive: Diagnostic performance of seven rapid IgG/IgM antibody tests and the Euroimmun IgA/IgG ELISA in COVID-19 patients OBJECTIVES: To evaluate the diagnostic performance of seven rapid IgG/IgM tests and the Euroimmun IgA/IgG ELISA for antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in COVID-19 patients. METHODS: Specificity was evaluated in 103 samples collected before January 2020. Sensitivity and time to seropositivity was evaluated in 167 samples from 94 patients with COVID-19 confirmed with RT-PCR on nasopharyngeal swab. RESULTS: Specificity (confidence interval) of lateral flow assays (LFAs) was ≥91.3% (84.0-95.5) for IgM, ≥90.3% (82.9-94.8) for IgG, and ≥85.4% (77.2-91.1) for the combination IgM OR IgG. Specificity of the ELISA was 96.1% (90.1-98.8) for IgG and only 73.8% (64.5-81.4) for IgA. Sensitivity 14-25 days after the onset of symptoms was between ≥92.1% (78.5-98.0) and 100% (95.7-100) for IgG LFA compared to 89.5% (75.3-96.4) for IgG ELISA. Positivity of IgM OR IgG for LFA resulted in a decrease in specificity compared to IgG alone without a gain in diagnostic performance, except for VivaDiag. The results for IgM varied significantly between the LFAs with an average overall agreement of only 70% compared to 89% for IgG. The average dynamic trend to seropositivity for IgM was not shorter than for IgG. At the time of hospital admission the sensitivity of LFA was <60%. CONCLUSIONS: Sensitivity for the detection of IgG antibodies 14-25 days after the onset of symptoms was ≥92.1% for all seven LFAs compared to 89.5% for the IgG ELISA. The results for IgM varied significantly, and including IgM antibodies in addition to IgG for the interpretation of LFAs did not improve the diagnostic performance.

positive: Development and application of a recombinant M protein-based indirect ELISA for the detection of porcine deltacoronavirus IgG antibodies Abstract Porcine deltacoronavirus (PDCoV) is a recently identified coronavirus in the genus Deltacoronavirus that can cause enteric disease including diarrhea, vomiting, dehydration and mortality in neonatal piglets. Serological assays to detect anti-PDCoV antibodies are presently limited to certain laboratories and geographic regions. In this study, a recombinant M protein-based indirect enzyme-linked immunosorbent assay (PDCoV-rM ELISA) was developed and utilized to determine the prevalence of anti-PDCoV IgG in Hebei province. The PDCoV-rM ELISA showed no cross-reaction with antisera against transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV), porcine rotavirus (PRV), porcine circovirus 2 (PCV2), classical swine fever virus (CSFV) or porcine reproductive and respiratory syndrome virus (PRRSV). The diagnostic sensitivity was 90.6% and the diagnostic specificity was 93.3%. A total of 871 serum samples collected in Hebei from January 2015 to October 2016 were checked for presence of antibodies against PDCoV using the novel PDCoV-rM ELISA. Anti-PDCoV IgG antibodies were detected in 11% (96/871) of the samples and in 25% (10/40) of the investigated farms. The data suggest that PDCoV has a low seroprevalence in pig population in Hebei province, China.

positive: Evaluation of antibody responses against SARS coronaviral nucleocapsid or spike proteins by immunoblotting or ELISA Severe acute respiratory syndrome (SARS)‐CoV is a newly emerging virus that causes SARS with high mortality rate in infected people. To study the humoral responses against SARS‐CoV, we evaluated nucleocapsid (N) and spike (S) proteins‐specific antibodies in patients' sera by Western blotting and enzyme‐linked immunosorbent assay (ELISA). Recombinant N and S proteins of SARS‐CoV were purified from transformed E. coli. Serum specimens from 40 SARS‐CoV‐infected patients in the convalescent phase were analyzed by Western blotting using the purified antigens. Serial serum specimens from 12 RT‐PCR‐confirmed SARS patients were assayed by ELISA using the recombinant N protein as coated antigen. By Western blotting, 97.5% of the SARS patients were positive for N protein‐specific antibodies whereas only 47.5% of the samples were positive for S protein‐specific antibodies. Using N protein‐based ELISA, 10 out of the 12 patients were positive for N protein‐specific antibodies and 6 of them showed seroconversion at mean of 16 days after onset of fever. Immunoblotting was useful for detecting the humoral immune response after SARS‐CoV infection. Antibodies against SARS‐CoV N protein appear at the early stage of infection, therefore, N protein‐based ELISA could serve as a simple, sensitive, and specific test for diagnosing SARS‐CoV infection. J. Med. Virol. 73:338–346, 2004. © 2004 Wiley‐Liss, Inc.

positive: Comparison of four new commercial serologic assays for determination of SARS-CoV-2 IgG Abstract Background Facing the ongoing pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there is an urgent need for serological assays identifying individuals with past coronavirus disease 2019 (COVID-19). Study Design Our study is the first to compare four new commercially available assays using 75 sera from patients tested positive or negative by SARS-CoV-2 PCR: the anti SARS-CoV-2 ELISA (IgG) (Euroimmun, Germany), the EDI New Coronavirus COVID-19 IgG ELISA, (Epitope diagnostics (EDI), USA), the recomWell SARS-CoV-2 IgG ELISA (Mikrogen, Germany), and the SARS-CoV-2 Virachip IgG (Viramed, Germany). Results We found a sensitivity of 86.4%, 100%, 86.4%, and 77.3% and a specificity of 96,2%, 88,7%, 100%, and 100% for the Euroimmun assay, the EDI assay, the Mikrogen assay, and the Viramed assay, respectively. Conclusions Commercially available SARS-CoV-2 IgG assays have a sufficient specificity and sensitivity for identifying individuals with past SARS-CoV-2 infection.

positive: Significance of serology testing to assist timely diagnosis of SARS-CoV-2 infections: implication from a family cluster Confirmative diagnosis of SARS-CoV-2 infections has been challenged due to unsatisfactory positive rate of molecular assays. Here we identified a family cluster of SARS-CoV-2 infections, with five of six family members were SARS-CoV-2-specific immunoglobin serology testing positive, while molecular assays only detected two of this five patients even repeated twice. We comprehensively analyzed this familial cluster of cases based on the clinical characteristics, chest CT images, SARS-CoV-2 molecular detection results, and serology testing results. At last, two patients were diagnosed with COVID-19, two were suspected of COVID-19, and two were considered close contacts. Our results emphasized the significance of serology testing to assist timely diagnosis of SARS-CoV-2 infections, especially for COVID-19 close contacts screening.

positive: Clinical performance of different SARS-CoV-2 IgG antibody tests Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological assays are urgently needed for rapid diagnosis, contact tracing, and for epidemiological studies. So far, there is limited data on how commercially available tests perform with real patient samples, and if positive tested samples show neutralizing abilities. Focusing on IgG antibodies, we demonstrate the performance of two enzyme-linked immunosorbent assay (ELISA) assays (Euroimmun SARS-CoV-2 IgG and Vircell COVID-19 ELISA IgG) in comparison to one lateral flow assay (FaStep COVID-19 IgG/IgM Rapid Test Device) and two in-house developed assays (immunofluorescence assay [IFA] and plaque reduction neutralization test [PRNT]). We tested follow up serum/plasma samples of individuals polymerase chain reaction-diagnosed with COVID-19. Most of the SARS-CoV-2 samples were from individuals with moderate to the severe clinical course, who required an in-patient hospital stay. For all examined assays, the sensitivity ranged from 58.8 to 76.5% for the early phase of infection (days 5-9) and from 93.8% to 100% for the later period (days 10-18).

positive: Enzyme immunoassay for SARS-CoV-2 antibodies in dried blood spot samples: A minimally-invasive approach to facilitate community- and population-based screening Background Serological testing for SARS-CoV-2 IgG antibodies is needed to document the community prevalence and distribution of the virus, particularly since many individuals have mild symptoms and cannot access molecular diagnostic testing of naso-pharyngeal swabs. However, the requirement for serum/plasma limits serological testing to clinical settings where it is feasible to collect and process venous blood. To address this problem we developed a serological test for SARS-CoV-2 IgG antibodies that requires only a single drop of capillary whole blood, collected from a simple finger prick and dried on filter paper (dried blood spot, DBS). Methods Enzyme linked immunosorbent assay (ELISA) was optimized to detect SARS-CoV-2 IgG antibodies against the receptor-binding domain (RBD) of the spike protein. DBS samples were eluted overnight and transferred to a 96-well plate coated with antigen, and anti-human IgG-HRP was used to generate signal in proportion to bound antibody. DBS samples spiked with anti-SARS IgG antibody, and samples from known positive and negative cases, were compared to evaluate assay performance. Results Analysis of samples with known concentrations of anti-SARS IgG produced the expected pattern of dose-response. Optical density (OD) values were significantly elevated for known positive cases in comparison with samples from unexposed individuals. Discussion DBS ELISA provides a minimally-invasive alternative to venous blood collection that combines the convenience of sample collection in the home or non-clinical setting with the accuracy of ELISA in the lab. Serological testing for SARS-CoV-2 IgG antibodies in DBS samples should facilitate research across a wide range of community- and population-based settings on seroprevalence, predictors and duration of antibody responses, as well as correlates of protection from reinfection, each of which is critically important for pandemic control.

positive: Development of an enzyme-linked immunosorbent assay-based test with a cocktail of nucleocapsid and spike proteins for detection of severe acute respiratory syndrome-associated coronavirus-specific antibody. A new enzyme-linked immunosorbent assay (ELISA)-based immunoglobulin G (IgG)-plus-IgM antibody detection test for severe acute respiratory syndrome (SARS) has been developed by using a cocktail of four recombinant polypeptides as the antigen. These recombinant fragments were designed as parts of two different structural proteins from SARS-associated coronavirus (SARS-CoV). One recombinant polypeptide, S251-683, was designed as part of the spike glycoprotein, and the other three polypeptides comprised almost the whole nucleocapsid protein, avoiding the last 25 C-terminal amino acids. Immunization with a cocktail of these four polypeptides yielded a specific polyclonal antibody that is able to recognize SARS-CoV-infected cells by an immunofluorescence assay. This polypeptide cocktail was also used to set up an ELISA-based IgG-plus-IgM antibody detection test, which showed 99% specificity and 90% sensitivity upon evaluation using sera from 100 healthy negative controls and 20 SARS patients. Separate immunoreactivity assays with each recombinant polypeptide demonstrated that a combination of N and S protein fragments was more suitable than the individual peptides for developing a serological assay for SARS-CoV.

positive: Global profiling of SARS-CoV-2 specific IgG/ IgM responses of convalescents using a proteome microarray COVID-19 is caused by SARS-CoV-2, and has become a global pandemic. There is no highly effective medicine or vaccine, most of the patients were recovered by their own immune response, especially the virus specific IgG and IgM responses. However, the IgG/ IgM responses is barely known. To enable the global understanding of SARS-CoV-2 specific IgG/ IgM responses, a SARS-CoV-2 proteome microarray with 18 out of the 28 predicted proteins was constructed. The microarray was applied to profile the IgG/ IgM responses with 29 convalescent sera. The results suggest that at the convalescent phase 100% of patients had IgG/ IgM responses to SARS-CoV-2, especially to protein N, S1 but not S2. S1 purified from mammalian cell demonstrated the highest performance to differentiate COVID-19 patients from controls. Besides protein N and S1, significant antibody responses to ORF9b and NSP5 were also identified. In-depth analysis showed that the level of S1 IgG positively correlate to age and the level of LDH (lactate dehydrogenase), especially for women, while the level of S1 IgG negatively correlate to Ly% (Lymphocyte percentage). This study presents the first whole picture of the SARS-CoV-2 specific IgG/ IgM responses, and provides insights to develop precise immuno-diagnostics, effective treatment and vaccine.

positive: Diagnostic accuracy of an automated chemiluminescent immunoassay for anti‐SARS‐CoV‐2 IgM and IgG antibodies: an Italian experience A pandemic of coronavirus disease 2019 (COVID‐19) caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has been spreading throughout the world. Though molecular diagnostic tests are the gold standard for COVID‐19, serological testing is emerging as a potential surveillance tool, in addition to its complementary role in COVID‐19 diagnostics. Indubitably quantitative serological testing provides greater advantages than qualitative tests but today there is still little known about serological diagnostics and what the most appropriate role quantitative tests might play. Sixty‐one COVID‐19 patients and 64 patients from a control group were tested by iFlash1800 CLIA analyzer for anti‐SARS CoV‐2 antibodies IgM and IgG. All COVID‐19 patients were hospitalized in San Giovanni di Dio Hospital (Florence, Italy) and had a positive oro/nasopharyngeal swab reverse‐transcription polymerase chain reaction result. The highest sensitivity with a very good specificity performance was reached at a cutoff value of 10.0 AU/mL for IgM and of 7.1 for IgG antibodies, hence near to the manufacturer's cutoff values of 10 AU/mL for both isotypes. The receiver operating characteristic curves showed area under the curve values of 0.918 and 0.980 for anti‐SARS CoV‐2 antibodies IgM and IgG, respectively. iFlash1800 CLIA analyzer has shown highly accurate results for the anti‐SARS‐CoV‐2 antibodies profile and can be considered an excellent tool for COVID‐19 diagnostics.

positive: Clinical significance of IgM and IgG test for diagnosis of highly suspected COVID-19 infection Quick, simple and accurate diagnosis of suspected COVID-19 is very important for the screening and therapy of patients. Although several methods were performed in clinical practice, however, the IgM and IgG diagnostic value evaluation was little performed. 57 suspected COVID-19 infection patients were enrolled in our study. 24 patients with positive and 33 patients with negative nucleic acid test. The positive rate of COVID-19 nucleic acid was 42.10%. The positive detection rate of combination of IgM and IgG for patients with COVID-19 negative and positive nucleic acid test was 72.73% and 87.50%. The results were significantly higher than the nucleic acid or IgM, IgG single detection. hsCRP in the COVID-19 nucleic acid negative group showed significantly higher than the positive groups (P=0.0298). AST in the COVID-19 IgM negative group showed significantly lower than the positive groups (P=0.0365). We suggest a quick, simple, accurate aided detection method for the suspected patients and on-site screening in close contact with the population.

positive: Meta-analysis of diagnostic performance of serological tests for SARS-CoV-2 antibodies up to 25 April 2020 and public health implications We reviewed the diagnostic accuracy of SARS-CoV-2 serological tests. Random-effects models yielded a summary sensitivity of 82% for IgM, and 85% for IgG and total antibodies. For specificity, the pooled estimate were 98% for IgM and 99% for IgG and total antibodies. In populations with ≤ 5% of seroconverted individuals, unless the assays have perfect (i.e. 100%) specificity, the positive predictive value would be ≤ 88%. Serological tests should be used for prevalence surveys only in hard-hit areas.

positive: Serological responses in patients with severe acute respiratory syndrome coronavirus infection and cross-reactivity with human coronaviruses 229E, OC43, and NL63. The serological response profile of severe acute respiratory syndrome (SARS) coronavirus (CoV) infection was defined by neutralization tests and subclass-specific immunofluorescent (IF) tests using serial sera from 20 patients. SARS CoV total immunoglobulin (Ig) (IgG, IgA, and IgM [IgGAM]) was the first antibody to be detectable. There was no difference in time to seroconversion between the patients who survived (n = 14) and those who died (n = 6). Although SARS CoV IgM was still detectable by IF tests with 8 of 11 patients at 7 months postinfection, the geometric mean titers dropped from 282 at 1 month postinfection to 19 at 7 months (P = 0.001). In contrast, neutralizing antibody and SARS CoV IgGAM and IgG antibody titers remained stable over this period. The SARS CoV antibody response was sometimes associated with an increase in preexisting IF IgG antibody titers for human coronaviruses OC43, 229E, and NL63. There was no change in IF IgG titer for virus capsid antigen from the herpesvirus that was used as an unrelated control, Epstein-Barr virus. In contrast, patients who had OC43 infections, and probably also 229E infections, without prior exposure to SARS CoV had increases of antibodies specific for the infecting virus but not for SARS CoV. There is a need for awareness of cross-reactive antibody responses between coronaviruses when interpreting IF serology.

positive: A preliminary study on serological assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 238 admitted hospital patients Background The outbreak of the recently emerged novel corona virus disease 2019 (COVID-19) poses a challenge for public health laboratories. We aimed to evaluate the diagnostic value of serological assay for SARS-CoV-2. Methods A newly-developed ELISA assay for IgM and IgG antibodies against N protein of SARS-CoV-2 were used to screen the serums of 238 admitted hospital patients with confirmed or suspected SARS-CoV-2 infection from February 6 to February 14, 2020. SARS-CoV-2 RNA was detected by real time RT-PCR on pharyngeal swab specimens. Findings Of the 238 patients, 194 (81.5%) were detected to be antibody (IgM and/or IgG) positive, which was significantly higher than the positive rate of viral RNA (64.3%). There was no difference in the positive rate of antibody between the confirmed patients (83.0%, 127/153) and the suspected patients (78.8%, 67/85) whose nucleic acid tests were negative. After the patients were defined to the different stages of disease based on the day when the test samples were collected, the analysis results showed that the antibody positive rates were very low in the first five days after initial onset of symptoms, and then rapidly increased as the disease progressed. After 10 days, the antibody positive rates jumped to above 80% from less than 50%. On the contrary, the positive rates of viral RNA kept above 60% in the first 11 days after initial onset of symptoms, and then rapidly decreased. In addition, half of the suspected patients with symptoms for 6-10 days were detected to be antibody positive. Interpretation The suspected patients were most likely infected by SARS-CoV-2. Before the 11th day after initial onset of symptoms, nucleic acid test is important for confirmation of viral infection. The combination of serological assay can greatly improve the diagnostic efficacy. After that, the diagnosis for viral infection should be majorly dependent on serological assay. Keywords. SARS-CoV-2; diagnosis; serological assay; nucleic acid test

positive: Antibody tests suggest that coronavirus infections vastly exceed official counts.

positive: COVID-19 serology at population scale: SARS-CoV-2-specific antibody responses in saliva Non-invasive SARS-CoV-2 antibody testing is urgently needed to estimate the incidence and prevalence of SARS-CoV-2 infection at the general population level. Precise knowledge of population immunity could allow government bodies to make informed decisions about how and when to relax stay-at-home directives and to reopen the economy. We hypothesized that salivary antibodies to SARS-CoV-2 could serve as a non-invasive alternative to serological testing for widespread monitoring of SARS-CoV-2 infection throughout the population. We developed a multiplex SARS-CoV-2 antibody immunoassay based on Luminex technology and tested 167 saliva and 324 serum samples, including 134 and 118 negative saliva and serum samples, respectively, collected before the COVID-19 pandemic, and 33 saliva and 206 serum samples from participants with RT-PCR-confirmed SARS-CoV-2 infection. We evaluated the correlation of results obtained in saliva vs. serum and determined the sensitivity and specificity for each diagnostic media, stratified by antibody isotype, for detection of SARS-CoV-2 infection based on COVID-19 case designation for all specimens. Matched serum and saliva SARS-CoV-2 antigen-specific IgG responses were significantly correlated. Within the 10-plex SARS-CoV-2 panel, the salivary anti-nucleocapsid (N) protein IgG response resulted in the highest sensitivity for detecting prior SARS-CoV-2 infection (100% sensitivity at ≥10 days post-SARS-CoV-2 symptom onset). The salivary anti-receptor binding domain (RBD) IgG response resulted in 100% specificity. Among individuals with SARS-CoV-2 infection confirmed with RT-PCR, the temporal kinetics of IgG, IgA, and IgM in saliva were consistent with those observed in serum. SARS-CoV-2 appears to trigger a humoral immune response resulting in the almost simultaneous rise of IgG, IgM and IgA levels both in serum and in saliva, mirroring responses consistent with the stimulation of existing, cross-reactive B cells. SARS-CoV-2 antibody testing in saliva can play a critically important role in large-scale “sero”-surveillance to address key public health priorities and guide policy and decision-making for COVID-19.

positive: SARS-CoV-2 assays to detect functional antibody responses that block ACE2 recognition in vaccinated animals and infected patients SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) has caused a global pandemic of COVID-19 resulting in cases of mild to severe respiratory distress and significant mortality. The global outbreak of this novel coronavirus has now infected >8 million people worldwide with >2 million cases in the US (June 17th, 2020). There is an urgent need for vaccines and therapeutics to combat the spread of this coronavirus. Similarly, the development of diagnostic and research tools to determine infection and vaccine efficacy are critically needed. Molecular assays have been developed to determine viral genetic material present in patients. Serological assays have been developed to determine humoral responses to the spike protein or receptor binding domain (RBD). Detection of functional antibodies can be accomplished through neutralization of live SARS-CoV2 virus, but requires significant expertise, an infectible stable cell line, a specialized BioSafety Level 3 (BSL-3) facility. As large numbers of people return from quarantine, it is critical to have rapid diagnostics that can be widely adopted and employed to assess functional antibody levels in the returning workforce. This type of surrogate neutralization diagnostic can also be used to assess humoral immune responses induced in patients from the large number of vaccine and immunotherapy trials currently on-going. Here we describe a rapid serological diagnostic assay for determining antibody receptor blocking and demonstrate the broad utility of the assay by measuring the antibody functionality of sera from small animals and non-human primates immunized with an experimental SARS-CoV-2 vaccine and using sera from infected patients.

positive: SARS-CoV-2: diagnostic and design conundrums, and the male factor infertility The question on whether SARS-CoV-2 (Severe acute respiratory syndrome-related coronavirus (SARS-CoV or SARS-CoV-2, Covid-19) can be harboured in testes and/or the semen is currently unanswered. It is essential to understand the limitations of both antibody and real time polymerase chain reaction (RT-PCR) tests in interpreting SARS-CoV-2 data in relation to semen and testicular tissues analyses without appropriate controls. Here we critically analyse the evidence so far and the possible implications. The diagnostic test limitations posed in both sampling and testing methodologies, their validation, and relevancy in interpreting data are also highlighted.

positive: In vitro diagnostics of coronavirus disease 2019: Technologies and application Laboratory-based diagnostic measures including virological and serological tests are essential for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Real-time reverse transcription-polymerase chain reactions (rRT-PCR) can detect SARS-COV-2 by targeting open reading frame-1 antibodies (ORF1ab), envelope protein, nucleocapsid protein, RNA-dependent RNA polymerase genes, and the N1, N2, and N3 (3N) target genes. Therefore, rRT-PCR remains the primary method of diagnosing SARS-CoV-2 despite being limited by false-negative results, long turnaround, complex protocols, and a need for skilled personnel. Serological diagnosis of coronavirus disease 2019 (COVID-19) is simple and does not require complex techniques and equipment, rendering it suitable for rapid detection and massive screening. However, serological tests cannot confirm SARS-CoV-2, and results will be false-negative when antibody concentrations fall below detection limits. Balancing the increased use of laboratory tests, risk of testing errors, need for tests, burden on healthcare systems, benefits of early diagnosis, and risk of unnecessary exposure is a significant and persistent challenge in diagnosing COVID-19.

positive: Current laboratory diagnostics of coronavirus disease 2019 (COVID-19). Laboratory medicine provides an almost irreplaceable contribution to the diagnostic reasoning and managed care of most human pathologies. The novel coronavirus disease 2019 (COVID-19) is not an exception to this paradigm. Although the relatively recent emergence does not allow to draw definitive conclusions on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostics, some standpoints can be conveyed. First and foremost, it seems now clear that we will be living together with this virus for quite a long time, so that our vigilance and responsiveness against the emergence of new local outbreaks shall be maintained at the highest possible levels. The etiological diagnosis of COVID-19 is, and will remain for the foreseeable future, deeply based on direct identification of viral RNA by means of molecular biology techniques in biological materials, especially upper and lower respiratory tract specimens. Whether other materials, such as blood, urine, stools, saliva and throat washing, will become valid alternatives has not been unequivocally defined so far. As concerns serological testing, promising information can be garnered from preliminary investigations, showing that the vast majority of COVID-19 patients seem to develop a sustained immune response against the virus, characterized especially by emergence of anti-SARS-CoV-2 IgG and IgA, 1 to 2 weeks after the onset of fever and/or respiratory symptoms. Whether these antibodies will have persistent neutralizing activity against the virus is still to be elucidated on individual and general basis. The availability of rapid tests for detecting either viral antigens or anti-SARS-CoV-2 antibodies are a potentially viable opportunity for purposes of epidemiologic surveillance, though more information is needed on accuracy and reliability of these portable immunoassays.

positive: Brief clinical evaluation of six high-throughput SARS-CoV-2 IgG antibody assays Serological SARS-CoV-2 assays are urgently needed for diagnosis, contact tracing and for epidemiological studies. So far, there is limited data on how recently commercially available, high-throughput immunoassays, using different recombinant SARS-CoV-2 antigens, perform with clinical samples. Focusing on IgG and total antibodies, we demonstrate the performance of four automated immunoassays (Abbott Architect™ i2000 (N protein-based)), Roche cobas™ e 411 analyzer (N protein-based, not differentiating between IgA, IgM or IgG antibodies), LIAISON®XL platform (S1 and S2 protein-based), VIRCLIA® automation system (S1 and N protein-based) in comparison two ELISA assays (Euroimmun SARS-CoV-2 IgG (S1 protein-based) and Virotech SARS-CoV-2 IgG ELISA (N protein-based)) and an in-house developed plaque reduction neutralization test (PRNT). We tested follow up serum/plasma samples of individuals PCR-diagnosed with COVID-19. When calculating the overall sensitivity, in a time frame of 49 days after first PCR-positivity, the PRNT as gold standard, showed the highest sensitivity with 93.3% followed by the dual-target assay for the VIRCLIA® automation system with 89%. The overall sensitivity in the group of N protein-based assays ranged from 66.7 to 77.8% and in the S protein-based-assays from 71.1 to 75.6%. Five follow-up samples of three individuals were only detected in either an S and/or N protein-based assay, indicating an individual different immune response to SARS-CoV-2 and the influence of the used assay in the detection of IgG antibodies. This should be further analysed. The specificity of the examined assays was ≥ 97%. However, because of the low or unknown prevalence of SARS-CoV-2, the examined assays in this study are currently primarily eligible for epidemiological investigations, as they have limited information in individual testing.

positive: Testing For SARS-CoV-2: The Day the World Turned its Attention to the Clinical Laboratory In the last few months, an unprecedented number of laboratory tests for coronavirus disease 2019 (COVID-19) have been developed at a remarkable speed. With the rapid adoption of these tests into clinical practice, combined with the widespread publicity they received, questions arose related to the different types of tests, their utility, performance, and regulatory approval status. The aim of this publication is to provide a general landscape of laboratory testing for COVID-19 and offer a historical and regulatory perspective associated with them. Specifically, we aim to elaborate on the regulatory complexities of diagnostic testing in the United States and its implications to the present outbreak, as well as provide a synopsis of laboratory tests that have been developed for COVID-19. We will first address the detection of severe acute respiratory syndrome-coronavirus 2 directly by either nucleic acid amplification tests or by the detection of the viral protein for active infections. Subsequently, we will provide an overview of serological tests that can aid not only in diagnosis but additionally help to identify prior infections and potential immunity.

positive: [Analysis of false-positive associated with antibody tests for SARS-CoV in SLE patients]. To discuss the false-positive of serological diagnostic testing for coronavirus antibody in patients with systemic lupus erythematosus(SLE), 66 normal individual and 31 SLE with non-SARS patients were detected for SARS-associated coronavirus (SARS-CoV) antibody and RNA by enzymelinked immunosorbent assays(ELISA) and reverse transcriptase-polymerase chain reaction(RT-PCR). The result showed 2/66 cases(3.0%) were positive of SARS-CoV-IgG antibody and 66 cases were negative of SARS-CoV-IgM antibody in the 66 cases healthy controls; in 31 cases with SLE, positive rates of SARS-CoV-IgG and IgM antibody were 58.1% (18/31) and 29% (9/31), respectively, in which 7 cases(22.6%) were positive of both SARS-CoV-IgG and IgM antibody. All samples of positive SARS-CoV-IgG and IgM antibody were negative by RT-PCR. The ELISA kit coated by non-purification antigen may induce the false-positive of SARS-CoV antibody in patients with SLE. This result suggested that the specificity of ELISA tests for SARS was excellent and has low false-positive rates when using SARS-CoV-IgG and IgM antibody tests. A possible cause of false-positive of SARS-CoV-IgG and IgM antibody in SLE patients is coated antigens with SARS-CoV and Vero-E6 cells in ELISA methods.

positive: Kinetics of the humoral immune response to SARS-CoV-2: comparative analytical performance of seven commercial serology tests Background SARS-CoV-2 serology tests are clinically useful to document a prior SARS-CoV-2 infection in patients with no or inconclusive PCR results and suspected COVID-19 disease or sequelae. Data are urgently needed to select the assays with optimal sensitivity at acceptable specificity. Methods A comparative analysis of analytical sensitivity was performed of seven commercial SARS-CoV-2 serology assays on 171 sera from 135 subjects with PCR-confirmed SARS-CoV-2 infection, composed of 71 patients hospitalized for COVID-19 pneumonia and 64 healthcare workers with paucisymptomatic infections. The kinetics of IgA/IgM/IgG seroconversion to viral N- and S-protein epitopes were studied from 0 to 54 days after symptom onset. Specificity was verified on 57 pre-pandemic samples. Results Wantai SARS-COV-2 Ab ELISA and Orient Gene COVID-19 IgG/IgM Rapid Test achieved a superior overall sensitivity. Elecsys Anti-SARS-CoV-2 assay, EUROIMMUN Anti-SARS-CoV-2 combined IgG/IgA and EUROIMMUN Anti-SARS-CoV-2-NCP(IgG) also showed acceptable sensitivity (>95%) versus the consensus result of all assays from 10 days post symptom onset. Optimal specificity (>98%) was achieved only by Wantai SARS-COV-2 Ab ELISA, Elecsys Anti-SARS-CoV-2 assay and Innovita 2019-nCoV Ab rapid test. LIAISON SARS-CoV-2 S1/S2 IgG showed a significantly lower sensitivity as compared to all other assays. Lack of seroconversion by any test was seen in 1.4% of hospitalized and 4.7% of paucisymptomatic infections. Within 10 days from symptom onset, only the Wantai SARS-COV-2 Ab ELISA has acceptable sensitivity. Conclusions Wantai SARS-COV-2 Ab ELISA and Elecsys Anti-SARS-CoV-2 assays are suitable for sensitive and specific screening of a SARS-CoV-2 infection from 10 days after symptom onset.

positive: Evaluation of Enzyme-Linked Immunoassay and Colloidal Gold- Immunochromatographic Assay Kit for Detection of Novel Coronavirus (SARS-Cov-2) Causing an Outbreak of Pneumonia (COVID-19) Abstract BACKGROUND: In December 2019, a novel coronavirus (SARS-CoV-2) infected pneumonia (COVID-19) occurred in Wuhan, China. Travel-associated cases have also been reported in other countries. The number of cases has increased rapidly but laboratory diagnosis is limited. METHODS: We collect two groups of cases diagnosed with COVID-19 for experiments. One group collected 63 samples for Enzyme-linked immunosorbent assay (ELISA) IgG and IgM antibodies. The other group collected 91 plasma samples for colloidal gold-immunochromatographic assay (GICA). RESULTS: The sensitivity of the combined ELISA IgM and ELISA IgG detection was 55/63 ( 87.3%), The sensitivity of the combined GICA IgM and GICA IgG detection was 75/91 ( 82.4%), Both methods are negative for healthy controls, specificity of 100% .There is no significant difference between the sensitivity of between ELISA and GICA (IgM+ IgG). CONCLUSIONS: ELISA and GICA for specific IgM and IgG antibodies are conventional serological assays, they are simple, fast, and safe, the results can be used for clinical reference, and the huge clinical diagnosis and treatment pressure can be greatly relieved.

positive: Seroepidemiologic Study Designs for Determining SARS-COV-2 Transmission and Immunity Serologic studies are crucial for clarifying dynamics of the coronavirus disease pandemic. Past work on serologic studies (e.g., during influenza pandemics) has made relevant contributions, but specific conditions of the current situation require adaptation. Although detection of antibodies to measure exposure, immunity, or both seems straightforward conceptually, numerous challenges exist in terms of sample collection, what the presence of antibodies actually means, and appropriate analysis and interpretation to account for test accuracy and sampling biases. Successful deployment of serologic studies depends on type and performance of serologic tests, population studied, use of adequate study designs, and appropriate analysis and interpretation of data. We highlight key questions that serologic studies can help answer at different times, review strengths and limitations of different assay types and study designs, and discuss methods for rapid sharing and analysis of serologic data to determine global transmission of severe acute respiratory syndrome coronavirus 2.

positive: SARS-CoV-2 antibody characterization in emergency department, hospitalized and convalescent patients by two semi-quantitative immunoassays BACKGROUND: In the ongoing COVID-19 pandemic, there is an urgent need for comprehensive performance evaluation and clinical utility assessment of serological assays to understand the immune response to SARS-CoV-2. METHODS: IgM/IgG and total antibodies against SARS-CoV-2 were measured by a cyclic enhanced fluorescence assay (CEFA) and a microsphere immunoassay (MIA), respectively. Independent performance evaluation included imprecision, reproducibility, specificity and cross-reactivity (CEFA n = 320, MIA n = 364). Clinical utility was evaluated by both methods in 87 patients at initial emergency department visit, 28 during subsequent hospitalizations (106 serial samples), and 145 convalescent patients. Totally 916 patients and 994 samples were evaluated. RESULTS: Agreement of CEFA and MIA was 90.4%-94.5% (Kappa: 0.81-0.89) in 302 samples. CEFA and MIA detected SARS-CoV-2 antibodies in 26.2% and 26.3%, respectively, of ED patients. Detection rates increased over time reaching 100% after 21 days post-symptom onset. Longitudinal antibody kinetic changes by CEFA and MIA measurements correlated well and exhibited three types of seroconversion. Convalescent sera showed a wide range of antibody levels. CONCLUSION: Rigorously validated CEFA and MIA assays are reliable for detecting antibodies to SARS-CoV-2 and show promising clinical utility when evaluating immune response in hospitalized and convalescent patients, but are not useful for early screening at patient's initial ED visit.

positive: Estimating seroprevalence with imperfect serological tests: exploiting cutoff-free approaches Large-scale serological testing in the population is essential to determine the true extent of the current Coronavirus pandemic. Serological tests measure antibody responses against pathogens and define cutoff levels that dichotomize the quantitative test measures into sero-positives and negatives. With the imperfect tests that are currently available to test for past SARS-CoV-2 infection, the fraction of seropositive individuals in serosurveys is a biased estimator of seroprevalence and is usually corrected post-hoc to account for the sensitivity and specificity. Here we use a likelihood-based inference method — previously called mixture models — for the estimation of the seroprevalence that does not require to define cutoffs by integrating the quantitative test measures directly into the statistical inference procedure. We confirm that this likelihood-based method outperforms the methods based on cutoffs and post-hoc corrections leading to less variation in point-estimates of the seroprevalence and its temporal trend. We illustrate how the likelihood-based method can be used to optimize the design of serosurveys with imperfect serological tests. We also provide guidance on the number of control and case sera that are required to quantify the test’s ambiguity sufficiently to enable the reliable estimation of the seroprevalence. Lastly, we show how this approach can be used to identify classes of case sera with an unknown distribution of quantitative test measures that have not been used for test validation. An R-package with the likelihood and power analysis functions is provided. Our study advocates to using serological tests without cutoffs, especially if they are used to determine parameters characterizing populations rather than individuals. This approach circumvents some of the shortcomings of cutoff-based methods with post-hoc correction at exactly the low seroprevalence levels and test accuracies that we are currently facing in COVID-19 serosurveys. Author Summary As other pathogens, SARS-CoV-2 elicits antibody responses in infected people that can be detected in their blood serum as early as a week after the infection until long after recovery. The presence of SARS-CoV-2 specific antibodies can therefore be used as a marker of past infection, and the prevalence of seropositive people, i.e. people with specific antibodies, is a key measure to determine the extent of the Coronavirus pandemic. The serological tests, however, are usually not perfect, yielding false positive and negative results. Here we exploit an approach that refrains from classifying people as seropositive or negative, but rather compares the antibody level to that of confirmed cases and controls. This approach leads to more reliable seroprevalence estimates, especially for the low prevalence and low test accuracies that we face during the current Coronavirus pandemic. We also show how this approach can be extended to infer the presence of cases that have not been used for validating the test, such as people that underwent a mild or even asymptomatic infection.

positive: Serologiska test bör relateras till både syfte och population./ [Serological tests should be related to the aim of the testing, as well as the population] Expectations are high on serological tests for SARS-CoV-2. Further knowledge of the immunity is needed, but also evaluation of the reliability of the tests. Important for the latter is for which purpose the test is conducted and how common the outcome to be identified is (antibodies). For the determination of immunity at the individual level, the specificity of the test must be very high, preferably 100%. Even tests where the specificity is perceived as high, e.g. 95% or 99%, can lead to a large proportion of false positives, if the proportion of the population actually infected is small.

positive: Molecular, serological, and biochemical diagnosis and monitoring of COVID-19: IFCC taskforce evaluation of the latest evidence The global coronavirus disease 2019 (COVID-19) has presented major challenges for clinical laboratories, from initial diagnosis to patient monitoring and treatment. Initial response to this pandemic involved the development, production, and distribution of diagnostic molecular assays at an unprecedented rate, leading to minimal validation requirements and concerns regarding their diagnostic accuracy in clinical settings. In addition to molecular testing, serological assays to detect antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are now becoming available from numerous diagnostic manufacturers. In both cases, the lack of peer-reviewed data and regulatory oversight, combined with general misconceptions regarding their appropriate use, have highlighted the importance of laboratory professionals in robustly validating and evaluating these assays for appropriate clinical use. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Task Force on COVID-19 has been established to synthesize up-to-date information on the epidemiology, pathogenesis, and laboratory diagnosis and monitoring of COVID-19, as well as to develop practical recommendations on the use of molecular, serological, and biochemical tests in disease diagnosis and management. This review summarizes the latest evidence and status of molecular, serological, and biochemical testing in COVID-19 and highlights some key considerations for clinical laboratories operating to support the global fight against this ongoing pandemic. Confidently this consolidated information provides a useful resource to laboratories and a reminder of the laboratory's critical role as the world battles this unprecedented crisis.

positive: Protective immunity after COVID-19 has been questioned: what can we do without SARS-CoV-2-IgG detection? Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces a severe acute respiratory syndrome that is called COVID-19. Clinical manifestations of COVID-19 include diarrhea, pneumonia, lymphopenia, exhausted lymphocytes, and pro-inflammatory cytokine production. Immunology is part of the process of clinical evolution, but there are some questions around immunity-based protection: (1) why some infected people have only mild symptoms of the disease or are asymptomatic; (2) why delayed and weak antibody responses are associated with severe outcomes; and (3) why positivity in molecular tests does not represent protective antibody IgG. Perhaps T cell responses may be the key to solving those questions. SARS-CoV-2-specific memory T cells persist in peripheral blood and may be capable of providing effective information about protective immunity. The T cells studies can be helpful in elucidating the pathways for development of vaccines, therapies, and diagnostics for COVID-19 and for filling these immunology knowledge gaps.

positive: Clinical testing for COVID-19 As the novel coronavirus severe acute respiratory syndrome coronavirus 2 caused coronavirus disease 2019 cases in the United States, the initial test was developed and performed at the Centers for Disease Control and Prevention. As the number of cases increased, the demand for tests multiplied, leading the Centers for Disease Control and Prevention to use the Emergency Utilization Authorization to allow clinical and commercial laboratories to develop tests to detect the presence of the virus. Many nucleic acid tests based on RT-PCR were developed, each with different techniques, specifications, and turnaround time. As the illnesses turned into a pandemic, testing became more crucial. The test supply became inadequate to meet the need and so it had to be prioritized according to guidance. For surveillance, the need for serologic tests emerged. Here, we review the timeline of test development, the turnaround times, and the various approved tests, and compare them as regards the genes they detect. We concentrate on the point-of-care tests and discuss the basis for new serologic tests. We discuss the testing guidance for prioritization and their application in a hospital setting.

positive: Performance Characteristics of Four High-Throughput Immunoassays for Detection of IgG Antibodies against SARS-CoV-2 The role of serologic testing for SARS-CoV-2, both in the clinical and public health settings, will continue to evolve as we gain increasing insight into our immune response to the virus. Here, we evaluated four high throughput serologic tests for detection of anti-SARS-CoV-2 IgG antibodies, including assays from Abbott Laboratories (Abbott Park, IL), Epitope Diagnostics Inc. (San Diego, CA), Euroimmun (Lubeck, Germany), and Ortho-Clinical Diagnostics (Rochester, NY), using a panel of serially collected serum samples (N=224) from 56 patients with confirmed COVID-19, healthy donor sera from 2018 and a cross-reactivity serum panel collected in early 2020. Sensitivity of the Abbott, Epitope, Euroimmun and Ortho-Clinical IgG assays in convalescent serum samples collected more than 14 days post symptom onset or initial positive RT-PCR result was 92.9% (78/84), 88.1% (74/84), 97.6% (82/84) and 98.8% (83/84), respectively. Among unique convalescent patients, sensitivity of the Abbott, Epitope, Euroimmun and Ortho-Clinical anti-SARS-CoV-2 IgG assays was 97.3% (36/37), 73% (27/37), 94.6% (35/37) and 97.3% (36/37), respectively. Overall assay specificity and positive predictive values based on a 5% prevalence rate are 99.6%/92.8%, 99.6%/90.6%, 98.0%/71.2% and 99.6%/92.5%, respectively, for the Abbott, Epitope, Euroimmun and Ortho-Clinical IgG assays. In conclusion, we show high sensitivity in convalescent sera and high specificity for the Abbott, Euroimmun and Ortho-Clinical anti-SARS-CoV-2 IgG assays. With the unprecedented influx of commercially available serologic tests for detection of antibodies against SARS-CoV-2, it remains imperative that laboratories thoroughly evaluate such assays for accuracy prior to implementation.

positive: Using Serology with Models to clarify the trajectory of the SARS-CoV-2 emerging outbreak

positive: Detection of IgM and IgG antibodies in patients with coronavirus disease 2019 OBJECTIVES: This study aimed to determine the IgM and IgG responses against severe acute respiratory syndrome coronavirus (SARS‐CoV)‐2 in coronavirus disease 2019 (COVID‐19) patients with varying illness severities. METHODS: IgM and IgG antibody levels were assessed via chemiluminescence immunoassay in 338 COVID‐19 patients. RESULTS: IgM levels increased during the first week after SARS‐CoV‐2 infection, peaked 2 weeks and then reduced to near‐background levels in most patients. IgG was detectable after 1 week and was maintained at a high level for a long period. The positive rates of IgM and/or IgG antibody detections were not significantly different among the mild, severe and critical disease groups. Severe and critical cases had higher IgM levels than mild cases, whereas the IgG level in critical cases was lower than those in both mild and severe cases. This might be because of the high disease activity and/or a compromised immune response in critical cases. The IgM antibody levels were slightly higher in deceased patients than recovered patients, but IgG levels in these groups did not significantly differ. A longitudinal detection of antibodies revealed that IgM levels decreased rapidly in recovered patients, whereas in deceased cases, either IgM levels remained high or both IgM and IgG were undetectable during the disease course. CONCLUSION: Quantitative detection of IgM and IgG antibodies against SARS‐CoV‐2 quantitatively has potential significance for evaluating the severity and prognosis of COVID‐19.

positive: Clinical And Analytical Performance Of An Automated Serological Test That Identifies S1/S2 Neutralizing IgG In COVID-19 Patients Semiquantitatively BACKGROUND: In the COVID-19 pandemic, highly selective serological testing is essential to define exposure to SARS-CoV-2 virus. Many tests have been developed, yet with variable speed to first result, and of unknown quality, particularly when considering the prediction of neutralizing capacity. OBJECTIVES/METHODS: The LIAISON® SARS-CoV-2 S1/S2 IgG assay was designed to measure antibodies against the SARS-CoV-2 native S1/S2 proteins in a standardized automated chemiluminescent assay. Clinical and analytical performance of the test were validated in an observational study using residual samples (>1500) with positive or negative COVID-19 diagnosis. RESULTS: The LIAISON® SARS-CoV-2 S1/S2 IgG assay proved to be highly selective and specific, and offers semiquantitative measures of serum or plasma levels of anti-S1/S2 IgG with neutralizing activity. The assay's diagnostic sensitivity was 91.3% and 95.7% at >5 or ≥15 days from diagnosis, respectively, and 100% when assessed against a neutralizing assay. The assay's specificity ranged between 97% and 98.5%. The average imprecision of the assay was <5 % coefficient of variation. Assay performance at 2 different cut-offs was evaluated to optimize predictive values. CONCLUSIONS: The automated LIAISON® SARS-CoV-2 S1/S2 IgG assay brings efficient, sensitive, specific, and precise serological testing to the laboratory, with the capacity to test large amounts of samples per day: first results are available within 35 minutes with a throughput of 170 tests/hour. The semiquantitative results provided by the test also associate with the presence of neutralizing antibodies, and may provide a useful tool for the large scale screening of convalescent plasma for safe therapeutic use.

positive: Microscopy-based assay for semi-quantitative detection of SARS-CoV-2 specific antibodies in human sera Emergence of the novel pathogenic coronavirus Sars-CoV-2 and its rapid pandemic spread presents numerous questions and challenges that demand immediate attention. Among these is the urgent need for a better understanding of humoral immune response against the virus and assessment of seroprevalence levels in the population, both of which form the basis for developing public health strategies to control viral spread. For this, sensitive, specific and quantitative serological assays are required. Here we describe the development of a semi-quantitative high-content microscopy-based assay for detection of three major classes (IgG, IgA and IgM) of SARS-CoV-2 specific antibodies in human samples. The possibility to detect antibodies against the entire viral proteome together with a robust semi-automated image analysis workflow resulted in improvement of sensitivity and specificity compared to an approved ELISA-based diagnostic test. Combining both methods resulted in maximum specificity in a negative control cohort, while maintaining high sensitivity. The procedure described here is compatible with high-throughput microscopy approaches and may be applied for serological analysis of other virus infections.

positive: Virological and serological studies of porcine respiratory coronavirus infection on a Japanese farm. We detected transmissible gastroenteritis virus (TGEV) antibodies in pig farms in Tochigi prefecture, although the farms had no past record of TGEV vaccination or TGE. Among the farms, Farm A showed a high antibody incidence. We could not confirm if either TGEV or porcine respiratory coronavirus (PRCV) induced the antibodies, since conventional tests failed to discriminate PRCV from TGEV. Therefore, we conducted virological and serological examinations of this farm for 4 years to establish the etiology - TGEV or PRCV. Although no TGEV was detected, PRCVs were isolated from the nasal samples of pigs. Using a commercial ELISA kit, it was found that the antibodies detected in pigs of all the raising stages and sows were raised against PRCV but not TGEV. The phylogenetic analysis of the nucleotide sequences of the isolates showed that they were closely related to each other, and formed a separate cluster apart from the U.S.A. and European strains. In Cesarean-derived, colostrums-deprived piglets inoculated with a PRCV isolate, no clinical signs were seen, and the viruses were mainly isolated from the nasal samples. Moreover, viral genes were detected from the nasal sample of the contact pig. The result suggested that PRCV infection was located in the nasal cavity of pigs, and horizontal transmission easily occurs. From these results, PRCVs with different origins from the exotic PRCVs might be prevalent in pig farms in Japan.

positive: Comparison of diagnostic accuracies of rapid serological tests and ELISA to molecular diagnostics in patients with suspected coronavirus disease 2019 presenting to the hospital OBJECTIVES: To assess the diagnostic performance of rapid lateral flow immunochromatographic assays (LFAs) compared with an ELISA and nucleic acid amplification tests (NATs) in individuals with suspected coronavirus disease 2019 (COVID-19). METHODS: Patients presenting to a Dutch teaching hospital were eligible between 17 March and 10 April 2020, when they had respiratory symptoms that were suspected for COVID-19. The performances of six different LFAs were evaluated in plasma samples obtained on corresponding respiratory sample dates of NATs testing. Subsequently, the best performing LFA was evaluated in 228 patients and in 50 sera of a historical patient control group. RESULTS: In the pilot analysis, sensitivity characteristics of LFA were heterogeneous, ranging from 2/20 (10%; 95% CI 0%-23%) to 11/20 (55%; 95% CI 33%-77%). In the total cohort, Orient Gene Biotech COVID-19 IgG/IgM Rapid Test LFA had a sensitivity of 43/99 (43%; 95% CI 34%-53%) and specificity of 126/129 (98%; 95% CI 95%-100%). Sensitivity increased to 31/52 (60%; 95% CI 46%-73%) in patients with at least 7 days of symptoms, and to 21/33 (64%; 95% CI 47%-80%) in patients with C-reactive protein (CRP) ≥100 mg/L. Sensitivity and specificity of Wantai SARS-CoV-2 Ab ELISA was 59/95 (62%; 95% CI 52%-72%) and 125/128 (98%; 95% CI 95%-100%) in all patients, respectively, but sensitivity increased to 38/48 (79%; 95% CI 68%-91%) in patients with at least 7 days of symptoms. CONCLUSIONS: There is large variability in diagnostic test performance between rapid LFAs, but overall limited sensitivity and high specificity in acutely admitted patients. Sensitivity improved in patients with longer existing symptoms or high CRP. LFAs should only be considered as additional triage tools when these may lead to the improvement of hospital logistics.

positive: Characterization of monoclonal antibody against SARS coronavirus nucleocapsid antigen and development of an antigen capture ELISA Abstract This report describes the production of several MAbs against N195 protein, a major immunodomain of SARS CoV nucleocapsid protein [He, Q., Chong, K.H., Chang, H.H., Leung, B., Ling, A.E., Wei, T., Chan, S.W., Ooi, E.E., Kwang, J., 2004. Development of a Western blot assay for detection of antibodies against coronavirus causing severe acute respiratory syndrome. Clin. Diagn. Lab. Immunol. 11 (2) 417–422.]. One representative IgG1 monoclonal antibody (MAb), S-A5D5, was selected and characterized. S-A5D5 reacted specifically react with both recombinant and native nucleocapsid protein of SARS CoV. The reactivity of S-A5D5 with purified N195 protein and utilization of the MAb as a detector antibody to develop an antigen capture ELISA was assessed. As little as 37.5pg of purified N protein and 50 TCID50 of SARS CoV could be detected by the antigen capture ELISA. Specific binding of the MAb S-A5D5 to both purified N195 and SARS CoV nucleocapsid antigen was effectively inhibited by human SARS positive serum and guinea pig anti-N195 serum. The N protein in N195-spike recombinant baculovirus-infected Sf-9 cells could also be identified. N protein was detected in 18 IFA IgM-positive serum samples collected from SARS confirmed patients, but not in nine samples collected from SARS recovery patient. No false positive results were given when 60 samples from healthy individuals were tested, and no cross-reaction occurred when infectious bronchitis virus (IBV), chicken coronavirus, was tested. This monoclonal antibody-based antigen capture ELISA is thus a powerful tool for early diagnosis of SARS CoV infection.

positive: Clinical evaluation of serological IgG antibody response on the Abbott Architect for established SARS-CoV-2 infection OBJECTIVE: This study aimed to evaluate the diagnostic performance of the Abbott Architect SARS-CoV-2 IgG assay in COVID-19 patients. METHODS: Residual sera from 177 symptomatic SARS-CoV-2-positive patients and 163 non-COVID-19 patients were tested for antibody with the Abbott SARS-CoV-2 IgG assay (Abbott Diagnostics, Chicago, USA). Clinical records for COVID-19 patients were reviewed to determine the time from onset of clinical illness to testing. RESULTS: Specificity of the assay was 100.0% (95%CI: 97.1-100.0%). The clinical sensitivity of the assay varied depending on time from onset of symptoms, increasing with longer periods from the onset of clinical illness. The clinical sensitivity at ≤6 days was 8.6% (7/81; 95%CI: 3.8-17.5%), at 7-13 days 43.6% (17/39; 95%CI: 28.2-60.2%), at 14-20 days 84.0% (21/25; 95%CI: 63.1-94.7%), and at ≥21 days 84.4% (27/32; 95%CI: 66.5-94.1%). Clinical sensitivity was higher in the ≥14-day group compared to <14 days. There were no differences between the 14-20-day and ≥21-days groups; the combined clinical sensitivity for these groups (≥14 days) was 84.2% (49/57; 71.6-92.1%). CONCLUSION: The Abbott SARS-CoV-2 IgG test has high specificity. Clinical sensitivity was limited in the early stages of disease but improved from 14 days after the onset of clinical symptoms.

positive: Rapid and Sensitive Detection of anti-SARS-CoV-2 IgG, Using Lanthanide-Doped Nanoparticles-Based Lateral Flow Immunoassay The outbreak of 2019 coronavirus disease (COVID-19) has been a challenge for hospital laboratories because of the huge number of samples that must be tested for the presence of the causative pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Simple and rapid immunodiagnostic methods are urgently needed to identify positive cases. Here we report the development of a rapid and sensitive lateral flow immunoassay (LFIA) that uses lanthanide-doped polysterene nanoparticles (LNPs) to detect anti-SARV-CoV-2 IgG in human serum. A recombinant nucleocapsid phosphoprotein of SARS-CoV-2 was dispensed onto a nitrocellulose membrane to capture specific IgG. Mouse anti-human IgG antibody was labeled with self-assembled LNPs that served as a fluorescent reporter. A 100-µL aliquot of serum samples (1:1000 dilution) was used for this assay and the whole detection process took 10 min. The results of the validation experiment met the requirements for clinical diagnostic reagents. A value of 0.0666 was defined as the cutoff value by assaying 51 normal samples. We tested 7 samples that were positive by reverse-transcription (RT-)PCR and 12 that were negative but clinically suspicious for the presence of anti-SARS-CoV-2 IgG. One of the negative samples was determined to be SARS-CoV-2 IgG positive, while the results for the other samples were consistent with those obtained by RT-PCR. Thus, this assay can achieve rapid and sensitive detection of anti-SARS-CoV-2 IgG in human serum and allow positive identification in suspicious cases; it can also be useful for monitoring the progression COVID-19 and evaluating patients' response to treatment.

positive: Development and evaluation of an enzyme-linked immunosorbent assay for detection of antibodies against the spike protein of SARS-coronavirus Abstract Background: Severe acute respiratory syndrome (SARS) is caused by infection with SARS-associated coronavirus (CoV). Amino acid residues 450–650 of the spike (S) glycoprotein of SARS-CoV (S450-650) contains dominant epitopes for anti-viral antibodies (Abs) in patient sera. Objectives: To develop and evaluate an ELISA system for detection of anti-S Abs in patient sera. Study design: Express recombinant S450-650 in E. Coli and evaluate the sensitivity and specificity of an ELISA system based on the S450-650 polypeptide. Results: The S450-650-based ELISA detected IgG Abs in 41 out of 51 serum samples from 22 hospitalized patients with probable SARS, a result closely correlated with that obtained with a virus-based ELISA (r =0.75, k =0.8). Differential anti-S IgG responses were observed amongst SARS patients. Some of them produced anti-S Abs early during their infection, while others failed to make IgG Abs against the S450-650 polypeptide. None of the serum samples from 100 healthy blood donors was positive in the S450-650-based assay. Conclusion: The S450-650-based ELISA can detect anti-S IgG Abs with high sensitivity and specificity.

positive: Retest positive for SARS-CoV-2 RNA of "recovered" patients with COVID-19: Persistence, sampling issues, or re-infection? "Retest Positive" for severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) from "recovered" coronavirus disease-19 (COVID-19) has been reported and raised several important questions for this novel coronavirus and COVID-19 disease. In this commentary, we discussed several questions: (a) Can SARS-CoV-2 re-infect the individuals who recovered from COVID-19? This question is also associated with other questions: whether or not SARS-CoV-2 infection induces protective reaction or neutralized antibody? Will SARS-CoV-2 vaccines work? (b) Why could some recovered patients with COVID-19 be re-tested positive for SARS-CoV-2 RNA? (c) Are some recovered pwith atients COVID-19 with re-testing positive for SARS-CoV-2 RNA infectious? and (d) How should the COVID-19 patients with retest positive for SARS-CoV-2 be managed?

positive: Validation and performance of a quantitative IgG assay for the screening of SARS-CoV-2 antibodies The current COVID-19 epidemic imposed an unpreceded challenge to the scientific community in terms of treatment, epidemiology, diagnosis, social interaction, fiscal policies and many other areas. The development of accurate and reliable diagnostic tools (high specificity and sensitivity) is crucial in the current period, the near future and in the long term. These assays should provide guidance to identify immune presumptive protected persons, potential plasma, and/or B cell donors and vaccine development among others. Also, such assays will be contributory in supporting prospective and retrospective studies to identify the prevalence and incidence of COVID-19 and to characterize the dynamics of the immune response. As of today, only thirteen serological assays have received the Emergency Use Authorization (EUA) by the U.S. Federal Drug Administration (FDA). In this work we describe the development and validation of a quantitative IgG enzyme-linked immunoassay (ELISA) using the recombinant SARS-CoV-2 Spike Protein S1 domain, containing the receptor-binding domain (RBD), showing 98% sensitivity and 98.9% specificity. The assay showed to be useful to test for SARS-CoV-2 IgG antibodies in plasma samples from COVID-19-recovered subjects as potential donors for plasmapheresis. This assay is currently under review by the Federal Drug Administration for an Emergency Use Authorization request (Submission Number EUA201115).

positive: Reasons and solutions for 'false positive results' of 2019 Novel Coronavirus-specific antibodies detection Assays of specific immunoglobulin M (IgM) and immunoglobulin G (IgG) have been supplemented in 'diagnosis and treatment guidelines of Novel Coronavirus pneumonia' (7th edition) issued by National Health Commission of the People’s Republic of China as an auxiliary evidence to diagnose Novel Coronavirus pneumonia However, the false positive results is a major problem in the application of antibody assays The factors causing the false positive results were analyzed and the ways were discussed to reduce the false positive results The false positive results of antibody assays can be reduced, but they cannot be fully resolved Antibody assays are valuable criteria for the diagnosis of suspected cases with negative nucleic acid results only if at least two dynamic tests are used

positive: Laboratory Diagnosis of Coronavirus Disease-2019 (COVID-19) Abstract The outbreak of Coronavirus Disease-2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has threatened health worldwide. As of the end of 2020, there were nearly 10 million confirmed cases and nearly 5 million deaths associated with COVID-19. Rapid and early laboratory diagnosis of COVID-19 is the main focus of treatment and control. Molecular tests are the basis for confirmation of COVID-19, but serological tests for SARS-CoV-2 are widely available and play an increasingly important role in understanding the epidemiology of the virus and in identifying populations at higher risk for infection. Point-of-care tests have the advantage of rapid, accurate, portable, low cost and non-specific device requirements, which provide great help for disease diagnosis and detection. This review will discuss the performance of different laboratory diagnostic tests and platforms, as well as suitable clinical samples for testing, and related biosafety protection. This review shall guide for the diagnosis of COVID-19 caused by SARS-CoV-2.

positive: Antibody Testing For Covid-19: Can It Be Used As A Screening Tool In Areas With Low Prevalence?

positive: Analysis of adjunctive serological detection to nucleic acid test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection diagnosis BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused coronavirus disease 2019 (COVID-19) epidemic in China, December 2019. The clinical features and treatment of COVID-19 patients remain largely elusive. However, accurate detection is required for SARS-CoV-2 infection diagnosis. We aimed to evaluate the antibodies-based test and nucleic acid-based test for SARS-CoV-2-infected patients. METHODS: We retrospectively studied 133 patients diagnosed with SARS-CoV-2 and admitted to Renmin Hospital of Wuhan University, China, from January 23 to March 1, 2020. Demographic data, clinical records, laboratory tests, and outcomes were collected. Data were accessed by SARS-CoV-2 IgM-IgG antibody test and real-time reverse transcriptase PCR (RT-PCR) detection for SARS-CoV-2 nucleic acid in COVID-19 patients. RESULTS: Of 133 COVID-19 patients, there were 44 moderate cases, 52 severe cases, and 37 critical cases with no differences in gender and age among three subgroups. In RT-PCR detection, the positive rate was 65.9%, 71.2%, and 67.6% in moderate, severe, and critical cases, respectively. Whereas the positive rate of IgM/IgG antibody detection in patients was 79.5%/93.2%, 82.7%/100%, and 73.0%/97.3% in moderate, severe, and critical cases, respectively. Moreover, the IgM and IgG antibodies concentrations were also examined with no differences among three subgroups. CONCLUSION: The IgM-IgG antibody test exhibited a useful adjunct to RT-PCR detection, and improved the accuracy in COVID-19 diagnosis regardless of the severity of illness, which provides an effective complement to the false-negative results from a nucleic acid test for SARS-CoV-2 infection diagnosis after onsets.

positive: Rapid diagnosis of SARS-CoV-2 infection by detecting IgG and IgM antibodies with an immunochromatographic device: a prospective single-center study Objectives: SARS-CoV-2 infection constitutes a diagnostic challenge in patients from 2-3 weeks after the onset of symptoms, due to the low positivity rate of the PCR, especially in upper respiratory samples. Serologic tests based on ELISA have been developed and evaluated as useful complements to PCR in these situations. However, there is scarce information about the usefulness of rapid tests based on immunochromatography. The aim of our study was to analyze the diagnostic performance of these rapid tests in COVID-19 pneumonia patients. Methods: We evaluated an immunochromatographic test (AllTest COV-19 IgG / IgM kit) which detects IgG and IgM antibodies. First, we performed a validation of the serologic test using serum samples from 45 healthy control patients (group 1) and 55 confirmed by PCR cases of COVID-19 (group 2) in order to establish the specificity and sensitivity, respectively. Then we prospectively employed the test in 63 patients diagnosed with pneumonia of unknown etiology that were SARS-CoV-2 negative by PCR (group 3), to establish the diagnostic performance in these patients. Results: All patients from group 1 (healthy controls) resulted negative for the serologic test (specificity = 100%). Regarding group 2 (PCR positive) patients, the median time from the onset of symptoms was 11 days and the test was positive for either IgM or IgG in 26 out of 55 patients (overall sensitivity = 47.3%). However, in those patients with 14 days or more from onset of symptoms, the sensitivity was 73.9%. Regarding group 3 patients, the median days from onset of symptoms was 17 and the test was positive in 56 out of 63 patients (88.9% positivity rate). In these group 3 patients with 14 days or more from onset of symptoms, the positivity rate was 91.1%. Conclusions: Our study shows that serologic rapid tests can be used as a complement of PCR to diagnose SARS-CoV-2 infection after 14 days from the onset of symptoms. These immunochromatographic devices could be especially useful in hospitalized patients with pneumonia of unknown etiology with 14 or more days from the onset of symptoms and in whom the PCR has been negative.

positive: Beyond the Spike: identification of viral targets of the antibody response to SARS-CoV-2 in COVID-19 patients Background: The SARS-CoV-2 virus emerged in December 2019 and caused a pandemic associated with a spectrum of COVID-19 disease ranging from asymptomatic to lethal infection. Serology testing is important for diagnosis of infection, determining infection attack rates and immunity in the population. It also informs vaccine development. Although several serology tests are in use, improving their specificity and sensitivity for early diagnosis on the one hand and for detecting past infection for population-based studies, are priorities. Methods: We evaluated the anti-SARS-CoV-2 antibody profiles to 15 SARS-CoV-2 antigens by cloning and expressing 15 open reading frames (ORFs) in mammalian cells and screened antibody responses to them in COVID-19 patients using the Luciferase Immunoprecipitation System (LIPS). Results: The LIPS technique allowed us to detect antibody responses in COVID-19 patients to 11 of the 15 SARS-CoV-2 antigens tested, identifying novel immunogenic targets. This technique shows that antigens ORF3b and ORF8 allow detection of antibody early in infection in a specific manner and reveals the immuno-dominance of the N antigen in COVID-19 patients. Conclusion: Our report provides an unbiased characterization of antibody responses to a range of SARS-CoV-2 antigens. The combination of 3 SARS-CoV-2 antibody LIPS assays, i.e. N, ORF3b, and ORF8, is sufficient to identify all COVID-19 patients of our cohort even at early time-points of illness, whilst Spike alone fails to do so. Furthermore, our study highlights the importance of investigating new immunogens NSP1, ORF3b, ORF7a and ORF8 which may mediate immune functions other than neutralization which may be beneficial or harmful to the patient.

positive: Profiles of antibody responses against severe acute respiratory syndrome coronavirus recombinant proteins and their potential use as diagnostic markers. A new coronavirus (severe acute respiratory syndrome coronavirus [SARS-CoV]) has been identified to be the etiological agent of severe acute respiratory syndrome. Given the highly contagious and acute nature of the disease, there is an urgent need for the development of diagnostic assays that can detect SARS-CoV infection. For determination of which of the viral proteins encoded by the SARS-CoV genome may be exploited as diagnostic antigens for serological assays, the viral proteins were expressed individually in mammalian and/or bacterial cells and tested for reactivity with sera from SARS-CoV-infected patients by Western blot analysis. A total of 81 sera, including 67 from convalescent patients and seven pairs from two time points of infection, were analyzed, and all showed immunoreactivity towards the nucleocapsid protein (N). Sera from some of the patients also showed immunoreactivity to U274 (59 of 81 [73%]), a protein that is unique to SARS-CoV. In addition, all of the convalescent-phase sera showed immunoreactivity to the spike (S) protein when analyzed by an immunofluorescence method utilizing mammalian cells stably expressing S. However, samples from the acute phase (2 to 9 days after the onset of illness) did not react with S, suggesting that antibodies to N may appear earlier than antibodies to S. Alternatively, this could be due to the difference in the sensitivities of the two methods. The immunoreactivities to these recombinant viral proteins are highly specific, as sera from 100 healthy donors did not react with any of them. These results suggest that recombinant N, S, and U274 proteins may be used as antigens for the development of serological assays for SARS-CoV.

positive: Molecular and Serological Tests for COVID-19. A Comparative Review of SARS-CoV-2 Coronavirus Laboratory and Point-of-Care Diagnostics Validated and accurate laboratory testing for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a crucial part of the timely management of Coronavirus Disease 2019 (COVID-19) disease, supporting the clinical decision-making process for infection control at the healthcare level and detecting asymptomatic cases. This would facilitate an appropriate treatment, a prompt isolation and consequently deceleration of the pandemic. Various laboratory tests can identify the genetic material of SARS-CoV-2 that causes COVID-19 in specimens, or specific anti-viral antibodies in blood/serum. Due to the current pandemic situation, a development of point-of-care diagnostics (POCD) allows us to substantially accelerate taking clinical decisions and implement strategic planning at the national level of preventative measures. This review summarizes and compares the available POCD and those currently under development, including quantitative reverse transcription PCR (RT-qPCR), serology immunoassays (SIAs) and protein microarray method (PMM) designed for standard and rapid COVID-19 diagnosis.

positive: A Peptide-based Magnetic Chemiluminescence Enzyme Immunoassay for Serological Diagnosis of Corona Virus Disease 2019 (COVID-19) A respiratory illness has been spreading rapidly in China, since its outbreak in Wuhan city, Hubei province in December 2019. The illness was caused by a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Clinical manifestations related to SARS-CoV-2 infection ranged from no symptom to fatal pneumonia. World Health Organization (WHO) named the diseases associated with SARS-CoV-2 infection as COVID-19. Real time RT-PCR is the only laboratory test available till now to confirm the infection. However, the accuracy of real time RT-PCR depends on many factors, including sampling location and of methods, quality of RNA extraction and training of operators etc. Variations in these factors might significantly lower the sensitivity of the detection. We developed a peptide-based luminescent immunoassay to detect IgG and IgM. Cut-off value of this assay was determined by the detection of 200 healthy sera and 167 sera from patients infected with other pathogens than SARS-CoV-2. To evaluate the performance of this assay, we detected IgG and IgM in the 276 sera from confirmed patients. The positive rate of IgG and IgM were 71.4% (197/276) and 57.2% (158/276) respectively. By combining with real time RT-PCR detection, this assay might help to enhance the accuracy of diagnosis of SARS-CoV-2 infection.

positive: Diagnostic accuracy of six commercial SARS-CoV-2 IgG/total antibody assays and identification of SARS-CoV-2 neutralizing antibodies in convalescent sera The reliable detection of immunoglobulin G (IgG) or total antibodies directed against the novel severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is important for clinical diagnostics and epidemiological studies. Here, we compare the diagnostic accuracy of six commercially available SARS-CoV-2 IgG (Abbott SARS-CoV-2 IgG; Diasorin Liaison SARS-CoV-2 S1/2 IgG; Epitope EDI Novel Coronavirus COVID-19 IgG ELISA Kit; Euroimmun Anti-SARS-CoV-2 ELISA (IgG); Mikrogen recomWell SARS-CoV-2 IgG) or total SARS-CoV-2 antibody assays (Roche Elecsys Anti-SARS-CoV-2). The test sensitivities were analyzed with a set of 34 sera obtained from 26 patients after PCR-confirmed SARS-CoV-2 infection and varied from 76.9% (Euroimmun) to 96.2% (Abbott). The majority of assay results were confirmed in a laboratory-developed plaque reduction neutralization test and by a SARS-CoV-2 IgG-specific line assay including measurement of generally low IgG avidities (Mikrogen recomLine Coronavirus IgG [Aviditaet], prototype). Moreover, 100 stored sera collected during summer 2018 (N = 50) and winter season 2018/2019 (N = 50) were included to demonstrate test specificities. These varied from 96.0% (DiaSorin) to 100% (Epitope EDI). A subset of sera were retested with a lateral flow test (STANDARD Q COVID-19 IgM/IgG Duo) and a considerably lower sensitivity was noted. Overall, the diagnostic accuracy of the six SARS-CoV-2 IgG/total antibody assays was good and varied from 92.9% (Euroimmun) to 98.4% (Abbott). Due to the different specificities, results of commercially available SARS-CoV-2 antibody tests should be interpreted with caution. A high proportion of antibody-positive patient sera demonstrated neutralizing capacity against SARS-CoV-2.

positive: Ultra-Sensitive High-Resolution Profiling of Anti-SARS-CoV-2 Antibodies for Detecting Early Seroconversion in COVID-19 Patients The COVID-19 pandemic continues to infect millions of people worldwide. In order to curb its spread and reduce morbidity and mortality, it is essential to develop sensitive and quantitative methods that identify infected individuals and enable accurate population-wide screening of both past and present infection. Here we show that Single Molecule Array assays detect seroconversion in COVID-19 patients as soon as one day after symptom onset using less than a microliter of blood. This multiplexed assay format allows us to quantitate IgG, IgM and IgA immunoglobulins against four SARS-CoV-2 targets, thereby interrogating 12 antibody isotype-viral protein interactions to give a high resolution profile of the immune response. Using a cohort of samples collected prior to the outbreak as well as samples collected during the pandemic, we demonstrate a sensitivity of 86% and a specificity of 100% during the first week of infection, and 100% sensitivity and specificity thereafter. This assay should become the gold standard for COVID19 serological profiling and will be a valuable tool for answering important questions about the heterogeneity of clinical presentation seen in the ongoing pandemic.

positive: Poor correlation between antibody titers and neutralizing activity in sera from SARS-CoV-2 infected subjects Plenty of serologic tests for SARS-CoV-2 have been developed so far, thus documenting the importance of evaluating the relevant features of the immune response to this viral agent. The performance of these assays is currently under investigation. Amongst them, LIAISON SARS-CoV-2 S1/S2 IgG by DiaSorin and Elecsys Anti-SARS-CoV-2 cobas by Roche are currently used by laboratory medicine hospital departments in Italy and many other countries. In the present study, we have firstly compared two serologic tests on serum samples collected at two different time points from forty-six laboratory-confirmed COVID-19 subjects. Secondly, eighty-five negative serum samples collected before the SARS-CoV-2 pandemic were analyzed. Thirdly, possible correlations between antibody levels and the resulting neutralizing activity against a clinical isolate of SARS-CoV-2 were evaluated. Results revealed that both tests are endowed with low sensitivity on the day of hospital admission, which increased to 97.8 and 100% for samples collected after 15 days for DiaSorin and Roche tests, respectively. The specificity of the two tests ranges from 96.5 to 100%, respectively. Importantly, a poor direct correlation between antibody titers and neutralizing activity levels was evidenced in the present study.

positive: Detection of the nucleocapsid protein of severe acute respiratory syndrome coronavirus in serum: Comparison with results of other viral markers Abstract A capture enzyme-enhanced chemiluminescence immunoassay (ECLIA) based on three specific monoclonal antibodies to detect the nucleocapsid (N) protein of severe acute respiratory syndrome (SARS) associated coronavirus (SARS-CoV) in the serial serum samples from SARS patients was developed. The anti-SARS-CoV IgG and the viral RNA were also detected in the sera by ELISA and RT-PCR, respectively. During the first 10 days after onset, anti-SARS-CoV IgG, SARS-CoV RNA and the N protein were detected in 21.4, 42.9, and 90% of the patients’ sera, respectively. The detection rate of the N protein during days 11–15 of the disease was still significantly higher than those of anti-SARS-CoV IgG and SARS-CoV RNA. The data demonstrated that detection of the N protein with the capture ECLIA appears to be more useful than detection of other viral makers for rapid diagnosis of SARS in patients.

positive: Comparison of test performance of commercial anti-SARS-CoV-2 immunoassays in serum and plasma samples Abstract Background For epidemiologic, social and economic reasons, assessment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection prevalence and immunity are important to adapt decisions to current demands. Hence, immunoassays for detection of anti-SARS-CoV-2 antibodies are introduced rapidly without requiring FDA emergency use authorization approval. Thus, evaluation of test performance predominantly relies on laboratories. This study aimed to evaluate the test performance of recently launched commercial immunoassays in serum and plasma samples. Methods 51 serum samples from 26 patients with confirmed SARS-CoV-2 infection after end of quarantine and 25 control patients were analyzed using anti-SARS-CoV-2 IgG immunoassays from Roche, Euroimmun and Epitope to assess diagnostic sensitivity and specificity. 20 matching pairs of serum and plasma samples were included to analyze comparability between different specimens. Results Overall, a diagnostic sensitivity of 92.3%, 96.2-100% and 100% with a respective diagnostic specificity of 100%, 100% and 84-86% for the immunoassays from Roche, Euroimmun and Epitope were determined. In total, 84-96 % of samples were correctly classified as negative and 92.3-95.2% as positive. The level of concordance between plasma- and serum-based testing diverged between the assays (Epitope r2=0.97; Euroimmun r2=0.91; Roche r2=0.76). Conclusions The immunoassays from Euroimmun and Roche revealed a higher specificity than the Epitope assay without a substantial drop of diagnostic sensitivity. Significant differences between plasma- and serum-based testing highlights the need for determination of appropriate cut-offs per specimen type. Hence, there is an urgent need for test harmonization and establishment of quality standards for an appropriate use of COVID-19 serological tests.

positive: SARS-CoV-2 Antibody Testing – Questions to be asked ABSTRACT SARS-CoV-2 infection and development of COVID-19 disease presents a major healthcare challenge of global dimensions. Laboratory diagnostics of infected patients, and the assessment of immunity against the SARS-CoV-2 virus presents a major cornerstone in handling the pandemic. Currently there is an increase in demand of antibody testing and a large number of tests are already marketed or in the late stage of development. However, the interpretation of test results depends on many variables and factors, including sensitivity, specificity, potential cross-reactivity and cross-protectivity; the diagnostic value of antibodies of different isotypes, the use of antibody testing in identification of acutely ill patients or in epidemiological settings. In this article the recently established COVID-19 Task Force of the German Society for Clinical Chemistry and Laboratory Medicine (DGKL) addresses these issues based on the currently available datasets in this rapidly moving field.

positive: Profiles of IgG antibodies to nucleocapsid and spike proteins of the SARS-associated coronavirus in SARS patients. To evaluate humoral immunity against the SARS-associated coronavirus (SARS-CoV), we studied the profiles of IgG antibodies to the nucleocapsid (N) and spike (S) proteins of SARS-CoV. Serum specimens from 10 SARS patients were analyzed by Western blotting and an enzyme-linked immunosorbent assay (ELISA) using purified recombinant N and truncated S (S1, S2, and S3) proteins as antigens. Western blotting results demonstrated that 100% of the SARS patients tested positive for N protein-specific antibodies, 50% for S1 protein-specific antibodies, 30% for S2 protein-specific antibodies, and 70% for S3 protein-specific antibodies. The ELISA results, which showed positive rates of IgG reactivity against recombinant proteins N, S1, S2, and S3, were, respectively, 28.57, 14.29, 14.29, and 14.29% at week 1, 77.78, 55.56, 44.44, and 66.67% at week 2, 100, 75, 75, and 87.5% at week 3, and 100, 77.78, 77.78, and 88.89% after 3 weeks. The average titers of IgG against recombinant proteins N, S1, S2, and S3 were, respectively, 691, 56, 38, and 84 after 3 weeks. These results suggest that the recombinant proteins N and S3 are potentially useful antigens for a serological diagnosis of SARS. In consideration of possible cross-reactivity among N proteins of SARS-CoV and other coronaviruses, immunoassays using recombinant N protein in combination with S3 as antigens might improve the specificity of SARS diagnoses.

positive: A serological assay to detect SARS-CoV-2 seroconversion in humans. Here, we describe a serological enzyme-linked immunosorbent assay for the screening and identification of human SARS-CoV-2 seroconverters. This assay does not require the handling of infectious virus, can be adjusted to detect different antibody types in serum and plasma and is amenable to scaling. Serological assays are of critical importance to help define previous exposure to SARS-CoV-2 in populations, identify highly reactive human donors for convalescent plasma therapy and investigate correlates of protection.

positive: Validation of a commercially available SARS-CoV-2 serological immunoassay OBJECTIVES: To validate the diagnostic accuracy of a Euroimmun SARS-CoV-2 IgG and IgA immunoassay for COVID-19. METHODS: In this unmatched (1:2) case-control validation study, we used sera of 181 laboratory-confirmed SARS-CoV-2 cases and 326 controls collected before SARS-CoV-2 emergence. Diagnostic accuracy of the immunoassay was assessed against a whole spike protein-based recombinant immunofluorescence assay (rIFA) by receiver operating characteristic (ROC) analyses. Discrepant cases between ELISA and rIFA were further tested by pseudo-neutralization assay. RESULTS: COVID-19 patients were more likely to be male and older than controls, and 50.3% were hospitalized. ROC curve analyses indicated that IgG and IgA had high diagnostic accuracies with AUCs of 0.990 (95% Confidence Interval [95%CI]: 0.983-0.996) and 0.978 (95%CI: 0.967-0.989), respectively. IgG assays outperformed IgA assays (p=0.01). Taking an assessed 15% inter-assay imprecision into account, an optimized IgG ratio cut-off > 2.5 displayed a 100% specificity (95%CI: 99-100) and a 100% positive predictive value (95%CI: 96-100). A 0.8 cut-off displayed a 94% sensitivity (95%CI: 88-97) and a 97% negative predictive value (95%CI: 95-99). Substituting the upper threshold for the manufacturer’s, improved assay performance, leaving 8.9% of IgG ratios indeterminate between 0.8-2.5. CONCLUSIONS: The Euroimmun assay displays a nearly optimal diagnostic accuracy using IgG against SARS-CoV-2 in patient samples, with no obvious gains from IgA serology. The optimized cut-offs are fit for rule-in and rule-out purposes, allowing determination of whether individuals in our study population have been exposed to SARS-CoV-2 or not. IgG serology should however not be considered as a surrogate of protection at this stage.

positive: Antibody Detection and Dynamic Characteristics in Patients with COVID-19 BACKGROUND: The corona virus disease 2019 (COVID-19) caused by the corona virus 2 (SARS-CoV-2) has been rapidly spreading nationwide and abroad. A serologic test to identify antibody dynamics and response to SARS-CoV-2 was developed. METHODS: The antibodies against SARS-CoV-2 were detected by an enzyme-linked immunosorbent assay (ELISA) based on the recombinant nucleocapsid protein of SARS-CoV-2 in patients with confirmed or suspected COVID-19 at 3-40 days after symptom onset. The gold standard for COVID-19 diagnosis was nucleic acid testing for SARS-CoV-2 by RT-PCR. The serodiagnostic power of the specific IgM and IgG antibodies against SARS-CoV-2 was investigated in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and consistency rate. RESULTS: The seroconversion of specific IgM and IgG antibodies were observed as early as the 4(th) day after symptom onset. In the confirmed patients with COVID-19, sensitivity, specificity, PPV, NPV, and consistency rate of IgM were 77.3% (51/66), 100%, 100%, 80.0%, and 88.1%, and those of IgG were 83.3.3% (55/66), 95.0%, 94.8%, 83.8%, and 88.9 %. In patients with suspected COVID-19, sensitivity, specificity, PPV, NPV, and consistency rate of IgM were 87.5% (21/24), 100%, 100%, 95.2%, and 96.4%, and those of IgG were 70.8% (17/24), 96.6%, 85.0%, 89.1%, and 88.1%. Both antibodies performed well in serodiagnosis for COVID-19 rely on great specificity. CONCLUSIONS: The antibodies against SARS-CoV-2 can be detected in the middle and later stage of the illness. Antibody detection may play an important role in the diagnosis of COVID-19 as complement approach for viral nucleid acid assays.

positive: Antibody dynamics to SARS-CoV-2 in Asymptomatic and Mild COVID-19 patients Humoral immunity in asymptomatic infections with SARS-CoV-2 has not been well established. 63 healthy contacts, 63 asymptomatic individuals, and 51 mild patients were enrolled in this study and screened using nucleic acid testing (NAT) and commercial kits of serum IgM and IgG antibodies against recombinant nucleoprotein (N) and spike (S) proteins of SARS-CoV-2. Asymptomatic and mild patients were classified into at least four types based on NAT and serological tests, especially 81% and 25.4% negative NAT but positive IgM/IgG responses, respectively. Antibody dynamics were further demonstrated by IgM and IgG profile responses to SARS-CoV-2 proteome. IgM antibody responses against S1 were elicited in asymptomatic individuals as early to the seventh day after exposure and peaked on days from 17d to 25d, which might be used as early diagnostic biomarkers. Moreover, asymptomatic individuals evoked weaker S1 specific IgM and neutralizing antibody responses than mild patients. Most importantly, S1 specific IgM/IgG responses and the titers of neutralizing antibody in asymptomatic individuals gradually vanished in two months. Our findings might have important implications for serological survey, public health and immunization strategy.

positive: Longitudinal profile of immunoglobulin G (IgG), IgM, and IgA antibodies against the severe acute respiratory syndrome (SARS) coronavirus nucleocapsid protein in patients with pneumonia due to the SARS coronavirus. By using a recombinant severe acute respiratory syndrome coronavirus (SARS-CoV) nucleocapsid protein-based enzyme-linked immunosorbent assay (ELISA) and serum specimens serially collected (from day 0 to day 240 after symptom onset) from patients with pneumonia due to SARS-CoV, we analyzed the longitudinal profiles of immunoglobulin G (IgG), IgM, and IgA antibodies against the SARS-CoV nucleocapsid protein in patients with pneumonia due to SARS-CoV. For IgG, the median optical density at 450 nm (OD450) turned positive at day 17 and a biphasic response was observed. At day 240, all patients were still positive for anti-nucleocapsid protein IgG antibody. For IgM, the median OD450 turned positive at day 20.5, peaked at about day 80, and fell to below the baseline level at about day 180. At day 240, 36% of the patients were still positive for anti-nucleocapsid protein IgM antibody. For IgA, the median OD450 turned positive at day 17, peaked at about day 50, and fell to below the baseline level at about day 180. At day 240, 36% of the patients were still positive for anti-nucleocapsid protein IgA antibody. The time of seroconversion detected by the recombinant SARS-CoV nucleocapsid protein-based ELISA and that detected by indirect immunofluorescence assay were similar. The median times of seroconversion for IgG, IgM, and IgA detected by the indirect immunofluorescence assay were 17 days (17 days by ELISA), 16.5 days (20.5 days by ELISA), and 17.5 days (17 days by ELISA), respectively, after disease onset. One, four, and one of the six patients who died did not produce any IgG, IgM, and IgA antibodies against the nucleocapsid protein of SARS-CoV, respectively, although these antibodies were detected in all six patients by the indirect immunofluorescence assay. Further studies should be performed to see whether SARS-CoV nucleocapsid protein antibody positivity has any prognostic significance.

positive: COVID-19 Serological Tests: How Well Do They Actually Perform? In only a few months after initial discovery in Wuhan, China, SARS-CoV-2 and the associated coronavirus disease 2019 (COVID-19) have become a global pandemic causing significant mortality and morbidity and implementation of strict isolation measures In the absence of vaccines and effective therapeutics, reliable serological testing must be a key element of public health policy to control further spread of the disease and gradually remove quarantine measures Serological diagnostic tests are being increasingly used to provide a broader understanding of COVID-19 incidence and to assess immunity status in the population However, there are discrepancies between claimed and actual performance data for serological diagnostic tests on the market In this study, we conducted a review of independent studies evaluating the performance of SARS-CoV-2 serological tests We found significant variability in the accuracy of marketed tests and highlight several lab-based and point-of-care rapid serological tests with high levels of performance The findings of this review highlight the need for ongoing independent evaluations of commercialized COVID-19 diagnostic tests

positive: Immunochromatographic assays for COVID-19 epidemiological screening: our experience In March 2020, the World Health Organization (WHO) declared a pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Due to the absence of effective treatment or biomedical prevention, understanding potential post infection immunity has important implications for epidemiologic assessments. For this reason, increasing number of in vitro diagnostic companies are developing serological assays to detect antibodies against SARS-CoV-2, but most of them lack the validation by third parties in relation to their quality, limiting their usefulness. We submitted to serological screening by two different immunochromatographic (IC) rapid testing for detection of IgG and IgM against SARS-CoV-2, 151 asymptomatic or minimally symptomatic healthcare workers previously tested positive for SARS-CoV-2 RT-PCR in order to evaluate the performance of rapid assays. Results showed discrepancies between molecular and IC results, and an inconsistency of immunoglobulins positivity patterns when compared to ELISA/CLIA results, highlighting the absolute necessity of assays performance validation before their marketing and use, in order to avoid errors in the results evaluation at both clinical and epidemiological level.

positive: Evaluation of the EDI enzyme linked immunosorbent assays for the detection of SARS-CoV-2 IgM and IgG antibodies in human plasma BACKGROUND: Besides SARS-CoV-2 RT-PCR testing, serological testing is emerging as additional option in COVID-19 diagnostics. Aim of this study was to evaluate novel immunoassays for detection of SARS-CoV-2 antibodies in human plasma. METHODS: Using EDI(TM) Novel Coronavirus COVID-19 Enzyme Linked Immunosorbent Assays (ELISAs), we measured SARS-CoV-2 IgM and IgG antibodies in 64 SARS-CoV-2 RT-PCR confirmed COVID-19 patients with serial blood samples (n=104) collected at different time points from symptom onset. Blood samples from 200 healthy blood donors and 256 intensive care unit (ICU) patients collected before the COVID-19 outbreak were also used. RESULTS: The positivity rates in the COVID-19 patients were 5.9% for IgM and 2.9% for IgG ≤5 days after symptom onset; Between day 5 and day 10 the positivity rates were 37.1% for IgM and 37.1% for IgG and rose to 76.4% for IgM and 82.4% for IgG after >10-15 days. After 15-22 days the “true” positivity rates were 94.4% for IgM and 100% for IgG. The “false” positivity rates were 0.5% for IgM and 1.0% for IgG in the healthy blood donors, 1.6% for IgM and 1.2% for IgG in ICU patients. CONCLUSIONS: This study shows high “true” vs. low “false” positivity rates for the EDI(TM) SARS-CoV-2 IgM and IgG ELISAs.

positive: Review of Viral Testing (Polymerase Chain Reaction) and Antibody/Serology Testing for Severe Acute Respiratory Syndrome-Coronavirus-2 for the Intensivist OBJECTIVE: As the severe acute respiratory syndrome-coronavirus-2 pandemic develops, assays to detect the virus and infection caused by it are needed for diagnosis and management. To describe to clinicians how each assay is performed, what each assay detects, and the benefits and limitations of each assay. DATA SOURCES: Published literature and internet. STUDY SELECTION: As well done, relevant and recent as possible. DATA EXTRACTION: Sources were read to extract data from them. DATA SYNTHESIS: Was synthesized by all coauthors. CONCLUSIONS: Available assays test for current or previous severe acute respiratory syndrome-coronavirus-2 infection. Nucleic acid assays such as quantitative, or real-time, polymerase chain reaction and loop-mediated isothermal amplification are ideal for acute diagnosis with polymerase chain reaction testing remaining the “gold standard” to diagnose acute infection by severe acute respiratory syndrome-coronavirus-2, specifically the presence of viral RNA. Assays that detect serum antibodies can theoretically diagnose both acute and remote infection but require time for the patient to develop immunity and may detect nonspecific antibodies. Antibody assays that quantitatively measure neutralizing antibodies are needed to test efficacy of convalescent plasma therapy but are more specialized.

positive: Performance Characteristics of the Abbott Architect SARS-CoV-2 IgG Assay and Seroprevalence in Boise, Idaho. Coronavirus disease-19 (COVID19), the novel respiratory illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with severe morbidity and mortality. The rollout of diagnostic testing in the United States was slow, leading to numerous cases that were not tested for SARS-CoV-2 in February and March 2020, necessitating the use of serological testing to determine past infections. Here, we evaluated the Abbott SARS-CoV-2 IgG test for detection of anti-SARS-CoV-2 IgG antibodies by testing 3 distinct patient populations. We tested 1,020 serum specimens collected prior to SARS-CoV-2 circulation in the United States and found one false positive, indicating a specificity of 99.90%. We tested 125 patients who tested RT-PCR positive for SARS-CoV-2 for which 689 excess serum specimens were available and found sensitivity reached 100% at day 17 after symptom onset and day 13 after PCR positivity. Alternative index value thresholds for positivity resulted in 100% sensitivity and 100% specificity in this cohort. We tested 4,856 individuals from Boise, Idaho collected over one week in April 2020 as part of the Crush the Curve initiative and detected 87 positives for a positivity rate of 1.79%. These data demonstrate excellent analytical performance of the Abbott SARS-CoV-2 IgG test as well as the limited circulation of the virus in the western United States. We expect the availability of high-quality serological testing will be a key tool in the fight against SARS-CoV-2.

positive: An enzyme-linked immunosorbent assay using canine coronavirus-infected CRFK cells as antigen for detection of anti-coronavirus antibody in cat Abstract From the reasons that canine coronavirus (CCV) grows more efficiently than feline coronavirus in a cell culture and they are mutually related in their antigenicities, an enzyme-linked immunosorbent assay (ELISA) using CCV-infected feline kidney (CRFK) cells as substrate antigens was developed for detection of anti-coronavirus antibodies in cats. It was indispensable for generating coronavirus-specific ELISA antibody activities that the sample was applied to the mock-infected, normal CRFK cells in parallel with the CCV-infected cells and then the optical density values given by the mock-infected cell antigen were subtracted from those given by the virus-infected cell antigen. On the basis of ELISA antibody titers obtained in sera from the cats experimentally infected with CCV and from the spontaneous feline infectious peritonitis (FIP) cases, the ELISA described in the present study was found to be applicable as a simple and easy serologic test which was able to detect anti-coronavirus antibodies as efficiently as the indirect immunofluorescence assay with homologous FIP virus.

positive: Performance evaluation of Abbott ARCHITECT SARS-CoV-2 IgG immunoassay in comparison with indirect immunofluorescence and virus microneutralization test BACKGROUND: Serological tests for anti-SARS-CoV-2 antibodies are becoming of great interest to determine seroprevalence in a given population, define previous exposure and identify highly reactive human donors for the generation of convalescent serum as therapeutic. OBJECTIVES: We evaluated the diagnostic performance of the Abbott ARCHITECT SARS-CoV-2 IgG test, a fully automated indirect immunoassay that detects antibodies directed to a recombinant SARS-CoV-2 Nucleocapsid antigen. STUDY DESIGN: Abbott ARCHITECT SARS-CoV-2 IgG immunoassay was compared to an indirect immunofluorescence assay (IFA) on sera from patients with COVID-19 collected at different days after symptoms onset or infected by other human coronaviruses. Comparison with neutralization test was also performed. RESULTS: After 7, 14 and >14 days after onset ARCHITECT was positive on 8.3%; 61.9% and 100% of the tested samples compared to 58.3%; 85.7% and 100% by IFA. The sensitivity was 72% vs. IFA and 66.7% vs. a real-time PCR, the specificity was 100%. On 18 samples with neutralizing activity, 17 were positive by Abbott ARCHITECT SARS-CoV-2 IgG. CONCLUSIONS: In our study, Abbott ARCHITECT SARS-CoV-2 IgG assay showed a satisfactory performance, with a very high specificity. IgG reactivity against SARSCoV-2 N antigen was detectable in all patients by two weeks after symptoms onset. In addition, concordance between this serological response and viral neutralization suggests that a strong humoral response may be predictive of a neutralization activity, regardless of the target antigens. This finding supports the use of this automated serological assay in diagnostic algorithm and public health intervention, especially for high loads of testing.

positive: High SARS-CoV-2 Antibody Prevalence among Healthcare Workers Exposed to COVID-19 Patients The seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was examined among 105 healthcare workers (HCWs) exposed to four patients who were laboratory confirmed with coronavirus disease 2019 (COVID-19), the disease caused by SARS-CoV-2 infection. These HCWs were immediately under quarantine for 14 days as soon as they were identified as close contacts. The nasopharyngeal swab samples were collected on the first and 14(th) day of the quarantine, while the serum samples were obtained on the 14(th) day of the quarantine. With the assay of enzyme immunoassay (EIA) and microneutralization assay, 17.14% (18/105) of HCWs were seropositive, while their swab samples were found to be SARS-CoV-2 RNA negative. Risk analysis revealed that wearing face mask could reduce the infection risk (odds ratio [OR], 0.127, 95% confidence interval [CI] 0.017, 0.968), while when exposed to COVID-19 patients, doctors might have higher risk of seroconversion (OR, 346.837, 95% CI 8.924, 13479.434), compared with HCWs exposed to colleagues as well as nurses and general service assistants who exposed to patients. Our study revealed that the serological testing is useful for the identification of asymptomatic or subclinical infection of SARS-CoV-2 among close contacts with COVID-19 patients.

positive: Covid-19: Antibody test that claims to be 99% accurate is certified by EU

positive: Evaluation and validation of an enzyme-linked immunosorbent assay and an immunochromatographic test for serological diagnosis of severe acute respiratory syndrome. A newly developed severe acute respiratory syndrome (SARS)-specific enzyme-linked immunosorbent assay (ELISA) was further validated to confirm cutoff values and evaluate its diagnostic performance with clinical samples. In parallel, an immunochromatographic test was also evaluated. A total of 227 clinical serum specimens collected from SARS patients were used in the study, together with 385 samples from healthy donors. By use of an immunofluorescent (IF) test as the "gold standard", both the ELISA and the immunochromatographic test were able to detect immunoglobulin G antibodies to SARS not only from late-convalescent-stage samples (>21 days from the onset of clinical symptoms), as previously established, but also from early-acute-phase samples (1 to 10 days from onset). The ELISA, using an optical density (OD) of 0.25 as its cutoff value, produced the best sensitivity while maintaining high specificity. It detected SARS-specific antibodies in 58, 70, 75, and 95%, respectively, of the four groups of samples collected from patients 1 to 10 days, 11 to 20 days, 21 to 30 days, and more than 30 days after the onset of clinical symptoms. Similarly, the immunochromatographic test detected SARS-specific antibodies in 55, 68, 81, and 79% of the four groups, respectively. The overall specificities for the ELISA and the rapid test were 99.5 and 97.7%, respectively. Although the positive correlation observed between the ELISA OD values and the IF titers was moderate (r = 0.6915; P < 0.001), the detection rates of both the ELISA and the rapid test were found well in agreement with the IF titers.

positive: Evaluating the serological status of COVID-19 patients using an indirect immunofluorescent assay, France. An indirect immunofluorescent assay was developed in order to assess the serological status of 888 RT-PCR-confirmed COVID-19 patients (1,302 serum samples) and controls in Marseille, France. Incorporating an inactivated clinical SARS CoV-2 isolate as the antigen, the specificity of the assay was measured as 100% for IgA titre [≥] 1:200; 98.6% for IgM titre [≥] 1:200; and 96.3% for IgG titre [≥] 1:100 after testing a series of negative controls as well as 150 serums collected from patients with non-SARS-CoV-2 Coronavirus infection, non-Coronavirus pneumonia and infections known to elicit false-positive serology. Seroprevalence was then measured at 3% before a five-day evolution up to 47% after more than 15 days of evolution. We observed that the seroprevalence as well as the titre of specific antibodies were both significantly higher in patients with a poor clinical outcome than in patients with a favourable evolution. These data, which have to be integrated into the ongoing understanding of the immunological phase of the infection, suggest that serotherapy may not be a therapeutic option in patients with severe COVID-19 infection. The IFA assay reported here is useful for monitoring SARS-CoV-2 exposure at the individual and population levels.

positive: The RBD Of The Spike Protein Of SARS-Group Coronaviruses Is A Highly Specific Target Of SARS-CoV-2 Antibodies But Not Other Pathogenic Human and Animal Coronavirus Antibodies A new Severe Acute Respiratory Syndrome Coronavirus variant (SARS-CoV-2) that first emerged in late 2019 is responsible for a pandemic of severe respiratory illness. People infected with this highly contagious virus present with clinically inapparent, mild or severe disease. Currently, the presence of the virus in individual patients and at the population level is being monitored by testing symptomatic cases by PCR for the presence of viral RNA. There is an urgent need for SARS-CoV-2 serologic tests to identify all infected individuals, irrespective of clinical symptoms, to conduct surveillance and implement strategies to contain spread. As the receptor binding domain (RBD) of the viral spike (S) protein is poorly conserved between SARS-CoVs and other pathogenic human coronaviruses, the RBD represents a promising antigen for detecting CoV specific antibodies in people. Here we use a large panel of human sera (70 SARS-CoV-2 patients and 71 control subjects) and hyperimmune sera from animals exposed to zoonotic CoVs to evaluate the performance of the RBD as an antigen for accurate detection of SARS-CoV-2-specific antibodies. By day 9 after the onset of symptoms, the recombinant SARS-CoV-2 RBD antigen was highly sensitive (98%) and specific (100%) to antibodies induced by SARS-CoVs. We observed a robust correlation between levels of RBD binding antibodies and SARS-CoV-2 neutralizing antibodies in patients. Our results, which reveal the early kinetics of SARS-CoV-2 antibody responses, strongly support the use of RBD-based antibody assays for population-level surveillance and as a correlate of neutralizing antibody levels in people who have recovered from SARS-CoV-2 infections.

positive: Clinical Performance of Two SARS-CoV-2 Serologic Assays BACKGROUND: The recent emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a rapid proliferation of serologic assays. However, little is known about their clinical performance. Here, we compared two commercial SARS-CoV-2 IgG assays. METHODS: 103 specimens from 48 patients with PCR confirmed SARS-CoV-2 infections and 153 control specimens were analyzed using SARS-CoV-2 serologic assays by Abbott and EUROIMMUN (EI). Duration from symptom onset was determined by medical record review. Diagnostic sensitivity, specificity, and concordance were calculated. RESULTS: The Abbott SARS-CoV-2 assay had a diagnostic specificity of 99.4% (95% CI; 96.41-99.98%), and sensitivity of 0.0% (95% CI; 0.00-26.47%) at <3 days post symptom onset, 30.0% (95% CI; 11.89-54.28) at 3-7d, 47.8% (95% CI; 26.82-69.41) at 8-13d and 93.8% (95% CI; 82.80-98.69) at ≥14d. Diagnostic specificity on the EI assay was 94.8% (95% CI; 89.96-97.72) if borderline results were considered positive and 96.7% (95% CI; 92.54-98.93) if borderline results were considered negative. The diagnostic sensitivity was 0.0% (95% CI; 0.00-26.47%) at <3d, 25.0% (95% CI; 8.66-49.10) at 3-7d, 56.5% (95% CI; 34.49-76.81) at 3-7d and 85.4% (95% CI; 72.24-93.93) at ≥14d if borderline results were considered positive. The qualitative concordance between the assays was 0.83 (95% CI; 0.75-0.91). CONCLUSIONS: The Abbott SARS-CoV-2 assay had fewer false positive and false negative results than the EI assay. However, diagnostic sensitivity was poor in both assays during the first 14 days of symptoms.

positive: Laboratory diagnosis of SARS-CoV-2 - A review of current methods At present the whole world is facing pandemic of the Coronavirus disease (COVID-19); caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This disease has rapidly spreads across the world from its origin of Wuhan, China and affected millions people worldwide and make them to remain in their homes. The knowledge of available laboratory methods is essential for early and correct diagnosis of COVID-19 to identify new cases as well as monitoring treatment of confirmed cases. In this review we aim to provide the updated information about selection of specimens and availability of various diagnostic methods and their utility with current findings for the laboratory diagnosis of SARS-CoV-2 infection. This will guide the healthcare professionals and government organizations to make strategy for establishing diagnostic facilities for SARS-CoV-2 infections.

positive: Laboratory diagnosis of SARS-CoV-2: available approaches and limitations Abstract The ongoing pandemic of SARS-CoV-2 is a one of the most devastating outbreaks witnessed in the last 100 years. The outbreak started in China's hinterland and spread rapidly to almost every country culminating in woefully overwhelmed healthcare systems in most countries. The only approved diagnostic test to accompany radiographic evaluation is the reverse-transcriptase PCR. However, the applicability of this test in diagnosis and surveillance is challenged by global shortage in reagents and unavailability of well-equipped laboratories with specialized staff in several low- and middle-income countries. The need for development of accurate and rapid diagnostic assays became apparent. Handful of immunodiagnostic tests and other molecular approaches were developed and tested. Other recently developed point-of-care molecular tests are expected to be helpful in pandemic management since no particular skills are required from the operator. Fortunately, handful of serological tests have granted authorization to be used under emergency situation by FDA in diagnosis of SARS-CoV-2.

positive: Retrospective Clinical Evaluation of Four Lateral Flow Assays for the Detection of SARS-CoV-2 Antibodies Coronavirus disease 2019 (COVID-19) is a potentially life-threatening respiratory infection caused by severe acute respiratory coronavirus 2 (SARS-CoV-2), for which numerous serologic assays are available. In a CLIA laboratory setting, we used a retrospective sample set (n = 457) to evaluate two lateral flow immunoassays (LFIAs; two iterations of Rapid Response COVID-19 Test Cassette, BTNX Inc.) and a subset of to evaluate SARS-COV-2 IgG/IgM Rapid Test, ACON Laboratories (n = 200); and Standard Q COVID-19 IgM/IgG Duo, SD BIOSENSOR (n = 155) for their capacity to detect of SARS-CoV-2 IgG. In a cohort of primarily hospitalized patients with RT-PCR confirmed COVID-19, the BTNX assays demonstrated 95% and 92% agreement with the Abbott SARS-CoV-2 IgG assay and sensitivity was highest at [≥] 14 days from symptom onset [BTNX kit 1, 95%; BTNX kit 2, 91%]. ACON and SD assays demonstrated 99% and 100% agreement with the Abbott assay at [≥] 14 days from symptom onset. Specificity was measured using 74 specimens collected prior to SARS-CoV-2 circulation in the United States and 31 cross-reactivity challenge specimens, including those from patients with a history of seasonal coronavirus infection and was 98% for BTNX kit 1 and ACON and 100% for BTNX kit 2 and SD. Taken with data from EUA assays, these results suggest that LFIAs may provide adequate results for rapid detection of SARS-CoV-2. Replicating these results in fingerstick blood in outpatient populations, would further support the possibility that LFIAs may be useful to increase access to serologic testing.

positive: Recurrent pneumonia in a patient with new coronavirus infection after discharge from hospital for insufficient antibody production: a case report BACKGROUND: The rapid spread of coronavirus disease 2019 (COVID-19) was declared as an emerging public health threat by the World Health Organization. As various measures have been taken successfully to combat the epidemic caused by SARS-CoV-2, a growing number of fully recovered patients have been discharged from hospitals. However, some of them have relapsed. Little is known about the causes that triggered the relapse. CASE PRESENTATION: We report a case of a 40 years old man who suffered from recurrent pulmonary infection with progression of lesions on chest computed tomography (CT), elevated levels of ferritin and IL2R, reduced lymphocyte count and positive oropharyngeal swab test for SARS-CoV-2 again after 5 days discharge from hospital. The anti-SARS-CoV-2 antibody level of this patient was very low at the time of relapse, suggesting a weak humoral immune response to the virus. Total exon sequencing revealed mutations in TRNT1 gene, which may be responsible for B cell immunodeficiency. Therefore, uncleared SARS-CoV-2 at his first discharge was likely to lead to his recurrence. However, viral superinfection and non-infectious organizing pneumonia could not be completely excluded. CONCLUSION: COVID-19 relapse may occur in a part of discharged patients with low titers of anti-SARS-CoV-2 antibodies. These patients should be maintained in isolation for longer time even after discharge. A more sensitive method to detect SARS-CoV-2 needs to be established and serological testing for specific antibodies may be used as a reference to determine the duration of isolation.

positive: Role of Anti-SARS-CoV-2 antibodies in different cohorts: Can they provide clues for appropriate patient triaging? The emergence of coronavirus disease 2019 (COVID-19) has become a major global health crisis. Currently, diagnosis is based on molecular techniques, which detect the viral nucleic acids when present at detectable levels. The serum IgG response against SARS-CoV-2 was examined by using an ELISA-based assay. Serum samples, along with nasopharyngeal specimens were collected from various cohorts and analyzed by ELISA and rRT-PCR, respectively. A total of 167 serum samples were tested for serum IgG antibodies against SARS-CoV-2 in outpatient cohorts, 15 (8.9%) were positive by rRT-PCR and the remaining 152 (91%) were negative. We used these data to generate two different assay cutoffs for serum IgG assay and investigated percent concordance with rRT-PCR test results. The emergency department data revealed, out of 151 nasopharyngeal swabs, 4 (2.6%) were positive by rRT-PCR and 18 (11.9%) were positive for serum IgG assay. Among the 18 patients that were positive for serum IgG, 13 (72.2%) exhibited 1-3 symptoms of COVID-19 and 5 (27.7%) patients did not present with any COVID-19 related symptoms, per CDC criteria. All 4 (100%) patients that were positive by rRT-PCR had symptoms of COVID-19 disease. A longitudinal study from the inpatient population suggested there was a sharp increase in the serum IgG titers in 5 patients, a moderate increase in 1 patient and a plateau in 3 patients. Sero-prevalence of COVID-19 disease in pre-procedure patients was 5.5%. Our findings suggest serological tests can be used for appropriate patient triaging when performed as an adjunct to existing molecular testing.

positive: Multiplex detection and dynamics of IgG antibodies to SARS-CoV2 and the highly pathogenic human Coronaviruses SARS-CoV and MERS-CoV BACKGROUND: Knowledge of the COVID-19 epidemic extent and the level of herd immunity is urgently needed to help manage this pandemic. METHODS: We used a panel of 167 samples (77 pre-epidemic and 90 COVID-19 seroconverters) and SARS-CoV1, SARS-CoV2 and MERS-CoV Spike and/or Nucleopcapsid (NC) proteins to develop a high throughput multiplex screening assay to detect IgG antibodies in human plasma. Assay performances were determined by ROC curves analysis. A subset of the COVID-19+ samples (n = 36) were also tested by a commercial NC-based ELISA test and the results compared with those of the novel assay. RESULTS: On samples collected ≥14 days after symptoms onset, the accuracy of the assay is 100% (95% CI: 100-100) for the Spike antigen and 99.9% (95% CI:99.7-100) for NC. By logistic regression, we estimated that 50% of the patients have seroconverted at 5.7 ± 1.6; 5.7 ± 1.8 and 7.9 ± 1.0 days after symptoms onset against Spike, NC or both antigens, respectively and all have seroconverted two weeks after symptoms onset. IgG titration in a subset of samples showed that early phase samples present lower IgG titers than those from later phase. IgG to SARS-CoV2 NC cross-reacted at 100% with SARS-CoV1 NC. Twenty-nine of the 36 (80.5%) samples tested were positive by the commercial ELISA while 31/36 (86.1%) were positive by the novel assay. CONCLUSIONS: Our assay is highly sensitive and specific for the detection of IgG antibodies to SARS-CoV2 proteins, suitable for high throughput epidemiological surveys. The novel assay is more sensitive than a commercial ELISA.

positive: [Development of a SPA-ELISA method for detecting anti-coronavirus IgG antibodies in serum samples from fulvous fruit bats]. OBJECTIVE To develop an simple and sensitive method for detecting anti-coronavirus IgG antibodies in bat sera based on enzyme-linked immunosorbent assay (ELISA). METHODS A commercial ELISA kit for detecting SARS-CoV antibody was modified for detecting coronavirus antibodies in bat serum samples. The second antibody in the kit was replaced with horseradish peroxidase-conjugated protein-A (HRP-SPA) based on the characteristics of binding between Staphylococcus aureus protein A (SPA) and mammal IgG Fc fragment. The sera of 55 fulvous fruit bats (Rousettus dasymallus) were tested using the SPA-ELISA. RESULTS The test results of the positive and negative controls in the kit and the serum samples from convalescent ;patient were consistent with expectation. Coronavirus antibody was detected in 2 out of the 55 bat serum samples. Serum neutralization test confirmed the validity of the SPA-ELISA method. CONCLUSION This SPA-ELISA method is applicable for detecting coronavirus antibody in bat sera.

positive: Recombinant protein‐based ELISA and immuno‐cytochemical assay for the diagnosis of SARS A new Coronavirus (SARS‐CoV) is the aetiological agent of the severe acute respiratory syndrome (SARS). Because of the critical role played by serological assays for SARS diagnosis, an in‐house ELISA based on SARS‐CoV recombinant antigens was developed. The SARS‐CoV nucleocapsid protein (N), three N fragments (N1, N2, and N3) and the intraviral domain of the membrane protein (M2) were cloned and expressed in Escherichia coli as histidine‐tagged proteins. Six reference sera from SARS patients were used to detect virus‐specific IgG in an ELISA using each recombinant protein as coating antigen. High‐titre positive reactions were detected in all SARS positive sera. The specificity of the assay appears to be high as no positive reaction was detected in the sera of 20 healthy subjects and 73 patients with non‐SARS, low‐tract respiratory infections. Specific hyper‐immune sera to SARS‐CoV and the recombinant proteins, N, N1, N2, N3, and M2 were also generated in mice and rabbits. The specificity of these sera was confirmed by an immunocytochemical assay on biochips of SARS‐CoV infected and uninfected cells. J. Med. Virol. 76:137–142, 2005. © 2005 Wiley‐Liss, Inc.

positive: Qualitative serology in patients recovered from SARS CoV 2 infection

positive: Development and validation of the Elecsys Anti-SARS-CoV-2 immunoassay as a highly specific tool for determining past exposure to SARS-CoV-2 Background: The Elecsys(R) Anti-SARS-CoV-2 immunoassay (Roche Diagnostics) was developed to provide an accurate and reliable method for the detection of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluated the sensitivity, specificity, and cross-reactivity of the Elecsys Anti-SARS-CoV-2 immunoassay. Methods: The performance of the Elecsys Anti-SARS-CoV-2 immunoassay was assessed at Roche Diagnostics (Penzberg, Germany). Sensitivity was evaluated using anonymised residual frozen samples from patients who had previously tested positive for SARS-CoV-2 infection by polymerase chain reaction (PCR); one or more consecutive samples were collected from patients at various timepoints after PCR confirmation. Specificity was evaluated using anonymised unselected residual frozen samples from routine diagnostic testing or from blood donors; all samples were collected before December 2019 and thus deemed negative for SARS-CoV-2-specific antibodies. Cross-reactivity was evaluated using anonymised frozen samples containing a wide range of potentially cross-reacting analytes, which were purchased from commercial vendors. For sensitivity and specificity, point estimates and 95% confidence intervals (CIs) were calculated. Results: Sensitivity of the Elecsys Anti-SARS-CoV-2 immunoassay in 496 samples from 102 patients with prior PCR-confirmed SARS-CoV-2 infection was 99.5% (95% CI 97.0-100.0) at [≥]14 days after PCR confirmation. Overall specificity in 10,453 samples from routine diagnostic testing (n = 6305) and blood donors (n = 4148) was 99.80% (95% CI 99.69-99.88). Only 4/752 samples containing potential cross-reacting analytes were reactive with the Elecsys Anti-SARS-CoV-2 immunoassay, resulting in an overall specificity in this cohort of 99.5% (95% CI 98.6-99.9). Conclusion: The Elecsys Anti-SARS-CoV-2 immunoassay demonstrated a sensitivity of 99.5% at [≥]14 days after PCR confirmation and a very high specificity of 99.80%. Our findings support the use of the Elecsys Anti-SARS-CoV-2 immunoassay as a tool for the identification of past SARS-CoV-2 infection, including in populations with a low disease prevalence.

positive: High seroprevalence for SARS-CoV-2 among household members of essential workers detected using a dried blood spot assay Objective: Serological testing is needed to investigate the extent of transmission of SARS-CoV-2 from front-line essential workers to their household members. However, the requirement for serum/plasma limits serological testing to clinical settings where it is feasible to collect and process venous blood. To address this problem we developed a serological test for SARS-CoV-2 IgG antibodies that requires only a single drop of finger stick capillary whole blood, collected in the home and dried on filter paper (dried blood spot, DBS). Methods: An ELISA to the receptor binding domain of the SARS-CoV-2 spike protein was optimized to quantify IgG antibodies in DBS. Samples were self-collected from a community sample of 232 participants enriched with health care workers, including 30 known COVID-19 cases and their household members. Results: Among 30 individuals sharing a household with a virus-confirmed case of COVID-19, 80% were seropositive. Of 202 community individuals without prior confirmed acute COVID-19 diagnoses, 36% were seropositive. Of documented convalescent COVID-19 cases from the community, 29 of 30 (97%) were seropositive for IgG antibodies to the receptor binding domain. Conclusion: DBS ELISA provides a minimally-invasive alternative to venous blood collection. Early analysis suggests a high rate of transmission among household members. High rates of seroconversion were also noted following recovery from infection. Serological testing for SARS-CoV-2 IgG antibodies in DBS samples can facilitate seroprevalence assessment in community settings to address epidemiological questions, monitor duration of antibody responses, and assess if antibodies against the spike protein correlate with protection from reinfection.

positive: Dynamic profile for the detection of anti-SARS-CoV-2 antibodies using four immunochromatographic assays In order to fight the SARS-CoV-2 pandemic infection, there is a growing need and demand for diagnostic tools that are complementary and different from the RT-PCR currently in use. Multiple serological tests are or will be very soon available but need to be evaluated and validated. We have thus tested 4 immunochromatographic tests for the detection of antibodies to SARS-CoV-2. In addition, we assessed the kinetics of antibody appearance using these assays in 22 patients after they were tested positive by RT-PCR. We observed great heterogeneity in antibody detection post-symptom onset. The median antibody detection time was between 8 and 10 days according to the manufacturers. All the tests showed a sensitivity of 60 to 80% on day 10 and 100% on day 15. In addition, a single cross-reaction was observed with other human coronavirus infections. Thus, immunochromatographic tests for the detection of anti-SARS-CoV-2 antibodies may have their place for the diagnostic panel of COVID-19.

positive: Serological Diagnosis of Feline Coronavirus Infection by Immunochromatographic Test The immunochromatographic assay (ICA) is a simple antibody–antigen detection method, the results of which can be rapidly obtained at a low cost. We designed an ICA to detect anti-feline coronavirus (FCoV) antibodies. A colloidal gold-labeled recombinant FCoV nucleocapsid protein (rNP) is used as a conjugate. The Protein A and affinity-purified cat anti-FCoV IgG are blotted on the test line and the control line, respectively, of the nitrocellulose membrane. The specific detection of anti-FCoV antibodies was possible in all heparin-anticoagulated plasma, serum, whole blood, and ascitic fluid samples from anti-FCoV antibody positive cats, and nonspecific reaction was not noted in samples from anti-FCoV antibody negative cats.

positive: Dynamics of the SARS-CoV-2 epidemic in the earliest-affected areas in Italy: 1 Mass screening for SARS-CoV-2 serological positivity (SARS-2-SCREEN). Background Several municipalities in the Lombardy Region have been affected by the SARS-CoV-2 infection since the earliest stages of the epidemic. To date, 89442 confirmed cases have been diagnosed in Lombardy, and mortality in several municipalities has already surpassed that of the past decade. Currently, the true extent of the SARS-CoV-2 infection remains unknown as several affected subjects may have been asymptomatic or have presented mild disease, thus not resulting in the identified COVID-19 cases. Methods This cross-sectional study aims to define the spread of infection within the population by determining the seroprevalence of IgG antibodies directed against SARS-CoV-2 by rapid immunochromatographic testing and subsequent confirmation by serology on venous blood by liquid phase immunochemical testing, also allowing to compare the two methods. Testing will be performed on adults and minors residing, domiciled or working in several municipalities of the Lombardy Region, involved in the initial stages of the epidemic. The study will include rapid finger-prick testing and venous sampling for antibodies against SARS-CoV-2, and nasopharyngeal swabbing (NPS). Concurrent notification of test results will occur via the regional healthcare information system (SISS). Discussion This study was developed with the desire to understand the seroprevalence of SARS-CoV-2 infection and the epidemiological transmission characteristics of this virus. Understanding the spread and severity of the disease could help in the implementation of effective infection surveillance containment and countermeasures facilitating the identification of cases that have been exposed to the virus and the traceability of contacts. This study has been approved by the Ethics Committee of the University of Milan (35/2020).

positive: Development of a diagnostic system for detection of specific antibodies and antigens against Middle East respiratory syndrome coronavirus Middle East respiratory syndrome coronavirus (MERS‐CoV) is a single‐stranded RNA virus that causes severe respiratory disease in humans with a high fatality rate. Binding of the receptor binding domain (RBD) of the spike (S) glycoprotein to dipeptidyl peptidase 4 is the critical step in MERS‐CoV infection of a host cell. No vaccines or clinically applicable treatments are currently available for MERS‐CoV. Therefore, rapid diagnosis is important for improving patient outcomes through prompt treatment and protection against viral outbreaks. In this study, the aim was to establish two ELISA systems for detecting antigens and antibodies against MERS‐CoV. Using a recombinant full‐length S protein, an indirect ELISA was developed and found to detect MERS‐CoV‐specific antibodies in animal sera and sera of patient with MERS. Moreover, MAbs were induced with the recombinant S protein and RBD and used for sandwich ELISA to detect the MERS‐CoV S protein. Neither ELISA system exhibited significant intra‐assay or inter‐assay variation, indicating good reproducibility. Moreover, the inter‐day precision and sensitivity were adequate for use as a diagnostic kit. Thus, these ELISAs can be used clinically to diagnose MERS‐CoV.

positive: Evaluation of commercial and automated SARS-CoV-2 IgG and IgA ELISAs using coronavirus disease (COVID-19) patient samples Antibody-screening methods to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) need to be validated. We evaluated SARS-CoV-2 IgG and IgA ELISAs in conjunction with the EUROLabworkstation (Euroimmun, Lübeck, Germany). Overall specificities were 91.9% and 73.0% for IgG and IgA ELISAs, respectively. Of 39 coronavirus disease patients, 13 were IgG and IgA positive and 11 IgA alone at sampling. IgGs and IgAs were respectively detected at a median of 12 and 11 days after symptom onset.

positive: Molecular immune pathogenesis and diagnosis of COVID-19 Coronavirus disease 2019 (COVID-19) is a kind of viral pneumonia which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The emergence of SARS-CoV-2 has been marked as the third introduction of a highly pathogenic coronavirus into the human population after the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV) in the twenty-first century. In this minireview, we provide a brief introduction of the general features of SARS-CoV-2 and discuss current knowledge of molecular immune pathogenesis, diagnosis and treatment of COVID-19 on the base of the present understanding of SARS-CoV and MERS-CoV infections, which may be helpful in offering novel insights and potential therapeutic targets for combating the SARS-CoV-2 infection.

positive: Development of a competitive enzyme-linked immunosorbent assay for detection of turkey coronavirus antibodies. A competitive enzyme-linked immunosorbent assay (cELISA) was developed for detection of turkey coronavirus (TCV) antibodies. The cELISA utilized a recombinant baculovirus (Autographa californica nuclear polyhedrosis virus)-expressed TCV nucleocapsid (N) protein and biotin-labeled TCV N protein-specific monoclonal antibody. Sensitivity and specificity of the cELISA for detection of TCV antibodies were determined by comparison with the indirect fluorescent antibody test (IFAT) with 1269 reference, experimentally derived, and field-origin sera. Sera with discordant cELISA and IFAT results were further evaluated by western immunoblot analyses. The cELISA detected antibodies specific for TCV and infectious bronchitis virus, a closely related coronavirus, but did not detect antibodies specific for other avian viruses. A high degree of concordance was observed between the cELISA and IFAT; sensitivity and specificity of the cELISA relative to IFAT were 92.9% and 96.2%, respectively. Western immunoblot analyses provided additional evidence of cELISA specificity. The findings indicate that the cELISA is a rapid, sensitive, and specific serologic test for detection of TCV antibodies in turkeys.

positive: Meta-analysis of diagnostic performance of serological tests for SARS-CoV-2 antibodies and public health implications Serology-based tests have become a key public health element in the COVID-19 pandemic to assess the degree of herd immunity that has been achieved in the population. These tests differ between one another in several ways. Here, we conducted a systematic review and meta-analysis of the diagnostic accuracy of currently available SARS-CoV-2 serological tests, and assessed their real-world performance under scenarios of varying proportion of infected individuals. We included independent studies that specified the antigen used for antibody detection and used quantitative methods. We identified nine independent studies, of which six were based on commercial ELISA or CMIA/CLIA assays, and three on in-house tests. Test sensitivity ranged from 68% to 93% for IgM, from 65% to 100% for IgG, and from 83% to 98% for total antibodies. Random-effects models yielded a summary sensitivity of 82% (95%CI 75-88%) for IgM, and 85% for both IgG (95%CI 73-93%) and total antibodies (95%CI 74-94%). Specificity was very high for most tests, and its pooled estimate was 98% (95%CI 92-100%) for IgM and 99% (95%CI 98-100%) for both IgG and total antibodies. The heterogeneity of sensitivity and specificity across tests was generally high (I2[≤]50%). In populations with a low prevalence ([≤]5%) of seroconverted individuals, the positive predictive value would be [≤]88% for most assays, except those reporting perfect specificity. Our data suggest that the use of serological tests for large-scale prevalence surveys (or to grant "immunity passports") are currently only justified in hard-hit regions, while they should be used with caution elsewhere.

positive: Profiling Early Humoral Response to Diagnose Novel Coronavirus Disease (COVID-19) BACKGROUND: The emergence of coronavirus disease 2019 (COVID-19) is a major healthcare threat. The current method of detection involves a quantitative polymerase chain reaction (qPCR)–based technique, which identifies the viral nucleic acids when present in sufficient quantity. False-negative results can be achieved and failure to quarantine the infected patient would be a major setback in containing the viral transmission. We aim to describe the time kinetics of various antibodies produced against the 2019 novel coronavirus (SARS-CoV-2) and evaluate the potential of antibody testing to diagnose COVID-19. METHODS: The host humoral response against SARS-CoV-2, including IgA, IgM, and IgG response, was examined by using an ELISA-based assay on the recombinant viral nucleocapsid protein. 208 plasma samples were collected from 82 confirmed and 58 probable cases (qPCR negative but with typical manifestation). The diagnostic value of IgM was evaluated in this cohort. RESULTS: The median duration of IgM and IgA antibody detection was 5 (IQR, 3–6) days, while IgG was detected 14 (IQR, 10–18) days after symptom onset, with a positive rate of 85.4%, 92.7%, and 77.9%, respectively. In confirmed and probable cases, the positive rates of IgM antibodies were 75.6% and 93.1%, respectively. The detection efficiency by IgM ELISA is higher than that of qPCR after 5.5 days of symptom onset. The positive detection rate is significantly increased (98.6%) when combining IgM ELISA assay with PCR for each patient compared with a single qPCR test (51.9%). CONCLUSIONS: The humoral response to SARS-CoV-2 can aid in the diagnosis of COVID-19, including subclinical cases.

positive: The paramount importance of serological surveys of SARS-CoV-2 infection and immunity

positive: Evaluation of eleven rapid tests for detection of antibodies against SARS-CoV-2 Objectives SARS-CoV-2, causing COVID-19, has emerged to cause a human pandemic. Detection of SARS-CoV-2 in respiratory samples by using PCR is the standard laboratory diagnostic tool. Our aim was to perform a limited evaluation of the diagnostic performance and user-friendliness of eleven rapid tests for detection of antibodies against SARS-CoV-2. Methods All participants were tested with PCR against SARS-CoV-2 at a clinical microbiology laboratory. Comparing with results from PCR tests, we evaluated the rapid tests' performances in three arms; 1) 20 hospitalized patients with PCR-confirmed COVID-19, 2) 23 recovered outpatients with former PCR-confirmed COVID-19, and 3) 49 participants with suspected COVID-19 presenting at a primary care emergency room. Results All eleven tests detected antibodies in hospitalized COVID-19 patients, though with varying sensitivities. In former outpatients recovered from COVID-19, there were differences between tests in the immunoglobulin type G (IgG) sensitivity, with five tests having a sensitivity below 65%. In participants with suspected COVID-19 infection, the rapid tests had very low sensitivities. Most rapid tests were easy to perform and interpret. Conclusions Rapid tests were not suited as stand-alone tests to detect present infection in a Norwegian primary care emergency room population. All the rapid tests were able to detect SARS-CoV-2 antibodies, although sensitivities varied and were generally higher in the study arm of more severely affected participants. Rapid tests with high IgG sensitivity (and specificity) may be useful for confirmation of past infection. An independent evaluation should be performed in the intended population before introducing a rapid test.

positive: The production of antibodies for SARS-CoV-2 and its clinical implication Background: Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), a novel betacoronavirus, has caused an outburst of pneumonia cases in Wuhan, China. We report the production of specific IgM and IgG antibodies after the infection of SARS-CoV-2 and its implication for the diagnosis, pathology and the course of the disease as well as the recurrence of positive nucleic acid tests after discharge. Methods: Test results for SARS-CoV-2 IgM and IgG antibodies of 221 confirmed COVID-19 patients were retrospectively examined, and their clinical data were collected and analyzed based on various subgroups. SARS-CoV-2 IgM and IgG antibodies were determined with the chemiluminescence method. Findings: The concentration (S/CO) of SARS-CoV-2 IgM and IgG antibodies peaked on day 19-21 after symptom onset, with a median of 17.38 (IQR 4.39-36.4) for IgM and 5.59 (IQR 0.73-13.65) for IgG. Detection rates reached highest on day 16-18 and day 19-21 for IgM and IgG, which were 73.6% and 98.6%, respectively, with significantly higher concentration of IgG in critically ill patients than in those with mild to moderate disease (P=0.027). The concentration of the antibodies on day 16-21 is not correlated with the course or outcome of the disease (Spearman r < 0.20, P > 0.05). Nasopharyngeal swabs revealed positive SARS-CoV-2 RNA in up to 52.7% of recovered patients after discharge, whose IgG proved to be significantly lower than that of those with negative RNA results (P = 0.009). IgG and IgM were tested twice within 14 days after discharge with a 7-day interval, and the second testing of these antibodies displayed a decrease in concentration of 21.2% (IQR, 11.2%34.48%) for IgG and 23.05% (IQR, -27.96%46.13%) for IgM, without statistical significance between the patients with re-detectable positive RNA results and those with negative RNA results after discharge. However, those with positive results experienced a count decrease in lymphocyte subsets. Interpretation: The concentration of SARS-CoV-2 IgM and IgG antibodies peaked on day 19-21 after symptom onset, and antibody testing on day 16-21 is associated with increased detection rates, but the antibody concentration does not affect the course and outcome of the infection. Recovering patients with re-detectable positive SARS-CoV-2 RNA displayed lower concentration of IgG, but the downward trend of IgG during recovery indicated its limited duration of protection, and the protective effect of IgG remains to be investigated.

positive: In-depth virological assessment of kidney transplant recipients with COVID-19 Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread widely, causing coronavirus disease 2019 (COVID-19) and significant mortality. However, data on viral loads and antibody kinetics in immunocompromised populations are lacking. We aimed to determine nasopharyngeal and plasma viral loads via RT-PCR and SARS-CoV-2 serology via ELISA and study their association with severe forms of COVID-19 and death in kidney transplant recipients. In this study we examined hospitalized kidney transplant recipients with non-severe (n = 21) and severe (n =19) COVID-19. SARS-CoV-2 nasopharyngeal and plasma viral load and serological response were evaluated based on outcomes and disease severity. Ten recipients (25%) displayed persistent viral shedding 30 days after symptom onset. The SARS-CoV-2 viral load of the upper respiratory tract was not associated with severe COVID-19, whereas the plasma viral load was associated with COVID-19 severity (p=0.0087) and mortality (p=0.024). All patients harbored antibodies the second week after symptom onset that persisted for two months. We conclude that plasma viral load is associated with COVID-19 morbidity and mortality, whereas nasopharyngeal viral load is not. SARS-CoV-2 shedding is prolonged in kidney transplant recipients and the humoral response to SARS-CoV-2 does not show significant impairment in this series of transplant recipients.

positive: COVID-19 diagnostic approaches: different roads to the same destination “SARS-CoV2”, a previously unknown strain of coronaviruses caused a severe respiratory disease called Coronavirus disease (COVID-19) which emerged from Wuhan city of China on 30 December 2019, and declared as Global health problem by World Health Organisation within a month. In less than two and half months (11 March, 2020) it was declared as a pandemic disease due to its rapid spreading ability, it covered more than 211 countries infecting around 1.7 million persons and claiming around 1.1 lakhs lives within merely 100 days of its emergence. Containment of the infection of this virus is the only available measure to control the disease as no vaccine or specific antiviral treatment is available. Confirmed detection of the virus followed by isolation of the infected person at the earliest possible is the only measure to prevent this disease. Although there are number of methods available for detection of virus and to combat this disease in the present pandemic situation, but these available diagnostic methods have their own limitations. The speedy and exponential global spread of this disease strongly urges the fast and economic diagnostics tools. Additional to the available diagnostic methods, there is a sudden surge for development of various of methods and platforms to diagnose the COVID-19. The review summarized the advantage and disadvantage of various diagnostic approaches being used presently for COVID-19, newer detection methods in developmental stage and the feasibility of advanced platforms like newer nano-sensor based on-the-spot detection technologies.

positive: Quantitation of antibody to non-hemagglutinating viruses by single radial hemolysis: serological test for human coronaviruses. A single radial hemolysis test was developed for quantitation of specific antibody to non-hemagglutinating viruses. With the human coronaviruses as models, this test utilizes the binding properties of the chromic cation to attach viruses to glutaraldehyde-treated sheep erythrocytes. The most satisfactory system consisted of stabilizing washed sheep erythrocytes with 0.0073% glutaraldehyde for 15 min at 23 degrees C, binding a high concentration of virus to a 25% erythrocyte suspension with 0.0016% chromic chloride for 20 min at 23 degrees C, stopping the reaction with phosphate-saline, and finally mixing the treated, rewashed cells with complement and agarose at 45 degrees C to prepare a slide gel. The gel mix, which was dispensed in plastic plates (23 by 73 mm) in 3-ml volumes, consisted of 1% agarose, 0.1% sodium azide, 5% reconstituted complement, and 0.82% treated cells. Wells 2 mm in diameter were loaded with 5 mul of antiserum, incubated for 18 h at 4 degrees C for diffusion of antiserum and fixation of complement, and then incubated for 8 to 24 h at 37 degrees C for development of hemolysis zones. The diameter of a zone was linearly related to antibody concentration, as determined by conventional serological tests. This single radial hemolysis test was applicable to human and animal coronaviruses and to selected serotypes of the adenovirus, picornavirus, rhabdovirus, and rotavirus groups.

positive: Antibody tests for COVID-19: drawing attention to the importance of analytical specificity

positive: Two enzyme immunoassays for the detection of antibody to rodent coronaviruses Abstract Two enzyme immunoassays for detection of antibody to rodent coronaviruses were compared. Mouse hepatitis virus (MHV), strain JHM, antigen was in the form of formalin-fixed, infected 17 C1 1 cells. This antigen detected antibody to the homologous strain of MHV as well as to two heterologous MHV strains and a serologically related rat coronavirus, sialodacryodenititis virus. Antibody titers in assays using horseradish peroxidase (HRP)-conjugated or ureiase-conjugated anti-mouse IgG were substantially higher than in an indirect immunofluorescence assay. The ureiase assay was somewhat more sensitive than the HRP assay. MHV-JHM antigen was stable under a variety of storage conditions for at least two months.

positive: Serological tests for COVID-19 antibodies: Limitations must be recognized

positive: Development and comparison of enzyme-linked immunosorbent assays based on recombinant trimeric full-length and truncated spike proteins for detecting antibodies against porcine epidemic diarrhea virus BACKGROUND: Since 2010, outbreaks of genotype 2 (G2) porcine epidemic diarrhea virus (PEDV) have caused high mortality in neonatal piglets and have had devastating impacts on the swine industry in many countries. A reliable serological assay for evaluating the PEDV-specific humoral and mucosal immune response is important for disease survey, monitoring the efficacy of immunization, and designing strategies for the prevention and control of PED. Two PEDV spike (S) glycoprotein-based indirect enzyme-linked immunosorbent assays (ELISAs) were developed using G2b PEDV-Pintung 52 (PEDV-PT) trimeric full-length S and truncated S(1–501) proteins derived from the human embryonic kidney (HEK)-293 cell expression system. The truncated S(1–501) protein was selected from a superior expressed stable cell line. The sensitivity and specificity of these two ELISAs were compared to immunostaining of G2b PEDV-PT infected cells and to a commercial nucleocapsid (N)-based indirect ELISA kit using a panel of PEDV negative and hyperimmune sera. RESULTS: The commercial N-based ELISA exhibited a sensitivity of 37%, a specificity of 100%, and a fair agreement (kappa = 0.37) with the immunostaining result. In comparison, the full-length S-based ELISA showed a sensitivity of 97.8%, a specificity of 94%, and an almost perfect agreement (kappa = 0.90) with the immunostaining result. Interestingly, the S(1–501)-based ELISA had even higher sensitivity of 98.9% and specificity of 99.1%, and an almost perfect agreement (kappa = 0.97) with the immunostaining result. A fair agreement (kappa< 0.4) was seen between the commercial N-based ELISA and either of our S-based ELISAs. However, the results of the full-length S-based ELISA shared an almost perfect agreement (kappa = 0.92) with that of S(1–501)-based ELISA. CONCLUSIONS: Both full-length S-based and S(1–501)-based ELISAs exhibit high sensitivity and high specificity for detecting antibodies against PEDVs. Considering the high protein yield and cost-effectiveness, the S(1–501)-based ELISA could be used as a reliable, sensitive, specific, and economic serological test for PEDV.

positive: Improvement of a recombinant antibody-based serological assay for foot-and-mouth disease virus Abstract Differentiating foot-and-mouth disease virus (FMDV) antibodies generated during a natural infection from those due to vaccination (DIVA) is crucial for proving freedom from disease after an outbreak and allowing resumption of trade in livestock products. The World Organisation for Animal Health (OIE) recommends that FMDV vaccines are composed of inactivated virus that has been purified to remove non-structural viral proteins. Such purified vaccines primarily induce antibodies to viral structural proteins, whereas replicating virus stimulates host antibodies specific for both structural and non-structural proteins. The current preferred FMDV DIVA test is a competitive ELISA (C-ELISA) designed to detect antibodies to the non-structural protein 3ABC. Previously, we described the development of an FMDV DIVA test based entirely on recombinant proteins (the recombinant detecting antibody and the 3ABC coating antigen) produced in Escherichia coli. In this study, we have determined the precise binding site of the recombinant detecting antibody to a conserved sequence within the 3B region of the 3ABC protein, replaced the original E-tag of the detecting antibody with two in-house tags and engineered a direct antibody–reporting enzyme (alkaline phosphatase) fusion protein. These modifications have further improved the DIVA test, providing great potential for large scale production and uptake due to its simplicity, reproducibility and low cost.

positive: Comparison of serologic techniques for the detection of antibodies against feline coronaviruses. The seroprevalence of feline coronavirus (FCoV) antibodies was studied in cats in southern Italy. One hundred twenty sera collected from cats belonging to catteries or community shelters and to households were tested for FCoV type I and II antibodies. The virus neutralization (VN) was performed and compared with indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA). Ninety-six sera tested positive for FCoV antibodies by VN and ELISA. Interestingly, ELISA revealed 2 more positive sera than did the VN test and 3 more positive sera than did the IFAT. All results were confirmed by Western blotting. ELISA proved to be more sensitive and detected a seroprevalence of about 82%. Considering the cross-reactivity of FCoV type I and type II, ELISA was able to detect antibodies against both serotypes, allowing the use of the assay as a reference test for sera screening. The high prevalence of antibodies observed indicates that FCoVs are common in southern Italian cat populations.

positive: Characteristics of patients with coronavirus disease (COVID-19) confirmed using an IgM-IgG antibody test Coronavirus disease (COVID-19), caused by a novel betacoronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly developed into a pandemic since it was first reported in December 2019. Nucleic acid testing is the standard method for the diagnosis of viral infections. However, this method reportedly has a low positivity rate. To increase the sensitivity of COVID-19 diagnoses, we developed an IgM-IgG combined assay and tested it in patients with suspected SARS-CoV-2 infection. In total, 56 patients were enrolled in this study and SARS-CoV-2 was detected by using both IgM-IgG antibody and nucleic acid tests. Clinical and laboratory data were collected and analyzed. Our findings suggest that patients who develop severe illness might experience longer virus exposure times and develop a more severe inflammatory response. The IgM-IgG test is an accurate and sensitive diagnostic method. A combination of nucleic acid and IgM-IgG testing is a more sensitive and accurate approach for diagnosis and early treatment of COVID-19.

positive: Combination of serological total antibody and RT-PCR test for detection of SARS-COV-2 infections The purpose of this study was to investigate the feasibility of serological total antibody tests combined with RT-PCR for detection of SARS-COV-2. We conducted a retrospective study in which 375 patients were enrolled during the outbreak of SARS-COV-2 from 25th January to 16th March 2020. Patients were divided into a COVID-19 group (n = 141) and a control group (n = 234). Serum samples and throat swabs were collected from 375 patients for total antibody testing against SARS-COV-2 and RT-PCR analysis, respectively. The results indicated that diagnostic sensitivity and specificity were 95.7 % and 98.7 %, 92.2 % and 100 % by total antibody tests and RT-PCR, respectively. The sensitivity and specificity of total antibody tests combined with RT-PCR were 98.6 % and 98.7 %. The sensitivity of the combined method was significantly higher than RT-PCR (X2 = 5.16, P < 0.05), and similar to that of total antibody tests (X2 = 1.15, P> 0.05). This study supported the advantage of the combined method for detection of SARS-COV-2 with a high degree of sensitivity and specificity, as a useful tool for accurate diagnosis and timely treatment of suspected patients, epidemiological investigation, as well as monitoring ongoing outbreaks of infections with SARS-COV-2.

positive: The effect of serological screening for SARS-CoV-2 antibodies to participants' attitudes and risk behaviour: a study on a tested population sample of industry workers in Split-Dalmatia County, Croatia Rapid serological tests for SARS-CoV-2 antibodies have been questioned by scientists and the public because of unexplored effects of negative test results on behaviour and attitudes, that could lower the level of adherence to protective measures. Therefore, our study aimed to investigate the changes in personal attitudes and behaviour before and after negative serological test results for SARS-CoV-2 antibodies. We conducted a survey questionnaire on 200 industry workers (69% males and 31% females) that have been previously tested negative. The survey examined participants' self-reported general attitudes towards COVID-19, sense of fear, as well as their behaviour related to protective measures before and after the testing. The participants perceived the disease as a severe health threat and acknowledged the protective measures as appropriate. They reported a high level of adherence to measures and low level of fear both before and after the testing. Although those indicators were statistically significantly reduced after the test (P < 0.004), they did not result in risk behaviour. Therefore, the serological tests are not an additional threat regarding the risk behaviour in an environment where protective measures are efficient. In contrast, they might contribute to reducing the fear in the society and working environment.

positive: Identification of IgG antibody response to SARS-CoV-2 spike protein and its receptor binding domain does not predict rapid recovery from COVID-19 Diagnostic testing and evaluation of patient immunity against the novel severe acute respiratory syndrome (SARS) corona virus that emerged last year (SARS-CoV-2) are essential for health and economic crisis recovery of the world. It is suggested that potential acquired immunity against SARS-CoV-2 from prior exposure may be determined by detecting the presence of circulating IgG antibodies against viral antigens, such as the spike glycoprotein and its receptor binding domain (RBD). Testing our asymptomatic population for evidence of COVID-19 immunity would also offer valuable epidemiologic data to aid health care policies and health care management. Currently, there are over 100 antibody tests that are being used around the world without approval from the FDA or similar regulatory bodies, and they are mostly for rapid and qualitative assessment, with different degrees of error rates. ELISA-based testing for sensitive and rigorous quantitative assessment of SARS-CoV-2 antibodies can potentially offer mechanistic insights into the COVID-19 disease and aid communities uniquely challenged by limited financial resources and access to commercial testing products. Employing recombinant SARS-CoV-2 RBD and spike protein generated in the laboratory, we devised a quantitative ELISA for the detection of circulating serum antibodies. Serum from twenty SARS-CoV-2 RT-PCR confirmed COVID-19 hospitalized patients were used to detect circulating IgG titers against SARS-CoV-2 spike protein and RBD. Quantitative detection of IgG antibodies to the spike glycoprotein or the RBD in patient samples was not always associated with faster recovery, compared to patients with borderline antibody response to the RBD. One patient who did not develop antibodies to the RBD completely recovered from COVID-19. In surveying 99 healthy donor samples (procured between 2017-February 2020), we detected RBD antibodies in one donor from February 2020 collection with three others exhibiting antibodies to the spike protein but not the RBD. Collectively, our study suggests that more rigorous and quantitative analysis, employing large scale sample sets, is required to determine whether antibodies to SARS-CoV-2 spike protein or RBD is associated with protection from COVID-19 disease. It is also conceivable that humoral response to SARS-CoV-2 spike protein or RBD works in association with adaptive T cell response to determine clinical sequela and severity of COVID-19 disease.

positive: Comparison and Application of Different Immunoassay Methods for the Detection of SARS‐CoV‐2 The detection data of IgM and IgG antibodies in 169 patients with coronavirus disease (COVID‐19) were analyzed to evaluate differences in clinical performance between the colloidal gold method and chemiluminescence method. In this study, chemiluminescence detection of IgM antibody showed a positive conversion earlier (about 1~2 days earlier), positive conversion rates higher in different stages of disease, and a trend of declining positive rate later than colloidal gold method. For IgG antibody, the chemiluminescence method showed a positive conversion earlier and the positive rate climbing more quickly than the colloidal gold method. No obvious negative‐converting tendency of IgG detection was observed within 35 days after the onset of disease. Although colloidal gold method is generally less sensitive than chemiluminescence method, it shows advantages of shorter turn‐around time, more simple procedure and no special equipment required. The two methodologies can be chosen according to different laboratory conditions. A reasonable understanding of the performance of reagents with different methodologies can help in clinical disease diagnosis effectively and assist in the diagnosis of the progression of COVID‐19, for which the dynamic changes of antibody will provide reliable evidence. This article is protected by copyright. All rights reserved.

positive: Differential sensitivities of severe acute respiratory syndrome (SARS) coronavirus spike polypeptide enzyme-linked immunosorbent assay (ELISA) and SARS coronavirus nucleocapsid protein ELISA for serodiagnosis of SARS coronavirus pneumonia. The use of recombinant severe acute respiratory syndrome-coronavirus (SARS-CoV) nucleocapsid protein (N) enzyme-linked immunosorbent assay (ELISA)-based antibody and antigen tests for diagnosis of SARS-CoV infections have been widely reported. However, no recombinant SARS-CoV spike protein (S)-based ELISA is currently available. In this article, we describe the problems and solutions of setting up the recombinant SARS-CoV S-based ELISA for antibody detection. The SARS-CoV S-based immunoglobulin M (IgM) and IgG ELISAs were evaluated and compared with the corresponding N-based ELISA for serodiagnosis of SARS-CoV pneumonia, using sera from 148 healthy blood donors who donated blood 3 years ago as controls and 95 SARS-CoV pneumonia patients in Hong Kong. Results obtained by the recombinant S (rS)-based IgG ELISA using the regenerated S prepared by dialysis with decreasing concentrations of urea or direct addition of different coating buffers, followed by addition of different regeneration buffer, identified 4 M urea and 1 M sarcosine for plate coating and no regeneration buffer as the most optimal conditions for antibody detection. The specificities of the S-based ELISA for IgG and IgM detection were 98.6% and 93.9%, with corresponding sensitivities of 58.9% and 74.7%, respectively. The sensitivity of the rN IgG ELISA (94.7%) is significantly higher than that of the rS IgG ELISA (P < 0.001), whereas the sensitivity of the rS IgM ELISA is significantly higher than that of the rN IgM ELISA (55.2%) (P < 0.01). An ELISA for detection of IgM against S and N could be more sensitive than one that detects IgM against N alone for serodiagnosis of SARS-CoV pneumonia.

positive: Characterization and application of monoclonal antibodies against N protein of SARS-coronavirus Abstract Severe acute respiratory syndrome-coronavirus (SARS-CoV) causes an infectious disease through respiratory route. Diagnosing the disease effectively and accurately at early stage is essential for preventing the disease transmission and performing antiviral treatment. In this study, we raised monoclonal antibodies (mAbs) against the nucleocapsid (N) protein of SARS-CoV and mapped epitopes by using different truncated N protein fragments. The mapping of those epitopes was valuable for constructing pair-Abs used in serological diagnosis. The results showed that all of the six raised mAbs were divided into two groups recognizing the region of amino acids 249–317 (A group) or 317–395 (B group). This region spanning amino acids 249–395 contains predominant B cell epitopes located at the C-terminus of N protein. One pair-Abs, consisting of N protein-specific rabbit polyclonal antibody and SARS-CoV N protein-specific mAb, was selected to construct a sandwich ELISA-kit. The kit was able to specifically detect SARS-CoV N proteins in serum samples.

positive: Antibody tests in detecting SARS-CoV-2 infection: a meta-analysis With the emergence of SARS-CoV-2 and the associated Coronavirus disease 2019 (COVID-19), there is an imperative need for diagnostic tests that can identify the infection. Although Nucleic Acid Test (NAT) is considered to be the gold standard, serological tests based on antibodies could be very helpful. However, individual studies measuring the accuracy of the various tests are usually underpowered and inconsistent, thus, a comparison of different tests is needed. We performed a systematic review and meta-analysis following the PRISMA guidelines. We conducted the literature search in PubMed, medRxiv and bioRxiv. For the statistical analysis we used the bivariate method for meta-analysis of diagnostic tests pooling sensitivities and specificities. We evaluated IgM and IgG tests based on Enzyme-linked immunosorbent assay (ELISA), Chemiluminescence Enzyme Immunoassays (CLIA), Fluorescence Immunoassays (FIA) and the point-of-care (POC) Lateral Flow Immunoassays (LFIA) that are based on immunochromatography. In total, we identified 38 eligible studies that include data from 7,848 individuals. The analyses showed that tests using the S antigen are more sensitive than N antigen-based tests. IgG tests perform better compared to IgM ones, and show better sensitivity when the samples were taken longer after the onset of symptoms. Moreover, irrespective of the method, a combined IgG/IgM test seems to be a better choice in terms of sensitivity than measuring either antibody type alone. All methods yielded high specificity with some of them (ELISA and LFIA) reaching levels around 99%. ELISA- and CLIA-based methods performed better in terms of sensitivity (90-94%) followed by LFIA and FIA with sensitivities ranging from 80% to 86%. ELISA tests could be a safer choice at this stage of the pandemic. POC tests (LFIA), that are more attractive for large seroprevalence studies show high specificity but lower sensitivity and this should be taken into account when designing and performing seroprevalence studies.

positive: Diagnosis of severe acute respiratory syndrome (SARS) by detection of SARS coronavirus nucleocapsid antibodies in an antigen-capturing enzyme-linked immunosorbent assay. Recombinant severe acute respiratory syndrome (SARS) coronavirus nucleocapsid protein was employed to establish an antigen-capturing enzyme-linked immunosorbent assay (ELISA). Antinucleocapsid protein antibodies could be detected in 68.4% of probable SARS patients 6 to 10 days after illness and in 89.6% of the patients 11 to 61 days after illness. No false-positive results were observed in 20 non-SARS fever patients, 24 non-SARS respiratory illness patients, and 20 health care workers. Among 940 other non-SARS clinical serum samples, only 1 was found to be weakly positive. This method provides a new, sensitive, and specific approach for SARS diagnosis.

positive: Diagnostic performance of immunochromatography assay for rapid detection of IgM and IgG in coronavirus disease 2019 Serologic assays have been developed to detect infection with coronavirus disease 2019 (COVID-19). This study was conducted to evaluate the diagnostic performance of an immunochromatography-based assay of human serum for COVID-19. The present study enrolled 149 subjects who had been tested by real-time reverse transcription-polymerase chain reaction (RT-PCR) for COVID-19 and were classified into two groups: 70 who were positive for COVID-19 and 79 who were negative for COVID-19 based on RT-PCR. An immunochromatography-based COVID-19 immunoglobulin G (IgG)/immunoglobulin M (IgM) rapid test on the sera of the study population was applied to measure the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and receiver operating characteristic (ROC) curve compared to RT-PCR, with a 95% confidence interval (CI). IgM or IgG antibodies were detected in 65 subjects (92.9%) classified as positive for COVID-19 and in three subjects (3.8%) classified as negative for COVID-19. The sensitivity and specificity percentages for IgM or IgG antibodies were 92.9% (95% CI: 84.1-97.6) and 96.2% (95% CI: 89.3-99.2), respectively, with 95.6% PPV and 93.8% NPV. The PPV rapidly improved with increasing disease prevalence from 19.8% to 96.1% in the presence of either IgM or IgG, while the NPV remained high with a change from 99.9% to 93.1%. The area under the ROC curve was 0.945 (95% CI: 0.903-0.988) for subjects with either IgM or IgG positivity. In conclusion, the immunochromatography-based COVID-19 IgG/IgM rapid test is a useful and practical diagnostic assay for detection of COVID-19, especially in the presence of IgM or IgG antibodies.

positive: Serological assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), March 2020 BackgroundThe ongoing coronavirus disease (COVID-19) pandemic has major impacts on health systems, the economy and society. Assessing infection attack rates in the population is critical for estimating disease severity and herd immunity which is needed to calibrate public health interventions. We have previously shown that it is possible to achieve this in real time to impact public health decision making.AimOur objective was to develop and evaluate serological assays applicable in large-scale sero-epidemiological studies.MethodsWe developed an ELISA to detect IgG and IgM antibodies to the receptor-binding domain (RBD) of the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluated its sensitivity and specificity in combination with confirmatory microneutralisation (MN) and 90% plaque reduction neutralisation tests (PRNT90) in 51 sera from 24 patients with virologically confirmed COVID-19 and in age-stratified sera from 200 healthy controls.ResultsIgG and IgM RBD ELISA, MN and PRNT90 were reliably positive after 29 days from illness onset with no detectable cross-reactivity in age-stratified controls. We found that PRNT90 tests were more sensitive in detecting antibody than MN tests carried out with the conventional 100 tissue culture infectious dose challenge. Heparinised plasma appeared to reduce the infectivity of the virus challenge dose and may confound interpretation of neutralisation test.ConclusionUsing IgG ELISA based on the RBD of the spike protein to screen sera for SARS-CoV-2 antibody, followed by confirmation using PRNT90, is a valid approach for large-scale sero-epidemiology studies.

positive: The researchers taking a gamble with antibody tests for coronavirus

positive: An Evolving Approach to the Laboratory Assessment of COVID‐19 As the COVID‐19 outbreak has evolved in each country, the approach to the laboratory assessment of SARS‐CoV‐2 infection has had to evolve as well. This review addresses the evolving approach to the laboratory assessment of COVID‐19 and discusses how algorithms for testing have been driven, in part, by the demand for testing overwhelming the capacity to accomplish such testing. This review focused on testing in the United States as this testing is evolving whereas in China and other countries such as South Korea testing is widely available and includes both molecular testing for SARS‐CoV‐2 as well as serological testing using both ELISA methodology and lateral flow immunoassay methodology. Although commercial testing systems are becoming available, there will likely be insufficient numbers of such tests due to high demand. Serological testing will be the next testing issue as the COVID‐19 begins to subside. This will allow immunity testing as well as will allow the parameters of the COVID‐19 outbreak to be defined. This article is protected by copyright. All rights reserved.

positive: Bounding the Predictive Values of COVID-19 Antibody Tests COVID-19 antibody tests have imperfect accuracy. There has been lack of clarity on the meaning of reported rates of false positives and false negatives. For risk assessment and clinical decision making, the rates of interest are the positive and negative predictive values of a test. Positive predictive value (PPV) is the chance that a person who tests positive has been infected. Negative predictive value (NPV) is the chance that someone who tests negative has not been infected. The medical literature regularly reports different statistics, sensitivity and specificity. Sensitivity is the chance that an infected person receives a positive test result. Specificity is the chance that a non-infected person receives a negative result. Knowledge of sensitivity and specificity permits one to predict the test result given a person's true infection status. These predictions are not directly relevant to risk assessment or clinical decisions, where one knows a test result and wants to predict whether a person has been infected. Given estimates of sensitivity and specificity, PPV and NPV can be derived if one knows the prevalence of the disease, the rate of illness in the population. There is considerable uncertainty about the prevalence of COVID-19. This paper addresses the problem of inference on the PPV and NPV of COVID-19 antibody tests given estimates of sensitivity and specificity and credible bounds on prevalence. I explain the methodological problem, show how to estimate bounds on PPV and NPV, and apply the findings to some tests authorized by the FDA.

positive: Detection of antibodies against SARS‐CoV‐2 in patients with COVID‐19 Detection of IgM and IgG against SARS-CoV-2 is a fast and simple screening method. As an effective supplement to RNA testing, antibody detection is of epidemiological significance and an important means to understand the occurrence, development, prognosis, and outcome of COVID-19. However, more medical research is needed on the expression level of antibodies against SARS-CoV-2 and the prognosis of COVID-19. This article is protected by copyright. All rights reserved.

positive: A Comparative Study of Clinical Features and Outcomes in Young and Older Adults with Severe Acute Respiratory Syndrome Objectives: To determine the clinical presentation, findings, and outcomes of older adults (> 60) with severe acute respiratory syndrome (SARS) and compare these with a control group of younger patients (≤60). Design: Retrospective cohort study. Setting: A community‐based, acute hospital in Hong Kong. Participants: All adult inpatients with a clinical diagnosis of SARS. Measurements: Clinical presentations, investigations, treatment, and 30‐ and 150‐day mortality. Results: There were 52 young and 25 older patients with a mean age±standard deviation of 39.5±11.7 and 72.1±7.2, respectively. Fever, chills, and diarrhea were more common in younger patients, whereas decrease in appetite and general condition occurred only in older patients. The prevalence of positive reverse‐transcriptase polymerase chain reaction for SARS‐associated coronavirus (SARS‐CoV) in nasopharyngeal secretions and stool samples was similar in the two groups. The prevalence of positive serological tests for SARS‐CoV was significantly lower in older patients (42% vs 92%, P<.001). This was largely due to incomplete testing in elderly patients. Older patients were more likely to develop secondary nosocomial infection, be admitted to an intensive care unit, and require mechanical ventilation. The cumulative 30‐ and 150‐day mortality rates were 3.8% and 7.6%, respectively, in young patients with SARS and 56% and 60%, respectively, in older patients (P<.001). Conclusion: Older patients with SARS more often presented with nonspecific symptoms, and the prognosis was poor. Reverse‐transcriptase polymerase chain reaction was useful in diagnosing SARS in older patients, but the role of serological tests in individual elderly is limited.

positive: Serology for SARS-CoV-2: Apprehensions, opportunities, and the path forward. Serological testing for SARS-CoV-2 has enormous potential to contribute to COVID-19 pandemic response efforts. However, the required performance characteristics of antibody tests will critically depend on the use case (individual-level vs. population-level).

positive: Development and Multicenter Performance Evaluation of The First Fully Automated SARS-CoV-2 IgM and IgG Immunoassays BACKGROUND: The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread globally. The laboratory diagnosis of SARS-CoV-2 infection has relied on nucleic acid tests. However, there are many limitations of nucleic acid tests, including low throughput and high rates of false negatives. More sensitive and accurate tests to effectively identify infected patients are needed. METHODS: This study has developed fully automated chemiluminescent immunoassays (CLIA) to determine IgM and IgG antibodies to SARS-CoV-2 in human serum. The assay performance has been evaluated at 10 hospitals. Clinical specificity was evaluated by measuring 972 hospitalized patients with diseases other than COVID-19, and 586 donors of a normal population. Clinical sensitivity was assessed on 503 confirmed cases of SARS-CoV-2 by RT-PCR and 52 suspected cases. RESULTS: The assays demonstrated satisfied assay precision with coefficient of variation (CV) of less than 4.45%. Inactivation of specimen does not affect assay measurement. SARS-CoV-2 IgM shows clinical specificity of 97.33% and 99.49% for hospitalized patients and normal population respectively. SARS-CoV-2 IgG shows clinical specificity of 97.43% and 99.15% for the hospitalized patients and the normal population respectively. SARS-CoV-2 IgM and IgG show clinical sensitivity of 85.88% and 96.62% respectively for confirmed SARS-Cov-2 infection with RT-PCR, of 73.08% and 86.54% respectively for suspected cases. CONCLUSIONS: we have developed fully automated immunoassays for detecting SARS-CoV-2 IgM and IgG antibodies in human serum. The assays demonstrated high clinical specificity and sensitivity, and add great value to nucleic acid testing in fighting against the global pandemic of the SARS-CoV-2 infection.

positive: Serologic and Molecular Biologic Methods for SARS-associated Coronavirus Infection, Taiwan Severe acute respiratory syndrome (SARS) has raised a global alert since March 2003. After its causative agent, SARS-associated coronavirus (SARS-CoV), was confirmed, laboratory methods, including virus isolation, reverse transcriptase–polymerase chain reaction (RT-PCR), and serologic methods, have been quickly developed. In this study, we evaluated four serologic tests ( neutralization test, enzyme-linked immunosorbent assay [ELISA], immunofluorescent assay [IFA], and immunochromatographic test [ICT]) for detecting antibodies to SARS-CoV in sera of 537 probable SARS case-patients with correlation to the RT-PCR . With the neutralization test as a reference method, the sensitivity, specificity, positive predictive value, and negative predictive value were 98.2%, 98.7%, 98.7%, and 98.4% for ELISA; 99.1%, 87.8%, 88.1% and 99.1% for IFA; 33.6%, 98.2%, 95.7%, and 56.1% for ICT, respectively. We also compared the recombinant-based western blot with the whole virus–based IFA and ELISA; the data showed a high correlation between these methods, with an overall agreement of >90%. Our results provide a systematic analysis of serologic and molecular methods for evaluating SARS-CoV infection.

positive: SARS-CoV-2 antibody characterization in emergency department, hospitalized and convalescent patients by two semi-quantitative immunoassays BACKGROUND: In the ongoing COVID-19 pandemic, there is an urgent need for comprehensive performance evaluation and clinical utility assessment of serological assays to understand the immune response to SARS-CoV-2. METHODS: IgM/IgG and total antibodies against SARS-CoV-2 were measured by a cyclic enhanced fluorescence assay (CEFA) and a microsphere immunoassay (MIA), respectively. Independent performance evaluation included imprecision, reproducibility, specificity and cross-reactivity (CEFA n=320, MIA n=364). Clinical utility was evaluated by both methods in 87 patients at initial emergency department visit, 28 during subsequent hospitalizations (106 serial samples), and 145 convalescent patients. Totally 916 patients and 994 samples were evaluated. RESULTS: Agreement of CEFA and MIA was 90.4%-94.5% (Kappa: 0.81-0.89) in 302 samples. CEFA and MIA detected SARS-CoV-2 antibodies in 26.2% and 26.3%, respectively, of ED patients. Detection rates increased over time reaching 100% after 21 days post-symptom onset. Longitudinal antibody kinetic changes by CEFA and MIA measurements correlated well and exhibited three types of seroconversion. Convalescent sera showed a wide range of antibody levels. CONCLUSION: Rigorously validated CEFA and MIA assays are reliable for detecting antibodies to SARS-CoV-2 and show promising clinical utility when evaluating immune response in hospitalized and convalescent patients, but are not useful for early screening at patient’s initial ED visit.

positive: [Development of serological detection assays for human coronavirus HKU1 infection and its application]. OBJECTIVE To express the nuclear capsid protein (N protein) and the spike protein (S protein) of HCoV-HKU1, and to develop the corresponding serum assay for antibody detection. METHODS The N protein of HCoV-HKU1 was expressed in E. Coli, anti-N antibody assay was established using Western Blotting with turn-based membrane. HCoV-HKU1 S protein was constructed in the eukaryotic expression plasmids, and confirmed by Western Blotting, S antibody assay was established using indirect immunofluorescence assay (IFA). We analyzed anti-S and anti-N antibody among 100 normal adult serum. RESULTS Expression of S and N protein were confirmed; 100 normal adult serum were analyzed using the established serological detection assay, in which HCoV-HKU1 S antibody positive rate was 47%, N antibody positive rate was 48%, Both S and N antibodies positive were 21%, Both S and N antibodies negative were 22%. Co-detection S and N antibody was achieved 74% positive rate. CONCLUSION The methods we established here could be used for serological analysis of HCoV-HKU1. Either detection of HCoV-HKU1 S or N antibodies achieved good results. Higher positive detection rate of anti-S or anti-N antibody was found in the normal adults.

positive: Clinical performance of a rapid test compared to a microplate test to detect total anti SARS-CoV-2 antibodies directed to the spike protein

positive: Application of radioimmunological methods for checking the quality of class-specific antibodies against bovine and porcine immunoglobulins Class-specific antibodies against bovine IgG1, IgG2, IgM and IgA and porcine IgG, IgM and IgA immunoglobulins were prepared. Their class specificity was assessed by two radioimmunological methods, namely, radioimmunoelectrophoresis and double antibody sandwich radioimmunoassay. The methods are highly specific and sensitive and do not require the use of purified immunoglobulins, but can be performed with normal serum or colostrum. It was confirmed that antibodies found satisfactory in these tests were suitable for a wide range of use including radioimmunoassay and enzyme linked immunosorbent assay.

positive: The Strategic Alliance between Clinical and Molecular Science in the War against SARS-CoV-2, with the Rapid-Diagnostics Test as an Indispensable Weapon for Front Line Doctors Our work concerns the actual problem of spread of SARS- CoV-2 outbreak which requires fast and correct as possible answer. In current scenario, the need of rapid answer put away the imperative of proper methodology. We focus on the serogical immunoassay for diagnosis of Covid-19 as an important weapon not only for diagnostic purpose, but also for epidemiologic one. The right equilibrium between high speed, low cost and accuracy is obtained with easy-to-use decentralized point-of-care test as the colloidal gold-based immunochromatographic strip assay which detects IgM and IgG antibodies directed against SARS-CoV-2. As our aim is to evaluate the efficacy of Covid-19 rapid tests and of serological assays in real-life settings, we designed a research protocol aimed to establish how to use correctly these diagnostics, taking into account the different possible clinical and epidemiological scenarios.

positive: Evaluation of the EDI enzyme linked immunosorbent assays for the detection of SARS-CoV-2 IgM and IgG antibodies in human plasma BACKGROUND: Besides SARS-CoV-2 RT-PCR testing, serological testing is emerging as additional option in COVID-19 diagnostics. Aim of this study was to evaluate novel immunoassays for detection of SARS-CoV-2 antibodies in human plasma. METHODS: Using EDITM Novel Coronavirus COVID-19 Enzyme Linked Immunosorbent Assays (ELISAs), we measured SARS-CoV-2 IgM and IgG antibodies in 64 SARS-CoV-2 RT-PCR confirmed COVID-19 patients with serial blood samples (n = 104) collected at different time points from symptom onset. Blood samples from 200 healthy blood donors and 256 intensive care unit (ICU) patients collected before the COVID-19 outbreak were also used. RESULTS: The positivity rates in the COVID-19 patients were 5.9% for IgM and 2.9% for IgG ≤ 5 days after symptom onset; Between day 5 and day 10 the positivity rates were 37.1% for IgM and 37.1% for IgG and rose to 76.4% for IgM and 82.4% for IgG after > 10-15 days. After 15-22 days the "true" positivity rates were 94.4% for IgM and 100% for IgG. The "false" positivity rates were 0.5% for IgM and 1.0% for IgG in the healthy blood donors, 1.6% for IgM and 1.2% for IgG in ICU patients. CONCLUSIONS: This study shows high "true" vs. low "false" positivity rates for the EDITM SARS-CoV-2 IgM and IgG ELISAs.

positive: Quantitative and sensitive detection of the SARS-CoV spike protein using bispecific monoclonal antibody-based enzyme-linked immunoassay Abstract The severe acute respiratory syndrome coronavirus (SARS-CoV) spike protein is known to mediate receptor interaction and immune recognition and thus it is considered as a major target for vaccine design. The spike protein plays an important role in virus entry, virus receptor interactions, and virus tropism. Sensitive diagnosis of SARS is essential for the control of the disease in humans. Recombinant SARS-CoV S1 antigen was produced and purified for the development of monoclonal and bi-specific monoclonal antibodies. The hybridomas secreting anti-S1 antibodies, F26G18 and P136.8D12, were fused respectively with the YP4 hybridoma to generate quadromas. The sandwich ELISA was formed by using F26G18 as a coating antibody and biotinylated F26G18 as a detection antibody with a detection limit of 0.037μg/ml (p <0.02). The same detection limit was found with P136.8D12 as a coating antibody and biotinylated F26G18 as a detection antibody. The sensitivity was improved (detection limit of 0.019μg/ml), however, when using bi-specific monoclonal antibody (F157) as the detection antibody. In conclusion, the method described in this study allows sensitive detection of a recombinant SARS spike protein by sandwich ELISA with bi-specific monoclonal antibody and could be used for the diagnosis of patients suspected with SARS.

positive: The diagnostic value of joint detection of serum IgMand IgG antibodies to 2019-nCoV in 2019-nCoV infection/ 中华检验医学杂志 Objective@#To investigate the diagnostic value of immunoglobulin M (IgM) and immunoglobulin G(IgG) antibodies to 2019 Novel Coronavirus (2019-nCoV) in 2019-nCoV infection.@*Method@#This is a retrospective study. Serum samples were collected from 284 patients including outpatients and inpatients in the Renmin Hospital of Wuhan University from January 20, 2020 to February 17, 2020. Among them 205 cases were 2019-nCoV infected patients, including 186 cases confirmed with nucleic acid test and 19 cases diagnosed by clinical symptoms and CT characteristics according to "the New Coronavirus Pneumonia Control Protocol (5th edition)" . A total of 79 subjects with other diseases but negative to 2019-nCoV infection were recruited as control group. Serum IgM and IgG antibodies to 2019-nCoV were measured with fully automated immunoassay technology for all subjects. Statistical significance between 2019-nCoV antibodies test and 2019-nCoV nucleic acid test was determined using the χ2 tests.@*Result@#The sensitivity of serum IgM and IgG antibodies to 2019-nCoV were 70.24%(144/205) and 96.10%(197/205) respectively and the specificity were 96.20%(76/79) and 92.41%(73/79) respectively. The positive and negative predictive values of 2019-nCoV antibodies were 95.63%(197/206) and 91.03% (71/78) respectively, and the positive and negative predictive values of 2019-nCoV nucleic acid test were 100%(186/186) and 80.61%(79/98) respectively. The total coincidence rate of diagnosing 2019-nCoV infection between antibody tests and nucleic acid test for 2019-nCoV were 88.03%(250/284).@*Conclusion@#Joint detection of serum IgM and IgG antibodies to 2019-nCoV is an effective screening and diagnostic indicators for 2019-nCoV infection, and an effective complement to the false negative results to nucleic acid test.

negative: Testing times in Coronavirus disease (Covid-19): A tale of two nations The Coronavirus Disease (Covid-19) pandemic is caused by the severe acute respiratory syndrome virus 2 and was first identified in Wuhan, China, in December 2019. The disease spread globally, leading to the World Health Organization declaring it a pandemic in March 2020. The condition is often fatal in its severe form. As it is a previously unknown virus, no treatment is identified or any vaccine available. The burden of disease control and containment, therefore, falls upon a robust and geographically appropriate testing strategy. Testing policies are modified, in turn, by the rapidly evolving patterns of the disease in various nations and by the evolving nature of tests in development. It is, therefore, helpful to study different national models to learn from the experience of different countries. This article compares testing strategies in the UK and India as the two countries travel different paths in controlling the pandemic. The UK is one of the most severely affected countries in the world. Initially restricted to hospitalised patients, the UK has broadened the scope of testing to many categories of individuals. In contrast, India appears to have a lower prevalence of the infection. However, the large Indian population and relatively insufficient testing capacities so far have led India to adopt a different testing trajectory, with the testing currently focused on high-risk groups in the community and hospitals. Owing to the rapidly changing nature of the disease, there can be no ‘one-size-fits-all’ policy but should be based on country-specific circumstances.

negative: Examination of seroprevalence of coronavirus HKU1 infection with S protein-based ELISA and neutralization assay against viral spike pseudotyped virus Abstract Background Human coronavirus HKU1 (HCoV-HKU1) is a recently identified coronavirus with a global distribution and known to cause mainly respiratory infections. Objectives To investigate the seroepidemiology of HKU1 infections in our local population. Study design An ELISA-based IgG antibody detection assay using recombinant HCoV-HKU1 nucleocapsid and spike (S) proteins (genotype A) were developed for the diagnosis of CoV-HKU1 infections, Additionally, a neutralization antibody assay using the HCoV-HKU1 pseudotyped virus was developed to detect the presence of neutralizing antibodies in serum with antibody positivity in an S protein-based ELISA. Results Results of the recombinant S protein-based ELISA were validated with Western blot, immunofluorescence analysis and flow cytometry. The coupled results demonstrated good correlation with Spearmen's coefficient of 0.94. Seroepidemiological study in a local hospital-based setting using this newly developed ELISA showed steadily increasing HCoV-HKU1 seroprevalence in childhood and early adulthood, from 0% in the age group of <10 years old to a plateau of 21.6% in the age group of 31–40 years old. Conclusions Our study demonstrated the usefulness of the S-based ELISA which could be applied to future epidemiological studies of HCoV-HKU1 in other localities.

negative: Leishmania infantum-specific IFN-γ production in stimulated blood from cats living in areas where canine leishmaniosis is endemic BACKGROUND: Feline leishmaniosis caused by Leishmania infantum is considered a rare disease in endemic areas, whereas subclinical infections are common. Immune response plays a key role in driving the course of L. infantum infection in other host species; however, the feline cell-mediated immune response to L. infantum infection has not yet been investigated. The aim of this study was to determine the cell-mediated immune response specific to L. infantum by means of interferon (IFN)-γ release in whole blood assay from cats living in endemic areas (66 in Sicily and 113 in Catalonia) and to compare with antibody levels to L. infantum [enzyme-linked immunosorbent assay (ELISA) and immunofluorescence antibody test (IFAT)], blood parasite load and retroviral infections. RESULTS: Most cats (n = 140) were L. infantum antibody negative and only 22% (n = 39) were positive. Only 9 and 2% of tested cats had a feline immunodeficency virus (FIV) infection or a feline leukemia virus (FeLV) infection, respectively. Thirty-two cats out of 179 (18%) produced IFN-γ after stimulation with L. infantum soluble antigen (LSA) while the majority of cats (93%) produced IFN-γ after stimulation with concanavalin A (ConA). Six LSA-IFN-γ-producer cats were seropositive (three to ELISA and five to IFAT) but they were polymerase chain reaction (PCR) negative, while only one cat was antibody- and PCR-positive. Significant positive correlations were found between IFN-γ concentrations after stimulation with LSA and ConA, and between serology and PCR testing. No association was found between FIV status and LSA or ConA-IFN-γ production. Combining PCR, serology and specific IFN-γ concentration results, we found that 36% of cats studied were exposed to L. infantum. CONCLUSIONS: As expected, cats from endemic areas produce IFN-γ after ex vivo blood stimulation with LSA and therefore are able to activate a cell-mediated adaptive immune response against the parasite that is variably associated with antibody or blood PCR positivity. The association of this assay to serological and molecular tests provides a better estimate of cat exposure to L. infantum.

negative: A review of enzyme immunoassay for detection of antibody to Brucella abortus in cattle Enzyme immunoassay has gained wide acceptance for serological diagnosis of bovine brucellosis because of its ability to detect antibody of all isotypes unlike the conventional tests. The indirect enzyme immunoassay, however, presents several parameters that require careful analysis. These parameters include the choice of antigen and antiglobulin-enzyme conjugate reagents for use in the assay, dealing with the large amount of data the semi-automatic or automatic assay can generate and the inter-and intralaboratory standardization and quality control. This review considers the various methods described in the literature and, briefly, how some of the problems have been overcome or how they might be dealt with.

negative: Predicting Whom to Test is More Important Than More Tests - Modeling the Impact of Testing on the Spread of COVID-19 Virus By True Positive Rate Estimation I estimate plausible true positive (TP) rates for the number of COVID-19 tests per day, most relevant when the number of test is on the same order of magnitude as number of infected persons. I then modify a standard SEIR model to model current growth patterns and detection rates in South Korea and New York state. Although reducing transmission rates have the largest impact, increasing TP rates by ~10% in New York can have an impact equal to adding tens of thousands of new tests per day. Increasing both TP rates and tests per day together can have significant impacts and likely be more easily sustained than social distancing restrictions. Systematic and standardized data collection, even beyond contact tracking, should be ongoing and quickly made available for research teams to maximize the efficacy of testing.

negative: A Review of SARS-CoV-2 and the Ongoing Clinical Trials The sudden outbreak of 2019 novel coronavirus (2019-nCoV, later named SARS-CoV-2) in Wuhan, China, which rapidly grew into a global pandemic, marked the third introduction of a virulent coronavirus into the human society, affecting not only the healthcare system, but also the global economy. Although our understanding of coronaviruses has undergone a huge leap after two precedents, the effective approaches to treatment and epidemiological control are still lacking. In this article, we present a succinct overview of the epidemiology, clinical features, and molecular characteristics of SARS-CoV-2. We summarize the current epidemiological and clinical data from the initial Wuhan studies, and emphasize several features of SARS-CoV-2, which differentiate it from SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), such as high variability of disease presentation. We systematize the current clinical trials that have been rapidly initiated after the outbreak of COVID-19 pandemic. Whereas the trials on SARS-CoV-2 genome-based specific vaccines and therapeutic antibodies are currently being tested, this solution is more long-term, as they require thorough testing of their safety. On the other hand, the repurposing of the existing therapeutic agents previously designed for other virus infections and pathologies happens to be the only practical approach as a rapid response measure to the emergent pandemic, as most of these agents have already been tested for their safety. These agents can be divided into two broad categories, those that can directly target the virus replication cycle, and those based on immunotherapy approaches either aimed to boost innate antiviral immune responses or alleviate damage induced by dysregulated inflammatory responses. The initial clinical studies revealed the promising therapeutic potential of several of such drugs, including favipiravir, a broad-spectrum antiviral drug that interferes with the viral replication, and hydroxychloroquine, the repurposed antimalarial drug that interferes with the virus endosomal entry pathway. We speculate that the current pandemic emergency will be a trigger for more systematic drug repurposing design approaches based on big data analysis.

negative: Development of a recombinase polymerase amplification combined with lateral-flow dipstick assay for detection of bovine ephemeral fever virus Abstract Bovine ephemeral fever virus (BEFV), identified as the causative pathogen of bovine ephemeral fever (BEF), is responsible for increasing numbers of epidemics/outbreaks and has a significant harmful effect on the livestock industry. Therefore, a rapid detection assay is imperative for BEFV diagnosis. In this study, we described the development of lateral-flow dipstick isothermal recombinase polymerase amplification (LFD-RPA) assays for detection of BEFV. RPA primers and LF probes were designed by targeting the specific G gene, and the amplification product can be visualized on a simple lateral flow dipstick with the naked eyes. The amplification reaction was performed at 38 °C for 20 min and LFD incubation time within 5 min. The detection limit of this assay was 8 copies per reaction, and there was no cross-reactivity with other bovine infectious viruses such as bovine viral diarrhea virus, infectious bovine rhinotracheitis virus, bovine respiratory syncytial virus, bovine coronavirus, bovine parainfluenza virus type 3, bovine vesicular stomatitis virus. In addition, the assay was performed with total 128 clinical specimens and the diagnostic results were compared with conventional RT-PCR, real-time quantative(q) PCR. The result showed that the coincidence rate of BEFV LFD-RPA and real-time qPCR was 96.09% (123/128), which was higher than conventional RT-PCR. The RPA combined with LFD assay probably provides a rapid and sensitive alternative for diagnosis of BEFV infections outbreak.

negative: An integrated in silico immuno-genetic analytical platform provides insights into COVID-19 serological and vaccine targets Background The COVID-19 pandemic is causing a major global health and socio-economic burden, instigating the mobilisation of resources into the development of control tools, such as diagnostics and vaccines. The poor performance of some diagnostic serological tools has emphasised the need for up to date immune-informatic analyses to inform the selection of viable targets for further study. This requires the integration and analysis of genetic and immunological data for SARS-CoV-2 and its homology with other human coronavirus species to understand cross-reactivity. Methods We have developed an online tool for SARS-CoV-2 research, which combines an extensive epitope mapping and prediction meta-analysis, with an updated variant database (55,944 non-synonymous mutations) based on 16,087 whole genome sequences, and an analysis of human coronavirus homology. To demonstrate its utility, we present an integrated analysis of the SARS-CoV-2 spike and nucleocapsid proteins, which are candidate vaccine and serological diagnostic targets. Results Our analysis reveals that the nucleocapsid protein in its native form appears to be a sub-optimal target for use in serological diagnostic platforms. Whilst, a further analysis suggests that orf3a proteins may be a suitable alternative target for diagnostic assays. Conclusions The tool can be accessed online (http://genomics.lshtm.ac.uk/immuno) and will serve as a useful tool for biological discovery in the fight against SARS-CoV-2. Further, it may be adapted to inform on biological targets in future outbreaks, including new human coronaviruses that spill over from animal hosts.

negative: Critical Role of Perforin-dependent CD8+ T Cell Immunity for Rapid Protective Vaccination in a Murine Model for Human Smallpox Vaccination is highly effective in preventing various infectious diseases, whereas the constant threat of new emerging pathogens necessitates the development of innovative vaccination principles that also confer rapid protection in a case of emergency. Although increasing evidence points to T cell immunity playing a critical role in vaccination against viral diseases, vaccine efficacy is mostly associated with the induction of antibody responses. Here we analyze the immunological mechanism(s) of rapidly protective vaccinia virus immunization using mousepox as surrogate model for human smallpox. We found that fast protection against lethal systemic poxvirus disease solely depended on CD4 and CD8 T cell responses induced by vaccination with highly attenuated modified vaccinia virus Ankara (MVA) or conventional vaccinia virus. Of note, CD4 T cells were critically required to allow for MVA induced CD8 T cell expansion and perforin-mediated cytotoxicity was a key mechanism of MVA induced protection. In contrast, selected components of the innate immune system and B cell-mediated responses were fully dispensable for prevention of fatal disease by immunization given two days before challenge. In conclusion, our data clearly demonstrate that perforin-dependent CD8 T cell immunity plays a key role in MVA conferred short term protection against lethal mousepox. Rapid induction of T cell immunity might serve as a new paradigm for treatments that need to fit into a scenario of protective emergency vaccination.

negative: Genetic diversity and evolution of SARS-CoV-2 Abstract COVID-19 is a viral respiratory illness caused by a new coronavirus called SARS-CoV-2. The World Health Organization declared the SARS-CoV-2 outbreak a global public health emergency. We performed genetic analyses of eighty-six complete or near-complete genomes of SARS-CoV-2 and revealed many mutations and deletions on coding and non-coding regions. These observations provided evidence of the genetic diversity and rapid evolution of this novel coronavirus.

negative: Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China BACKGROUND: A recent cluster of pneumonia cases in Wuhan, China, was caused by a novel betacoronavirus, the 2019 novel coronavirus (2019-nCoV). We report the epidemiological, clinical, laboratory, and radiological characteristics and treatment and clinical outcomes of these patients. METHODS: All patients with suspected 2019-nCoV were admitted to a designated hospital in Wuhan. We prospectively collected and analysed data on patients with laboratory-confirmed 2019-nCoV infection by real-time RT-PCR and next-generation sequencing. Data were obtained with standardised data collection forms shared by WHO and the International Severe Acute Respiratory and Emerging Infection Consortium from electronic medical records. Researchers also directly communicated with patients or their families to ascertain epidemiological and symptom data. Outcomes were also compared between patients who had been admitted to the intensive care unit (ICU) and those who had not. FINDINGS: By Jan 2, 2020, 41 admitted hospital patients had been identified as having laboratory-confirmed 2019-nCoV infection. Most of the infected patients were men (30 [73%] of 41); less than half had underlying diseases (13 [32%]), including diabetes (eight [20%]), hypertension (six [15%]), and cardiovascular disease (six [15%]). Median age was 49·0 years (IQR 41·0–58·0). 27 (66%) of 41 patients had been exposed to Huanan seafood market. One family cluster was found. Common symptoms at onset of illness were fever (40 [98%] of 41 patients), cough (31 [76%]), and myalgia or fatigue (18 [44%]); less common symptoms were sputum production (11 [28%] of 39), headache (three [8%] of 38), haemoptysis (two [5%] of 39), and diarrhoea (one [3%] of 38). Dyspnoea developed in 22 (55%) of 40 patients (median time from illness onset to dyspnoea 8·0 days [IQR 5·0–13·0]). 26 (63%) of 41 patients had lymphopenia. All 41 patients had pneumonia with abnormal findings on chest CT. Complications included acute respiratory distress syndrome (12 [29%]), RNAaemia (six [15%]), acute cardiac injury (five [12%]) and secondary infection (four [10%]). 13 (32%) patients were admitted to an ICU and six (15%) died. Compared with non-ICU patients, ICU patients had higher plasma levels of IL2, IL7, IL10, GSCF, IP10, MCP1, MIP1A, and TNFα. INTERPRETATION: The 2019-nCoV infection caused clusters of severe respiratory illness similar to severe acute respiratory syndrome coronavirus and was associated with ICU admission and high mortality. Major gaps in our knowledge of the origin, epidemiology, duration of human transmission, and clinical spectrum of disease need fulfilment by future studies. FUNDING: Ministry of Science and Technology, Chinese Academy of Medical Sciences, National Natural Science Foundation of China, and Beijing Municipal Science and Technology Commission.

negative: Development and evaluation of a competitive enzyme-linked immunosorbent assay using a monoclonal antibody for diagnosis of severe fever with thrombocytopenia syndrome virus in bovine sera Severe fever with thrombocytopenia syndrome (SFTS) caused by the SFTS virus (SFTSV), a phlebovirus in the family Bunyaviridae, is an emerging tick-borne infectious disease that impacts humans. This disease manifests as a decreased blood cell count and multi-organ failure, with a case-fatality rate of more than 12% in China. Because vaccines or antiviral drugs for the treatment of this disease are not available, monitoring the SFTS circulation in animals and controlling the tick-mammal cycle are important for preventing SFTS. Monoclonal antibodies against the recombinant nucleoprotein of SFTSV were generated to develop a competitive enzyme-linked immunosorbent assay (cELISA) for the detection of antibodies against SFTSV infection in cattle. The specificity and sensitivity of cELISA was assessed by comparing the results of this assay to those of an immunofluorescence assay (IFA). The results of the cELISA using 416 field bovine serum samples and laboratory-immunized positive sera showed 98.1% consistency with those of the IFA. The cELISA used in this study did not show cross-reactivity with antisera against other viral cattle diseases. The cELISA presented in this study can be applied to detect antibodies against SFTSV in cattle.

negative: Chapter 6 Ecoepidemiology of Alphaviruses and Flaviviruses Abstract Within the ecosystems, the balance is important since the populations maintain their size and the food habits that are constant over time; in contrast, the disappearance of natural sources or the alteration of habitat at different levels can cause major changes in the very structure of the ecosystem. Alterations in the habitats produced by human activity result in global warming, climatic changes, which together with globalization, increased trade, the shortening of distances thanks to transport, the increase in population and the socioeconomic activities of human cause imbalances. In many cases the vectors and hosts have adapted to the changes and have risen to higher latitudes and altitudes, which could contribute to the appearance of outbreaks or new outbreaks of new arboviruses of public health importance. Different cohabiting species can be reservoirs or vectors of arboviruses such as alphaviruses and flaviviruses. Currently, some viruses transmitted by mosquito vectors, such as dengue virus, Zika virus, and chikungunya virus, have caused epidemic outbreaks with important effects on human populations. It is possible that the expansion of vectors and their diseases reaches developed countries such as the United States and the European Union with a great impact on public health. The clinical signs of the diseases produced by arboviruses can vary from nonspecific febrile syndrome, encephalitis, hemorrhagic fever, and even death. Vectors and reservoirs in some cases are insects, such as mosquitoes and ticks; wild birds are reservoirs for the West Nile virus, small wild mammals such as rodents, bats, and domestic animals involved in food production can potentially harbor arboviruses, and the ecoepidemiological role of these is unknown.

negative: Canine coronavirus in Australian dogs Objective To estimate the frequency of serum antibodies (IgG and IgM) to canine coronavirus (CCV) in the Australian dog population and evaluate the role of CCV as a causative agent of gastroenteritis. Design A serological survey of antibodies to CCV among different dog populations. Procedure The development and characterisation of an indirect ELISA for the detection of antibodies (IgG and IgM) to CCV was undertaken. Sera collected from both diarrhoeal and non‐diarrhoeal dogs from various populations throughout Australia were tested for these antibodies to CCV. Results Serum samples (1396) collected from 1984 to 1998 were tested for the presence of IgG antibodies to CCV. Samples were divided into two categories on the basis of the number of dogs housed together. The groups were either an open population containing dogs housed as groups of three or less, or kennel populations. Sera from 15.8% of the open population and 40.8% of kennelled dogs were positive for CCV antibodies. The prevalence of antibodies varied from zero to 76% in kennelled dogs. About 23% of 128 dogs positive for IgG antibodies to CCV were also positive for IgM antibodies to CCV, indicating recent CCV infection. Of those dogs that were presented with clinical signs of gastroenteritis such as diarrhoea and vomiting(n = 29), 85% were positive in the IgM ELISA and 85.7% in the IgG ELISA for antibodies to CCV. In comparison, for those dogs presented without any history of gastroenteritis only 15% were positive for IgM and 30% positive for IgG. Conclusion Serological evidence indicates that infection with CCV in dogs is widespread throughout the Australian mainland. The prevalence of antibodies varies greatly among different populations, with an average of 40.8% positive in kennelled populations and 15.8% in the open population.

negative: Human-animal interactions and bat coronavirus spillover potential among rural residents in Southern China Abstract Human interaction with animals has been implicated as a primary risk factor for several high impact zoonoses, including many bat-origin viral diseases. However the animal-to-human spillover events that lead to emerging diseases are rarely observed or clinically examined, and the link between specific interactions and spillover risk is poorly understood. To investigate this phenomenon, we conducted biological-behavioral surveillance among rural residents in Yunnan, Guangxi, and Guangdong districts of Southern China, where we have identified a number of SARS-related coronaviruses in bats. Serum samples were tested for four bat-borne coronaviruses using newly developed enzyme-linked immunosorbent assays (ELISA). Survey data were used to characterize associations between human-animal contact and bat coronavirus spillover risk. A total of 1,596 residents were enrolled in the study from 2015 to 2017. Nine participants (0.6%) tested positive for bat coronaviruses. 265 (17%) participants reported severe acute respiratory infections (SARI) and/or influenza-like illness (ILI) symptoms in the past year, which were associated with poultry, carnivore, rodent/shrew, or bat contact, with variability by family income and district of residence. This study provides serological evidence of bat coronavirus spillover in rural communities in Southern China. The low seroprevalence observed in this study suggests that bat coronavirus spillover is a rare event. Nonetheless, this study highlights associations between human-animal interaction and zoonotic spillover risk. These findings can be used to support targeted biological behavioral surveillance in high-risk geographic areas in order to reduce the risk of zoonotic disease emergence.

negative: Zika fever and congenital Zika syndrome: An unexpected emerging arboviral disease Summary Unlike its mosquito-borne relatives, such as dengue, West Nile, and Japanese encephalitis viruses, which can cause severe human diseases, Zika virus (ZIKV) has emerged from obscurity by its association with a suspected “congenital Zika syndrome”, while causing asymptomatic or mild exanthematous febrile infections which are dengue- or rubella-like in infected individuals. Despite having been discovered in Uganda for almost 60 years, <20 human cases were reported before 2007. The massive epidemics in the Pacific islands associated with the ZIKV Asian lineage in 2007 and 2013 were followed by explosive outbreaks in Latin America in 2015. Although increased mosquito breeding associated with the El Niño effect superimposed on global warming is suspected, genetic changes in its RNA virus genome may have led to better adaptation to mosquitoes, other animal reservoirs, and human. We reviewed the epidemiology, clinical manifestation, virology, pathogenesis, laboratory diagnosis, management, and prevention of this emerging infection. Laboratory diagnosis can be confounded by cross-reactivity with other circulating flaviviruses. Besides mosquito bite and transplacental transmission, the risk of other potential routes of transmission by transfusion, transplantation, sexual activity, breastfeeding, respiratory droplet, and animal bite is discussed. Epidemic control requires adequate clearance of mosquito breeding grounds, personal protection against mosquito bite, and hopefully a safe and effective vaccine.

negative: SARS associated coronavirus has a recombinant polymerase and coronaviruses have a history of host-shifting Abstract The sudden appearance and potential lethality of severe acute respiratory syndrome associated coronavirus (SARS-CoV) in humans has focused attention on understanding its origins. Here, we assess phylogenetic relationships for the SARS-CoV lineage as well as the history of host-species shifts for SARS-CoV and other coronaviruses. We used a Bayesian phylogenetic inference approach with sliding window analyses of three SARS-CoV proteins: RNA dependent RNA polymerase (RDRP), nucleocapsid (N) and spike (S). Conservation of RDRP allowed us to use a set of Arteriviridae taxa to root the Coronaviridae phylogeny. We found strong evidence for a recombination breakpoint within SARS-CoV RDRP, based on different, well supported trees for a 5′ fragment (supporting SARS-CoV as sister to a clade including all other coronaviruses) and a 3′ fragment (supporting SARS-CoV as sister to group three avian coronaviruses). These different topologies are statistically significant: the optimal 5′ tree could be rejected for the 3′ region, and the optimal 3′ tree could be rejected for the 5′ region. We did not find statistical evidence for recombination in analyses of N and S, as there is little signal to differentiate among alternative trees. Comparison of phylogenetic trees for 11 known host-species and 36 coronaviruses, representing coronavirus groups 1–3 and SARS-CoV, based on N showed statistical incongruence indicating multiple host-species shifts for coronaviruses. Inference of host-species associations is highly sensitive to sampling and must be considered cautiously. However, current sampling suggests host-species shifts between mouse and rat, chicken and turkey, mammals and manx shearwater, and humans and other mammals. The sister relationship between avian coronaviruses and the 3′ RDRP fragment of SARS-CoV suggests an additional host-species shift. Demonstration of recombination in the SARS-CoV lineage indicates its potential for rapid unpredictable change, a potentially important challenge for public health management and for drug and vaccine development.

negative: Rapid and quantitative detection of COVID-19 markers in micro-liter sized samples COVID-19 pandemic has caused tens of thousands of deaths and is now a severe threat to global health. Clinical practice has demonstrated that the SARS-CoV-2 S1 specific antibodies and viral antigens can be used as diagnostic and prognostic markers of COVID-19. However, the popular point-of-care biomarker detection technologies, such as the lateral-flow test strips, provide only yes/no information and have very limited sensitivities. Thus, it has a high false negative rate and cannot be used for the quantitative evaluation of patient’s immune response. Conventional ELISA (enzyme-linked immunosorbent assay), on the other hand, can provide quantitative, accurate, and sensitive results, but it involves complicated and expensive instruments and long assay time. In addition, samples need to be sent to centralized labs, which significantly increases the turn-around time. Here, we present a microfluidic ELISA technology for rapid (15-20 minutes), quantitative, sensitive detection of SARS-CoV-2 biomarkers using SARS-CoV-2 specific IgG and viral antigen – S protein in serum. We also characterized various humanized monoclonal IgG, and identified a candidate with a high binding affinity towards SARS-CoV-2 S1 protein that can serve as the calibration standard of anti-SARS-CoV-2 S1 IgG in serological analyses. Furthermore, we demonstrated that our microfluidic ELISA platform can be used for rapid affinity evaluation of monoclonal anti-S1 antibodies. The microfluidic ELISA device is highly portable and requires less than 10 μL of samples for each channel. Therefore, our technology will greatly facilitate rapid and quantitative analysis of COVID-19 patients and vaccine recipients at point-of-care.

negative: Diseases of the Liver and Hepatobiliary System

negative: MERS-CoV Antibody Responses 1 Year after Symptom Onset, South Korea, 2015 We investigated the kinetics of the Middle East respiratory syndrome coronavirus (MERS-CoV) neutralizing and spike protein antibody titers over the course of 1 year in 11 patients who were confirmed by reverse transcription PCR to have been infected during the outbreak in South Korea in 2015. Robust antibody responses were detected in all survivors who had severe disease; responses remained detectable, albeit with some waning, for <1 year. The duration of viral RNA detection (but not viral load) in sputum significantly correlated with the antibody response magnitude. The MERS S1 ELISA antibody titers correlated well with the neutralizing antibody response. Antibody titers in 4 of 6 patients who had mild illness were undetectable even though most had evidence of pneumonia. This finding implies that MERS-CoV seroepidemiologic studies markedly underestimate the extent of mild and asymptomatic infection. Obtaining convalescent-phase plasma with high antibody titers to treat MERS will be challenging.

negative: Changes in cerebral oxygenation and cerebral blood flow during hemodialysis - A simultaneous near-infrared spectroscopy and positron emission tomography study. Near-infrared spectroscopy (NIRS) is used to monitor cerebral tissue oxygenation (rSO2) depending on cerebral blood flow (CBF), cerebral blood volume and blood oxygen content. We explored whether NIRS might be a more easy applicable proxy to [15O]H2O positron emission tomography (PET) for detecting CBF changes during hemodialysis. Furthermore, we compared potential determinants of rSO2 and CBF. In 12 patients aged ≥ 65 years, NIRS and PET were performed simultaneously: before (T1), early after start (T2), and at the end of hemodialysis (T3). Between T1 and T3, the relative change in frontal rSO2 (ΔrSO2) was -8 ± 9% ( P = 0.001) and -5 ± 11% ( P = 0.08), whereas the relative change in frontal gray matter CBF (ΔCBF) was -11 ± 18% ( P = 0.009) and -12 ± 16% ( P = 0.007) for the left and right hemisphere, respectively. ΔrSO2 and ΔCBF were weakly correlated for the left (ρ 0.31, P = 0.4), and moderately correlated for the right (ρ 0.69, P = 0.03) hemisphere. The Bland-Altman plot suggested underestimation of ΔCBF by NIRS. Divergent associations of pH, pCO2 and arterial oxygen content with rSO2 were found compared to corresponding associations with CBF. In conclusion, NIRS could be a proxy to PET to detect intradialytic CBF changes, although NIRS and PET capture different physiological parameters of the brain.

negative: A Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases: 2018 Update by the Infectious Diseases Society of America and the American Society for Microbiology The critical nature of the microbiology laboratory in infectious disease diagnosis calls for a close, positive working relationship between the physician/advanced practice provider and the microbiologists who provide enormous value to the healthcare team. This document, developed by experts in laboratory and adult and pediatric clinical medicine, provides information on which tests are valuable and in which contexts, and on tests that add little or no value for diagnostic decisions. This document presents a system-based approach rather than specimen-based approach, and includes bloodstream and cardiovascular system infections, central nervous system infections, ocular infections, soft tissue infections of the head and neck, upper and lower respiratory infections, infections of the gastrointestinal tract, intra-abdominal infections, bone and joint infections, urinary tract infections, genital infections, and other skin and soft tissue infections; or into etiologic agent groups, including arthropod-borne infections, viral syndromes, and blood and tissue parasite infections. Each section contains introductory concepts, a summary of key points, and detailed tables that list suspected agents; the most reliable tests to order; the samples (and volumes) to collect in order of preference; specimen transport devices, procedures, times, and temperatures; and detailed notes on specific issues regarding the test methods, such as when tests are likely to require a specialized laboratory or have prolonged turnaround times. In addition, the pediatric needs of specimen management are also emphasized. There is intentional redundancy among the tables and sections, as many agents and assay choices overlap. The document is intended to serve as a guidance for physicians in choosing tests that will aid them to quickly and accurately diagnose infectious diseases in their patients.

negative: Abstracts of the Papers Presented in the XIX National Conference of Indian Virological Society, “Recent Trends in Viral Disease Problems and Management”, on 18–20 March, 2010, at S.V. University, Tirupati, Andhra Pradesh

negative: Neutralizing Antibody to Calf Diarrhea Coronavirus in Various Animal Species in Japan

negative: Long-term Co-existence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) with Antibody Response in Non-severe Coronavirus Disease 2019 (COVID-19) Patients Severe acute respiratory syndrome coronavirus 2 infection causing coronavirus disease 2019 has spread worldwide. Whether antibodies are important for the adaptive immune responses against SARS-CoV-2 infection needs to be determined. Here, 26 cases of COVID-19 in Jinan, China, were examined and shown to be mild or with common clinical symptoms and no cases of severe symptoms were found among these patients. A striking feature of some patients is that SARS-CoV-2 could exist in patients who have virus-specific IgG antibodies for a very long period, with one case for up to 36 days. One COVID-19 patient who did not produce any SARS-CoV-2-bound IgG successfully cleared SARS-CoV-2 after 46 days of illness, revealing that without antibody-mediated adaptive immunity, innate immunity may still be powerful enough to eliminate SARS-CoV-2. Overall, this report may provide a basis for further analysis of both innate and adaptive immunity in SARS-CoV-2 clearance, especially in non-severe cases. This study also has implications for understanding the pathogenesis and treatment of SARS-CoV-2.

negative: SARS-CoV Pathogenesis Is Regulated by a STAT1 Dependent but a Type I, II and III Interferon Receptor Independent Mechanism Severe acute respiratory syndrome coronavirus (SARS-CoV) infection often caused severe end stage lung disease and organizing phase diffuse alveolar damage, especially in the elderly. The virus-host interactions that governed development of these acute end stage lung diseases and death are unknown. To address this question, we evaluated the role of innate immune signaling in protection from human (Urbani) and a recombinant mouse adapted SARS-CoV, designated rMA15. In contrast to most models of viral pathogenesis, infection of type I, type II or type III interferon knockout mice (129 background) with either Urbani or MA15 viruses resulted in clinical disease outcomes, including transient weight loss, denuding bronchiolitis and alveolar inflammation and recovery, identical to that seen in infection of wildtype mice. This suggests that type I, II and III interferon signaling play minor roles in regulating SARS pathogenesis in mouse models. In contrast, infection of STAT1−/− mice resulted in severe disease, high virus titer, extensive pulmonary lesions and 100% mortality by day 9 and 30 post-infection with rMA15 or Urbani viruses, respectively. Non-lethal in BALB/c mice, Urbani SARS-CoV infection in STAT1−/− mice caused disseminated infection involving the liver, spleen and other tissues after day 9. These findings demonstrated that SARS-CoV pathogenesis is regulated by a STAT1 dependent but type I, II and III interferon receptor independent, mechanism. In contrast to a well documented role in innate immunity, we propose that STAT1 also protects mice via its role as an antagonist of unrestrained cell proliferation.

negative: Comparison of Serologic Assays for Middle East Respiratory Syndrome Coronavirus Middle East respiratory syndrome coronavirus (MERS-CoV) was detected in humans in 2012. Since then, sporadic outbreaks with primary transmission through dromedary camels to humans and outbreaks in healthcare settings have shown that MERS-CoV continues to pose a threat to human health. Several serologic assays for MERS-CoV have been developed globally. We describe a collaborative study to investigate the comparability of serologic assays for MERS-CoV and assess any benefit associated with the introduction of a standard reference reagent for MERS-CoV serology. Our study findings indicate that, when possible, laboratories should use a testing algorithm including >2 tests to ensure correct diagnosis of MERS-CoV. We also demonstrate that the use of a reference reagent greatly improves the agreement between assays, enabling more consistent and therefore more meaningful comparisons between results.

negative: Immunological, structural, and preliminary X-ray diffraction characterizations of the fusion core of the SARS-coronavirus spike protein Abstract The SARS-CoV spike protein, a glycoprotein essential for viral entry, is a primary target for vaccine and drug development. Two peptides denoted HR-N(SN50) and HR-C(SC40), corresponding to the Leu/Ile/Val-rich heptad-repeat regions from the N-terminal and C-terminal segments of the SARS-CoV spike S2 sequence, respectively, were synthesized and predicted to form trimeric assembly of hairpin-like structures. The polyclonal antibodies produced by recombinant S2 protein were tested for antigenicity of the two heptad repeats. We report here the first crystallographic study of the SARS spike HR-N/HR-C complex. The crystal belongs to the triclinic space group P1 and the data-set collected to 2.98Å resolution showed noncrystallographic pseudo-222 and 3-fold symmetries. Based on these data, comparative modeling of the SARS-CoV fusion core was performed. The immunological and structural information presented herein may provide a more detailed understanding of the viral fusion mechanism as well as the development of effective therapy against SARS-CoV infection.

negative: Serologic prevalence of selected infectious diseases in cats with uveitis. Serologic evidence of infection by Toxoplasma gondii, feline leukemia virus, feline coronaviruses, or feline immunodeficiency virus (FIV) is commonly found in cats with uveitis. Serum samples from 124 cats with uveitis were assayed by use of ELISA for the detection of T gondii-specific immunoglobulin M (IgM), IgG, and circulating antigens (Ag), as well as an ELISA for feline leukemia virus Ag, an ELISA for antibodies to FIV, and an indirect fluorescent antibody assay for antibodies to feline coronaviruses. Serologic evidence of infection by 1 or more of the infectious agents was detected in 83.1% of the samples. Serologic evidence of T gondii infection, defined as the detection of T gondii-specific IgM, IgG, or Ag in serum, was found in 74.2% of the samples. The seroprevalence of T gondii infection was significantly greater in cats with uveitis than in healthy cats from a similar geographic area. Serum samples from cats with serologic evidence of both T gondii and FIV infections were more likely to contain T gondii-specific IgM without IgG than samples from cats with serologic evidence of T gondii infection alone. Cats with serologic evidence of FIV and T gondii coinfection had a higher T gondii-specific IgM titer geometric mean and a lower T gondii-specific IgG titer geometric mean than did cats with serologic evidence of T gondii infection alone. Serologic evaluation for T gondii infection should include assays that detect IgM, IgG, and Ag, particularly in cats coinfected with FIV.

negative: A review of the 2019 Novel Coronavirus (COVID-19) based on current evidence Abstract The pneumonia caused by novel coronavirus (SARS-CoV-2) in Wuhan, China in December 2019 is a highly contagious disease. The World Health Organization (WHO) has declared the ongoing outbreak as a global public health emergency. Currently, the research on novel coronavirus is still in the primary stage. Based on the current published evidence, we systematically summarizes the epidemiology, clinical characteristics, diagnosis, treatment and prevention of knowledge surrounding COVID-19. This review in the hope of helping the public effectively recognize and deal with the 2019 novel coronavirus (SARS-CoV-2), and providing a reference for future studies.

negative: Polymerase chain reaction for probe synthesis and for direct amplification in detection of bovine coronavirus Abstract The polymerase chain reaction (PCR) was used to synthesize ds and ss probes for the detection of bovine coronavirus (BCV) using recombinant plasmids as template molecules. The ds probes detected a minimum of about 2 × 105 viral genomes after exposure for 1 h, a detection limit similar to nick-translated probes after exposure of the films for 60 h. More than 8 h exposure to blots probed with these ds probes resulted in complete darkening of the film. The ss probes, synthesized by asymmetric PCR on linearized plasmids, permitted the detection of 5 × 104 genomes, which equalled the capacity of random-primed probes. Prolonged exposure did not increase the background as in case of ds PCR-probed blots. Probes, synthesized by asymmetric PCR and random-priming were labeled to similar specific activities and were better in terms of sensitivity and detectability as opposed to nick-translated probes. However, the specificity of detection with ss probes as to random primed probes was increased further. About 10 viral genomes, after fragment-specific amplification by PCR, were detected by agarose-gel analysis. PCR-probe synthesis was simple, highly reproducible, and allowed the synthesis of probes for specific fragments.

negative: Update on Human Rhinovirus and Coronavirus Infections Human rhinovirus (HRV) and coronavirus (HCoV) infections are associated with both upper respiratory tract illness (“the common cold”) and lower respiratory tract illness (pneumonia). New species of HRVs and HCoVs have been diagnosed in the past decade. More sensitive diagnostic tests such as reverse transcription-polymerase chain reaction have expanded our understanding of the role these viruses play in both immunocompetent and immunosuppressed hosts. Recent identification of severe acute respiratory syndrome and Middle East respiratory syndrome viruses causing serious respiratory illnesses has led to renewed efforts for vaccine development. The role these viruses play in patients with chronic lung disease such as asthma makes the search for antiviral agents of increased importance.

negative: Intrinsic resistance of feline peritoneal macrophages to coronavirus infection correlates with in vivo virulence. Cats infected with virulent feline coronavirus strains develop feline infectious peritonitis, an invariably fatal, immunologically mediated disease; avirulent strains cause either clinically inapparent infection or mild enteritis. Four virulent coronavirus isolates and five avirulent isolates were assessed by immunofluorescence and virus titration for their ability to infect and replicate in feline peritoneal macrophages in vitro. The avirulent coronaviruses infected fewer macrophages, produced lower virus titers, were less able to sustain viral replication, and spread less efficiently to other susceptible macrophages than the virulent coronaviruses. Thus, the intrinsic resistance of feline macrophages may play a pivotal role in the outcome of coronavirus infection in vivo.

negative: OC43 strain‐related coronavirus antibodies in different age groups Serum antibodies against human coronavirus OC43 in different age groups were measured by complement fixation (CF), haemagglutination inhibition (HI), radial diffusion haemolysis‐in‐gel (HIG), and solid‐phase radioimmunoassay (RIA) methods. Antigen grown in suckling mouse brain was used in all tests. Results obtained by the CF and HIG tests, and the RIA, were in good agreement with regard to the presence or absence of antibodies. Similar results were also obtained with the HI test if nonspecific haemagglutination inhibitors were first removed by treatment with phospholipase C and only titers of 1:20 or greater were considered positive. Children 6–23 months of age (n = 45) were without measurable coronavirus antibodies in all four assays. A rapid increase in the prevalence of antibodies then occurred in subsequent age groups, and practically all persons 6 years of age or older were found to have OC43 antibodies as measured by the HIG test or the RIA. The mean antibody levels determined by these two methods continued to increase, however, up to the age group of 10–14 years. This increase in antibody levels after the initial antibody incidence plateau may be due to boosting effects caused by related coronavirus strains, since OC43 antigens are known to cross‐react with antibodies induced by other human coronaviruses. Taken together, these data suggest that OC43 virus, or an antigenically related coronavirus strain, is very common in Finland.

negative: Prevalence of coronavirus antibodies in Iowa swine. Three hundred and forty-seven serum samples from 22 Iowa swine herds were screened for TGEV/PRCV neutralizing antibody. Ninety-one percent of the sera and all 22 herds were positive. These sera were then tested by the blocking ELISA test to distinguish TGEV and PRCV antibody. The ELISA test confirmed the high percentage of TGEV/PRCV positive sera. By the blocking ELISA test, 12 herds were PRCV positive, 6 herds were TGEV positive and 4 herds were mixed with sera either positive for TGEV or PRCV antibody. The results suggest a recent increase in TGEV/PRCV seroprevalence in Iowa swine most likely due to subclinical PRCV infections.

negative: Middle East respiratory syndrome coronavirus (MERS-CoV) — Surveillance and testing in North England from 2012 to 2019 Abstract Background Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in Saudi Arabia in 2012 and caused an epidemic in the Middle East. Public Health England (PHE) Manchester is one of the two PHE centres in the UK that perform testing for MERS-CoV. The results of the PHE Manchester MERS surveillance from 2012 to 2019 are presented in this report. Methods Retrospective data were collected for returning travellers from the Middle East fitting the PHE MERS case definition. Respiratory samples were tested for respiratory viruses and MERS-CoV using an in-house RT-PCR assay. Results Four hundred and twenty-six (426) samples from 264 patients were tested for MERS Co-V and respiratory viruses. No MERS-CoV infections were identified by PCR. Fifty-six percent of samples were PCR positive for viral or bacterial pathogen with Influenza A as the predominant virus (44%). Sixty-two percent of all patients had a pathogen identified with the highest positivity from sputum samples. Patients with multiple samples demonstrated a 100% diagnostic yield. Conclusions Although no cases of MERS were identified, the majority of patients had Influenza infection for which oseltamivir treatment was indicated and isolation warranted. Sputum samples were the most useful in diagnosing respiratory viruses with a 100% diagnostic yield from patients with multiple samples.

negative: Chapter 15 Molecular Testing in Emerging Infectious Diseases Abstract It was widely believed in the late 1960s that infectious diseases had been conquered by vaccines and antibiotics and humans were no longer under threat by microbial pathogens. Yet, since that time more than 60 pathogens have been discovered that can cause serious emerging infectious diseases. Molecular methods have played critical roles in the discovery, monitoring, and clinical diagnostics of emerging pathogens. In this chapter, we present well-recognized emerging pathogens. We provide examples of the utility of molecular assays in research and clinical care of emerging infectious diseases. We also discuss some theoretical and practical limitations of molecular tests and the future prospects of expanding molecular diagnostics for emerging pathogens based on new advances of knowledge and technologies.

negative: Emerging respiratory infections: The infectious disease pathology of SARS, MERS, pandemic influenza, and Legionella Abstract Lower respiratory infections remain one of the top global causes of death and the emergence of new diseases continues to be a concern. In the first two decades of the 21st century, we have born witness to the emergence of newly recognized coronaviruses that have rapidly spread around the globe, including severe acute respiratory syndrome virus (SARS) and Middle Eastern respiratory syndrome virus (MERS). We have also experienced the emergence of a novel H1N1 pandemic influenza strain in 2009 that caused substantial morbidity and mortality around the world and has transitioned into a seasonal strain. Although we perhaps most frequently think of viruses when discussing emerging respiratory infections, bacteria have not been left out of the mix, as we have witnessed an increase in the number of infections from Legionella spp. since the organisms’ initial discovery in 1976. Here, we explore the basic epidemiology, clinical presentation, histopathology, and clinical laboratory diagnosis of these four pathogens and emphasize themes in humans’ evolving relationship with our natural environment that have contributed to the infectious burden. Histology alone is rarely diagnostic for these infections, but has been crucial to bettering our understanding of these diseases. Together, we rely on the diagnostic acumen of pathologists to identify the clinicopathologic features that raise the suspicion of these diseases and lead to the early control of the spread in our populations.

negative: Chapter 6 The immunosuppressed traveler: infection risks with autoimmunity and immunosuppression, vaccinations, and general travel advice Abstract The travel-related infection risks in the significantly immunocompromised traveler are complex and comprise vaccine preventable, vector-borne, and other nonvaccine preventable infections. A thorough risk assessment should be performed before travel and advice sought from relevant specialists. Immunosuppression used to treat autoimmune diseases and their mechanisms of action need particular consideration.This risk assessment needs to take the patient's beliefs and preferences into account. It is also important not to neglect noninfectious travel considerations.

negative: Development of a nucleocapsid-based human coronavirus immunoassay and estimates of individuals exposed to coronavirus in a U.S. metropolitan population. Coronaviruses cause respiratory infections ranging from common colds to severe acute respiratory syndrome (SARS) in humans. Estimates for exposure to non-SARS coronaviruses are high, particularly for 229E and OC43; however, less information regarding seroprevalence is available for HKU1 and NL63. To measure exposure rates to these four coronavirus strains (229E, HKU1, NL63, and OC43), we devised an immunoassay based on amino- and carboxy-terminally tagged recombinant coronavirus nucleocapsid antigens. Four human and one feline coronavirus antigen were cloned into baculoviruses expressed in insect cells and recovered proteins bound in the solid phase of an enzyme-linked immunosorbent assay-based system. We screened sera from 10 children and 196 adults and established primary cutoff points based on immunoglobulin G (IgG) antibody levels of the predominantly seronegative children. The proportion of seropositive adults for each coronavirus was as follows: 229E, 91.3%; HKU1, 59.2%; NL63, 91.8%; and OC43, 90.8%. No evidence of a significant serological response to the feline coronavirus was observed. Significant associations of coronavirus seropositivity and antibody levels with age, gender, race, socioeconomic status, smoking status, and season of the blood draw were tested with chi-square and regression analyses. The group II coronaviruses (OC43 and HKU1) were significantly associated with race (P<or=0.009 and P<or=0.03, respectively). Elevated OC43 IgG levels were further significantly associated with smoking status (P<or=0.03), as were high NL63 titers with socioeconomic status (P<or=0.04). The high-level immunoreactivity of each coronavirus was significantly associated with the summer season (P<or=0.01 to 0.0001). In summary, high rates of exposure to 229E, NL63, and OC43 and a moderate rate of exposure to HKU1 characterized the seroprevalence among individuals in this population. Demographic factors, such as race, smoking status, and socioeconomic status, may confer an increased risk of susceptibility to these viruses.

negative: Machine intelligence design of 2019-nCoV drugs Wuhan coronavirus, called 2019-nCoV, is a newly emerged virus that infected more than 9692 people and leads to more than 213 fatalities by January 30, 2020. Currently, there is no effective treatment for this epidemic. However, the viral protease of a coronavirus is well-known to be essential for its replication and thus is an effective drug target. Fortunately, the sequence identity of the 2019-nCoV protease and that of severe-acute respiratory syndrome virus (SARS-CoV) is as high as 96.1%. We show that the protease inhibitor binding sites of 2019-nCoV and SARS-CoV are almost identical, which means all potential anti-SARS-CoV chemotherapies are also potential 2019-nCoV drugs. Here, we report a family of potential 2019-nCoV drugs generated by a machine intelligence-based generative network complex (GNC). The potential effectiveness of treating 2019-nCoV by using some existing HIV drugs is also analyzed.

negative: Gaining Insights into the Codon Usage Patterns of TP53 Gene across Eight Mammalian Species TP53 gene is known as the “guardian of the genome” as it plays a vital role in regulating cell cycle, cell proliferation, DNA damage repair, initiation of programmed cell death and suppressing tumor growth. Non uniform usage of synonymous codons for a specific amino acid during translation of protein known as codon usage bias (CUB) is a unique property of the genome and shows species specific deviation. Analysis of codon usage bias with compositional dynamics of coding sequences has contributed to the better understanding of the molecular mechanism and the evolution of a particular gene. In this study, the complete nucleotide coding sequences of TP53 gene from eight different mammalian species were used for CUB analysis. Our results showed that the codon usage patterns in TP53 gene across different mammalian species has been influenced by GC bias particularly GC(3) and a moderate bias exists in the codon usage of TP53 gene. Moreover, we observed that nature has highly favored the most over represented codon CTG for leucine amino acid but selected against the ATA codon for isoleucine in TP53 gene across all mammalian species during the course of evolution.

negative: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016 P001 - Sepsis impairs the capillary response within hypoxic capillaries and decreases erythrocyte oxygen-dependent ATP efflux R. M. Bateman, M. D. Sharpe, J. E. Jagger, C. G. Ellis P002 - Lower serum immunoglobulin G2 level does not predispose to severe flu. J. Solé-Violán, M. López-Rodríguez, E. Herrera-Ramos, J. Ruíz-Hernández, L. Borderías, J. Horcajada, N. González-Quevedo, O. Rajas, M. Briones, F. Rodríguez de Castro, C. Rodríguez Gallego P003 - Brain protective effects of intravenous immunoglobulin through inhibition of complement activation and apoptosis in a rat model of sepsis F. Esen, G. Orhun, P. Ergin Ozcan, E. Senturk, C. Ugur Yilmaz, N. Orhan, N. Arican, M. Kaya, M. Kucukerden, M. Giris, U. Akcan, S. Bilgic Gazioglu, E. Tuzun P004 - Adenosine a1 receptor dysfunction is associated with leukopenia: A possible mechanism for sepsis-induced leukopenia R. Riff, O. Naamani, A. Douvdevani P005 - Analysis of neutrophil by hyper spectral imaging - A preliminary report R. Takegawa, H. Yoshida, T. Hirose, N. Yamamoto, H. Hagiya, M. Ojima, Y. Akeda, O. Tasaki, K. Tomono, T. Shimazu P006 - Chemiluminescent intensity assessed by eaa predicts the incidence of postoperative infectious complications following gastrointestinal surgery S. Ono, T. Kubo, S. Suda, T. Ueno, T. Ikeda P007 - Serial change of c1 inhibitor in patients with sepsis – A prospective observational study T. Hirose, H. Ogura, H. Takahashi, M. Ojima, J. Kang, Y. Nakamura, T. Kojima, T. Shimazu P008 - Comparison of bacteremia and sepsis on sepsis related biomarkers T. Ikeda, S. Suda, Y. Izutani, T. Ueno, S. Ono P009 - The changes of procalcitonin levels in critical patients with abdominal septic shock during blood purification T. Taniguchi, M. O P010 - Validation of a new sensitive point of care device for rapid measurement of procalcitonin C. Dinter, J. Lotz, B. Eilers, C. Wissmann, R. Lott P011 - Infection biomarkers in primary care patients with acute respiratory tract infections – Comparison of procalcitonin and C-reactive protein M. M. Meili, P. S. Schuetz P012 - Do we need a lower procalcitonin cut off? H. Hawa, M. Sharshir, M. Aburageila, N. Salahuddin P013 - The predictive role of C-reactive protein and procalcitonin biomarkers in central nervous system infections with extensively drug resistant bacteria V. Chantziara, S. Georgiou, A. Tsimogianni, P. Alexandropoulos, A. Vassi, F. Lagiou, M. Valta, G. Micha, E. Chinou, G. Michaloudis P014 - Changes in endotoxin activity assay and procalcitonin levels after direct hemoperfusion with polymyxin-b immobilized fiber A. Kodaira, T. Ikeda, S. Ono, T. Ueno, S. Suda, Y. Izutani, H. Imaizumi P015 - Diagnostic usefullness of combination biomarkers on ICU admission M. V. De la Torre-Prados, A. Garcia-De la Torre, A. Enguix-Armada, A. Puerto-Morlan, V. Perez-Valero, A. Garcia-Alcantara P016 - Platelet function analysis utilising the PFA-100 does not predict infection, bacteraemia, sepsis or outcome in critically ill patients N. Bolton, J. Dudziak, S. Bonney, A. Tridente, P. Nee P017 - Extracellular histone H3 levels are inversely correlated with antithrombin levels and platelet counts and are associated with mortality in sepsis patients G. Nicolaes, M. Wiewel, M. Schultz, K. Wildhagen, J. Horn, R. Schrijver, T. Van der Poll, C. Reutelingsperger P018 - Il-8: is this a more reliable biomarker for sepsis severity than CRP, Procalcitonin, E-selectin, IL-6 and TNF-[alpha] S. Pillai, G. Davies, G. Mills, R. Aubrey, K. Morris, P. Williams, P. Evans P019 - Relation between adrenomedullin and short-term outcome in ICU patients: Results from the frog ICU study E. G. Gayat, J. Struck, A. Cariou, N. Deye, B. Guidet, S. Jabert, J. Launay, M. Legrand, M. Léone, M. Resche-Rigon, E. Vicaut, A. Vieillard-Baron, A. Mebazaa P020 - Impact of disease severity assessment on performance of heparin-binding protein for the prediction of septic shock R. Arnold, M. Capan, A. Linder, P. Akesson P021 - Kinetics and prognostic value of presepsin (sCD14) in septic patients. A pilot study M. Popescu, D. Tomescu P022 - Comparison of CD64 levels performed by the facs and accellix systems C. L. Sprung, R. Calderon Morales, G. Munteanu, E. Orenbuch-Harroch, P. Levin, H. Kasdan, A. Reiter, T. Volker, Y. Himmel, Y. Cohen, J. Meissonnier P023 - Diagnosing sepsis in 5 minutes: Nanofluidic technology study with pancreatic-stone protein (PSP/ reg) L. Girard, F. Rebeaud P024 - How nanotechnology-based approaches could contribute to sepsis prevention, diagnosis and treatment I. Herrmann P025 - Il7r transcriptional expression analysis during septic shock B. Delwarde, E. Peronnet, E. Cerrato, F. Venet, A. Lepape, T. Rimmelé, G. Monneret, J. Textoris P026 - Disbalance of microbial metabolites of aromatic acids affects the severity in critically ill patients N. Beloborodova, V. Moroz, A. Osipov, A. Bedova, Y. Sarshor, A. Pautova, A. Sergeev, E. Chernevskaya P027 - Copeptin predicts 10-year all-cause mortality in community patients J. Odermatt, R. Bolliger, L. Hersberger, M. Ottiger, M. Christ-Crain, B. Mueller, P. Schuetz P028 - Identification of differential proteomic response in septic patients secondary to community and hospital acquired pneumonia N. K. Sharma, A. K. Tashima, M. K. Brunialti, F. R. Machado, M. Assuncao, O. Rigato, R. Salomao P029 - Monocyte HLA-DR expression in community-acquired bacteremic sepsis - dynamics associated to aetiology and prediction of secondary sepsis S. C. Cajander, G. Rasmussen, E. Tina, B. Söderquist, J. Källman, K. Strålin P030 - Soluble B- and T-lymphocyte attenuator: A possible prognostic marker in sepsis A. L. Lange, J. S. Sundén-Cullberg, A. M. Magnuson, O. H. Hultgren P031 - Fractal dimension: A new biomarker for quantifying clot microstructure in patients across the sepsis spectrum G. Davies, S. Pillai, G. Mills, R. Aubrey, K. Morris, P. Williams, P. Evans P032 - Comparison between the new biomarker for coagulation, clot microstructure (Df) with rotational thromboelastometry (ROTEM) in patients across the sepsis spectrum S. Pillai, G. Davies, G. Mills, R. Aubrey, K. Morris, P. Williams, P. Evans P033 - Changes in fibrinolysis across the sepsis spectrum: The use of rotational thromboelastometry (ROTEM) lysis index (LI60) and D-Dimer concentration S. Pillai, G. Davies, G. Mills, R. Aubrey, K. Morris, P. Williams, P. Evans P034 - The intensive care infection score – a promising marker for the prediction of infection and its severity. P. Van der Geest, M. Mohseni, J. Linssen, R. De Jonge, S. Duran, J. Groeneveld P035 - Challenges in the clinical diagnosis of sepsis R. Miller III, B. K. Lopansri, L. C. McHugh, A. Seldon, J. P. Burke P036 - Does zero heat flux thermometry more accurately identify sepsis on intensive care? J. Johnston, R. Reece-Anthony, A. Bond, A. Molokhia P037 - Advancing quality (AQ) sepsis programme: Improving early identification & treatment of sepsis in North West England. C. Mcgrath, E. Nsutebu P038 - Prehospital transport of acute septic patients P. Bank Pedersen, D. Pilsgaard Henriksen, S. Mikkelsen, A. Touborg Lassen P039 - Vasodilatory plant extracts gel as an alternative treatment for fever in critically ill patients R. Tincu, C. Cobilinschi, D. Tomescu, Z. Ghiorghiu, R. Macovei P040 - Host response and outcome of hypothermic sepsis M. A. Wiewel, M. B. Harmon, L. A. Van Vught, B. P. Scicluna, A. J. Hoogendijk, J. Horn, A. H. Zwinderman, O. L. Cremer, M. J. Bonten, M. J. Schultz, T. Van der Poll, N. P. Juffermans, W. J. Wiersinga P041 - Septic shock alert over SIRS criteria has an impact on outcome but needs to be revised G. Eren, Y Tekdos, M. Dogan, O. Acicbe, E. Kaya, O. Hergunsel P042 - Association between previous prescription of βblockers and mortality rate among septic patients: A retrospective observational study S. Alsolamy, G. Ghamdi, L. Alswaidan, S. Alharbi, F. Alenezi, Y. Arabi P043 - Recognition and treatment of sepsis on labour ward– teaching & information resources can improve knowledge J. Heaton, A. Boyce, L. Nolan, J. Johnston, A. Dukoff-Gordon, A. Dean, A. Molokhia P044 - Culture negative sepsis in the ICU – what is unique to this patient population? T. Mann Ben Yehudah P045 - Organ dysfunction in severe sepsis patients identified in administrative data in Germany, 2007-2013 C. Fleischmann, D. Thomas-Rueddel, C. Haas, U. Dennler, K. Reinhart P046 - A comparison of residents’ knowledge regarding; the Surviving Sepsis Campaign 2012 guideline O. Suntornlohanakul, B. Khwannimit P047 - Effectiveness of a septic shock bundle to improve outcomes in the ICU F. Breckenridge, A. Puxty P048 - Dose of norepinephrine in the first 24 hours as a parameter evaluating the effectiveness of treatment in patients with severe sepsis and septic shock P. Szturz, P. Folwarzcny, J. Svancara, R. Kula, P. Sevcik P049 - Norepinephrine or vasopressin + norepinephrine in septic shock. A retrospective series of 39 patients L. Caneva, A. Casazza, E. Bellazzi, S. Marra, L. Pagani, M. Vetere, R. Vanzino, D. Ciprandi, R. Preda, R. Boschi, L. Carnevale P050 - Methylene blue effectiveness as contributory treatment in patients with septic shock V. Lopez, M. Aguilar Arzapalo, L. Barradas, A. Escalante, J. Gongora, M. Cetina P051 - Coagulation disorders in patients with severe sepsis and DIC evaluated with thromboelastometry. B Adamik, D Jakubczyk, A Kübler P052 - Frequency and outcome of early sepsis-associated coagulopathy A. Radford, T. Lee, J. Singer, J. Boyd, D. Fineberg, M. Williams, J. Russell P053 - Assessment of coagulopathy in cancer patients with severe sepsis or septic shock. A case-control pilot study E. Scarlatescu, D. Tomescu, G. Droc, S. Arama P054 - Thromboelastometry in critically ill patients with disseminated intravascular coagulation M. Müller, M. Straat, S. S. Zeerleder, N. P. Juffermans P055 - Cessation of a preexisting chronic antiplatelet therapy is associated with increased mortality rates in severe sepsis and septic shock C. F. Fuchs, C. S. Scheer, S. W. Wauschkuhn, M. V. Vollmer, K. M. Meissner, S. K. Kuhn, K. H. Hahnenkamp, S. R. Rehberg, M. G. Gründling P056 - Neutrophil Extracellular Traps (NETs) production under hypoxic condition N. Yamamoto, M. Ojima, S. Hamaguchi, T. Hirose, Y. Akeda, R. Takegawa, O. Tasaki, T. Shimazu, K. Tomono P057 - Impact of ultraviolet air sterilizer in intensive care unit room, and clinical outcomes of patients E. Gómez-Sánchez, M. Heredia-Rodríguez, E. Álvarez-Fuente, M. Lorenzo-López, E. Gómez-Pesquera, M. Aragón-Camino, P. Liu-Zhu, A. Sánchez-López, A. Hernández-Lozano, M. T. Peláez-Jareño, E. Tamayo P058 - Focus of infection in severe sepsis - comparison of administrative data and prospective cohorts from Germany D. O. Thomas-Rüddel, C. Fleischmann, C. Haas, U. Dennler, K. Reinhart P059 - “Zero CLABSI” – can we get there? Obstacles on the 4 year journey and our strategies to overcome them – experience from an Indian ICU V. Adora, A. Kar, A. Chakraborty, S. Roy, A. Bandyopadhyay, M. Das P060 - Novel molecular techniques to identify central venous catheter (CVC) associated blood stream infections (BSIs) T. Mann Ben Yehudah, G. Ben Yehudah, M. Salim, N. Kumar, L. Arabi, T. Burger, P. Lephart, E. Toth-martin P061 - Zero clabsi” – can we get there? Obstacles on the 4 year journey and our strategies to overcome them – experience from an Indian ICU R. Rao, A. Kar, A. Chakraborty P062 - Prevention of central line-associated bloodstream infections in intensive care units: An international online survey C. Valencia, N. Hammami, S. Blot, J. L. Vincent, M. L. Lambert P063 - 30 days antimicrobial efficacy of non-leaching central venous catheters J. Brunke, T. Riemann, I. Roschke P064 - Efficacy of noble metal alloy-coated catheter in prevention of bacteriuria R. Tincu, C. Cobilinschi, D. Tomescu, Z. Ghiorghiu, R. Macovei P065 - Predicting bacteremic urinary tract infection in community setting: A prospective observational study S. Nimitvilai, K. Jintanapramote, S. Jarupongprapa P066 - Eight-year analysis of acinetobacter spp. monobacteremia in surgical and medical intensive care units at university hospital in Lithuania D. Adukauskiene, D. Valanciene P067 - Group A and group B streptococcal infections in intensive care unit – our experience in a tertiary centre G. Bose, V. Lostarakos, B. Carr P068 - Improved detection of spontaneous bacterial peritonitis by uritop + tm strip test and inoculation of blood culture bottles with ascitic fluid S. Khedher, A. Maaoui, A. Ezzamouri, M. Salem P069 - Increased risk of cellulitis in patients with congestive heart failure: a population based cohort study J. Chen P070 - Outcomes of severe cellulitis and necrotizing fasciitis in the critically ill D. R. Cranendonk, L. A. Van Vught, M. A. Wiewel, O. L. Cremer, J. Horn, M. J. Bonten, M. J. Schultz, T. Van der Poll, W. J. Wiersinga P071 - Botulism outbreak associated with people who inject drugs (PWIDs) in Scotland. M. Day, G. Penrice, K. Roy, P. Robertson, G. Godbole, B. Jones, M. Booth, L. Donaldson P072 - Surveillance of ESBL-producing enterobacteriaceae fecal carriers in the ICU Y. Kawano, H. Ishikura P073 - Prevalence of ESBL and carbapenemase producing uropathogens in a newly opened hospital in south India S. Sreevidya, N. Brahmananda Reddy, P. Muraray Govind, R. Pratheema, J. Devachandran Apollo Speciality Hospital - OMR, Chennai, India P074 - Prevalence, risk factors and outcomes of methicillin-resistant staphylococcus aureus nasal colonization in critically ill patients H. Al-Dorzi, M. Almutairi, B. Alhamadi, A. Crizaldo Toledo, R. Khan, B. Al Raiy, Y. Arabi P075 - Multidrug-resistant Acinetobacter baumannii infection in intensive care unit patients in a hospital with building construction: Is there an association? H. Talaie P076 - Multidrug-resistant organisms in a Dutch ICU J. A. Van Oers, A. Harts, E. Nieuwkoop, P. Vos P077 - Epidemiology and risk factors of ICU acquired infections caused by multidrug-resistant gram negative bacilli Y. Boussarsar, F. Boutouta, S. Kamoun, I. Mezghani, S. Koubaji, A. Ben Souissi, A. Riahi, M. S. Mebazaa P078 - Improving outcomes of severe infections by multidrug-resistant pathogens with polyclonal IgM-enriched immunoglobulins E. Giamarellos-Bourboulis, N. Tziolos, C. Routsi, C. Katsenos, I. Tsangaris, I. Pneumatikos, G. Vlachogiannis, V. Theodorou, A. Prekates, E. Antypa, V. Koulouras, N. Kapravelos, C. Gogos, E. Antoniadou, K. Mandragos, A. Armaganidis P079 - Must change the medical practice in ICU? A. R. Robles Caballero, B. Civantos, J. C. Figueira, J. López P080 - Mediterranean spotted fever in an infectious diseases intensive care unit A. Silva-Pinto, F. Ceia, A. Sarmento, L. Santos P081 - Clinical features and outcomes of patients with Middle East respiratory syndrome requiring admission to a saudi intensive care unit: A retrospective analysis of 31 cases G. Almekhlafi, Y. Sakr P082 - The ICU response to a hospital outbreak of Middle East respiratory syndrome coronavirus infection H. Al-Dorzi, R. Khan, S. Baharoon, A. Aldawood, A. Matroud, J. Alchin, S. Al Johani, H. Balkhy, Y. Arabi P083 - Middle East respiratory syndrome: Surveillance data analysis S. Alsolamy, S. Y. Yousif, B. O. Alotabi, A. S. Alsaawi P085 - Use of Taqman array card molecular diagnostics in severe pneumonia: A case series J. Ang, MD Curran, D. Enoch, V. Navapurkar, A. Conway Morris P086 - ‘BUNS’: An investigation protocol improves the ICU management of pneumonia R. Sharvill, J. Astin P087 - Pneumonia in patients following secondary peritonitis: epidemiological features and impact on mortality M. Heredia-Rodríguez, E. Gómez-Sánchez, M. T. Peláez-Jareño, E. Gómez-Pesquera, M. Lorenzo-López, P. Liu-Zhu, M. Aragón-Camino, A. Hernández-Lozano, A. Sánchez-López, E. Álvarez-Fuente, E. Tamayo P088 - The use of the “CURB-65 score” by emergency room clinicians in a large teaching hospital J. Patel, C. Kruger P089 - Incidence of community acquired pneumonia with viral infection in mechanically ventilated patients in the medical intensive care unit J. O’Neal, H. Rhodes, J. Jancik P090 - The SAATELLITE Study: Prevention of S aureus Nosocomial Pneumonia (NP) with MEDI4893, a Human Monoclonal Antibody (mAb) Against S aureus B. François, P. F. Laterre, P. Eggimann, A. Torres, M. Sánchez, P. F. Dequin, G. L. Bassi, J. Chastre, H. S. Jafri P091 - Risk factors and microbiological profile for nosocomial infections in trauma patients M. Ben Romdhane, Z. Douira, S. Kamoun, M. Bousselmi, A. Ben Souissi, Y. Boussarsar, A. Riahi, M.S. Mebazaa P092 - Correlation between percentages of ventilated patients developed vap and use of antimicrobial agents in ICU patients. A. Vakalos, V. Avramidis P093 - A comparison of two ventilator associated pneumonia surveillance techniques T. H. Craven, G. Wojcik, K. Kefala, J. McCoubrey, J. Reilly, R. Paterson, D. Inverarity, I. Laurenson, T. S. Walsh P094 - Lung ultrasound before and after fiberbronchoscopy - modifications may improve ventilator-associated pneumonia diagnosis S. Mongodi, B. Bouhemad, A. Orlando, A. Stella, G. Via, G. Iotti, A. Braschi, F. Mojoli P095 - Comparing the accuracy of predictors of mortality in ventilator-associated pneumonia M. Haliloglu, B. Bilgili, U. Kasapoglu, I. Sayan, M. Süzer Aslan, A. Yalcın, I. Cinel P096 - Impact of pRBCs transfusion on percentage of ventilated patients developed VAP in ICU patients A. Vakalos, V. Avramidis P097 - The impact of a series of interventions on the rate of ventilator associated pneumonia in a large teaching hospital H. E. Ellis, K. Bauchmuller, D. Miller, A Temple P098 - The EVADE study: Prevention of Nosocomial Pneumonia (NP) caused by P aeruginosa with MEDI3902, a Novel Bispecific Monoclonal Antibody, against P aeruginosa virulence factors J. Chastre, B. François, A. Torres, C. E. Luyt, M. Sánchez, M. Singer, H. S. Jafri P099 - Short-term inhaled colistin adjunctive therapy for ventilator-associated pneumonia Y. Nassar, M. S. Ayad P100 - Effect of aerosolised colistin on weaning from mechanical ventilation A. Trifi, S. Abdellatif, F. Daly, R. Nasri, S. Ben Lakhal P101 - Septic shock is an independent risk factor for colistin-induced severe acute kidney injury: a retrospective cohort study B. Bilgili, M. Haliloglu, F. Gul, I. Cinel P102 - Nosocomial pneumonia - emphasis on inhaled tobramycin A. Kuzovlev, A. Shabanov, S. Polovnikov, V. Moroz P103 - In vitro evaluation of amikacin inhale and commercial nebulizers in a mechanical ventilator N. Kadrichu, T. Dang, K. Corkery, P. Challoner P104 - The effects of nebulized amikacin/fosfomycin and systemic meropenem on severe amikacin-resistant meropenem-susceptible P.aeruginosa pneumonia G. Li Bassi, E. Aguilera, C. Chiurazzi, C. Travierso, A. Motos, L. Fernandez, R. Amaro, T. Senussi, F. Idone, J. Bobi, M. Rigol, A. Torres P105 - Optimization of gentamicin peak concentrations in critically ill patients C. J. Hodiamont, N. P. Juffermans, J. M. Janssen, C. S. Bouman, R. A. Mathôt, M. D. De Jong, R. M. Van Hest P106 - Systematic review of cefepime induced neurotoxicity L. Payne, G. L. Fraser P107 - Unasyn® causes QT prolongation during treatment of intensive care patients B. Tudor, M. Lahner, G. Roth, C. Krenn P108 - Comparative study between teicoplanin and vancomycin in methicillin-resistant staphylococcus aureus (mrsa) infectious of toxicological intensive care unit (ticu) patients – Tehran, Iran H. Talaie P109 - Phage therapy against antimicrobial resistance, design of the first clinical study phagoburn P. Jault, J. Gabard, T. Leclerc, S. Jennes, Y. Que, A. Rousseau, F. Ravat P110 - Antibiotic dosing errors in critically ill patients with severe sepsis or septic shock H. Al-Dorzi, A. Eissa, S. Al-Harbi, T. Aldabbagh, R. Khan, Y. Arabi P111 - Does empiric antifungal therapy improve survival in septic critically ill patients? (immunocompromised excluded) A. Trifi, S. Abdellatif, F. Daly, R. Nasri, S. Ben Lakhal P112 - Neurocysticercosis-Qatar experience F. Paramba, N. Purayil, V. Naushad, O. Mohammad, V. Negi, P. Chandra P113 - Early indicators in acute haemorrhagic shock A. Kleinsasser P114 - Filtering of red blood cells reduces the inflammatory response of pulmonary cells in an in vitro model of mechanical ventilation M. R. Witrz, J. F. Buchner-Doeven, A. M. Tuip-de Boer, J. C. Goslings, N. P. Juffermans P115 - Microparticles from red blood cell transfusion induce a pro-coagulant and pro-inflammatory endothelial cell response M. Van Hezel, M. Straat, A Boing, R Van Bruggen, N Juffermans P116 - The contribution of cytokines on thrombosis development during hospitalization in ICU D. Markopoulou, K. Venetsanou, V. Kaldis, D. Koutete, D. Chroni, I. Alamanos P117 - Prophylactic enoxaparin dosing and adjustment through anti-xa monitoring in an inpatient burn unit L. Koch, J. Jancik, H. Rhodes, E. Walter P118 - Determination of optimal cut-off values of haemoglobin, platelet count and fibrinogen at 24 hours after injury associated with mortality in trauma patients K. Maekawa, M. Hayakawa, S. Kushimoto, A. Shiraishi, H. Kato, J. Sasaki, H. Ogura, T. Matauoka, T. Uejima, N. Morimura, H. Ishikura, A. Hagiwara, M. Takeda P119 - Trauma-induced coagulopathy - prothrombin complex concentrate vs fresh frozen plasma O. Tarabrin, S. Shcherbakow, D. Gavrychenko, G. Mazurenko, V. Ivanova, O. Chystikov P120 - First study to prove the superiority of prothrombin complex concentrates on mortality rate over fresh frozen plasma in patients with acute bleeding C. Plourde, J. Lessard, J. Chauny, R. Daoust P121 - Prothrombin complex concentrate vs fresh frozen plasma in obstetric massive bleeding S. Shcherbakow, O. Tarabrin, D. Gavrychenko, G. Mazurenko, O. Chystikov P122 - Impact of FFP transfusion on VAP in ICU patients A. Vakalos, V. Avramidis P123 - Preoperative platelet function test and the thrombin generation assay are predictive for blood loss after cardiac surgery L. Kropman, L. In het Panhuis, J. Konings, D. Huskens, E. Schurgers, M. Roest, B. De Laat, M. Lance P124 - Rotational thromboelastometry versus standard coagulation tests before surgical interventions M. Durila, P. Lukas, M. Astraverkhava, J. Jonas P125 - Correction of impaired clot quality and stability by fibrinogen and activated prothrombin complex concentrate in a model of severe thrombocytopenia I. Budnik, B. Shenkman P126 - Assessment of point-of-care prothrombin time analyzer as a monitor after cardiopulmonary bypass H. Hayami, Y. Koide, T. Goto P127 - Disseminated intravascular coagulation (dic) is underdiagnosed in critically ill patients: do we need d-dimer measurements? R. Iqbal, Y. Alhamdi, N. Venugopal, S. Abrams, C. Downey, C. H. Toh, I. D. Welters P128 - Validity of the age-adjusted d-dimer cutoff in patients with COPD B. Bombay, J. M. Chauny, R. D. Daoust, J. L. Lessard, M. M. Marquis, J. P. Paquet P129 - A scoping review of strategies for prevention and management of bleeding following paediatric cardiopulmonary bypass surgery K. Siemens, D. Sangaran, B. J. Hunt, A. Durward, A. Nyman, I. A. Murdoch, S. M. Tibby P130 - Nadir hemoglobulin during cardiopulmonary bypass: impact on postoperative morbidity and mortality F. Ampatzidou, D. Moisidou, E. Dalampini, M. Nastou, E. Vasilarou, V. Kalaizi, H. Chatzikostenoglou, G. Drossos P131 - Red blood cell transfusion do not influence the prognostic value of RDW in critically ill patients S. Spadaro, A. Fogagnolo, T. Fiore, A. Schiavi, V. Fontana, F. Taccone, C. Volta P132 - Reasons for admission in the paediatric intensive care unit and the need for blood and blood products transfusions E. Chochliourou, E. Volakli, A. Violaki, E. Samkinidou, G. Evlavis, V. Panagiotidou, M. Sdougka P133 - The implementation of a massive haemorrhage protocol (mhp) for the management of major trauma: a ten year, single-centre study R. Mothukuri, C. Battle, K. Guy, G. Mills, P. Evans P134 - An integrated major haemorrhage protocol for pre-hospital and retrieval medical teams J. Wijesuriya, S. Keogh P135 - The impact of transfusion thresholds on mortality and cardiovascular events in patients with cardiovascular disease (non-cardiac surgery): a systematic review and meta-analysis A. Docherty, R. O’Donnell, S. Brunskill, M. Trivella, C. Doree, L. Holst, M. Parker, M. Gregersen, J. Almeida, T. Walsh, S. Stanworth P136 - The relationship between poor pre-operative immune status and outcome from cardiac surgery is specific to the peri-operative antigenic threat S. Moravcova, J. Mansell, A. Rogers, R. A. Smith, C. Hamilton-Davies P137 - Impact of simple clinical practice guidelines for reducing post-operative atrial fibrillation after cardiac surgery. A. Omar, M. Allam, O. Bilala, A. Kindawi, H. Ewila P138 - Dexamethasone administration during cardiopulmonary bypass has no beneficial effects on elective postoperative cardiac surgery patients F. Ampatzidou, D. Moisidou, M. Nastou, E. Dalampini, A. Malamas, E. Vasilarou, G. Drossos P139 - Intra-aortic balloon counterpulsation in patients undergoing cardiac surgery (IABCS): preliminary results G. Ferreira, J. Caldas, J. Fukushima, E. A. Osawa, E. Arita, L. Camara, S. Zeferino, J. Jardim, F. Gaioto, L. Dallan, F. B. Jatene, R. Kalil Filho, .F Galas, L. A. Hajjar P140 - Effects of low-dose atrial natriuretic peptide infusion on cardiac surgery-associated acute kidney injury C. Mitaka, T. Ohnuma, T. Murayama, F. Kunimoto, M. Nagashima, T. Takei, M. Tomita P141 - Acute kidney injury influence on high sensitive troponin measurements after cardiac surgery A. Omar, K. Mahmoud, S. Hanoura, S. Sudarsanan, P. Sivadasan, H. Othamn, Y. Shouman, R. Singh, A. Al Khulaifi P142 - Complex evaluation of endothelial dysfunction markers for prognosis of outcomes in patients undergoing cardiac surgery I. Mandel, S. Mikheev, I. Suhodolo, V. Kiselev, Y. Svirko, Y. Podoksenov P143 - New-onset atrial fibrillation in intensive care: incidence, management and outcome S. A. Jenkins, R. Griffin P144 - One single spot measurement of the sublingual microcirculation during acute pulmonary hypertension in a pig model of shock M. S. Tovar Doncel, A. Lima, C. Aldecoa, C. Ince P145 - Assessment of levosimendan as a therapeutic option to recruit the microcirculation in cardiogenic shock – initial experience in cardiac ICU A. Taha, A. Shafie, M. Mostafa, N. Syed, H. Hon P146 - Terlipressin vs. norepinephrine in the Potential Multiorgan Donor(PMD) F. Righetti, E. Colombaroli, G. Castellano P147 - Echocardiography in the potential heart donor exposed to substitution hormonotherapy F. Righetti, E. Colombaroli P148 - Machine learning can reduce rate of monitor alarms M. Hravnak, L. C. Chen, A. D. Dubrawski, G. C. Clermont, M. R. Pinsky P149 - Peripherally inserted central catheters placed in the ICU S. Gonzalez, D. Macias, J. Acosta, P. Jimenez, A. Loza, A. Lesmes, F. Lucena, C. Leon P150 - Recordings of abnormal central venous pressure waveform morphology during an episode of pulmonary hypertension in a porcine shock model M. S. Tovar Doncel, C. Ince, C. Aldecoa, A. Lima P151 - Ultrasound guided central venous access technique among French intensivists M. Bastide, J. Richecoeur, E. Frenoy, C. Lemaire, B. Sauneuf, F. Tamion, S. Nseir, D. Du Cheyron, H. Dupont, J. Maizel P152 - Predictive ability of the Pv-aCO2 gap in patients with shock M. Shaban, R. Kolko, N. Salahuddin, M. Sharshir, M. AbuRageila, A. AlHussain P153 - Comparison of echocardiography and pulmonary artery catheter measurements of hemodynamic parameters in critical ill patients P. Mercado, J. Maizel, L. Kontar, D. Titeca, F. Brazier, A. Riviere, M. Joris, T. Soupison, B. De Cagny, M. Slama P154 - The volume clamp method for noninvasive cardiac output measurement in postoperative cardiothoracic surgery patients: a comparison with intermittent pulmonary artery thermodilution J. Wagner, A. Körner, M. Kubik, S. Kluge, D. Reuter, B. Saugel P155 - Hemodynamic monitoring in patients with septic shock (SS) – CPCCO (continuous pulse contour cardiac output) vs. TEE (transesophageal echocardiography) E. Colombaroli, F. Righetti, G. Castellano P156 - Cardiac output measurement with transthoracic echocardiography in critically ill patients: a pragmatic clinical study T. Tran, D. De Bels, A. Cudia, M. Strachinaru, P. Ghottignies, J. Devriendt, C. Pierrakos P157 - Left ventricular outflow tract velocity time integral correlates with stroke volume index in mechanically ventilated patients Ó. Martínez González, R. Blancas, J. Luján, D. Ballesteros, C. Martínez Díaz, A. Núñez, C. Martín Parra, B. López Matamala, M. Alonso Fernández, M. Chana P158 - Transpulmonary thermodilution (TPTD) derived from femoral vs. jugular central venous catheter: validation of a previously published correction formula and a proprietary correction formula for global end-diastolic volume index (GEDVI) W. Huber, M. Eckmann, F. Elkmann, A. Gruber, I. Klein, R. M. Schmid, T. Lahmer P160 - Dynamic arterial elastance calculated with lidcoplus monitor does not predict changes in arterial pressure after a fluid challenge in postsurgical patients D. Bastoni, H. Aya, L. Toscani, L. Pigozzi, A. Rhodes, M. Cecconi P159 - Venous return driving pressure and resistance in acute blood volume changes P. W. Moller, S. Sondergaard, S. M. Jakob, J. Takala, D. Berger P160 - Dynamic arterial elastance calculated with lidcoplus monitor does not predict changes in arterial pressure after a fluid challenge in postsurgical patients D. Bastoni, H. Aya, L. Toscani, L. Pigozzi, A. Rhodes, M. Cecconi P161 - Analysis of duration of post-operative goal-directed therapy protocol C. Ostrowska, H. Aya, A. Abbas, J. Mellinghoff, C. Ryan, D. Dawson, A. Rhodes, M. Cecconi P162 - Hemodynamic optimization – back to square one? M. Cronhjort, O. Wall, E. Nyberg, R. Zeng, C. Svensen, J. Mårtensson, E. Joelsson-Alm P163 - Effectiveness of fluid thoracic content measurement by bioimpedance guiding intravascular volume optimization in patients with septic shock M. Aguilar Arzapalo, L. Barradas, V. Lopez, M. Cetina P164 - A systematic review on the role of internal jugular vein ultrasound measurements in assessment of volume status in critical shock patients N. Parenti, C. Palazzi, L. A. Amidei, F. B. Borrelli, S. C. Campanale, F. T. Tagliazucchi, G. S. Sedoni, D. L. Lucchesi, E. C. Carella, A. L Luciani P165 - Importance of recognizing dehydration in medical Intensive Care Unit M. Mackovic, N. Maric, M. Bakula P166 - Effect of volume for a fluid challenge in septic patients H. Aya, A. Rhodes, R. M. Grounds, N. Fletcher, M. Cecconi P167 - Fluid bolus practices in a large Australian intensive care unit B. Avard, P. Zhang P168 - Liberal late fluid management is associated with longer ventilation duration and worst outcome in severe trauma patients: a retrospective cohort of 294 patients M. Mezidi, J. Charbit, M. Ould-Chikh, P. Deras, C. Maury, O. Martinez, X. Capdevila P169 - Association of fluids and outcomes in emergency department patients hospitalized with community-acquired pneumonia P. Hou, W. Z. Linde-Zwirble, I. D. Douglas, N. S. Shapiro P170 - Association of positive fluid balance with poor outcome in medicosurgical ICU patients A. Ben Souissi, I. Mezghani, Y. Ben Aicha, S. Kamoun, B. Laribi, B. Jeribi, A. Riahi, M. S. Mebazaa P171 - Impact of fluid balance to organ dysfunction in critically ill patients C. Pereira, R. Marinho, R. Antunes, A. Marinho P172 - Volume bolus in ICU patients: do we need to balance our crystalloids? M. Crivits, M. Raes, J. Decruyenaere, E. Hoste P173 - The use of 6 % HES solution do not reduce total fluid requirement in the therapy of patients with burn shock V. Bagin, V. Rudnov, A. Savitsky, M. Astafyeva, I. Korobko, V. Vein P174 - Electron microscopic assessment of acute kidney injury in septic sheep resuscitated with crystalloids or different colloids T. Kampmeier , P. Arnemann, M. Hessler, A. Wald, K. Bockbreder, A. Morelli, H. Van Aken, S. Rehberg, C. Ertmer P175 - Alterations of conjunctival microcirculation in a sheep model of haemorrhagic shock and resuscitation with 0.9 % saline or balanced tetrastarch P. Arnemann, M. Hessler, T. Kampmeier, S. Rehberg, H. Van Aken, C. Ince, C. Ertmer P176 - A single centre nested pilot study investigating the effect of using 0.9 % saline or Plasma-Lyte 148 ® as crystalloid fluid therapy on gastrointestinal feeding intolerance in mechanically ventilated patients receiving nasogastric enteral nutrition S. Reddy, M. Bailey, R. Beasley, R. Bellomo, D. Mackle, A. Psirides, P. Young P177 - A single centre nested pilot study investigating the effect on post-operative bleeding of using 0.9 % saline or Plasma-Lyte® 148 as crystalloid fluid therapy in adults in ICU after heart surgery S. Reddy, M. Bailey, R. Beasley, R. Bellomo, D. Mackle, P. Young P178 - Extreme hypernatremia and sepsis in a patient with Huntington’s dementia: a conundrum in fluid management H. Venkatesh, S. Ramachandran, A. Basu, H. Nair P179 - Diagnosis and management of severe hypernatraemia in the critical care setting S. Egan, J. Bates P180 - Correlation between arterial blood gas and electrolyte disturbances during hospitalization and outcome in critically ill patients S. Oliveira, N. R. Rangel Neto, F. Q. Reis P181 - Missing the “I” in MUDPILES – a rare cause of high anion gap metabolic acidosis (HAGMA) C. P. Lee, X. L. Lin, C. Choong , K. M. Eu, W. Y. Sim , K. S. Tee, J. Pau , J. Abisheganaden P182 - Plasma NGAL and urinary output: potential parameters for early initiation of renal replacement therapy K. Maas, H. De Geus P183 - Renal replacement therapy for critically ill patients: an intermittent continuity E. Lafuente, R. Marinho, J. Moura, R. Antunes, A. Marinho P184 - A survey of practices related to renal replacement therapy in critically ill patients in the north of England. T. E. Doris, D. Monkhouse, T. Shipley, S. Kardasz, I Gonzalez P185 - High initiation creatinine associated with lower 28-day mortality in critically ill patients necessitating continuous renal replacement therapy S. Stads, A. J. Groeneveld P186 - The impact of Karnofsky performance scale on outcomes in acute kidney injury patients receiving renal replacement therapy on the intensive care unit I. Elsayed, N. Ward, A. Tridente, A. Raithatha P187 - Severe hypophosphatemia during citrate-anticoagulated CRRT A. Steuber, C. Pelletier, S. Schroeder, E. Michael, T. Slowinski, D. Kindgen-Milles P188 - Citrate regional anticoagulation for post dilution continuous renal replacement therapy S. Ghabina P189 - Citrate 18 mmol/l improves anticoagulation during RRT with adsorbing filters F. Turani, A. Belli, S. Busatti, G. Barettin, F. Candidi, F. Gargano, R. Barchetta, M. Falco P190 - Calcium gluconate instead of calcium chloride in citrate-anticoagulated CVVHD O. Demirkiran, M. Kosuk, S. Bozbay P191 - Enhanced clearance of interleukin-6 with continuous veno-venous haemodialysis (CVVHD) using Ultraflux EMiC2 vs. Ultraflux AV1000S V. Weber, J. Hartmann, S. Harm, I. Linsberger, T. Eichhorn, G. Valicek, G. Miestinger, C. Hoermann P192 - Removal of bilirubin with a new adsorbent system: in vitro kinetics S. Faenza, D. Ricci, E. Mancini, C. Gemelli, A. Cuoghi, S. Magnani, M. Atti P193 - Case series of patients with severe sepsis and septic shock treated with a new extracorporeal sorbent T. Laddomada, A. Doronzio, B. Balicco P194 - In vitro adsorption of a broad spectrum of inflammatory mediators with CytoSorb® hemoadsorbent polymer beads M. C. Gruda, P. O’Sullivan, V. P. Dan, T. Guliashvili, A. Scheirer, T. D. Golobish, V. J. Capponi, P. P. Chan P195 - Observations in early vs. late use of cytosorb therapy in critically ill patients K. Kogelmann, M. Drüner, D. Jarczak P196 - Oxiris membrane decreases endotoxin during rrt in septic patients with basal EAA > 0,6 F. Turani, A. B. Belli, S. M. Martni, V. C. Cotticelli, F. Mounajergi, R. Barchetta P197 - An observational prospective study on the onset of augmented renal clearance: the first report S. Morimoto, H. Ishikura P198 - An ultrasound- guided algorithm for the management of oliguria in severe sepsis I. Hussain, N. Salahuddin, A. Nadeem, K. Ghorab, K. Maghrabi P199 - Ultrasound in acute kidney injury (aki). First findings of farius, an education-programme in structural ultrasonography S. K. Kloesel, C. Goldfuss, A. Stieglitz, A. S. Stieglitz, L. Krstevska, G. Albuszies P200 - Effectiveness of renal angina index score predicting acute kidney injury on critically ill patients M. Aguilar Arzapalo, L. Barradas, V. Lopez, A. Escalante, G. Jimmy, M. Cetina P201 - Time length below blood pressure thresholds and progression of acute kidney injury in critically ill patients with or without sepsis: a retrospective, exploratory cohort study J. Izawa, T. Iwami, S. Uchino, M. Takinami, T. Kitamura, T. Kawamura P202 - Anaemia does not affect renal recovery in acute kidney injury J. G. Powell-Tuck, S. Crichton, M. Raimundo, L. Camporota, D. Wyncoll, M. Ostermann P203 - Estimated glomerular filtration rate based on serum creatinine: actual practice in Dutch ICU’s A. Hana, H. R. De Geus P204 - Comparison of estimated glomerular filtration rate calculated by mdrd, ckd-epi-serum-creatinine and ckd-epi-cystatin-c in adult critically ill patients H. R. De Geus, A. Hana P205 - Early diagnosis of septic acute kidney injury in medical critical care patients with a urine cell cycle arrest marker: insulin like growth factor binding protein-7 (IGFBP-7) M. Aydogdu, N. Boyaci, S. Yuksel, G. Gursel, A. B. Cayci Sivri P206 - Urinary neutrophil gelatinase-associated lipocalin as early biomarker of severe acute kidney injury in intensive care J. Meza-Márquez, J. Nava-López, R. Carrillo-Esper P207 - Shrunken pore syndrome is associated with a sharp rise in mortality in patients undergoing elective coronary artery bypass grafting A. Dardashti, A. Grubb P208 - The biomarker nephrocheck™ can discriminate the septic shock patients with an akin 1 or 2 acute renal failure who will not progress toward the akin 3 level J. Maizel, M. Wetzstein, D. Titeca, L. Kontar, F. Brazier, B. De Cagny, A. Riviere, T. Soupison, M. Joris, M. Slama P209 - A worldwide multicentre evaluation of acute kidney injury in septic and non-septic critically ill patients: the intensive care over nations (icon) audit E. Peters, H. Njimi, P. Pickkers, J. L. Vincent P210 - Does enhanced recovery after surgery reduce the incidence of acute kidney injury in those undergoing major gynae-oncological surgery? M. Waraich , J. Doyle, T. Samuels, L. Forni P211 - Identification of risk factors for the development of acute kidney injury after lower limb arthroplasty N. Desai, R. Baumber, P. Gunning, A. Sell P212 - Incidences and associations of acute kidney injury after major trauma S. Lin, H. Torrence, M. O’Dwyer, C. Kirwan, J. Prowle P213 - Acute kidney injury of major trauma patients T Kim P214 - Trajectory of serum creatinine after major surgery and the diagnosis of acute kidney injury M. E. O’Connor, R. W. Hewson, C. J. Kirwan, R. M. Pearse, J. Prowle P215 - Epidemiology of acute kidney injury after cardiac surgery. 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Bhandari P221 - Setting optimal flow rate during high flow nasal cannula support: preliminary results T. Mauri, C. Turrini, T. Langer, P. Taccone, C. A. Volta, C. Marenghi, L. Gattinoni, A. Pesenti P222 - Dose to dose consistency across two different gas flow rates using cystic fibrosis and normal adult breathing profiles during nasal high flow oxygen therapy L. Sweeney, A . O’ Sullivan, P. Kelly, E. Mukeria, R. MacLoughlin P223 - Final results of an evaluation of airway medix closed suction system compared to a standard closed suction system M. Pfeffer, J. T. Thomas, G. B. Bregman, G. K. Karp, E. K. Kishinevsky, D. S. Stavi, N. A. Adi P224 - Different cuff materials and different leak tests - one size does not fit all T. Poropat, R. Knafelj P225 - Observational study on the value of the cuff-leak test and the onset of upper airway obstruction after extubation E. Llopart, M. Batlle, C. De Haro, J. Mesquida, A. Artigas P226 - A device for emergency transtracheal lung ventilation D. Pavlovic, L. Lewerentz, A. Spassov, R. Schneider P227 - Long-term outcome and health-related quality of life in patients discharged from the intensive care unit with a tracheostomy and with or without prolonged mechanical ventilation S. De Smet, S. De Raedt, E. Derom, P Depuydt, S. Oeyen, D. Benoit, J. Decruyenaere P228 - Ultrasound-guided percutaneous dilational tracheostomy versus bronchoscopy-guided percutaneous dilational tracheostomy in critically ill patients (trachus): a randomized clinical trial A. Gobatto, B. Bese, P. Tierno, L. Melro, P. Mendes, F. Cadamuro, M. Park, L. M. Malbouisson P229 - Is it safe to discharge patients with tracheostomy from the ICU to the ward? B. C. Civanto, J. L. Lopez, A. Robles, J. Figueira, S. Yus, A. Garcia P230 - The application of tracheostomy in children in ICU A. Oglinda, G. Ciobanu, C. Oglinda, L. Schirca, T. Sertinean, V. Lupu P231 - The impact of passive humidifiers on aerosol drug delivery during mechanical ventilation P. Kelly, A. O’Sullivan, L. Sweeney, R. MacLoughlin P232 - Evaluation of vibrating mesh and jet nebuliser performance at two different attachment setups in line with a humidifier nebuliser system A. O’Sullivan, P. Kelly, L. Sweeney, E. Mukeria, M. Wolny , R. MacLoughlin P233 - Psv-niv versus cpap in the treatment of acute cardiogenic pulmonary edema A. Pagano, F. Numis, G. Vison, L. Saldamarco, T. Russo, G. Porta, F. Paladino P234 - Noninvasive ventilation in patients with haematologic malignancy: a retrospective review C. Bell, J. Liu, J. Debacker, C. Lee, E. Tamberg, V. Campbell, S. Mehta P235 - Use of non-invasive ventilation in infectious diseases besides classical indications A. Silva-Pinto, A. Sarmento, L. Santos P236 - The impact of fragility on noninvasive mechanical ventilation application and results in the ICU Ý. Kara, F. Yýldýrým, A. Zerman, Z. Güllü, N. Boyacý, B. Basarýk Aydogan, Ü. Gaygýsýz, K. Gönderen, G. Arýk, M. Turkoglu, M. Aydogdu, G. Aygencel, Z. Ülger, G. Gursel P237 - Effects of metabolic alkalosis on noninvasive ventilation success and ICU outcome in patients with hypercapnic respiratory failure N. Boyacý, Z. Isýkdogan, Ö. Özdedeoglu, Z. Güllü, M. Badoglu, U. Gaygýsýz, M. Aydogdu, G. Gursel P238 - Asynchrony index and breathing patterns of acute exacerbation copd patients assisted with noninvasive pressure support ventilation and neurally adjusted ventilatory assist N. Kongpolprom, C. Sittipunt P239 - High frequency jet ventilation for severe acute hypoxemia A. Eden, Y. Kokhanovsky, S. Bursztein – De Myttenaere, R. Pizov P240 - HFOV revisited: a 7 year retrospective analysis of patients receiving HFOV who met oscillate trial entry criteria L. Neilans, N. MacIntyre P241 - Implementation of a goal-directed mechanical ventilation order set driven by respiratory therapists can improve compliance with best practices for mechanical ventilation M. Radosevich, B. Wanta, V. Weber, T. Meyer, N. Smischney, D. Brown, D. Diedrich P242 - A reduction in tidal volumes for ventilated patients on ICU calculated from IBW. can it minimise mortality in comparison to traditional strategies? A . Fuller, P. McLindon, K. Sim P243 - Predictive value of lung aeration scoring using lung ultrasound in weaning failure M. Shoaeir, K. Noeam, A. Mahrous, R. Matsa, A. Ali P244 - Conventional versus automated weaning from mechanical ventilation using SmartCare™ C. Dridi, S. Koubaji, S. Kamoun, F. Haddad, A. Ben Souissi, B. Laribi, A. Riahi, M. S. Mebazaa P245 - Ultrasonographic evaluation protocol for weaning from mechanichal ventilation A. Pérez-Calatayud, R. Carrillo-Esper, A. Zepeda-Mendoza, M. Diaz-Carrillo, E. Arch-Tirado P246 - Diaphragm ultrasonography: a method for weaning patients from mechanical ventilation S. Carbognin, L. Pelacani, F. Zannoni, A. Agnoli, G. Gagliardi P247 - Dorsal diaphragmatic excursion tracks transpulmonary pressure in ventilated ARDS patients: a potential non-invasive indicator of lung recruitment? R. Cho, A. Adams , S. Lunos, S. Ambur, R. Shapiro, M. Prekker P248 - Pulse oximetry in the icu patient: is the perfusion index of any value? M. Thijssen, L. Janssen, N. Foudraine P249 - Ventilation is a better assessment of respiratory status than EtCO2 C. J. Voscopoulos, J. Freeman P250 - Evaluation of the relationship between non-invasive minute ventilation and end-tidal CO2 in patients undergoing general vs spinal anesthesia C. J. Voscopoulos, J. Freeman, E. George P251 - Respiratory volume monitoring provides early warning of respiratory depression and can be used to reduce false alarms in non-intubated patients C. J. Voscopoulos, D. Eversole, J. Freeman, E. George P252 - P/i index: a predictive edi-derived weaning index during nava S. Muttini, R. Bigi, G. Villani, N. 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Zakynthinos P269 - Cell counts in endobronchial aspirate to assess airway inflammation in ARDS patients: a pilot study S. Spadaro, I. Kozhevnikova, F. Dalla Corte, S. Grasso, P. Casolari, G. Caramori, C. Volta P270 - Epidemiological and clinical profile of patients with acute respiratory distress syndrome in the surgical intensive care unit surgical, hospital JRA, Antananarivo T. Andrianjafiarinoa, T. Randriamandrato, T. Rajaonera P271 - Effect of high PEEP after recruitment maneuver on right ventricular function in ARDS. Is it good for the lung and for the heart? S. El-Dash, ELV Costa, MR Tucci, F Leleu, L Kontar, B. De Cagny, F. Brazier, D. Titeca, G. Bacari-Risal, J. Maizel, M. Amato, M. Slama P272 - Effect of recruitment maneuver on left ventricular systolic strain P. Mercado, J. Maizel, L. Kontar, D. Titeca, F. Brazier, A. Riviere, M. Joris, T. Soupison, B. De Cagny, S. El Dash, M. Slama P273 - Inhaled nitric oxide – is switching supplier cost effective? Remmington, A. Fischer, S. Squire, M. Boichat P274 - Epidemiological study of severe acute pancreatitis in Japan, comparison of the etiology and the patient outcomes on 1159 patients. H. Honzawa, H. Yasuda, T. Adati, S. Suzaki, M. Horibe, M. Sasaki, M. Sanui P275 - Extracorporeal liver support therapy. Experience in an intensive care unit R. Marinho, J. Daniel, H. Miranda, A. Marinho P276 - Accuracy of mortality prediction models in acute versus acute-on-chronic liver failure in the intensive care setting K. Milinis, M. Cooper, G. R. Williams, E. McCarron, S. Simants, I. Patanwala, I. Welters P277 - Risk of coronary artery disease in patients with chronic liver disease: a population based cohort study Y. Su P278 - 20 years of liver transplantation in Santiago de Compostela (Spain). Experience review J. Fernández Villanueva, R. Fernández Garda, A. López Lago, E. Rodríguez Ruíz, R. Hernández Vaquero, S. Tomé Martínez de Rituerto, E. Varo Pérez P279 - Diarrhea is a risk factor for liver injury and may lead to intestinal failure associated liver disease in critical illness N. Lefel, F. Schaap, D. Bergmans, S. Olde Damink, M. Van de Poll P280 - Bowel care on the intensive care unit: constipation guideline compliance and complications K. Tizard, C. Lister, L. Poole P281 - Malnutrition assessed by phase angle determines outcomes in low risk cardiac surgery patients D. Ringaitiene, D. Gineityte, V. Vicka, I. Norkiene, J. Sipylaite P282 - Preoperative fasting times in an irish hospital A. O’Loughlin, V. Maraj, J. Dowling P283 - Costs and final outcome of early x delayed feeding in a private Brazil ICU M. B. Velasco, D. M. Dalcomune, E. B. Dias, S. L. Fernandes P284 - Can ventilator derived energy expenditure measurements replace indirect calorimetry? T. Oshima, S. Graf, C. Heidegger, L. Genton, V. Karsegard, Y. Dupertuis, C. Pichard P285 - Revisiting the refeeding syndrome: results of a systematic review N. Friedli, Z. Stanga, B. Mueller, P. Schuetz P286 - Compliance with the new protocol for parenteral nutrition in our ICU L. Vandersteen, B. Stessel, S. Evers, A. Van Assche, L. Jamaer, J. Dubois P287 - Nutrition may be another treatment in the intensive care unit where less is more? R. Marinho, H. Castro, J. Moura, J. Valente, P. Martins, P. Casteloes, C. Magalhaes, S. Cabral, M. Santos, B. Oliveira, A. Salgueiro, A. Marinho P288 - Should we provide more protein to critically ill patients? R. Marinho, M. Santos, E. Lafuente, H. Castro, S. Cabral, J. Moura, P. Martins, B. Oliveira, A. Salgueiro, S. Duarte, S. Castro, M. Melo, P. Casteloes, A. Marinho P289 Protein provision in an adult intensive care unit S. Gray P290 - Prevalence and clinical outcomes of vitamin d deficiency in the medical critically ill patients in Songklanagarind hospital K. Maipang, R. Bhurayanontachai P291 - Vitamin d deficiency strongly predicts adverse medical outcome across different medical inpatient populations: results from a prospective study L. G. Grädel, P. Schütz P292 - Omega-3 fatty acids in patients undergoing cardiac surgery: a systematic review and meta-analysis P. Langlois, W. Manzanares P293 - Can 5-hydroxytriptophan prevent post-traumatic stress disorder in critically ill patients? R. Tincu, C. Cobilinschi, D. Tomescu, Z. Ghiorghiu, R. Macovei P294 - Parenteral selenium in the critically ill: an updated systematic review and meta-analysis W. Manzanares, P. Langlois, M. Lemieux, G. Elke, F. Bloos, K. Reinhart, D. Heyland P295 - Probiotics in the critically ill: an updated systematic review and meta-analysis P. Langlois, M. Lemieux, I. Aramendi, D. Heyland, W. Manzanares P296 - Diabetes with hyperglycemic crisis episodes may be associated with higher risk of pancreatic cancer: a population-based cohort study Y. 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Dean, A. Stilwell, G. Friedlaender P308 Dispatcher-assisted telephone cardiopulmonary resuscitation using a French-language compression-ventilation pediatric protocol M. Peters, S. Stipulante, A. Delfosse, AF Donneau, A. Ghuysen P309 Dantrolene versus amiodarone for resuscitation – an experimental study C. Feldmann, D. Freitag, W. Dersch, M. Irqsusi, D. Eschbach, T. Steinfeldt, H. Wulf, T. Wiesmann P310 Long term survival and functional neurological outcome in comatose survivors undergoing therapeutic hypothermia N. Kongpolprom, J. Cholkraisuwat P311 Impact of kidney disease on mortality and neurological outcome in out-of-hospital cardiac arrest: a prospective observational study S. Beitland , E. Nakstad, H. Stær-Jensen , T. Drægni , G. Andersen , D. Jacobsen , C. Brunborg, B. Waldum-Grevbo , K. Sunde P312 ICU dependency of patients admitted after primary percutaneous coronary intervention (PPCI) following out of the hospital cardiac arrest K. Hoyland, D. 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Perkins P335 Timing of endovascular and surgical treatment for aneurysmal subarachnoid haemorrhage: early but not so fast. J. Rubio, J. A. Rubio, R. Sierra P336 Red blood cell transfusion in aneurysmal subarachnoid hemorrhage – the Sahara cohort study S. English, M. Chasse, A. Turgeon, F. Lauzier, D. Griesdale, A. Garland, D. Fergusson, R. Zarychanski, A. Tinmouth, C. Van Walraven, K. Montroy, J. Ziegler, R. Dupont Chouinard, R. Carignan, A. Dhaliwal, C. Lum, J. Sinclair, G. Pagliarello, L. McIntyre P337 - Aneurysmal subarachnoid hemorrhage and anemia: a canadian multi-centre retrospective cohort study S. English, M. Chasse, A. Turgeon, F. Lauzier, D. Griesdale, A. Garland, D. Fergusson, R. Zarychanski, A. Tinmouth, C. Van Walraven, K. Montroy, J. Ziegler, R. Dupont Chouinard, R. Carignan, A. Dhaliwal, C. Lum, J. Sinclair, G. Pagliarello, L. 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Suchomel P343 - Evaluation of levetiracetam pharmacokinetics after severe traumatic brain injury in neurocritical care patients at a level one trauma center N. Ebert, J. Jancik, H. Rhodes P344 - Model based time series cluster analysis to determine unique patient states in traumatic brain injury T. Bylinski, C. Hawthorne, M. Shaw, I. Piper, J. Kinsella P345 - Brain compartment monitoring capabilities from ICP to BI (bioimpedance) during HS (hypertonic saline) administration. State of art simulation outcome depending on brain swelling type A. K. Kink , I. R. Rätsep P346 - Transfusion of red blood cells in patients with traumatic brain injury admitted to Canadian trauma health centers: a multicenter cohort study A. Boutin, L. Moore, M. Chasse, R. Zarychanski, F. Lauzier, S. English, L. McIntyre, J. Lacroix, D. Griesdale, P. Lessard-Bonaventure, A. F. 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Schuetz P351 - Developing an innovative emergency medicine point-of-care simulation programme T. Brown, J. Collinson, C. Pritchett, T. Slade P352 - The InSim program: an in situ simulation program for junior trainees in intensive care M. Le Guen, S. Hellings, R. Ramsaran P353 - Impact of excessive and inappropriate troponin testing in the emergency setting how good are we A. Alsheikhly P354 - The development of time tracking monitor at emergency department T. Abe P355 - Role of focussed echocardiography in emergency assessment of syncope L. Kanapeckaite, M. Abu-Habsa, R. Bahl P356 - Insertion of an open-ended 14-gauge catheter through the chest wall causes a significant pneumothorax in a self-ventilating swine model M. Q Russell, K. J. Real, M. Abu-Habsa , R. M. Lyon, N. P. Oveland P357 - Ez-io® intraosseous access teaching in the workplace using a mobile ‘tea trolley’ training method J. Penketh, M. Mcdonald, F. 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Leclerc P364 - A comparison of mortality scores in burns patients on the intensive care unit. O. Howarth, K. Davenport, P. Jeanrenaud, S. Raftery P365 - Clasification of pain and its treatment and an intensive care rehabiliation clinic P. MacTavish, H. Devine, J. McPeake, M. Daniel, J. Kinsella, T. Quasim P366 - Pain management adequacy in critical care areas ,the process and the barriers perceived by critical care nurses S. Alrabiee, A. Alrashid , S. Alsolamy P367 - Pain assessment in critically ill adult patients: validation of the Turkish version of the critical-care pain observation tool O. Gundogan, C. Bor, E. Akýn Korhan, K. Demirag , M. Uyar P368 - An audit of pain and sedation assessments in the intensive care unit: recommendations for clinical practice F. Frame, C. Ashton, L. Bergstrom Niska P369 - Impact of pharmaceutical care on treatment of pain and agitation in medical intensive care unit P. Dilokpattanamongkol, T. Suansanae, C. Suthisisang, S. Morakul, C. 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Bielka P377 - Hemodynamic effects of dexmedetomidine in a porcine model of septic shock Z. Aidoni, V. Grosomanidis, K. Kotzampassi, G. Stavrou, B. Fyntanidou, S. Patsatzakis, C. Skourtis P378 - Ketamine for analgosedation in severe hypoxic respiratory failure S. D. Lee, K. Williams, I. D. Weltes P379 - Madness from the moon? lunar cycle and the incidence of delirium on the intensive care unit S. Berhane, C. Arrowsmith, C. Peters, S. Robert P380 - Impaired dynamic cerebral autoregulation after coronary artery bypass grafting and association with postoperative delirium J. Caldas, R. B. Panerai, T. G. Robinson, L. Camara, G. Ferreira, E. Borg-Seng-Shu, M. De Lima Oliveira, N. C. Mian, L. Santos, R. Nogueira, S. P. Zeferino, M. Jacobsen Teixeira, F. Galas, L. A. Hajjar P381 - Risk factors predicting prolonged intensive care unit length of stay after major elective surgery. P. Killeen, M. McPhail, W. Bernal, J. Maggs, J. Wendon, T. Hughes P382 - Systemic inflammatory response syndrome criteria and hospital mortality prediction in a brazilian cohort of critically ill patients L. U. Taniguchi, E. M. Siqueira, J. M. Vieira Jr, L. C. Azevedo P383 - Evaluating the efficacy of a risk predictor panel in identifying patients at elevated risk of morbidity following emergency admission A. N. Ahmad, M. Abu-Habsa, R. Bahl, E. Helme, S. Hadfield, R. Loveridge P384 - A retrospective comparison of outcomes for elective surgical patients admitted post-operatively to the critical care unit or general ward J. Shak, C. Senver, R. Howard-Griffin P385 - Effect of obesity on mortality in surgical critically ill patients. P. Wacharasint, P. Fuengfoo, N. Sukcharoen, R. Rangsin P386 - The national early warning score (news) reliably improves adverse clinical outcome prediction in community-acquired pneumonia - results from a 6 year follow-up D. Sbiti-Rohr, P. 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Muraray Govind, N. Brahmananda Reddy, R. Pratheema, E. D. Arul, J. Devachandran P409 - Mortality and outcomes in elderly patients 80 years of age or older admitted to the icu M. B. Velasco , D. M. Dalcomune P410 - Octagenerians in medical icu - adding days to life or life to days? R. Knafelj, M. Fister P411 - The very elderly admitted to intensive care unit: outcomes and economic evaluation N. Chin-Yee, G. D’Egidio, K. Thavorn, D. Heyland, K. Kyeremanteng P412 - The very elderly in intensive care: relationship between acuity of illness and long-term mortality A. G. Murchison, K. Swalwell, J. Mandeville, D. Stott P413 - Acquired weakness in an oncological intensive care unit I. Guerreiro P414 - Musculoskeletal problems in intensive care unit (ICU) patients post-discharge H. Devine, P. MacTavish, J. McPeake, T. Quasim, J. Kinsella, M. Daniel P415 - Premorbid obesity, but not nutrition, prevents critical illness-induced muscle wasting and weakness C. Goossens M. B. Marques, S. Derde, S. Vander Perre, T. Dufour, S. E. Thiessen, F. Güiza, T. Janssens, G. Hermans, I. Vanhorebeek, K. De Bock, G. Van den Berghe, L. Langouche P416 - Physical outcome measures for critical care patients following intensive care unit (icu) discharge H. Devine, P. MacTavish, T. Quasim, J. Kinsella, M. Daniel, J. McPeake P417 - Improving active mobilisation in a general intensive care unit B. Miles , S. Madden, H. Devine P418 - Mobilization in patients on vasoactive drugs use – a pilot study. M. Weiler, P. Marques, C. Rodrigues, M. Boeira, K. Brenner, C. Leães, A. Machado, R. Townsend, J. Andrade P419 - Pharmacy intervention at an intensive care rehabilitation clinic P. MacTavish, J. McPeake, H. Devine, J. Kinsella, M. Daniel, R. Kishore, C. Fenlon, T. Quasim P420 - Interactive gaming is feasible and potentially increases icu patients’ motivation to be engaged in rehabilitation programs T. Fiks, A. Ruijter, M. Te Raa, P. Spronk P421 - Simulation-based design of a robust stopping rule to ensure patient safety Y. S. Chiew, P. Docherty, J. Dickson, E. Moltchanova, C. Scarrot, C. Pretty, G. M. Shaw, J. G. Chase P422 - Are daily blood tests on the intensive care unit necessary? T. Hall, W. C. Ngu, J. M. Jack, P. Morgan P423 - Measuring urine output in ward patients: is it helpful? B. Avard, A. Pavli, X. Gee P424 - The incidence of pressure ulcers in an adult mixed intensive care unit in turkey C . Bor, E. Akin Korhan, K. Demirag, M. Uyar P425 - Intensivist/patient ratios in closed ICUs in Alexandria, Egypt; an overview M. Shirazy, A. Fayed P426 - Eicu (electronic intensive care unit): impact on ALOS (average length of stay) in a developing country like India S. Gupta, A. Kaushal, S. Dewan, A. Varma P427 - Predicting deterioration in general ward using early deterioration indicator E. Ghosh, L. Yang, L. Eshelman, B. Lord, E. Carlson P428 - High impact enhanced critical care outreach - the imobile service: making a difference E. Helme, R. Broderick, S. Hadfield, R. Loveridge P429 - Impact of bed availability and cognitive load on intensive care unit (ICU) bed allocation: a vignette-based trial J. Ramos, D. Forte P430 - Characteristics of critically ill patients admitted through the emergency department F. Yang, P. Hou P431 - Admission to critical care: the quantification of functional reserve J. Dudziak, J. Feeney, K. Wilkinson, K. Bauchmuller, K. Shuker, M. Faulds, A. Raithatha, D. Bryden, L. England, N. Bolton, A. Tridente P432 - Admission to critical care: the importance of frailty K. Bauchmuller, K Shuker, A Tridente, M Faulds, A Matheson, J. Gaynor, D Bryden, S South Yorkshire Hospitals Research Collaboration P433 - Development of an instrument to aid triage decisions for intensive care unit admission J. Ramos, B. Peroni, R. Daglius-Dias, L. Miranda, C. Cohen, C. Carvalho, I . Velasco, D. Forte P434 - Using selective serotonin re-uptake inhibitors and serotonin-norepinephrine re-uptake inhibitors in critical care: a systematic review of the evidence for benefit or harm J. M. Kelly, A. Neill, G. Rubenfeld, N. Masson, A. Min P435 - Measuring adaptive coping of hospitalized patients with a severe medical condition:the sickness insight in coping questionnaire (sicq) E. Boezeman, J. Hofhuis , A. Hovingh, R. De Vries, P. Spronk P436 - Results of a national survey regarding intensive care medicine training G. Cabral-Campello, I. Aragão, T. Cardoso P437 - Work engagement among healthcare professionals in the intensive care unit M. Van Mol, M. Nijkamp, E . Kompanje P438 - Empowering the intensive care practitioners. is it a burnout ameliorating intervention? P. Ostrowski, A. Omar P439 - Icu patients suffer from circadian rhythm desynchronisation K. Kiss , B. Köves, V. Csernus, Z. Molnár P440 - Noise reduction in the ICU: feasible ? Y. Hoydonckx, S. Vanwing, B. Stessel, A. Van Assche, L. Jamaer, J. Dubois P441 - Accidental removal of invasive devices in the critical patient into the bed-washing. does the presence of professional nurse modify his incidence? V. Medo, R. Galvez, J. P. Miranda P442 - Deprivation of liberty safeguards (dols): audit of compliance in a of a 16-bed specialist cancer critical care unit. C. Stone, T. Wigmore P443 - Use of a modified cristal score to predict futility of critical care in the elderly Y. Arunan, A. Wheeler, K. Bauchmuller, D. Bryden P444 - Improvement of Referral Rate to Palliative Care for Patients with Poor Prognosis in Neurosurgical Intensive Care Unit Y. Wong, C. Poi, C. Gu P445 - Factors associated with limitation of life supporting care (lsc) in a medico-surgical intermediate care unit, and outcome of patients with lsc limitation: a monocentric, six-month study. P. Molmy, N. Van Grunderbeeck, O. Nigeon, M. Lemyze, D. Thevenin, J. Mallat P446 - Palliative care consultation and intensive care unit admission request: a cohort study J. Ramos, M. Correa, R. T. Carvalho, D. Forte P447 - Nursing and medicine together in postsurgical intensive care unit: situations of prognostic conflict at the end of life. our critical care nurses suffer with our medical activism? A. Fernandez, C. McBride P448 - End of life who may decide E. Koonthalloor, C. Walsh P449 - Correctly diagnosing death A. Webber, M. Ashe, K. Smith, P. Jeanrenaud P450 - Skin procurement performed by intensive care physicians: yes, we can. A. Marudi , S. Baroni, F. Ragusa, E. Bertellini P451 - Death analysis in pediatric intensive care patients E. A. Volakli , E. Chochliourou, M. Dimitriadou, A. Violaki, P. Mantzafleri, E. Samkinidou, O. Vrani, A. Arbouti, T. Varsami, M. Sdougka P452 - The potential impact of euthanasia on organ donation: analysis of data from belgium J. A. Bollen, T. C. Van Smaalen, W. C. De Jongh, M. M. Ten Hoopen, D. Ysebaert, L. W. Van Heurn, W. N. Van Mook P453 - Communication within an intensive care setting K. Sim, A. Fuller P454 - Development and implementation of a longitudinal communication curriculum for critical care medicine fellows A. Roze des Ordons, P. Couillard, C. Doig P455 - Staff-family conflict in a multi-ethnic intensive care unit R. V. Van Keer, R. D. Deschepper, A. F. Francke, L. H. Huyghens, J. B. Bilsen P456 - Does the source of admission to critical care affect family satisfaction? B. Nyamaizi, C. Dalrymple, A. Molokhia, A. Dobru P457 - A simple alternative to the family satisfaction survey (fs-icu) E. Marrinan, A. Ankuli, A. Molokhia P458 - A study to explore the experiences of patient and family volunteers in a critical care environment: a phenomenological analysis J. McPeake, R. Struthers, R. Crawford , H. Devine , P. Mactavish , T. Quasim P459 - Prevalence and risk factors of anxiety and depression in relatives of burn patients. P. Morelli, M. Degiovanangelo, F. Lemos, V. MArtinez, F. Verga, J. Cabrera, G. Burghi P460 - Guidance of visiting children at an adult intensive care unit (icu) A. Rutten , S. Van Ieperen, S. De Geer, M. Van Vugt, E. Der Kinderen P461 - Visiting policies in Italian pediatric ICUs: an update A. Giannini, G Miccinesi, T Marchesi, E Prandi

negative: Middle East respiratory syndrome coronavirus neutralising serum antibodies in dromedary camels: a comparative serological study Summary Background A new betacoronavirus—Middle East respiratory syndrome coronavirus (MERS-CoV)—has been identified in patients with severe acute respiratory infection. Although related viruses infect bats, molecular clock analyses have been unable to identify direct ancestors of MERS-CoV. Anecdotal exposure histories suggest that patients had been in contact with dromedary camels or goats. We investigated possible animal reservoirs of MERS-CoV by assessing specific serum antibodies in livestock. Methods We took sera from animals in the Middle East (Oman) and from elsewhere (Spain, Netherlands, Chile). Cattle (n=80), sheep (n=40), goats (n=40), dromedary camels (n=155), and various other camelid species (n=34) were tested for specific serum IgG by protein microarray using the receptor-binding S1 subunits of spike proteins of MERS-CoV, severe acute respiratory syndrome coronavirus, and human coronavirus OC43. Results were confirmed by virus neutralisation tests for MERS-CoV and bovine coronavirus. Findings 50 of 50 (100%) sera from Omani camels and 15 of 105 (14%) from Spanish camels had protein-specific antibodies against MERS-CoV spike. Sera from European sheep, goats, cattle, and other camelids had no such antibodies. MERS-CoV neutralising antibody titres varied between 1/320 and 1/2560 for the Omani camel sera and between 1/20 and 1/320 for the Spanish camel sera. There was no evidence for cross-neutralisation by bovine coronavirus antibodies. Interpretation MERS-CoV or a related virus has infected camel populations. Both titres and seroprevalences in sera from different locations in Oman suggest widespread infection. Funding European Union, European Centre For Disease Prevention and Control, Deutsche Forschungsgemeinschaft.

negative: No Serologic Evidence for Zoonotic Canine Respiratory Coronavirus Infections among Immunocompetent Adults Zoonotic diseases continue to emerge and threaten both human and animal health. Overcrowded shelters and breeding kennels create the perfect environment for amplified infectious disease transmission among dogs and present a critical opportunity for zoonotic pathogens to emerge and infect people who work in close contact with dogs. Coronaviruses’ widespread prevalence, extensive host range, various disease manifestations and increased frequency of recombination events all underline their potential for interspecies transmission (Methods Mol. Biol. 2008, 454, 43). The objectives of this study were to determine whether people with occupational contact with dogs were more likely to have antibodies against canine respiratory coronavirus (CRCoV) compared to persons with no dog exposure. A seroepidemiological cohort study was completed, for which 302 canine‐exposed and 99 non‐canine‐exposed study subjects enrolled in the study by providing a serum sample and completing a self‐administered questionnaire. A competitive enzyme‐linked immunosorbent assay (ELISA) was developed to detect human antibodies against CRCoV while controlling for cross‐reacting antibodies against the human coronavirus OC43. All study subjects were negative for antibodies against CRCoV by this competitive ELISA. This study supports the premise that humans are not at risk for CRCoV infections; however, infrequent cross‐species transmission of CRCoV cannot be ruled out.

negative: Single radial haemolysis for the determination of antibody to reoviruses A single radial haemolysis (SRH) for reovirus antibody determination was developed and compared to standard haemagglutination-inhibition (HI) and complement fixation (CF) techniques. SRH appeared more simple and sensitive than CF, but less sensitive and less specific than HI.

negative: Development of an equine coronavirus-specific enzyme-linked immunosorbent assay to determine serologic responses in naturally infected horses. Equine coronavirus (EqCoV) infection has been documented in most reports through quantitative qPCR analysis of feces and viral genome sequencing. Although qPCR is used to detect antigen during the acute disease phase, there is no equine-specific antibody test available to study EqCoV seroprevalence in various horse populations. We developed an enzyme-linked immunosorbent assay (ELISA) targeting antibodies to the spike (S) protein of EqCoV and validated its use, using acute and convalescent sera from 83 adult horses involved in 6 outbreaks. The EqCoV S protein-based ELISA was able to reliably detect antibodies to EqCoV in naturally infected horses. The greatest seroconversion rate was observed in horses with clinical signs compatible with EqCoV infection and EqCoV qPCR detection in feces. The EqCoV S protein-based ELISA could be used effectively for seroepidemiologic studies in order to better characterize the overall infection rate of EqCoV in various horse populations.

negative: Genomic relationship between turkey and bovine enteric coronaviruses identified by hybridization with BCV or TCV specific cDNA probes Genomic relationships between turkey and bovine coronavirus (TCV and BCV), which are currently placed in distinct antigenic groups, were demonstrated by hybridization using specific cDNA probes. BCV-specific recombinant plasmid probes p 52, p 27, and p 247, holding inserts derived from (probably nonstructural) genes, and plasmids pN 17 and pN 9 holding the N and M gene, respectively, permitted the detection of isolates of both BCV and TCV with similar sensitivities. Similarly, probing supernatants of cell cultures infected with several isolates of TCV, using probes pN 17 and pM 78, respectively holding the N gene of BCV and TCV, resulted in equally intense detection signals. Only a slight detection of MHV-3, which is antigenically related to BCV, was observed, whereas the probes did not allow the detection of IBV, TGEV, and HCV-229E, which are placed in antigenic groups separate from those of BCV and TCV. Detection of TCV was improved by hybridization with BCV-specific single-stranded (ss) probes holding sequences of the N and M genes and synthesized by the polymerase chain reaction. Diagnosis of TCV in 134 clinical samples by hybridization was better with PCR-produced ss BCV-specific probes than with ds PCR-produced probes or a combination of six recombinant plasmid probes holding non-overlapping BCV-specific cDNA sequences. Detection signals were absent when probing clinical samples with(32)P-labelled pUC-DNA.

negative: Global rheumatology in the time of COVID-19

negative: A novel double antibody sandwich-lateral flow immunoassay for the rapid and simple detection of hepatitis C virus The objective of this study was to screen for antigens of the hepatitis C virus (HCV) to establish a new double antibody sandwich-lateral flow immunoassay (DAS-LFIA) method for testing the presence of anti-HCV antibodies in human serum or plasma. A series of different recombinant HCV proteins in Escherichia coli cells were constructed, expressed, purified and the new DAS-LFIA strip was developed. The sensitivity and specificity of new the DAS-LFIA strip were evaluated by detecting 23 HCV-positive sera, a set of quality control references for anti-HCV detection that contain known amounts of anti-HCV antibodies, and 8 HCV-negative sera. A total of 300 clinical serum samples was examined by both the new DAS-LFIA strip and enzyme-linked immunosorbent assay (ELISA). Data were analyzed using SPSS 11.5 software. The sensitivity and specificity of the new DAS-LFIA strip were 100%. The lowest test line of the HCV DAS-LFIA strips was 2 NCU/ml. Additionally, the concordance between the new DAS-LFIA strip and ELISA methods was 94.33%. In conclusion, our new testing method is rapid, simple, sensitive and specifically detects the presence of anti-HCV antibodies in human serum or plasma. Therefore, it may be used for monitoring HCV.

negative: Cross-reactive antibodies in convalescent SARS patients' sera against the emerging novel human coronavirus EMC (2012) by both immunofluorescent and neutralizing antibody tests Summary Objectives A severe acute respiratory syndrome (SARS)-like disease due to a novel betacoronavirus, human coronavirus EMC (HCoV-EMC), has emerged recently. HCoV-EMC is phylogenetically closely related to Tylonycteris-bat-coronavirus-HKU4 and Pipistrellus-bat-coronavirus-HKU5 in Hong Kong. We conducted a seroprevalence study on archived sera from 94 game-food animal handlers at a wild life market, 28 SARS patients, and 152 healthy blood donors in Southern China to assess the zoonotic potential and evidence for intrusion of HCoV-EMC and related viruses into humans. Methods Anti-HCoV-EMC and anti-SARS-CoV antibodies were detected using screening indirect immunofluorescence (IF) and confirmatory neutralizing antibody tests. Results Two (2.1%) animal handlers had IF antibody titer of ≥1:20 against both HCoV-EMC and SARS-CoV with neutralizing antibody titer of <1:10. No blood donor had antibody against either virus. Surprisingly, 17/28 (60.7%) of SARS patients had significant IF antibody titers with 7/28 (25%) having anti-HCoV-EMC neutralizing antibodies at low titers which significantly correlated with that of HCoV-OC43. Bioinformatics analysis demonstrated a significant B-cell epitope overlapping the heptad repeat-2 region of Spike protein. Virulence of SARS-CoV over other betacoronaviruses may boost cross-reactive neutralizing antibodies against other betacoronaviruses. Conclusions Convalescent SARS sera may contain cross-reactive antibodies against other betacoronaviruses and confound seroprevalence study for HCoV-EMC.

negative: Chapter 11 Microbiological Quality Control for Laboratory Rodents and Lagomorphs Mice (Mus musculus), rats (Rattus norvegicus), other rodent species, and domestic rabbits (Oryctolagus cuniculus) have been used in research for over 100 years. During the first half of the 20th century, microbiological quality control of lab animals was at best rudimentary as colonies were conventionally housed and little or no diagnostic testing was done. Hence, animal studies were often curtailed and confounded by infectious disease (Mobraaten and Sharp, 1999; Morse, 2007; Weisbroth, 1999). By the 1950s, it became apparent to veterinarians in the nascent field of comparative medicine that disease-free animals suitable for research could not be produced by standard veterinary disease control measures (e.g., improved sanitation and nutrition, antimicrobial treatments) in conventional facilities. Henry Foster, the veterinarian who founded Charles River Breeding Laboratories in 1948 and a pioneer in the large-scale production of laboratory rodents, stated in a seminar presented at the 30th anniversary of AALAS, “After a variety of frustrating health-related problems, it was decided that a major change in the company’s philosophy was required and an entirely different approach was essential”. Consequently, he and others developed innovative biosecurity systems to eliminate and exclude pathogens (Allen, 1999). In 1958, Foster reported on the Cesarean-originated barrier-sustained (COBS) process for the large-scale production of specific pathogen-free (SPF) laboratory rodents (Foster, 1958). To eliminate horizontally transmitted pathogens, a hysterectomy was performed on a near-term dam from a contaminated or conventionally housed colony. The gravid uterus was pulled through a disinfectant solution into a sterile flexible film isolator where the pups were removed from the uterus and suckled on axenic (i.e., germ-free) foster dams. After being mated to expand their number and associated with a cocktail of nonpathogenic bacteria to normalize their physiology and prime their immune system, rederived rodents were transferred to so-called barrier rooms for large-scale production. The room-level barrier to adventitious infection entailed disinfection of the room, equipment, and supplies, limiting access to trained and properly gowned personnel, and the application of new technologies such as high-efficiency particulate air-filtration of incoming air (Dubos and Schaedler, 1960; Foster, 1980; Schaedler and Orcutt, 1983; Trexler and Orcutt, 1999). The axenic and associated rodents mentioned in the COBS process are collectively classified as gnotobiotic to indicate that they have a completely known microflora. By contrast, barrier-reared rodent colonies are not gnotobiotic because they are housed in uncovered cages and thus acquire a complex microflora from the environment, supplies, personnel, and other sources. Instead, they are described as SPF to indicate that according to laboratory testing, they are free from infection with a defined list of infectious agents, commonly known as an ‘exclusion’ list.

negative: Interpreting Diagnostic Studies in SARS—Defining the Reference

negative: Molecular and serological assays for SARS-CoV-2: insights from genome and clinical characteristics BACKGROUND: The ongoing outbreak of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has posed a challenge for worldwide public health. A reliable laboratory assay is essential both to confirm suspected patients and to exclude patients infected with other respiratory viruses, thereby facilitating the control of global outbreak scenarios. CONTENT: In this review, we focus on the genomic, transmission and clinical characteristics of SARS-CoV-2, and comprehensively summarize the principles and related details of assays for SARS-CoV-2. We also explore the quality assurance measures for these assays. SUMMARY: SARS-CoV-2 has some unique gene sequences and specific transmission and clinical features that can inform the conduct of molecular and serological assays in many aspects, including the design of primers, the selection of specimens and testing strategies at different disease stages. Appropriate quality assurance measures for molecular and serological assays are needed to maintain testing proficiency. Because serological assays have the potential to identify later stages of the infection and to confirm highly suspected cases with negative molecular assay results, a combination of these two assays is needed to achieve a reliable capacity to detect SARS-CoV-2.

negative: Recent Advances in EPAC-Targeted Therapies: A Biophysical Perspective The universal second messenger cAMP regulates diverse intracellular processes by interacting with ubiquitously expressed proteins, such as Protein Kinase A (PKA) and the Exchange Protein directly Activated by cAMP (EPAC). EPAC is implicated in multiple pathologies, thus several EPAC-specific inhibitors have been identified in recent years. However, the mechanisms and molecular interactions underlying the EPAC inhibition elicited by such compounds are still poorly understood. Additionally, being hydrophobic low molecular weight species, EPAC-specific inhibitors are prone to forming colloidal aggregates, which result in non-specific aggregation-based inhibition (ABI) in aqueous systems. Here, we review from a biophysical perspective the molecular basis of the specific and non-specific interactions of two EPAC antagonists—CE3F4R, a non-competitive inhibitor, and ESI-09, a competitive inhibitor of EPAC. Additionally, we discuss the value of common ABI attenuators (e.g., TX and HSA) to reduce false positives at the expense of introducing false negatives when screening aggregation-prone compounds. We hope this review provides the EPAC community effective criteria to evaluate similar compounds, aiding in the optimization of existing drug leads, and informing the development of the next generation of EPAC-specific inhibitors.

negative: SARS-CoV-2 Seroconversion in Humans: A Detailed Protocol for a Serological Assay, Antigen Production, and Test Setup In late 2019, cases of atypical pneumonia were detected in China. The etiological agent was quickly identified as a betacoronavirus (named SARS-CoV-2), which has since caused a pandemic. Several methods allowing for the specific detection of viral nucleic acids have been established, but these only allow detection of the virus during a short period of time, generally during acute infection. Serological assays are urgently needed to conduct serosurveys, to understand the antibody responses mounted in response to the virus, and to identify individuals who are potentially immune to re-infection. Here we describe a detailed protocol for expression of antigens derived from the spike protein of SARS-CoV-2 that can serve as a substrate for immunological assays, as well as a two-stage serological enzyme-linked immunosorbent assay (ELISA). These assays can be used for research studies and for testing in clinical laboratories. © 2020 The Authors. Basic Protocol 1: Mammalian cell transfection and protein purification Basic Protocol 2: A two-stage ELISA for high-throughput screening of human serum samples for antibodies binding to the spike protein of SARS-CoV-2.

negative: Infectious disease surveillance in captive and free‐living cheetahs: An integral part of the species survival plan During the formulative stages of developing the Species Survival Plan (SSP) for the cheetah, the impact of infectious disease upon its survival in captivity was of prime consideration, together with genetics, nutrition, physiology, and behavior. This paper summarizes the results of an infectious disease surveillance program, initially designed to monitor the infectious agents associated with clinically normal and clinically ill cheetahs in captivity, but subsequently supplemented with data from free‐living cheetahs. The focus was on two viral infections, feline infectious peritonitis (FIP) and feline rhinotracheitis virus. Results indicated that between 1989 and 1991, there was an increase in the seroprevalence (number antibody‐positive animals) of cheetahs to feline coronavirus from 41% to 64% in captivity. During this same time period, there were only two documented cases of FIP in cheetahs in the United States. The results suggest that feline coronavirus (feline enteric coronavirus‐‐feline infectious peritonitis group) or a closely related coronavirus of cheetahs is becoming endemic in the captive cheetah population. Further serologic results from 39 free‐living cheetahs demonstrated that there was a high seroprevalence (61%) to feline coronavirus, although serum antibody titers were considerably lower than those encountered in captive cheetahs. The observation of a high percentage of free‐living cheetahs, which were seropositive to feline herpesvirus (44%), was unexpected, since it has been generally regarded that this infection is primarily associated with cheetahs in captivity. © 1993 Wiley‐Liss, Inc.

negative: Prevalence of canine coronavirus (CCoV) in dog in Japan: detection of CCoV RNA and retrospective serological analysis We collected rectal swabs from dogs in Japan during 2011 to 2014, and canine coronavirus (CCoV) nucleocapsid gene was detected by RT-PCR. The relationship between CCoV infection and the manifestation of diarrhea symptoms was investigated, and a correlation was noted (df=1, χ(2)=8.90, P<0.005). The types of CCoV detected in samples from CCoV-infected dogs were CCoV-I in 88.9% and CCoV-II in 7.4%, respectively. We retrospectively investigated the seroprevalence of CCoV-I in dogs in Japan during 1998 to 2006. The sera were tested with a neutralizing antibody test. In the absence of CCoV-I laboratory strain, we used feline coronavirus (FCoV)-I that shares high sequence homology in the S protein with CCoV-I. 77.7% of the sera were positive for neutralizing anti-FCoV-I antibodies.

negative: Virologie : l’apport de la biologie moléculaire dans le diagnostic microbiologique en pneumopédiatrie Résumé Les outils traditionnels du diagnostic virologique comprennent la recherche antigénique directe par immunofluorescence (IF) ou test immunoenzymatique (EIA), et l’isolement en culture. Les techniques d’IF ou EIA ont une sensibilité en général légèrement inférieure à celle de la culture, mais elles permettent de détecter également une fraction d’échantillons faussement négatifs en culture. Les résultats de plusieurs équipes, utilisant des techniques de reverse transcription-polymerase chain reaction (RT-PCR), montrent que les méthodes moléculaires détectent plus d’échantillons positifs que les méthodes traditionnelles. Le travail est en cours pour élargir le nombre de virus identifiés par des RT-PCR multiplex et découvrir de nouveaux virus, tels le métapneumovirus humain, en cause dans les atteintes respiratoires de l’enfant. En conclusion, afin de concilier rapidité, contrôle des coûts et un fort taux de détection des virus respiratoires, l’utilisation combinée de l’IF et de la RT-PCR multiplex semble ce jour la meilleure façon de progresser dans le diagnostic des maladies respiratoires de l’enfant. Summary The conventionnal tools used for virological diagnosis include direct antigen detection by immunofluorescence (IFA) or an immunoenzymatic test (EIA), and viral isolation technique (VIT). In most cases, IFA and EIA have a slightly lower sensitivity than VIT but are also able to detect some VIT-negative samples. Results of several teams using RT-PCR technologies show that the molecular methods detect more positive cases than the conventional tools. Work is under way to expand the number of viruses detected by multiplex RT-PCR and to determine wether newly discovered viruses, such as human metapneumovirus, contribute to burden of paediatric lower respiratory infections. In conclusion, according to requirements of speed, low cost of the methods, and to achieve the highest rate of detection of respiratory viruses, the combined use of IFA and multiplex RT-PCR is today likely to be the best way to improve diagnosis of respiratory illnesses in children.

negative: Emerging Highly Virulent Porcine Epidemic Diarrhea Virus: Molecular Mechanisms of Attenuation and Rational Design of Live Attenuated Vaccines The highly virulent porcine epidemic diarrhea virus (PEDV) emerged in China in 2010. It infects pigs of all ages, and causes severe diarrhea and high mortality rates in newborn pigs, leading to devastating economic losses in the pork industry worldwide. Effective and safe vaccines against highly virulent PEDV strains are still unavailable, hampering the further prevention, control and eradication of the disease in herds. Vaccination of pregnant sows with live attenuated vaccines (LAVs) is the most effective strategy to induce lactogenic immunity in the sows, which provides A passive protection of suckling piglets against PEDV via the colostrum (beestings, or first milk) and milk. Several LAV candidates have been developed via serially passaging the highly virulent PEDV isolates in non-porcine Vero cells. However, their efficacies in the induction of sufficient protection against virulent PEDV challenge vary in vivo. In this review, we summarize the current knowledge of the virulence-related mutations of PEDV and their potential roles in PEDV attenuation in vivo. With the successful development of reverse genetics systems for PEDV, we also discuss how to use them to generate promising LAV candidates that are safe, effective and genetically stable. This article provides timely insight into the rational design of effective and safe PEDV LAV candidates.

negative: Serological studies of transmissible gastroenteritis in Great Britain, using a competitive ELISA. A competitive ELISA which differentiates between transmissible gastroenteritis virus (TGEV) and porcine respiratory coronavirus (PRCV) was used to detect non-neutralising antibodies to the peplomer protein of TGEV in porcine sera. The test was shown to be TGEV specific, having a relative specificity of 100 per cent, and to have a relative sensitivity of 94.9 per cent when compared with the virus neutralisation test. The prevalence of TGEV in Great Britain is low; only 0.6 per cent of sows sampled in 1990 were seropositive to TGEV. Seroconversion to the virus neutralisation test occurred in a closed herd in 1984, with no apparent spread, but later testing by the ELISA did not detect any blocking antibodies. The possibility of the existence of a less contagious strain of PRCV is discussed. All British isolates of TGEV tested by the indirect fluorescent antibody test were recognised by the monoclonal antibody 1D.B12, the indicator antibody in the ELISA.

negative: Viral Shedding and Antibody Response in 37 Patients With Middle East Respiratory Syndrome Coronavirus Infection Background. The Middle East respiratory syndrome (MERS) coronavirus causes isolated cases and outbreaks of severe respiratory disease. Essential features of the natural history of disease are poorly understood. Methods. We studied 37 adult patients infected with MERS coronavirus for viral load in the lower and upper respiratory tracts (LRT and URT, respectively), blood, stool, and urine. Antibodies and serum neutralizing activities were determined over the course of disease. Results. One hundred ninety-nine LRT samples collected during the 3 weeks following diagnosis yielded virus RNA in 93% of tests. Average (maximum) viral loads were 5 × 10(6) (6 × 10(10)) copies/mL. Viral loads (positive detection frequencies) in 84 URT samples were 1.9 × 10(4) copies/mL (47.6%). Thirty-three percent of all 108 serum samples tested yielded viral RNA. Only 14.6% of stool and 2.4% of urine samples yielded viral RNA. All seroconversions occurred during the first 2 weeks after diagnosis, which corresponds to the second and third week after symptom onset. Immunoglobulin M detection provided no advantage in sensitivity over immunoglobulin G (IgG) detection. All surviving patients, but only slightly more than half of all fatal cases, produced IgG and neutralizing antibodies. The levels of IgG and neutralizing antibodies were weakly and inversely correlated with LRT viral loads. Presence of antibodies did not lead to the elimination of virus from LRT. Conclusions. The timing and intensity of respiratory viral shedding in patients with MERS closely matches that of those with severe acute respiratory syndrome. Blood viral RNA does not seem to be infectious. Extrapulmonary loci of virus replication seem possible. Neutralizing antibodies do not suffice to clear the infection.

negative: Chapter 8 Single-Stranded RNA Viruses In this chapter, we describe 73 zoonotic viruses that were isolated in Northern Eurasia and that belong to the different families of viruses with a single-stranded RNA (ssRNA) genome. The family includes viruses with a segmented negative-sense ssRNA genome (families Bunyaviridae and Orthomyxoviridae) and viruses with a positive-sense ssRNA genome (families Togaviridae and Flaviviridae). Among them are viruses associated with sporadic cases or outbreaks of human disease, such as hemorrhagic fever with renal syndrome (viruses of the genus Hantavirus), Crimean–Congo hemorrhagic fever (CCHFV, Nairovirus), California encephalitis (INKV, TAHV, and KHATV; Orthobunyavirus), sandfly fever (SFCV and SFNV, Phlebovirus), Tick-borne encephalitis (TBEV, Flavivirus), Omsk hemorrhagic fever (OHFV, Flavivirus), West Nile fever (WNV, Flavivirus), Sindbis fever (SINV, Alphavirus) Chikungunya fever (CHIKV, Alphavirus) and others. Other viruses described in the chapter can cause epizootics in wild or domestic animals: Geta virus (GETV, Alphavirus), Influenza A virus (Influenzavirus A), Bhanja virus (BHAV, Phlebovirus) and more. The chapter also discusses both ecological peculiarities that promote the circulation of these viruses in natural foci and factors influencing the occurrence of epidemic and epizootic outbreaks

negative: Bacterial resistance: A sensitive issue Complexity of the challenge and containment strategy in Europe Abstract The development of antimicrobial agents has been a key achievement of modern medicine. However, their overuse has led to an increasing incidence of infections due to antibiotic-resistant microorganisms. Quantitative figures on the current economic and health impact of antimicrobial resistance are scant, but it is clearly a growing challenge that requires timely action. That action should be at the educational, ethical, economic and political level. An important first step would be to increase public awareness and willingness to take the necessary measures to curb resistance. Hence, studies are needed that would provide solid, quantitative data on the societal impact of antibiotic resistance. This review discusses the complexity of resistance, identifies its main drivers and proposes measures to contain it on a European scale.

negative: Human enteric Coronaviruses: Antigenic Relatedness to Human Coronavirus OC43 and Possible Etiologic Role in Viral Gastroenteritis In a group of infants with acute nonbacterial gastroenteritis, examination of paired sera for antibody to human coronavirus (HCV) OC43 and neonatal calf diarrhea coronavirus showed a peculiar pattern of serological response, restricted only to HCV OC43 surface antigens, in a significantly higher proportion than among age-matched controls. In another group of infants and young children with acute nonbacterial gastroenteritis, fecal excretion of coronavirus-like particles was detected by electron microscopy in 34 (16.3%) of 208 patients as compared with three (1.6%) of 182 controls (P < .01). Two strains of human enteric coronavirus (HECV) were purified from stools of two patients, and immune sera were raised in mice and guinea pigs. Immune electron microscopy showed a two-way cross-reactivity between HECV and HCV OC43 when tested with immune sera and convalescent-phase sera from patients with infection due to HECV or HCV OC43.

negative: Comparison Of Four Anti-Avian IgY Secondary Antibodies Used In Western Blot And Dot-Blot ELISA To Detect Avian Bornavirus Antibodies In Four Different Bird Species PURPOSE: This study evaluated the specificity of different avian secondary antibodies used in Western blot and dot-blot ELISA to detect avian bornavirus antibodies in bird plasma. METHODS: Plasma samples were collected from: two Blue and gold macaws, one positive and one negative for avian bornavirus by RT-PCR; a Cockatiel and a Monk parakeet prior to and following experimental infection; and, two Mallards, one positive and one negative for avian bornavirus by RT-PCR Samples were analyzed by Western blot and dot-blot ELISA that incorporated recombinant avian bornavirus nucleoprotein as the target analyte. Four species-specific anti-IgY secondary antibodies were used in the assays: goat anti-macaw IgY, goat anti-bird IgY, goat anti-duck IgY, and rabbit anti-chicken IgY. RESULTS: In the Western blot, anti-macaw IgY secondary antibody produced strong signals with Blue and gold macaw and Cockatiel positive plasma, but no signal with Mallard positive plasma. Anti-bird IgY secondary antibody produced strong signals with Blue and gold macaw, Cockatiel, and Mallard positive plasma. Anti-duck and anti-chicken IgY secondary antibody produced a strong and moderate signal, respectively, only with Mallard positive plasma. In the dot-blot ELISA, there was a distinct and significant difference (P<0.05) in the signal intensity between the different secondary antibodies within a bird species. Anti-macaw IgY secondary antibody produced significantly (P<0.05) stronger signals than the other secondary antibodies in Blue and gold macaw, Cockatiel, and Monk parakeet positive plasma, while anti-duck IgY secondary antibody produced significantly (P<0.05) stronger signals than the other secondary antibodies in Mallard positive plasma. CONCLUSION: In testing psittacines with immunoassays, and especially in assays that incorporate short incubation reaction times such as a dot-blot ELISA, species-specific anti-IgY secondary antibodies provided more accurate results.

negative: Development of indirect enzyme-linked immunosorbent assay for detection of porcine epidemic diarrhea virus specific antibodies (IgG) in serum of naturally infected pigs BACKGROUND: Porcine epidemic diarrhea virus (PEDV) infection is a highly contagious infectious disease causing watery diarrhea, vomiting, dehydration and high mortality rate in newborn piglets. PEDV infection can cause high economic losses in pig industry. In Japan, a PEDV outbreak occurred with high mortality from 2013 to 2015. Even though until now, PEDV infection occurs sporadically. For the control and monitoring of PEDV infection, not only symptomatic pigs, but also asymptomatic pigs should be identified. The objective of this study is to develop and optimize novel indirect ELISA as a simple, rapid, sensitive and specific method for the detection of anti-PEDV antibodies and evaluate the efficacy of the assay as a diagnostic method for PED. RESULTS: One hundred sixty-two serum samples, consisting of 81 neutralization test (NT) positive and 81 NT negative sera, were applied to the assay. Indirect ELISA test based on whole virus antigen (NK94P6 strain) derived from Vero cell culture was evaluated by receiver operating characteristic (ROC) analysis with neutralization test (NT) as a reference method, and cut-off value was determined as 0.320 with sensitivity and specificity of 92.6 and 90.1%, respectively. The area under curve (AUC) was 0.949, indicating excellent accuracy of indirect ELISA test. There was significant positive correlation between indirect ELISA and neutralization test (R = 0.815, P < 0.05). Furthermore, the kappa statics showed the excellent agreement between these two tests (kappa value = 0.815). In addition, the sensitivity and specificity of preserved plates with different periods (1 day, 2 weeks, 1, 2, 3, 4, 5 and 6 months) after drying antigen coated plates were 100% and 80–100%, respectively. CONCLUSIONS: The developed indirect ELISA test in our study would be useful as a reliable test for serological survey and disease control of PEDV infection, and our pre-antigen coated ELISA plates can be preserved at 4 °C until at least 6 months.

negative: Diagnostic Techniques: Serological and Molecular Approaches☆ Abstract Virus laboratory diagnostics has an increasingly important role in modern patient care. Virological methods are needed to investigate the etiology of acute viral infection or the reactivation of a latent infection, as well as to follow virus load in antiviral treatments. Serological assays are also used for screening of blood products for the risk of certain chronic infections, evaluation of the immune status, and need for prophylactic treatments in connection with organ transplantations. For diagnostic purposes the following approaches can be used: demonstration of presence of infectious virus or its structural components directly from a patient's specimens or investigation of specific antibody response in serum specimens. Amplification techniques, most commonly polymerase chain reaction (PCR) is currently the workhorse of nucleic acid testing for the detection and quantitation of virus genomes. Virus isolation is used to demonstrate infectious virus in a patient's specimens, whereas virus antigens are investigated by antigen detection assays. Serological diagnosis is based on either the demonstration of the presence of virus-specific IgM antibodies or a significant increase in the levels and/or avidity of specific IgG antibodies. Immunoassays are the most commonly used serological assays. Point-of-care tests (POC tests), for antigens, antibodies, and also nucleic acids are also becoming more and more common in diagnostic use. In order to reach the best diagnostic efficiency for each patient it is important to select the most suitable method using the right sample collected at the right time.

negative: Preliminary Identification of Potential Vaccine Targets for the COVID-19 Coronavirus (SARS-CoV-2) Based on SARS-CoV Immunological Studies The beginning of 2020 has seen the emergence of COVID-19 outbreak caused by a novel coronavirus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). There is an imminent need to better understand this new virus and to develop ways to control its spread. In this study, we sought to gain insights for vaccine design against SARS-CoV-2 by considering the high genetic similarity between SARS-CoV-2 and SARS-CoV, which caused the outbreak in 2003, and leveraging existing immunological studies of SARS-CoV. By screening the experimentally-determined SARS-CoV-derived B cell and T cell epitopes in the immunogenic structural proteins of SARS-CoV, we identified a set of B cell and T cell epitopes derived from the spike (S) and nucleocapsid (N) proteins that map identically to SARS-CoV-2 proteins. As no mutation has been observed in these identified epitopes among the 120 available SARS-CoV-2 sequences (as of 21 February 2020), immune targeting of these epitopes may potentially offer protection against this novel virus. For the T cell epitopes, we performed a population coverage analysis of the associated MHC alleles and proposed a set of epitopes that is estimated to provide broad coverage globally, as well as in China. Our findings provide a screened set of epitopes that can help guide experimental efforts towards the development of vaccines against SARS-CoV-2.

negative: Population-Level Antibody Estimates to Novel Influenza A/H7N9 There are no contemporary data available describing human immunity to novel influenza A/H7N9. Using 1723 prospectively collected serum samples in southern Vietnam, we tested for antibodies to 5 avian influenza virus antigens, using a protein microarray. General-population antibody titers against subtype H7 virus are higher than antibody titers against subtype H5 and lower than titers against H9. The highest titers were observed for human influenza virus subtypes. Titers to avian influenza virus antigens increased with age and with geometric mean antibody titer to human influenza virus antigens. There were no titer differences between the urban and the rural location in our study.

negative: Celiac and non-celiac gluten sensitivity: a review on the association with schizophrenia and mood disorders An association between many psychiatric and gluten-related disorders has been known for some time. In the case of schizophrenia and mood disorders, the major psychiatric disorders, there is much evidence, not without contradictions, of a possible association between schizophrenia and celiac disease. The association between mood disorders and gluten-related disorders, especially celiac disease, has only been studied for depression, often coupled with anxiety, and very recently for bipolar disorder. Since non-celiac gluten sensitivity is now known to be different from celiac disease, many studies have shown that gluten sensitivity is also associated with major psychiatric disorders. Here we review the literature on the association between schizophrenia/mood disorders and celiac disease/gluten sensitivity, pointing out the differences between these associations.

negative: Molecular Diagnosis of Severe Acute Respiratory Syndrome : The State of the Art Severe acute respiratory syndrome (SARS) first appeared in Guangdong Province, China, in November 2002. Although virus isolation and serology were useful early in the SARS outbreak for diagnosing new cases, these tests are not generally useful because virus culture requires a BSL-3 laboratory and seroconversion is often delayed until 2 to 3 weeks after infection. The first qualitative reverse transcriptase-polymerase chain reaction tests for SARS-coronavirus (CoV) were sensitive and capable of detecting 1 to 10 genome equivalents. These assays were quickly supplemented with quantitative real-time assays that helped elucidate the natural history of SARS, particularly the initial presence of low viral loads in the upper respiratory tract and high viral loads in the lower respiratory tract. The unique natural history of SARS-CoV infection dictates the testing of both respiratory and nonrespiratory specimens, the testing of multiple specimens from the same patient, and sending out positives to be confirmed by a reference laboratory. Commercially available reverse transcriptase-polymerase chain reaction tests for SARS have recently appeared; however, meaningful evaluations of these assays have not yet been performed and their true performance has not been determined. These and other issues related to diagnosis of SARS-CoV infection are discussed in this review.

negative: Emerging Animal Coronaviruses: First SARS and Now MERS The first major pandemic of the new millennium that arose from southern China in 2002 was of zoonotic origin from wild game animals, called severe acute respiratory syndrome [SARS]. The culprit was determined to be a coronavirus of animal origin [SARS-CoV]. The discovery of the SARS-CoV, which caused an outbreak of >8000 people in >30 countries with fatality of about 10%, resulted in intense search for novel coronaviruses with potentially high pathogenicity. Ten years later after the SARS pandemic, another novel coronavirus crossed the species barrier from bats to humans through an intermediate camel host, to produce a severe lower respiratory infection labeled the Middle East respiratory syndrome [MERS]. A novel coronavirus [MERS-CoV] was first identified in September 2012, from patients who resided or traveled to Saudi Arabia. The MERS-CoV spread through contacts with camel and subsequently from human to human via droplet transmission. MERS cases occurred in several other countries including in Europe and the United States, mainly from residence or travel to the Arabian Peninsula, but was not of pandemic potential. However, in the spring of 2015, a MERS outbreak started in South Korea which was initiated by a returning traveler from Saudi Arabia, and subsequently secondary infection of over 186 local residents occurred. Recent estimate in May 2015 indicates that the MERS-CoV have afflicted 1167 patients with MERS worldwide with 479 deaths [41% fatality]. Thus MERS is more deadly than SARS but appears to be less contagious. However, unlike SARS which has not reappeared since 2002–2003, MERS-CoV have the potential to cause sporadic or local outbreaks for many years as the virus may now be entrenched endemically in dromedary camels of the Middle East.

negative: Steps towards Serological Diagnosis of Human Bocavirus Infections

negative: Chapter 13 Viral Disease Abstract This chapter discusses infections of rats with viruses in the following 14 virus families: Adenoviridae, Arenaviridae, Coronaviridae, Flaviviridae, Hantaviridae, Hepeviridae, Herpesviridae, Paramyxoviridae, Parvoviridae, Picornaviridae, Pneumoviridae, Polyomaviridae, Poxviridae, and Reoviridae. Serological surveys indicate that parvoviruses, coronaviruses, cardioviruses, and pneumoviruses are the most prevalent in laboratory rats. A new polyomavirus and a new cardiovirus that cause disease in laboratory rats are described. Metagenomic analyses of feces or intestinal contents from wild rats have detected viruses from an additional nine virus families that could potentially cause infections in laboratory rats.

negative: A SARS-CoV-2-Human Protein-Protein Interaction Map Reveals Drug Targets and Potential Drug-Repurposing An outbreak of the novel coronavirus SARS-CoV-2, the causative agent of COVID-19 respiratory disease, has infected over 290,000 people since the end of 2019, killed over 12,000, and caused worldwide social and economic disruption(1,2). There are currently no antiviral drugs with proven efficacy nor are there vaccines for its prevention. Unfortunately, the scientific community has little knowledge of the molecular details of SARS-CoV-2 infection. To illuminate this, we cloned, tagged and expressed 26 of the 29 viral proteins in human cells and identified the human proteins physically associated with each using affinity- purification mass spectrometry (AP-MS), which identified 332 high confidence SARS-CoV-2-human protein-protein interactions (PPIs). Among these, we identify 66 druggable human proteins or host factors targeted by 69 existing FDA-approved drugs, drugs in clinical trials and/or preclinical compounds, that we are currently evaluating for efficacy in live SARS-CoV-2 infection assays. The identification of host dependency factors mediating virus infection may provide key insights into effective molecular targets for developing broadly acting antiviral therapeutics against SARS-CoV-2 and other deadly coronavirus strains.

negative: TREC-COVID: Constructing a Pandemic Information Retrieval Test Collection TREC-COVID is a community evaluation designed to build a test collection that captures the information needs of biomedical researchers using the scientific literature during a pandemic. One of the key characteristics of pandemic search is the accelerated rate of change: the topics of interest evolve as the pandemic progresses and the scientific literature in the area explodes. The COVID-19 pandemic provides an opportunity to capture this progression as it happens. TREC-COVID, in creating a test collection around COVID-19 literature, is building infrastructure to support new research and technologies in pandemic search.

negative: Current research on respiratory viral infections: Third International Symposium

negative: Evaluation of an enzyme‐linked immunosorbent assay that measures rhinovirus‐specific antibodies in human sera and nasal secretions Rhinovirus‐specific antibodies have traditionally been detected by their ability to neutralise the homologous rhinovirus serotype in tissue culture. Recently, however, we have described an enzyme‐linked immunosorbent assay that detects rhinovirus‐specific antibodies in sera and nasal secretions [Barclay and Al‐Nakib, 1987]. Here we describe an evaluation of the ELISA in a study involving 71 adult volunteers inoculated intranasally with human rhinovirus type 2 (HRV‐2). Pre‐and post‐inoculation serum samples and pre‐inoculation nasal washings were tested for the presence of HRV‐2‐specific antibodies by ELISA. Such antibodies were associated with protection against infection when present locally in nasal secretions, but when also present in the serum they were associated with protection against both infection and the development of illness. The antibody concentrations showed strong correlation with each other and with that of antibodies detected by the neutralisation test. Following HRV‐2 infection, rises in HRV‐2‐specific IgA in sera detected by ELISA occurred more frequently than rises in neutralizing antibody. These results suggest that the ELISA is a sensitive and reliable indicator of recent infection, as well as a predictor of homologous immune status.

negative: Antibody-Dependent Cellular Phagocytosis in Antiviral Immune Responses Antiviral activities of antibodies may either be dependent only on interactions between the antibody and cognate antigen, as in binding and neutralization of an infectious virion, or instead may require interactions between antibody–antigen immune complexes and immunoproteins or Fc receptor expressing immune effector cells. These Fc receptor-dependent antibody functions provide a direct link between the innate and adaptive immune systems by combining the potent antiviral activity of innate effector cells with the diversity and specificity of the adaptive humoral response. The Fc receptor-dependent function of antibody-dependent cellular phagocytosis (ADCP) provides mechanisms for clearance of virus and virus-infected cells, as well as for stimulation of downstream adaptive immune responses by facilitating antigen presentation, or by stimulating the secretion of inflammatory mediators. In this review, we discuss the properties of Fc receptors, antibodies, and effector cells that influence ADCP. We also provide and interpret evidence from studies that support a potential role for ADCP in either inhibiting or enhancing viral infection. Finally, we describe current approaches used to measure antiviral ADCP and discuss considerations for the translation of studies performed in animal models. We propose that additional investigation into the role of ADCP in protective viral responses, the specific virus epitopes targeted by ADCP antibodies, and the types of phagocytes and Fc receptors involved in ADCP at sites of virus infection will provide insight into strategies to successfully leverage this important immune response for improved antiviral immunity through rational vaccine design.

negative: A Simple and Multiplex Loop-Mediated Isothermal Amplification (LAMP) Assay for Rapid Detection of SARS-CoV The current diagnosis of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) relies on laboratory-based tests since its clinical features are nonspecific, unlike other respiratory pathogens. Therefore, the development of a rapid and simple method for on-site detection of SARS-CoV is crucial for the identification and prevention of future SARS outbreaks. In this study, a simple colorimetric and multiplex loop-mediated isothermal amplification (LAMP) assay was developed to rapid screening of severe acute respiratory syndrome-associated coronavirus (SARS-CoV). It can be visually detected based on color change and monitored in real-time with fluorescent signals. The performance of this assay, based on six primers targeting open reading frame (ORF1b) and nucleocapsid (N) genes located in different regions of the SARS-CoV, was compared with real-time RT-PCR assay using various concentrations of target genes. The detection limit of the LAMP assay was comparable to that of real-time RT-PCR assay and therefore a few target RNA to 10(4)-10(5) copies could be detected within a short period of time (20–25 min). In addition, we established a multiplex real-time LAMP assay to simultaneously detect two target regions within the SARS-CoV genome. Two target sequences were amplified by specific primers in the same reaction tube and revealed that it was able to detect down to 10(5) copies. The standard curve had a linear relationship with similar amplification efficiencies. The LAMP assay results in shorter “sample-to-answer” time than conventional PCR method. Therefore, it is suitable not only for diagnosis of clinical test, but also for surveillance of SARS virus in developing countries. ELECTRONIC SUPPLEMENTARY MATERIAL: Supplementary material is available for this article at 10.1007/s13206-019-3404-3 and is accessible for authorized users.

negative: Antibody responses against SARS-coronavirus and its nucleocaspid in SARS patients Abstract Background: SARS-Cov is the etiologic agent of severe acute respiratory syndrome. An understanding of the antibody responses to the viral components is very important for diagnosis and vaccine development. Objective: The spectrum of SARS-specific antibody profiles in SARS patients was investigated from 7 to 210 days after the onset of the symptoms. Study design: Serial serum samples from 14 SARS patients were isolated from 7 to 210 days after the onset of the symptoms, and were tested for anti-viral IgG and IgM by indirect immunofluorescence tests (IFA), anti-nucleocaspid antibody by ELISA tests and viral neutralization. Results: Anti-viral (IgG) and anti-nucleocaspid antibodies were observed in 13 of 14 patients at 14 days after the onset of symptoms, and in all 14 patients at 30–210 days thereafter. Anti-viral antibody (IgM) was detected maximally at 30 days, later than that for the IgG class. IgM antibody declined and became undetectable between 60 to 180 days after the onset of the symptoms. Neutralizing viral antibodies were demonstrated in the sera from all of the patients with SARS symptoms. Conclusions: Anti-viral IgG, IgM, and anti-nucleocaspid antibodies were detected 7–30 days in patients after the onset of SARS symptoms. Anti-viral IgM antibodies disappeared earlier than IgG. Viral neutralization was demonstrated in the sera from the convalescent patients.

negative: Potent binding of 2019 novel coronavirus spike protein by a SARS coronavirus-specific human monoclonal antibody The newly identified 2019 novel coronavirus (2019-nCoV) has caused more than 11,900 laboratory-confirmed human infections, including 259 deaths, posing a serious threat to human health. Currently, however, there is no specific antiviral treatment or vaccine. Considering the relatively high identity of receptor-binding domain (RBD) in 2019-nCoV and SARS-CoV, it is urgent to assess the cross-reactivity of anti-SARS CoV antibodies with 2019-nCoV spike protein, which could have important implications for rapid development of vaccines and therapeutic antibodies against 2019-nCoV. Here, we report for the first time that a SARS-CoV-specific human monoclonal antibody, CR3022, could bind potently with 2019-nCoV RBD (KD of 6.3 nM). The epitope of CR3022 does not overlap with the ACE2 binding site within 2019-nCoV RBD. These results suggest that CR3022 may have the potential to be developed as candidate therapeutics, alone or in combination with other neutralizing antibodies, for the prevention and treatment of 2019-nCoV infections. Interestingly, some of the most potent SARS-CoV-specific neutralizing antibodies (e.g. m396, CR3014) that target the ACE2 binding site of SARS-CoV failed to bind 2019-nCoV spike protein, implying that the difference in the RBD of SARS-CoV and 2019-nCoV has a critical impact for the cross-reactivity of neutralizing antibodies, and that it is still necessary to develop novel monoclonal antibodies that could bind specifically to 2019-nCoV RBD.

negative: Association of COVID-19 Infections in San Francisco in Early March 2020 with Travel to New York and Europe Real-time dissemination of epidemiological survey data from positive COVID-19 cases is critical to support efforts to contain or reduce spread of viral infection in the community. Here we detected a significant association between domestic travel or travel to Europe and the identification of new cases in San Francisco, California, USA. These findings suggest that domestic and European travelers may need to be prioritized for evaluation of acute infection from COVID-19 in the setting of limited testing capacity.

negative: Techniques to Study Antigen-Specific B Cell Responses Antibodies against foreign antigens are a critical component of the overall immune response and can facilitate pathogen clearance during a primary infection and also protect against subsequent infections. Dysregulation of the antibody response can lead to an autoimmune disease, malignancy, or enhanced infection. Since the experimental delineation of a distinct B cell lineage in 1965, various methods have been developed to understand antigen-specific B cell responses in the context of autoimmune diseases, primary immunodeficiencies, infection, and vaccination. In this review, we summarize the established techniques and discuss new and emerging technologies for probing the B cell response in vitro and in vivo by taking advantage of the specificity of B cell receptor (BCR)-associated and secreted antibodies. These include ELISPOT, flow cytometry, mass cytometry, and fluorescence microscopy to identify and/or isolate primary antigen-specific B cells. We also present our approach to identify rare antigen-specific B cells using magnetic enrichment followed by flow cytometry. Once these cells are isolated, in vitro proliferation assays and adoptive transfer experiments in mice can be used to further characterize antigen-specific B cell activation, function, and fate. Transgenic mouse models of B cells targeting model antigens and of B cell signaling have also significantly advanced our understanding of antigen-specific B cell responses in vivo.

negative: Retinal pathology in multiple sclerosis: insight into the mechanisms of neuronal pathology

negative: Epidemiology of coronavirus respiratory infections. Human coronaviruses were found by enzyme linked immunosorbent assay in upper respiratory tract secretions taken during 30% of 108 acute respiratory infections experienced by 30 children under age 6 years with recurrent respiratory infections (index group), and during 29% of 51 acute infections experienced by their siblings. Lower respiratory tract infection--predominantly wheezy bronchitis--occurred in 30% of the index children's coronavirus positive infections but in none of their siblings' infections. Reinfections were common. Two peaks of infection were seen each year in the late autumn/early winter and in the early summer.

negative: Does COVID-19 influence sexual behaviours?

negative: Prolonged viral shedding in feces of pediatric patients with coronavirus disease 2019 Abstract Objective To determine the dynamic changes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in respiratory and fecal specimens in children with coronavirus disease 2019 (COVID-19). Methods From January 17, 2020 to February 23, 2020, three paediatric cases of COVID-19 were reported in Qingdao, Shandong Province, China. Epidemiological, clinical, laboratory, and radiological characteristics and treatment data were collected. Patients were followed up to March 10, 2020, and dynamic profiles of nucleic acid testing results in throat swabs and fecal specimens were closely monitored. Results Clearance of SARS-CoV-2 in respiratory tract occurred within two weeks after abatement of fever, whereas viral RNA remained detectable in stools of pediatric patients for longer than 4 weeks. Two children had fecal SARS-CoV-2 undetectable 20 days after throat swabs showing negative, while that of another child lagged behind for 8 days. Conclusions SARS-CoV-2 may exist in children's gastrointestinal tract for a longer time than respiratory system. Persistent shedding of SARS-CoV-2 in stools of infected children raises the possibility that the virus might be transmitted through contaminated fomites. Massive efforts should be made at all levels to prevent spreading of the infection among children after reopening of kindergartens and schools.

negative: Serological relation between calf diarrhea coronavirus and hemagglutinating encephalomyelitis virus Neutralizing (NT) and hemagglutination-inhibiting (HI) antibodies to calf diarrhea coronavirus (CDCV) and hemagglutinating encephalomyelitis virus of swine (HEV) (strain 67 N) were detected in high proportions of normal adult cattle and pigs in Japan. Since comparison of NT and HI titers in the serum samples suggested an antigenic difference between the viruses, cross NT and HI tests of these viruses were carried out with antisera raised in rabbits. The homologous NT titers were markedly higher than the heterologous titers. In HI tests essentially the same results were obtained. These findings indicate the presence of a marked difference in antigenic make-up between CDCV and HEV. NT and HI tests can clearly differentiate the viruses, although there is some cross reaction.

negative: Roles of meteorological conditions in COVID-19 transmission on a worldwide scale The novel coronavirus (SARS-CoV-2/ 2019-nCoV) identified in Wuhan, China, in December 2019 has caused great damage to public health and economy worldwide with over 140,000 infected cases up to date. Previous research has suggested an involvement of meteorological conditions in the spread of droplet-mediated viral diseases, such as influenza. However, as for the recent novel coronavirus, few studies have discussed systematically about the role of daily weather in the epidemic transmission of the virus. Here, we examine the relationships of meteorological variables with the severity of the outbreak on a worldwide scale. The confirmed case counts, which indicates the severity of COVID-19 spread, and four meteorological variables, i.e., air temperature, relative humidity, wind speed, and visibility, were collected daily between January 20 and March 11 (52 days) for 430 cities and districts all over China, 21 cities/ provinces in Italy, 21 cities/ provinces in Japan, and 51 other countries around the world. Four different time delays of weather (on the day, 3 days ago, 7 days ago, and 14 days ago) as to the epidemic situation were taken for modeling and we finally chose the weather two weeks ago to model against the daily epidemic situation as its correlated with the outbreak best. Taken Chinese cities as a discovery dataset, it was suggested that temperature, wind speed, and relative humidity combined together could best predict the epidemic situation. The meteorological model could well predict the outbreak around the world with a high correlation (r2>0.6) with the real data. Using this model, we further predicted the possible epidemic situation in the future 12 days in several high-latitude cities with potential outbreak. This model could provide more information for government's future decisions on COVID-19 outbreak control.

negative: Coronavirus as a possible cause of severe acute respiratory syndrome Summary Background An outbreak of severe acute respiratory syndrome (SARS) has been reported in Hong Kong. We investigated the viral cause and clinical presentation among 50 patients. Methods We analysed case notes and microbiological findings for 50 patients with SARS, representing more than five separate epidemiologically linked transmission clusters. We defined the clinical presentation and risk factors associated with severe disease and investigated the causal agents by chest radiography and laboratory testing of nasopharyngeal aspirates and sera samples. We compared the laboratory findings with those submitted for microbiological investigation of other diseases from patients whose identity was masked. Findings Patients' age ranged from 23 to 74 years. Fever, chills, myalgia, and cough were the most frequent complaints. When compared with chest radiographic changes, respiratory symptoms and auscultatory findings were disproportionally mild. Patients who were household contacts of other infected people and had older age, lymphopenia, and liver dysfunction were associated with severe disease. A virus belonging to the family Coronaviridae was isolated from two patients. By use of serological and reverse-transcriptase PCR specific for this virus, 45 of 50 patients with SARS, but no controls, had evidence of infection with this virus. Interpretation A coronavirus was isolated from patients with SARS that might be the primary agent associated with this disease. Serological and molecular tests specific for the virus permitted a definitive laboratory diagnosis to be made and allowed further investigation to define whether other cofactors play a part in disease progression.

negative: The Tecumseh Study of Respiratory Illness. VI. Frequency of and Relationship between Outbreaks of Coronavims Infection Specimens of blood collected in Tecumseh, Michigan over a four-year period were studied for rise in antibody titer against coronavirus OC43. Peaks of infection were found in the winter and spring of 1966, 1968, and 1969; at other times, infections occurred sporadically. All age groups were involved, especially the very young. Rises in titer by CF and by HAI tests frequently did not occur together in the same individual. Agreement between the two tests was better in 1966 and 1969 than in the other years. A portion of the paired specimens showing rises in CF and/ or HAI titer was tested by neutralization. Rises in neutralizing antibody were usually found in pairs collected in 1966 and 1969 but not in those collected in 1967 and 1968. The infecting viruses in 1966 and 1969 thus appeared more closely related to OC43 than did those in 1967 and 1968.

negative: [Serum antibodies detection for serological diagnosis of severe acute respiratory syndrome]. OBJECTIVE To evaluate the significance of serum specific antibodies against severe acute respiratory syndrome (SARS) virus in the diagnosis of SARS and the concordance of IFA and ELISA in the antibodies measurements. METHODS Specific antibodies of IgM and IgG against SARS virus in 267 serum specimens from patients with SARS and 132 from non-SARS patients or healthy persons were assayed with IFA or ELISA. The sensitivity, specificity, positive predictive value (ppv), negative predictive value (NPV), and accuracy were used to evaluate the significance of the antibodies in diagnosis of SARS. The concordance of different measurements was tested with Kappa. RESULTS The positive rate of specific IgM and IgG detected by IFA increased sharply on the eleventh day of the disease. The sensitivity, specificity, PPV, NPV, and accuracy of IgM in diagnosis of SARS on eleventh day or later were 65.6%, 100.0%, 100.0%, 71.0% and 81.3%, respectively, and IgG were 91.1%, 97.0% 97.3%, 90.1%, and 93.8%, respectively. Similar results could be seen when IgM and IgG were detected by ELISA. The Kappa of IFA and ELISA for IgM and IgG were 0.640 and 0.779 respectively. CONCLUSIONS The antibodies against SARS virus can be detected in the mid-and late stage of SARS. The antibodies can be used in the serological diagnosis of SARS. There is high concordance of IFA and ELISA results in measurement of SARS antibodies.

negative: SARS Antibody Test for Serosurveillance A peptide-based enzyme-linked immunosorbent assay (ELISA) can be used for retrospective serosurveillance of severe acute respiratory syndrome (SARS) by helping identify undetected chains of disease transmission. The assay was developed by epitope mapping, using synthetic peptides from the spike, membrane, and nucleocapsid protein sequences of SARS-associated coronavirus. The new peptide ELISA consistently detected seroconversion by week 2 of onset of fever, and seropositivity remained through day 100. Specificity was 100% on normal blood donor samples, on serum samples associated with infection by other pathogens, and on an interference panel. The peptide-based test has advantages of safety, standardization, and automation over previous immunoassays for SARS. The assay was used for a retrospective survey of healthy healthcare workers in Taiwan who treated SARS patients. Asymptomatic seroconversions were detected in two hospitals that had nosocomial disease.

negative: Virologic and clinical characteristics for prognosis of severe COVID-19: a retrospective observational study in Wuhan, China Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has progressed to a pandemic associated with substantial morbidity and mortality. The WHO and the United States Center for Disease Control and Prevention (CDC) have issued interim clinical guidance for management of patients with confirmed coronavirus disease (COVID-19), but there is limited data on the virologic and clinical characteristics for prognosis of severe COVID-19. Methods: A total of 50 patients with severe COVID-19 were divided into good and poor recovery groups. The dynamic viral shedding and serological characteristics of SARS-CoV-2 were explored. The risk factors associated with poor recovery and lung lesion resolutions were identified. In addition, the potential relationships among the viral shedding, the pro-inflammatory response, and lung lesion evolutions were characterized. Results: A total of 58% of the patients had poor recovery and were more likely to have a prolonged interval of viral shedding. The longest viral shedding was 57 days after symptom onset. Older age, hyperlipemia, hypoproteinemia, corticosteroid therapy, consolidation on chest computed-tomography (CT), and prolonged SARS-CoV-2 IgM positive were all associated with poor recovery. Additionally, the odds of impaired lung lesion resolutions were higher in patients with hypoproteinemia, hyperlipemia, and elevated levels of IL-4 and ferritin. Finally, viral shedding and proinflammatory responses were closely correlated with lung lesion evolutions on chest CT. Conclusions Patients with severe COVID-19 have prolonged SARS-CoV-2 infection and delayed intermittent viral shedding. Older age, hyperlipemia, hypoproteinemia, corticosteroid usage, and prolonged SARS-CoV-2 IgM positive might be utilized as predicative factors for the patients with poor recovery.

negative: Molecular and serological investigation of 2019-nCoV infected patients: implication of multiple shedding routes In December 2019, a novel coronavirus (2019-nCoV) caused an outbreak in Wuhan, China, and soon spread to other parts of the world. It was believed that 2019-nCoV was transmitted through respiratory tract and then induced pneumonia, thus molecular diagnosis based on oral swabs was used for confirmation of this disease. Likewise, patient will be released upon two times of negative detection from oral swabs. However, many coronaviruses can also be transmitted through oral–fecal route by infecting intestines. Whether 2019-nCoV infected patients also carry virus in other organs like intestine need to be tested. We conducted investigation on patients in a local hospital who were infected with this virus. We found the presence of 2019-nCoV in anal swabs and blood as well, and more anal swab positives than oral swab positives in a later stage of infection, suggesting shedding and thereby transmitted through oral–fecal route. We also showed serology test can improve detection positive rate thus should be used in future epidemiology. Our report provides a cautionary warning that 2019-nCoV may be shed through multiple routes.

negative: Racing Towards the Development of Diagnostics for a Novel Coronavirus (2019-nCoV)

negative: Genetic deletion of Sphk2 confers protection against Pseudomonas aeruginosa mediated differential expression of genes related to virulent infection and inflammation in mouse lung BACKGROUND: Pseudomonas aeruginosa (PA) is an opportunistic Gram-negative bacterium that causes serious life threatening and nosocomial infections including pneumonia. PA has the ability to alter host genome to facilitate its invasion, thus increasing the virulence of the organism. Sphingosine-1- phosphate (S1P), a bioactive lipid, is known to play a key role in facilitating infection. Sphingosine kinases (SPHK) 1&2 phosphorylate sphingosine to generate S1P in mammalian cells. We reported earlier that Sphk2(−/−) mice offered significant protection against lung inflammation, compared to wild type (WT) animals. Therefore, we profiled the differential expression of genes between the protected group of Sphk2(−/−) and the wild type controls to better understand the underlying protective mechanisms related to the Sphk2 deletion in lung inflammatory injury. Whole transcriptome shotgun sequencing (RNA-Seq) was performed on mouse lung tissue using NextSeq 500 sequencing system. RESULTS: Two-way analysis of variance (ANOVA) analysis was performed and differentially expressed genes following PA infection were identified using whole transcriptome of Sphk2(−/−) mice and their WT counterparts. Pathway (PW) enrichment analyses of the RNA seq data identified several signaling pathways that are likely to play a crucial role in pneumonia caused by PA such as those involved in: 1. Immune response to PA infection and NF-κB signal transduction; 2. PKC signal transduction; 3. Impact on epigenetic regulation; 4. Epithelial sodium channel pathway; 5. Mucin expression; and 6. Bacterial infection related pathways. Our genomic data suggests a potential role for SPHK2 in PA-induced pneumonia through elevated expression of inflammatory genes in lung tissue. Further, validation by RT-PCR on 10 differentially expressed genes showed 100% concordance in terms of vectoral changes as well as significant fold change. CONCLUSION: Using Sphk2(−/−) mice and differential gene expression analysis, we have shown here that S1P/SPHK2 signaling could play a key role in promoting PA pneumonia. The identified genes promote inflammation and suppress others that naturally inhibit inflammation and host defense. Thus, targeting SPHK2/S1P signaling in PA-induced lung inflammation could serve as a potential therapy to combat PA-induced pneumonia.

negative: Molecular Techniques for Blood and Blood Product Screening Blood product safety is a high priority for manufacturing industries, hospitals, and regulatory agencies. An important step in ensuring safety is the screening of donated blood for infectious diseases. Molecular technologies for screening infectious diseases have improved remarkably over the years. Molecular biological assay significantly reduced the risk of transfusion-transmitted infections. Unlike previous methods, molecular technologies for screening infectious diseases are specific, efficient, easy to use, and economical. A new era in molecular biology is coming to the field of blood safety.

negative: 2019-nCoV: The Identify-Isolate-Inform (3I) Tool Applied to a Novel Emerging Coronavirus 2019 Novel Coronavirus (2019-nCoV) is an emerging infectious disease closely related to MERS-CoV and SARS-CoV that was first reported in Wuhan City, Hubei Province, China in December 2019. As of January 2020, cases of 2019-nCoV are continuing to be reported in other Eastern Asian countries as well as in the United States, Europe, Australia, and numerous other countries. An unusually high volume of domestic and international travel corresponding to the beginning of the 2020 Chinese New Year complicated initial identification and containment of infected persons. Due to the rapidly rising number of cases and reported deaths, all countries should be considered at risk of imported 2019-nCoV. Therefore, it is essential for prehospital, clinic, and emergency department personnel to be able to rapidly assess 2019-nCoV risk and take immediate actions if indicated. The Identify-Isolate-Inform (3I) Tool, originally conceived for the initial detection and management of Ebola virus and later adjusted for other infectious agents, can be adapted for any emerging infectious disease. This paper reports a modification of the 3I Tool for use in the initial detection and management of patients under investigation for 2019-nCoV. After initial assessment for symptoms and epidemiological risk factors, including travel to affected areas and exposure to confirmed 2019-nCoV patients within 14 days, patients are classified in a risk-stratified system. Upon confirmation of a suspected 2019-nCoV case, affected persons must immediately be placed in airborne infection isolation and the appropriate public health agencies notified. This modified 3I Tool will assist emergency and primary care clinicians, as well as out-of-hospital providers, in effectively managing persons with suspected or confirmed 2019-nCoV.

negative: Direct Diagnostic Tests for Lyme Disease Borrelia burgdorferi was discovered to be the cause of Lyme disease in 1983, leading to seroassays. The 1994 serodiagnostic testing guidelines predated a full understanding of key B. burgdorferi antigens and have a number of shortcomings. These serologic tests cannot distinguish active infection, past infection, or reinfection. Reliable direct-detection methods for active B. burgdorferi infection have been lacking in the past but are needed and appear achievable. New approaches have effectively been applied to other emerging infections and show promise in direct detection of B. burgdorferi infections.

negative: Transmission of Avian Influenza Viruses to and between Humans

negative: Serological characterization of guinea pigs infected with H3N2 human influenza or immunized with hemagglutinin protein BACKGROUND: Recent and previous studies have shown that guinea pigs can be infected with, and transmit, human influenza viruses. Therefore guinea pig may be a useful animal model for better understanding influenza infection and assessing vaccine strategies. To more fully characterize the model, antibody responses following either infection/re-infection with human influenza A/Wyoming/03/2003 H3N2 or immunization with its homologous recombinant hemagglutinin (HA) protein were studied. RESULTS: Serological samples were collected and tested for anti-HA immunoglobulin by ELISA, antiviral antibodies by hemagglutination inhibition (HI), and recognition of linear epitopes by peptide scanning (PepScan). Animals inoculated with infectious virus demonstrated pronounced viral replication and subsequent serological conversion. Animals either immunized with the homologous HA antigen or infected, showed a relatively rapid rise in antibody titers to the HA glycoprotein in ELISA assays. Antiviral antibodies, measured by HI assay, were detectable after the second inoculation. PepScan data identified both previously recognized and newly defined linear epitopes. CONCLUSIONS: Infection and/or recombinant HA immunization of guinea pigs with H3N2 Wyoming influenza virus resulted in a relatively rapid production of viral-specific antibody thus demonstrating the strong immunogenicity of the major viral structural proteins in this animal model for influenza infection. The sensitivity of the immune response supports the utility of the guinea pig as a useful animal model of influenza infection and immunization.

negative: Serological and molecular findings during SARS-CoV-2 infection: the first case study in Finland, January to February 2020 The first case of coronavirus disease (COVID-19) in Finland was confirmed on 29 January 2020. No secondary cases were detected. We describe the clinical picture and laboratory findings 3–23 days since the first symptoms. The SARS-CoV-2/Finland/1/2020 virus strain was isolated, the genome showing a single nucleotide substitution to the reference strain from Wuhan. Neutralising antibody response appeared within 9 days along with specific IgM and IgG response, targeting particularly nucleocapsid and spike proteins.

negative: Recognizing COVID-19-related myocarditis: the possible pathophysiology and proposed guideline for diagnosis and management Abstract Human coronavirus-associated myocarditis is known, and a number of COVID-19-related myocarditis cases have been reported. The pathophysiology of COVID-19-related myocarditis is thought to be a combination of direct viral injury and cardiac damage due to the host’s immune response. COVID-19 myocarditis diagnosis should be guided by insights from previous coronavirus and other myocarditis experience. The clinical findings include changes in ECG, cardiac biomarkers, and impaired cardiac function. When cardiac MRI is infeasible, cardiac CT angiography with delayed myocardial imaging may serve to exclude significant coronary artery disease and identify myocardial inflammatory patterns. Because many COVID-19 patients have cardiovascular comorbidities, myocardial infarction should be considered. Where the diagnosis remains uncertain, an endomyocardial biopsy may help identify active cardiac infection through viral genome amplification and possibly refine the treatment risks of systemic immunosuppression. Arrhythmias are not uncommon in the COVID-19 patients; however, its pathophysiology is still speculative. Nevertheless, clinicians should be vigilant to provide prompt monitoring and treatments. The long-term impact of COVID-19 myocarditis, including in the majority of mild cases remains unknown.

negative: An outbreak of severe Kawasaki-like disease at the Italian epicentre of the SARS-CoV-2 epidemic: an observational cohort study BACKGROUND: The Bergamo province, which is extensively affected by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic, is a natural observatory of virus manifestations in the general population. In the past month we recorded an outbreak of Kawasaki disease; we aimed to evaluate incidence and features of patients with Kawasaki-like disease diagnosed during the SARS-CoV-2 epidemic. METHODS: All patients diagnosed with a Kawasaki-like disease at our centre in the past 5 years were divided according to symptomatic presentation before (group 1) or after (group 2) the beginning of the SARS-CoV-2 epidemic. Kawasaki- like presentations were managed as Kawasaki disease according to the American Heart Association indications. Kawasaki disease shock syndrome (KDSS) was defined by presence of circulatory dysfunction, and macrophage activation syndrome (MAS) by the Paediatric Rheumatology International Trials Organisation criteria. Current or previous infection was sought by reverse-transcriptase quantitative PCR in nasopharyngeal and oropharyngeal swabs, and by serological qualitative test detecting SARS-CoV-2 IgM and IgG, respectively. FINDINGS: Group 1 comprised 19 patients (seven boys, 12 girls; aged 3·0 years [SD 2·5]) diagnosed between Jan 1, 2015, and Feb 17, 2020. Group 2 included ten patients (seven boys, three girls; aged 7·5 years [SD 3·5]) diagnosed between Feb 18 and April 20, 2020; eight of ten were positive for IgG or IgM, or both. The two groups differed in disease incidence (group 1 vs group 2, 0·3 vs ten per month), mean age (3·0 vs 7·5 years), cardiac involvement (two of 19 vs six of ten), KDSS (zero of 19 vs five of ten), MAS (zero of 19 vs five of ten), and need for adjunctive steroid treatment (three of 19 vs eight of ten; all p<0·01). INTERPRETATION: In the past month we found a 30-fold increased incidence of Kawasaki-like disease. Children diagnosed after the SARS-CoV-2 epidemic began showed evidence of immune response to the virus, were older, had a higher rate of cardiac involvement, and features of MAS. The SARS-CoV-2 epidemic was associated with high incidence of a severe form of Kawasaki disease. A similar outbreak of Kawasaki-like disease is expected in countries involved in the SARS-CoV-2 epidemic. FUNDING: None.

negative: A cascade of causes that led to the COVID-19 tragedy in Italy and in other European Union countries

negative: The Seattle Flu Study: a multi-arm community-based prospective study protocol for assessing influenza prevalence, transmission, and genomic epidemiology Introduction. Influenza epidemics and pandemics cause significant morbidity and mortality. An effective response to a potential pandemic requires the infrastructure to rapidly detect, characterize, and potentially contain new and emerging influenza strains at a population level. The objective of this study is to use data gathered simultaneously from community and hospital sites to develop a model of how influenza enters and spreads in a population. Methods and Analysis. Starting in the 2018-19 season, we have been enrolling individuals with acute respiratory illness from community sites throughout the Seattle metropolitan area, including clinics, childcare facilities, Seattle-Tacoma International Airport, workplaces, college campuses, and homeless shelters. At these sites, we collect clinical data and mid-nasal swabs from individuals with at least two acute respiratory symptoms. Additionally, we collect residual nasal swabs and data from individuals who seek care for respiratory symptoms at four regional hospitals. Samples are tested using a multiplex molecular assay, and influenza whole genome sequencing is performed for samples with influenza detected. Geospatial mapping and computational modeling platforms are in development to characterize the regional spread of influenza and other respiratory pathogens. Ethics and Dissemination. The study was approved by the University of Washington's Institutional Review Board. Results will be disseminated through talks at conferences, peer-reviewed publications, and on the study website (www.seattleflu.org).

negative: Informational needs assessment of non‐Hodgkin lymphoma survivors and their physicians

negative: Renin-angiotensin system: The unexpected flaw inside the human immune system revealed by SARS-CoV-2

negative: Serum SARS-COV-2 Nucleocapsid Proteinï¼A Sensitivity and Specificity Early Diagnostic Marker for SARS-COV-2 Infection Objective: This study aimed to explore the diagnostic value of serum severe acute respiratory syndrome coronavirus 2 (SARSCoV2) nucleocapsid(N) protein assay in the early stage of SARSCOV2 infection. Method: Serum N protein in SARSCOV2 infected patients and non SARSCOV2 infected population was measured by enzyme-linked immunosorbent assay (ELISA) double antibody sandwich assay. Colloidal gold immunochromatography assay is used to detect serum N protein antibodies in the above population. Results: 50 cases of SARSCoV2 nucleic acid positive and SARSCoV2 antibody negative patients had a serum N protein positive rate of 76%, including 2% with a concentration of 10.00~49.99 pg / mL, 8% with a concentration of 50.00~99.99 pg / mL, 22% with a concentration of 100.00 ~299.99 pg/mL, and 44% with a concentration [≥]300.00 pg / mL. 37 samples of patients with serum SARSCoV2 antibody positive after infection had a serum SARSCoV2 N protein positive rate of 2.7%, of which 2.7% had the concentration of 10.00~49.99 pg / mL and 0% had the concentration of 50.00~99.99 pg / mL, 100.00 ~299.99 pg / mL, and [≥]300.00 pg / mL. Serum N protein test results of 633 non SARSCOV2 infected patients including pregnant women, other respiratory infections, and increased rheumatoid factor were all negative, having a serum N protein concentration less than 10.00 pg/mL, with a specificity of 100%. Using SPSS 19.0 to calculate the receiver operating characteristic curve, the area under the curve was 0.9756 (95% confidence interval 0.9485~1.000, p <0.0001), sensitivity and specificity were 92% (95% confidence interval 81.16% to 96.85%) and 96.84% (95% confidence interval 95.17% to 97.15%). The best CUTOFF value is 1.850 pg / mL. Conclusion: The measurement of SARSCOV2 serum N protein has a high diagnostic value for the infected patients before the antibody appears, and shortens the window period of serological diagnosis. The laboratory needs to establish an individual CUTOFF value according to purpose of the application.

negative: An in-depth study of Crohn's disease in two French families Abstract Background: Two French families were investigated. In the first a husband, wife, and 4 children had Crohn's disease; in the second 7 of 11 children had the disease. There was no history of Crohn's disease in antecedent generations and no linkage to HLA haplotypes. Methods: Methods included family interviews; review of medical records, radiographs, and pathology slides; serology; selective stool culture; enzyme-linked immunosorbent assay for fecal viral detection; and immunocytochemistry. Results: In both families multiple cases occurred among siblings in 7–13-month periods. There appeared to be a 4–8-year recurrence of new disease in both families. Radiographs showed a remarkable similarity in the pattern of disease, confined to distal ileum and cecum, in the members of family 1. Examination for pathology showed granulomas in all 8 patients for whom tissues were available. Acid-fast organisms or Campylobacter-like organisms were not found in tissue sections, and immunocytochemistry was negative for mycobacteria and Yersinia. Stool cultures were negative for mycobacteria, Yersinia, and Mycoplasma. Torovirus and coronavirus antigens were not found in stool. Serology was negative for antibodies to Brucella, Yersinia, influenza, and three enteropathogenic viruses of animals. Conclusions: The circumstances and data suggest that an infectious microorganism is responsible for these clusterings of Crohn's disease.

negative: The RNA Virus Database http://virus.zoo.ox.ac.uk/rnavirusdb; http://hivweb.sanbi.ac.za/rnavirusdb; http://bioinf.cs.auckland.ac.nz/rnavirusdb; http://tree.bio.ed.ac.uk/rnavirusdb.

negative: Extracorporeal Membrane Oxygenation During the Coronavirus Disease 2019 Pandemic

negative: Recombinant nucleocapsid protein-based enzyme-linked immunosorbent assay for detection of antibody to turkey coronavirus Abstract Nucleocapsid (N) protein gene of turkey coronavirus (TCoV) was expressed in a prokaryotic system and used to develop an enzyme-linked immunosorbent assay (ELISA) for detection of antibody to TCoV. Anti-TCoV hyperimmune turkey serum and normal turkey serum were used as positive or negative controls for optimization of the ELISA. Goat anti-turkey IgG (H+L) conjugated with horseradish peroxidase was used as detector antibody. Three hundred and twenty two turkey sera from the field were used to evaluate the performance of ELISA and determine the cut-off point of ELISA. The established ELISA was also examined with serum samples obtained from turkeys experimentally infected with TCoV. Those serum samples were collected at various time intervals from 1 to 63 days post-infection. The optimum conditions for differentiation between anti-TCoV hyperimmune serum and normal turkey serum were recombinant TCoV N protein concentration at 20μg/ml, serum dilution at 1:800, and conjugate dilution at 1:10,000. Of the 322 sera from the field, 101 were positive for TCoV by immunofluorescent antibody assay (IFA). The sensitivity and specificity of the ELISA relative to IFA test were 86.0% and 96.8%, respectively, using the optimum cut-off point of 0.2 as determined by logistic regression method. Reactivity of anti-rotavirus, anti-reovirus, anti-adenovirus, or anti-enterovirus antibodies with the recombinant N protein coated on the ELISA plates was not detected. These results indicated that the established antibody-capture ELISA in conjunction with recombinant TCoV N protein as the coating protein can be utilized for detection of antibodies to TCoV in turkey flocks.

negative: Chapter 12 Viral Disease Publisher Summary This chapter discusses the infections caused by DNA viruses and also RNA viruses. The chapter focuses on the detection, diagnosis, risk assessment, and decision-making regarding viral infections. Several infections caused by DNA viruses are parvoviruses, rat cytomegalovirus, poxviruses, adenovirus, and papovavirus. Several RNA viruses and infections caused by these viruses are coronaviruses, paramyxoviruses, rotavirus and reovirus, and picornaviruses. Monitoring for viral infections should cover at least three venues: animals in established breeding and experimental colonies, animals held in entry quarantine, and animal tissues and products destined for in vivo use. For established colonies, monitoring should be tailored to local conditions. Effective monitoring should encompass sampling on a pre-arranged schedule, which can be intensified if evidence or suspicion of viral infection emerges. Because viral infections of rats can spread insidiously, early detection and epidemiologic “staging” should employ a detection matrix that includes clinical observation, appropriate sampling, and sensitive and specific diagnostic testing.

negative: Development of an indirect ELISA for detecting porcine deltacoronavirus IgA antibodies Porcine deltacoronavirus (PDCoV) is a novel coronavirus that can cause vomiting and watery diarrhea in pigs and death in piglets. Since PDCoV was first detected in 2009 in Hong Kong, the prevalence of PDCoV has increased in recent years, resulting in serious economic losses to the swine industry. The coronavirus spike (S) protein is an antigen that has been demonstrated to contain epitopes that induce neutralizing antibodies. The presence of serum and milk IgA antibodies against pathogens that replicate primarily on mucosal surfaces is important for mucosal immunity. Here, an indirect anti-PDCoV IgA antibody enzyme-linked immunosorbent assay (PDCoV S1 IgA ELISA) using the purified S1 portion of S protein as the coating antigen was developed to detect PDCoV IgA antibodies in serum and sow’s milk. A receiver operating characteristic (ROC) curve analysis showed high specificity and sensitivity of the PDCoV-S1-IgA-ELISA based on samples confirmed by IFA. Anti-PDCoV IgA antibodies in 152 serum samples and 65 milk samples collected from six farms that had experienced diarrhea outbreaks within previous last two years were detected by this assay, and 62.5% of the serum samples and 100% of the milk samples were positive for PDCoV. The indirect ELISA method established in this study will provide a convenient tool for measurement of serum and milk IgA levels against PDCoV in pig herds, rapid detection of PDCoV infection in pigs, and evaluation of the immunogenicity of vaccines. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00705-020-04541-6) contains supplementary material, which is available to authorized users.

negative: Systemische Infektionen in der Geburtshilfe The importance of systemic infections in pregnancy is often underestimated. This is primarily due to the fact that pregnant women, in the majority of cases, do not notice any complaints or only have unspecific flu-like symptoms (e.g. toxoplasmosis). Serological screening within the framework of German maternity care is often insufficient to diagnose existing or emerging infections in time. However, the long-term consequences for the affected children and their parents can be immense. A serological TORCH analysis should be performed if a pregnant woman complains about any typical or unspecific symptoms on suspicion of an infection.

negative: Prevalence of antibody to human coronaviruses 229E, OC43 and neonatal calf diarrhea coronavirus (NCDCV) in patients of Northern Italy A seroepidemiological study for detection of antibody to human coronaviruses OC43, 229E, and neonatal calf diarrhea coronavirus (NCDCV), has been carried out using sera collected from hospitalized patients or healthy persons through routine laboratory tests in Northern Italy. Patients tested were children and adults with different pathological diseases. Antibody detection was performed by using an indirect immunoperoxidase staining technique (for all viruses) and, in the case of OC43 and NCDCV, antibody detection was obtained even with a hemagglutination inhibition test and a plaque reduction neutralization assay. Results obtained show a significant difference in the prevalence of antibody to 229E between children and adult group. Furthermore, a different titer was observed, within the two groups, between patients affected by hematological diseases (leukemia) and patients with other diseases. Finally, our data seem to confirm previous studies reporting a very high prevalence of antibody to coronavirus OC43 but a less detectable seropositivity to coronavirus 229E.

negative: Establishment and clinical performance evaluation of 2019 novel coronavirus antibody colloidal gold detection method/ 中华传染病杂志 Objective@#To establish a colloidal gold technique assay for the rapid detection of immunoglobulin(Ig) M and IgG antibodies against 2019 novel coronavirus (2019-nCoV) and to evaluate its clinical performance.@*Methods@#A total of 278 patients who were treated at Wuhan Hankou Hospital and the People's Hospital of Honghu from February 12, 2020 to February 20, 2020 were collected. According to the diagnostic criteria, 89 patients were confirmed with 2019-nCoV nucleic acid positive diagnosis, and 189 were 2019-nCoV nucleic acid-negative suspected patients. A total of 273 medical examiners from Nanfang Hospital, Southern Medical University from 2015 to 2018 were selected as controls. The serum samples of patients were collected. 2019-nCoV nucleic proteins were obtained from prokaryotic expression vectors. Indirect IgM and IgG colloidal gold techniques were established by using recombinant N protein. 2019-nCoV nucleic acid detection by reverse transcription-polymerase chain reaction (RT-PCR) was used as control. Serum specimens were tested for 2019-nCoV IgM and IgG. The specificity and sensitivity of colloidal gold assay were analyzed.@*Results@#The sensitivity and specificity of IgM detection reagents were 78.7% and 98.2%, respectively, those of IgG detection reagents were 73.0% and 99.3%, respectively, and those of IgM combined with IgG detection were 87.6% and 98.2%, respectively. For suspected patients with negative 2019-nCoV nucleic acid, the positive rates of IgM and IgG were 59.8% (113/189) and 52.9% (100/189), respectively, and the positive rate of IgM combined with IgG detection was 66.1% (125/189).@*Conclusion@#This reagent of 2019-nCoV antibodies detection (colloidal gold technique) fulfills the requirement for clinical application with high specificity and sensitivity, which can be served as a supplementary detection method for 2019-nCoV nucleic acid detection by RT-PCR.

negative: Management of heart transplant candidates in the time of COVID‐19 pandemic: Looking for answers Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-associated coronavirus disease 2019 (COVID-19) pandemic is dramatically challenging the healthcare system. In the absence of optimal testing and effective treatments, physicians are forced to make decisions relying on scarce or even controversial evidence. Setting of solid organ transplant (SOT) candidates and recipients offers clinical and organizational issues.

negative: Two Middle East respiratory syndrome vaccines: first step for other coronavirus vaccines?

negative: The phenotypic changes of Î³Î´ T cells in COVID-19 patients A novel pneumonia-associated respiratory syndrome named coronavirus disease-2019 (COVID-19), which caused by SARS-CoV-2 and broken in Wuhan, China in the end of 2019. Unfortunately, there is no specific antiviral agent or vaccine available to treat SARS-CoV-2 infections. Also, information regarding the immunological characteristics in COVID-19 patients remains limited. Here we collected the blood samples from 18 healthy donors (HD) and 38 COVID-19 patients to analyze changes in {gamma}{delta} T cells. In comparison to HD, the {gamma}{delta} T cells percentage was decreased. {gamma}{delta} T cells are able to immediately respond to SARS-CoV-2 infection and upregulate the activation marker CD25. In addition, the increased expression of CD4 in {gamma}{delta} T cells may serve as a biomarker for the assessment of SARS-CoV-2 infection.

negative: A prospective, community-based study on virologic assessment among elderly people with and without symptoms of acute respiratory infection Abstract Background and objective Community-based elderly studies concerning microbiology of acute respiratory infections are scarce. Data on subclinical infections are even totally absent, although asymptomatic persons might act as a source of respiratory infections. Methods In a 1-year community-based study, we prospectively investigated the possible virologic cause of acute respiratory infections in 107 symptomatic case episodes and 91 symptom-free control periods. Participants, persons ⩾60 years, reported daily the presence of respiratory symptoms in a diary. Virologic assessment was performed by polymerase chain reaction (PCR) and serology. Results In 58% of the case episodes a pathogen was demonstrated, the most common being rhinoviruses (32%), coronaviruses (17%), and influenzaviruses (7%). The odds ratio for demonstrating a virus in cases with symptoms vs. controls without symptoms was 30.0 (95% confidence interval 10.2–87.6). In 4% of the symptom-free control periods a virus was detected. Conclusion This study supports the importance of rhinovirus infections in community-dwelling elderly persons, whereas asymptomatic elderly persons can also harbor pathogens as detected by PCR, and thus might be a source of infection for their environment.

negative: Covid-19 in Chile. The experience of a Regional reference Center. Preliminary report During the first pandemic wave Covid-19 reached Latin America cities. Aim: To report clinical features and outcomes associated to Covid-19 in a group of patients admitted during the first wave in a regional reference Center in southern Chile designated to severe and critical cases. Methods: Cases were identified by a compatible clinical picture associated to positive RT-PCR or serological testing. A standard protocol was applied. Results: 21 adult patients (20 diagnosed by PCR, one by serology) were admitted between epidemiological weeks 13 to 20, involving 8.8% of total regional cases. Hospitalization occurred at a median of 11 days after symptoms onset. Patients [≥]60 years old predominated (57.1%). Hypertension (61.9%), obesity (57.1%) and diabetes mellitus 2 (38.1%) were prevalent but 19% had no comorbid conditions nor were elderly. Two cases involved second-trimester pregnant women. Positive IgM or IgM/IgG results obtained by rapid serological testing were limited (19% at 1st week; 42.9% at 2nd week). Nine patients (42.9%, critical group) were transferred to ICU and connected to mechanical ventilation due to respiratory failure. By univariate analysis admission to ICU was significantly associated to tachypnea and higher plasmatic LDH values. One pregnant woman required urgent cesarean section given birth to a premature neonate without vertical transmission. Two patients died (in-hospital mortality 9.5%) and length of stay was equal or higher than 14 days in 57.9% of patients. Conclusion: In our regional Center, Covid 19 was associated to known risk factors, had a prolonged stay and in-hospital mortality. Tachypnea [≥]30/min is predictive of transfer to ICU.

negative: Diagnosis of Canine Viral Infections Canine viral infections may be tentatively diagnosed on the basis of clinical signs, hematologic findings, and/or gross pathology; however, definitive diagnosis generally requires laboratory assistance. Laboratory diagnosis of these infections relies on one or more of the following procedures: histopathology, virus isolation, serology, and the detection of virus, or viral antigens, using electron microscopy, fluorescent antibody techniques, immunoperoxidase techniques, and enzyme immunosorbent assays.

negative: Sensitive and Specific Detection of Low-Level Antibody Responses in Mild Middle East Respiratory Syndrome Coronavirus Infections Middle East respiratory syndrome coronavirus (MERS-CoV) infections in humans can cause asymptomatic to fatal lower respiratory lung disease. Despite posing a probable risk for virus transmission, asymptomatic to mild infections can go unnoticed; a lack of seroconversion among some PCR-confirmed cases has been reported. We found that a MERS-CoV spike S1 protein–based ELISA, routinely used in surveillance studies, showed low sensitivity in detecting infections among PCR-confirmed patients with mild clinical symptoms and cross-reactivity of human coronavirus OC43–positive serum samples. Using in-house S1 ELISA and protein microarray, we demonstrate that most PCR-confirmed MERS-CoV case-patients with mild infections seroconverted; nonetheless, some of these samples did not have detectable levels of virus-neutralizing antibodies. The use of a sensitive and specific serologic S1-based assay can be instrumental in the accurate estimation of MERS-CoV prevalence.

negative: Serological microarray for detection of HSV-1, HSV-2, VZV, and CMV antibodies. The seroprevalence of human herpesviruses is high and reactivations occur frequently. A microarray was designed and tested for the detection of IgG and IgM antibodies for Puumala hantavirus (PUUV) and IgG antibodies against four herpesviruses. Initially, a microarray platform was set up using an unrelated in-house antigen, PUUV recombinant nucleocapsid protein, to optimize the protocol for the detection of antibodies. Detection of the four herpesviruses was set up in a microarray using the recombinant proteins of herpes simplex virus (HSV) glycoprotein G1 and G2, varicella-zoster virus (VZV) glycoprotein E, and cytomegalovirus (CMV) pp150 phosphoprotein. The results of the PUUV panel were in good agreement with the PUUV IgG immunofluorescent assay and IgM enzyme immunoassay (EIA). Seropositive and negative clinical reference panels were tested for herpesviruses by the serological microarray, and the results were compared to those of individual EIAs used for standard diagnostic purposes. The serologic microarray for HSV, VZV and CMV antibody detection gave good specificities for IgG. However, sensitivities of the assay varied depending on the herpesvirus detected. The serological microarray showed potential for screening purposes. The microarray based analyses were easy to perform, and HSV-1, HSV-2, VZV, and CMV antibodies could be detected on the same microarray.

negative: The potential role of Th17 immune responses in coronavirus immunopathology and vaccine-induced immune enhancement Increasing evidence points to host Th17 inflammatory responses as contributing to the severe lung pathology and mortality of lower respiratory tract infections from coronaviruses. This includes host inflammatory and cytokine responses to COVID-19 caused by the SARS-2 coronavirus (SARS CoV2). From studies conducted in laboratory animals, there are additional concerns about immune enhancement and the role of potential host immunopathology resulting from experimental human COVID-19 vaccines. Here we summarize evidence suggesting there may be partial overlap between the underlying immunopathologic processes linked to both coronavirus infection and vaccination, and a role for Th17 in immune enhancement and eosinophilic pulmonary immunopathology. Such findings help explain the link between viral-vectored coronavirus vaccines and immune enhancement and its reduction through alum adjuvants. Additional research may also clarify links between COVID-19 pulmonary immunopathology and heart disease.

negative: Evaluation of indirect immunofluorescence antibody test and enzyme-linked immunosorbent assay for the diagnosis of infection by Leishmania infantum in clinically normal and sick cats Abstract Cats that live in areas where canine and human leishmaniosis due to Leishmania infantum is endemic may become infected and may develop anti-Leishmania antibodies. In this study 50 clinically normal and 50 cats with cutaneous and/or systemic signs that lived in an endemic area and had been previously examined for infection by L. infantum using PCR in four different tissues were serologically tested for the presence of anti-Leishmania IgG (IFAT and ELISA) and IgM (IFAT). The aim was to compare the results of IFAT, ELISA and PCR and to investigate the possible associations between seropositivity to Leishmania spp and signalment, living conditions, season of sampling, health status of the cats, and seropositivity to other infectious agents. Low concentrations of anti-Leishmania IgG were detected by IFAT in 10% of the cats and by ELISA in 1%, whereas anti-Leishmania IgM were detected by IFAT in 1%. There was disagreement between the results of IFAT and ELISA for anti-Leishmania IgG (P = 0.039) and between all serological tests and PCR (P < 0.001). The diagnostic sensitivity of all serological tests, using PCR as the gold standard, was very low, but ELISA and IFAT for anti-Leishmania IgM had 100% specificity. The diagnostic sensitivity of all serological tests could not be improved by changing the cut-off values. Seropositivity for Leishmania spp was not associated with signalment, living conditions, season of sampling and health status of the cats or with seropositivity to feline leukemia virus, feline immunodeficiency virus, feline coronavirus, Toxoplasma gondii and Bartonella henselae. In conclusion, because of their low sensitivity and very high specificity two of the evaluated serological tests (ELISA for anti-Leishmania IgG and IFAT for anti-Leishmania IgM) may be useless as population screening tests but valuable for diagnosing feline infection by L. infantum.

negative: Host Immune Responses to SARS Coronavirus in Humans The severe acute respiratory syndrome (SARS) is a newly identified infectious disease caused by a novel zoonotic coronavirus (SARS-CoV) with unknown animal reservoirs. The risk of SARS reemergence in humans remains high due to the large animal reservoirs of SARS-CoV-like coronavirus and the genome instability of RNA coronaviruses. An epidemic in 2003 affected more than 8,000 patients in 29 countries, with 10% mortality. SARS infection is transmitted by air droplets. Clinical and laboratory manifestations include fever, chills, rigor, myalgia, malaise, diarrhea, cough, dyspnoea, pneumonia, lymphopenia, neutrophilia, thrombocytopenia, and elevated serum lactate dehydrogenase, alanine aminotransferase, and creatine kinase activities. Health care workers are a high-risk group, and advanced age is strongly associated with disease severity. Treatment has been empirical, and there is no licensed SARS vaccine for humans so far. However, presence of long-lived neutralizing antibodies and memory T- and B-lymphocytes in convalescent SARS patients raises hope for active immunization. Furthermore, results from preclinical SARS vaccines expressing spike protein to elicit neutralizing antibodies and cellular responses that are protective in mouse and nonhuman primate models are encouraging. Very little is known of the early events in viral clearance and the onset of innate and inflammatory responses during the SARS infection. Regulation of the innate immune response is associated with the development of adaptive immunity and disease severity in SARS infection. Notably, SARS-CoV has evolved evasive strategies to suppress antiviral type I interferon responses in infected cells. In addition, inflammatory responses are characterized by upregulation of proinflammatory cytokines/chemokines such as IL-6, IP-10, and MCP-1 in tissues and serum, and massive infiltrations of inflammatory cells such as macrophages in infected tissues. Due to the lack of animal models that mimic the clinical manifestations of human SARS infection for mechanistic study and vaccine evaluation, development of a safe prophylactic SARS vaccine for human use remains a huge challenge. This chapter is written to summarize and highlight the latest clinical, serological, and immunological parameters relevant to the pathogenesis and protective immunity of SARS infection in humans.

negative: Are pangolins the intermediate host of the 2019 novel coronavirus (2019-nCoV) ? The outbreak of 2019-nCoV pneumonia (COVID-19) in the city of Wuhan, China has resulted in more than 70,000 laboratory confirmed cases, and recent studies showed that 2019-nCoV (SARS-CoV-2) could be of bat origin but involve other potential intermediate hosts. In this study, we assembled the genomes of coronaviruses identified in sick pangolins. The molecular and phylogenetic analyses showed that pangolin Coronaviruses (pangolin-CoV) are genetically related to both the 2019-nCoV and bat Coronaviruses but do not support the 2019-nCoV arose directly from the pangolin-CoV. Our study also suggested that pangolin be natural host of Betacoronavirus, with a potential to infect humans. Large surveillance of coronaviruses in pangolins could improve our understanding of the spectrum of coronaviruses in pangolins. Conservation of wildlife and limits of the exposures of humans to wildlife will be important to minimize the spillover risks of coronaviruses from wild animals to humans.

negative: Clinical Characteristics of Hospitalized Patients with SARS-CoV-2 and Hepatitis B virus Co-infection Background & Aims The coronavirus disease 2019 (COIVD-19) caused by SARS-CoV-2 has been characterized as a pandemic, which causes a serious public health challenge in the world. A very large group of patients infected by HBV has been reported worldwide, especially in China. In order to answer whether specific treatment strategy on the patients coinfected with HBV and SARS-CoV-2, it requires profound understanding of the clinical characteristics on those patients. However, the impacts of SARS-CoV-2 infection on HBV patients remain largely unknown. Approach & Results In this retrospective investigation, we included 123 COVID-19 patients admitted to Zhongnan Hospital of Wuhan University, Wuhan, China, from January 5 to March 7, 2020. All enrolled patients are the laboratory confirmed COVID-19 pneumonia cases according to the criteria reported previously. A total of 123 patients were analyzed for their Clinical records, laboratory results including the diagnosis of HBV infection and liver function. Among 123 confirmed COVID-19 patients, the mean age was 51 years old and 59.3% were females (73/123). Fifteen were previously HBV infected patients, 66.7% of them were males (10/15), patients with HBV infection appeared to have a higher incidence of liver cirrhosis and an increased level of total bilirubin. Seven (46.7%) patients with HBV infection were defined as severe cases, while the severity rate was 24.1% for the patients without HBV infection (26/108). The mortality of patients with HBV infection was 13.3% (2/15) compared to 2.8% (3/108) for the patients without HBV infection. Conclusions SARS-CoV-2 infection may cause liver function damage in COVID-19 cases and the patients with HBV infection are likely to have more severe disease outcome.

negative: Recombinant M protein-based ELISA test for detection of antibodies to canine coronavirus Abstract The membrane (M) protein of canine coronavirus (CCoV) was cloned and expressed in E. coli. The purified recombinant protein was then evaluated for its antigenicity and reliability in an enzyme-linked immunosorbent assay (ELISA) for detection of CCoV antibodies in dog sera. Fifty serum samples, screened previously by whole virus ELISA and Western blotting, were tested. When the performance of the new test was compared with those of whole virus ELISA and Western blotting, an excellent correlation was found with the latter two assays. The ELISA based on recombinant M protein represents an alternative and valid test for detection of antibodies to CCoV in dog sera.

negative: Low-Cost and High-Throughput Testing of COVID-19 Viruses and Antibodies via Compressed Sensing: System Concepts and Computational Experiments Coronavirus disease 2019 (COVID-19) is an ongoing pandemic infectious disease outbreak that has significantly harmed and threatened the health and lives of millions or even billions of people. COVID-19 has also negatively impacted the social and economic activities of many countries significantly. With no approved vaccine available at this moment, extensive testing of COVID-19 viruses in people are essential for disease diagnosis, virus spread confinement, contact tracing, and determining right conditions for people to return to normal economic activities. Identifying people who have antibodies for COVID-19 can also help select persons who are suitable for undertaking certain essential activities or returning to workforce. However, the throughputs of current testing technologies for COVID-19 viruses and antibodies are often quite limited, which are not sufficient for dealing with COVID-19 viruses' anticipated fast oscillating waves of spread affecting a significant portion of the earth's population. In this paper, we propose to use compressed sensing (group testing can be seen as a special case of compressed sensing when it is applied to COVID-19 detection) to achieve high-throughput rapid testing of COVID-19 viruses and antibodies, which can potentially provide tens or even more folds of speedup compared with current testing technologies. The proposed compressed sensing system for high-throughput testing can utilize expander graph based compressed sensing matrices developed by us \cite{Weiyuexpander2007}.

negative: Evaluation of antibody testing for SARS-Cov-2 using ELISA and lateral flow immunoassays Background: The SARS-CoV-2 pandemic caused >1 million infections during January-March 2020. There is an urgent need for robust antibody detection approaches to support diagnostics, vaccine development, safe individual release from quarantine and population lock-down exit strategies. The early promise of lateral flow immunoassay (LFIA) devices has been questioned following concerns about sensitivity and specificity. Methods: We used a panel of plasma samples designated SARS-CoV-2 positive (from SARS-CoV-2 RT-PCR-positive individuals; n=40) and negative (samples banked in the UK prior to December-2019 (n=142)). We tested plasma for SARS-Cov-2 IgM and IgG antibodies by ELISA and using nine different commercially available LFIA devices. Results: ELISA detected SARS-CoV-2 IgM or IgG in 34/40 individuals with an RT-PCR-confirmed diagnosis of SARS-CoV-2 infection (sensitivity 85%, 95%CI 70-94%), vs 0/50 pre-pandemic controls (specificity 100% [95%CI 93-100%]). IgG levels were detected in 31/31 RT-PCR-positive individuals tested ≥10 days after symptom onset (sensitivity 100%, 95%CI 89-100%). IgG titres rose during the 3 weeks post symptom onset and began to fall by 8 weeks, but remained above the detection threshold. Point estimates for the sensitivity of LFIA devices ranged from 55-70% versus RT-PCR and 65-85% versus ELISA, with specificity 95-100% and 93-100% respectively. Within the limits of the study size, the performance of most LFIA devices was similar. Conclusions: The performance of current LFIA devices is inadequate for most individual patient applications. ELISA can be calibrated to be specific for detecting and quantifying SARS-CoV-2 IgM and IgG and is highly sensitive for IgG from 10 days following symptoms onset.

negative: A systematic review of lopinavir therapy for SARS coronavirus and MERS coronavirus—A possible reference for coronavirus disease‐19 treatment option In the past few decades, coronaviruses have risen as a global threat to public health. Currently, the outbreak of coronavirus disease‐19 (COVID‐19) from Wuhan caused a worldwide panic. There are no specific antiviral therapies for COVID‐19. However, there are agents that were used during the severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) epidemics. We could learn from SARS and MERS. Lopinavir (LPV) is an effective agent that inhibits the protease activity of coronavirus. In this review, we discuss the literature on the efficacy of LPV in vitro and in vivo, especially in patients with SARS and MERS, so that we might clarify the potential for the use of LPV in patients with COVID‐19.

negative: Early detection of antibodies against various structural proteins of the SARS-associated coronavirus in SARS patients Severe acute respiratory syndrome (SARS), a new disease with symptoms similar to those of atypical pneumonia, raised a global alert in March 2003. Because of its relatively high transmissibility and mortality upon infection, probable SARS patients were quarantined and treated with special and intensive care. Therefore, instant and accurate laboratory confirmation of SARS-associated coronavirus (SARS-CoV) infection has become a worldwide interest. For this need, we purified recombinant proteins including the nucleocapsid (N), envelope (E), membrane (M), and truncated forms of the spike protein (S1–S7) of SARS-CoV inEscherichia coli. The six proteins N, E, M, S2, S5, and S6 were used for Western blotting (WB) to detect various immunoglobulin classes in 90 serum samples from 54 probable SARS patients. The results indicated that N was recognized in most of the sera. In some cases, S6 could be recognized as early as 2 or 3 days after illness onset, while S5 was recognized at a later stage. Furthermore, the result of recombinant-protein-based WB showed a 90% agreement with that of the whole-virus-based immunofluorescence assay. Combining WB with existing RT-PCR, the laboratory confirmation for SARS-CoV infection was greatly enhanced by 24.1%, from 48.1% (RT-PCR alone) to 72.2%. Finally, our results show that IgA antibodies against SARS-CoV can be detected within 1 week after illness onset in a few SARS patients.

negative: How the world's collective attention is being paid to a pandemic: COVID-19 related 1-gram time series for 24 languages on Twitter In confronting the global spread of the coronavirus disease COVID-19 pandemic we must have coordinated medical, operational, and political responses. In all efforts, data is crucial. Fundamentally, and in the possible absence of a vaccine for 12 to 18 months, we need universal, well-documented testing for both the presence of the disease as well as confirmed recovery through serological tests for antibodies, and we need to track major socioeconomic indices. But we also need auxiliary data of all kinds, including data related to how populations are talking about the unfolding pandemic through news and stories. To in part help on the social media side, we curate a set of 1000 day-scale time series of 1-grams across 24 languages on Twitter that are most `important' for March 2020 with respect to March 2019. We determine importance through our allotaxonometric instrument, rank-turbulence divergence. We make some basic observations about some of the time series, including a comparison to numbers of confirmed deaths due to COVID-19 over time. We broadly observe across all languages a peak for the language-specific word for `virus' in January followed by a decline through February and a recent surge through March. The world's collective attention dropped away while the virus spread out from China. We host the time series on Gitlab, updating them on a daily basis while relevant. Our main intent is for other researchers to use these time series to enhance whatever analyses that may be of use during the pandemic as well as for retrospective investigations.

negative: Nucleic acid-based diagnostics for infectious diseases in public health affairs Infectious diseases, mostly caused by bacteria and viruses but also a result of fungal and parasitic infection, have been one of the most important public health concerns throughout human history. The first step in combating these pathogens is to get a timely and accurate diagnosis at an affordable cost. Many kinds of diagnostics have been developed, such as pathogen culture, biochemical tests and serological tests, to help detect and fight against the causative agents of diseases. However, these diagnostic tests are generally unsatisfactory because they are not particularly sensitive and specific and are unable to deliver speedy results. Nucleic acid-based diagnostics, detecting pathogens through the identification of their genomic sequences, have shown promise to overcome the above limitations and become more widely adopted in clinical tests. Here we review some of the most popular nucleic acid-based diagnostics and focus on their adaptability and applicability to routine clinical usage. We also compare and contrast the characteristics of different types of nucleic acid-based diagnostics.

negative: Curso atípico o incompleto de la enfermedad de Kawasaki en edades pediátricas

negative: Diagnosis of Acute Respiratory Syndrome Coronavirus 2 Infection by Detection of Nucleocapsid Protein BACKGROUND Nucleic acid test and antibody assay have been employed in the diagnosis for SARS-CoV-2 infection, but the use of viral antigen for diagnosis has not been successfully developed. Theoretically, viral antigen is the specific marker of the virus and precedes antibody appearance within the infected population. There is a clear need of detection of viral antigen for rapid and early diagnosis. METHODS We included a cohort of 239 participants with suspected SARS-CoV-2 infection from 7 centers for the study. We measured nucleocapsid protein in nasopharyngeal swab samples in parallel with the nucleic acid test. Nucleic acid test was taken as the reference standard, and statistical evaluation was taken in blind. We detected nucleocapsid protein in 20 urine samples in another center, employing nasopharyngeal swab nucleic acid test as reference standard. RESULTS We developed a fluorescence immunochromatographic assay for detecting nucleocapsid protein of SARS-CoV-2 in nasopharyngeal swab sample and urine within 10 minutes. 100% of nucleocapsid protein positive and negative participants accord with nucleic acid test for same samples. Further, earliest participant after 3 days of fever can be identified by the method. In an additional preliminary study, we detected nucleocapsid protein in urine in 73.6% of diagnosed COVID-19 patients. CONCLUSIONS Those findings indicate that nucleocapsid protein assay is an accurate, rapid, early and simple method for diagnosis of COVID-19. Appearance of nucleocapsid protein in urine coincides our finding of the SARS-CoV-2 invading kidney and might be of diagnostic value.

negative: Serological survey on canine coronavirus antibodies in giant pandas by virus neutralization test In order to survey the infectious situation of canine coronavirus (CCV) in giant panda population, a virus neutralization test detecting specific antibodies against CCV in giant panda’s sera was established by using two-fold dilutions of serum and 100 TCID(50) of the virus. The 62 sera samples of giant pandas, which were gathered from zoos and reserve region of Sichuan Province, China were detected. The neutralization antibody titer of 1:4 was recognized as the positive criterion, 8 sera samples were detected to be positive, and the positive rate was 12.9%. The titers of neutralizing antibody ranged from 1:8 to 1:32. It was the first comprehensive investigation on neutralization antibodies against CCV in giant panda population in China. The results of study showed that the infection of CCV in giant panda population was universal, which has posed a threat to the health of giant panda. Therefore, it is incumbent on us to study safe and effective vaccines to protect giant panda against CCV infection.

negative: Chapter 14 Viral Diseases This chapter reviews the naturally occurring viral diseases and asymptomatic viral infections of rabbits and hares. The principal emphasis is on virus infections of domestic rabbits of the genus Oryctolagus. Included are Myxoma virus and other Poxviruses, Herpesviruses, Papilloma, and Polyoma viruses, Adenovirus, Parvovirus, Rotavirus, Caliciviruses, including rabbit hemorrhagic disease virus and European brown hare disease virus, Bunyaviruses, Togaviruses, Flaviviruses, Picobirnavirus, and Rabies virus. Each virus is discussed under the following topics, history, etiology, epidemiology, clinical signs, pathology, diagnosis, and control.

negative: The nature and classification of viruses of man

negative: On predicting the novel COVID-19 human infections by using Infectious Disease modelling method in the Indian State of Tamil Nadu during 2020 Since the introduction of the novel Corona Virus (The COVID 19) to the Chinese city Wuhan in the Hubei province during the late December 2019, the effectiveness of the deadly disease, its human infection, spreading severity and the mortality rate of the infection has been an issue of debate. The outbreak of the virus along the time has become a massive threat to the global public health security and has been declared as a pandemic. Accounting the radical number of increases in the infected cases and the death due to COVID 19 infections around the globe, there is a need to predict the infections among the people by making proper optimization and using various Infectious Disease modelling (IDM) methods, in order to challenge the outcome. In comparison with previous diseases like SARS and Ebola viruses, the new corona virus (COVID 19) infections are infectious during the incubation period. In addition to that, naturally produced droplets from humans (e.g. droplets produced by breathing, talking, sneezing, coughing) and Person-to-person contact transmission are reported to be the foremost ways of transmission of novel corona virus. By considering the above two factors, a modified SEIR (Susceptibility Exposure Infection Recovery) method have been used for predicting the spread of the infections in the state of Tamil Nadu which is located in the southern part of India. Further, we have utilized the current surveillance data from Health and Family Welfare Department, Government of Tamil Nadu to accurately predict the spreading trend of the infection on a state level.

negative: Nelfinavir inhibits replication of severe acute respiratory syndrome coronavirus 2 in vitro In December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, Hubei Province, China. No specific treatment has been established against coronavirus disease-2019 (COVID-19) so far. Therefore, it is urgently needed to identify effective antiviral agents for the treatment of this disease, and several approved drugs such as lopinavir have been evaluated. Here, we report that nelfinavir, an HIV-1 protease inhibitor, potently inhibits replication of SARS-CoV-2. The effective concentrations for 50% and 90% inhibition (EC50 and EC90) of nelfinavir were 1.13 µM and 1.76 µM respectively, the lowest of the nine HIV-1 protease inhibitors including lopinavir. The trough and peak serum concentrations of nelfinavir were three to six times higher than EC50 of this drug. These results suggest that nelfinavir is a potential candidate drug for the treatment of COVID-19 and should be assessed in patients with COVID-19.

negative: Lack of Antiviral Activity of Darunavir against SARS-CoV-2 Given the high need and the absence of specific antivirals for treatment of COVID-19 (the disease caused by severe acute respiratory syndrome-associated coronavirus-2 [SARS-CoV-2]), human immunodeficiency virus (HIV) protease inhibitors are being considered as therapeutic alternatives. Prezcobix/Rezolsta is a fixed-dose combination of 800 mg of the HIV protease inhibitor darunavir (DRV) and 150 mg cobicistat, a CYP3A4 inhibitor, which is indicated in combination with other antiretroviral agents for the treatment of HIV infection. There are currently no definitive data on the safety and efficacy of DRV/cobicistat for treatment of COVID-19. The in vitro antiviral activity of darunavir against a clinical isolate from a patient infected with SARS-CoV-2 was assessed. DRV showed no activity against SARS-CoV-2 at clinically relevant concentrations (EC50 >100 μM). Remdesivir, used as a positive control, showed potent antiviral activity (EC50 = 0.38 μM). Overall, the data do not support the use of DRV for treatment of COVID-19.

negative: Immune phenotyping based on neutrophil-to-lymphocyte ratio and IgG predicts disease severity and outcome for patients with COVID-19 Background: A recently emerging respiratory disease named coronavirus disease 2019 (COVID-19) has quickly spread across the world. This disease is initiated by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and uncontrolled cytokine storm, but it remains unknown as to whether a robust antibody response is related to clinical deterioration and poor outcome in laboratory-confirmed COVID-19 patients. Methods: Anti-SARS-CoV-2 IgG and IgM antibodies were determined by chemiluminescence analysis (CLIA) in COVID-19 patients from a single center in Wuhan. Median IgG and IgM levels in acute and convalescent-phase sera (within 35 days) for all included patients were calculated and compared among severe and nonsevere patients. Immune response phenotyping based on late IgG levels and neutrophil-to-lymphocyte ratio (NLR) was characterized to stratify patients with different disease severities and outcome. Laboratory parameters in patients with different immune response phenotypes and disease severities were analyzed. Findings: A total of 222 patients were included in this study. IgG was first detected on day 4 of illness, and its peak levels occurred in the fourth week. Severe cases were more frequently found in patients with high IgG levels, compared to those who with low IgG levels (51.8% versus 32.3%; p=0.008). Severity rates for patients with NLRhiIgGhi, NLRhiIgGlo, NLRloIgGhi, and NLRloIgGlo phenotype was 72.3%, 48.5%, 33.3%, and 15.6%, respectively (p<0.0001). Furthermore, severe patients with NLRhiIgGhi, NLRhiIgGlo had higher proinflammatory cytokines levels including IL-2, IL-6 and IL-10, and decreased CD4+ T cell count compared to those with NLRloIgGlo phenotype (p<0.05). Recovery rate for severe patients with NLRhiIgGhi, NLRhiIgGlo, NLRloIgGhi, and NLRloIgGlo phenotype was 58.8% (20/34), 68.8% (11/16), 80.0% (4/5), and 100% (12/12), respectively (p=0.0592). Dead cases only occurred in NLRhiIgGhi and NLRhiIgGlo phenotypes. Interpretation: COVID-19 severity is associated with increased IgG response, and an immune response phenotyping based on late IgG response and NLR could act as a simple complementary tool to discriminate between severe and nonsevere COVID-19 patients, and further predict their clinical outcome.

negative: COVID-19, an emerging coronavirus infection: advances and prospects in designing and developing vaccines, immunotherapeutics, and therapeutics The novel coronavirus infection (COVID-19 or Coronavirus disease 2019) that emerged from Wuhan, Hubei province of China has spread to many countries worldwide. Efforts have been made to develop vaccines against human coronavirus (CoV) infections such as MERS and SARS in the past decades. However, to date, no licensed antiviral treatment or vaccine exists for MERS and SARS. Most of the efforts for developing CoV vaccines and drugs target the spike glycoprotein or S protein, the major inducer of neutralizing antibodies. Although a few candidates have shown efficacy in in vitro studies, not many have progressed to randomized animal or human trials, hence may have limited use to counter COVID-19 infection. This article highlights ongoing advances in designing vaccines and therapeutics to counter COVID-19 while also focusing on such experiences and advances as made with earlier SARS- and MERS-CoVs, which together could enable efforts to halt this emerging virus infection.

negative: Acute respiratory infection due to Mycoplasma pneumoniae: current status of diagnostic methods Because of the absence of well-standardized both in-house and FDA-approved commercially available diagnostic tests, the reliable diagnosis of respiratory infection due to Mycoplasma pneumoniae remains difficult. In addition, no formal external quality assessment schemes which would allow to conclude about the performance of M. pneumoniae diagnostic tests exist. In this review, the current state of knowledge of M. pneumoniae-associated respiratory infections in the context of epidemiological studies published during the past 5 years is discussed, with particular emphasis on the diagnostic strategies used and their impact on results. The role of M. pneumoniae as a cause of respiratory tract infections (RTIs) differs from study to study due to geographical and epidemiological differences, as well as to the application of different diagnostic techniques and criteria used. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10096-010-0975-2) contains supplementary material, which is available to authorized users.

negative: Development of an indirect ELISA, blocking ELISA, fluorescent microsphere immunoassay and fluorescent focus neutralization assay for serologic evaluation of exposure to North American strains of Porcine Epidemic Diarrhea Virus BACKGROUND: Recent, severe outbreaks of porcine epidemic diarrhea virus (PEDV) in Asia and North America highlight the need for well-validated diagnostic tests for the identification of PEDV infected animals and evaluation of their immune status to this virus. PEDV was first detected in the U.S. in May 2013 and spread rapidly across the country. Some serological assays for PEDV have been previously described, but few were readily available in the U.S. Several U.S. laboratories quickly developed indirect fluorescent antibody (IFA) assays for the detection of antibodies to PEDV in swine serum, indicating prior exposure. However, the IFA has several disadvantages, including low throughput and relatively subjective interpretation. Different serologic test formats have advantages and disadvantages, depending on the questions being asked, so a full repertoire of tests is useful. Therefore, the objective of this study was to develop and validate multiple improved serological assays for PEDV, including an indirect ELISA (iELISA); a highly specific monoclonal antibody-based blocking ELISA (bELISA); fluorescent microsphere immunoassays (FMIA) that can be multiplexed to monitor exposure to multiple antigens and pathogens simultaneously; and a fluorescent focus neutralization assay (FFN) to measure functional virus neutralizing antibodies. RESULTS: A recombinant North American nucleoprotein (NP) based iELISA was developed and validated along with a bELISA using newly developed PEDV-NP specific biotinylated monoclonal antibodies (mAbs) and an FMIA using magnetic beads coupled with expressed NA PEDV-NP. Receiver operating characteristic (ROC) analysis was performed using swine serum samples (iELISA n = 1486, bELISA n = 1186, FMIA n = 1420). The ROC analysis for the FMIA showed estimated sensitivity and specificity of 98.2 and 99.2 %, respectively. The iELISA and bELISA showed a sensitivity and specificity of 97.9 and 97.6 %; and 98.2 and 98.9 %, respectively. Inter-rater (kappa) agreement was calculated to be 0.941 between iELISA and IFA, 0.945 between bELISA and IFA and 0.932 between FMIA and IFA. Similar comparative kappa values were observed between the iELISA, bELISA and FMIA, which demonstrated a significant level of testing agreement among the three assays. No cross-reactivity with the closely related coronaviruses, transmissible gastroenteritis virus (TGEV) or porcine respiratory coronavirus (PRCV) was noted with these assays. All three assays detected seroconversion of naïve animals within 6–9 days post exposure. The FFN assay allows relative quantitation of functional neutralizing antibodies in serum, milk or colostrum samples. CONCLUSION: Well-validated iELISA, bELISA and FMIA assays for the detection of PEDV antibodies were developed and showed good correlation with IFA and each other. Each assay format has advantages that dictate how they will be used in the field. Newly developed mAbs to the PEDV-NP were used in the bELISA and for expediting FFN testing in the detection and quantitation of neutralizing antibodies. In addition, these PEDV mAbs are useful for immunohistochemistry, fluorescent antibody staining and other antigen-based tests. Measurement of neutralizing antibody responses using the FFN assay may provide a valuable tool for assessment of vaccine candidates or protective immunity.

negative: Use of the Endoscopic Healing Index (EHI) for Monitoring of Disease Activity in Crohn’s Disease Patients in the COVID Era Management of Crohn’s disease (CD) during COVID-19 is challenging when colonoscopy is not feasible. This study describes a blood-based test that has been validated against colonoscopy in CD patients as an alternative even in patients with high inflammation from infections.

negative: Influence of maternal immunity on the outcome of mutine coronavirus JHM infection in suckling mice Adult C3H mice are resistant to intraperitoneal infection with murine coronavirus JHM, whereas suckling offspring of non-immune females are susceptible. Resistance can be conferred on suckling C3H mice by postnatal transmission of maternal immunity, if transfer preceeds infection. Suckling mice succumb to infection even when they receive maternal antibodies within 1 day after infection. Prenatal transmission alone without subsequent postnatal transmission of maternal immunity is not sufficient to provide resistance. Persistence of virus without clinical consequences was observed when the supply of breast milk anti-JHMV antibodies was terminated 5 days before infection. Immune reactions restricted by histocompatibility antigens do not play a crucial role in bestowing resistance. As neutralizing anti-JHM serum antibody titers of adult mice only rise sharply 5 to 7 days after infection, these results indicate that infection of adults can be arrested by immunological means but that, in addition, the rate of virus dissemination must be limited by other non-immunological mechanisms.

negative: Insulin-Like Growth Factor 1 Regulates Acute Inflammatory Lung Injury Mediated by Influenza Virus Infection The acute inflammatory lung injury is an important cause of death due to influenza A virus (IAV) infection. Insulin-like growth factor 1 (IGF1) played an important role in the regulation of inflammation in the immune system. To investigate the role of IGF1 in IAV-mediated acute inflammatory lung injury, the expression of IGF1 and inflammatory cytokines was tested after IAV A/Puerto Rico/8/1934 (H1N1; abbreviated as PR8) infection in A549 cells. Then, a BALB/c mouse model of PR8 infection was established. On days 3, 5, 7, and 9 post-infection, the mice lung tissue was collected to detect the expression changes in IGF1 mRNA and protein. The mice were divided into four groups: (1) PBS (abbreviation of phosphate buffered saline); (2) PR8 + PBS; (3) PR8 + IGF1; and (4) PR8 + PPP (abbreviation of picropodophyllin, the IGF1 receptor inhibitor). The body weight and survival rate of the mice were monitored daily, and the clinical symptoms of the mice were recorded. On day 5 post-infection, the mice were sacrificed to obtain the serum and lung tissues. The expression of inflammatory cytokines in the serum was detected by enzyme linked immunosorbent assay; lung injury was observed by hematoxylin-eosin staining; the viral proliferation in the lung was detected by real-time quantitative PCR; and the protein expression of the main molecules in the phosphatidylinositol-3-kinases/protein kinase B (PI3K/AKT) and mitogen-activated protein kinase (MAPK) signaling pathways was detected by Western blot. It was found that IGF1 expression is upregulated in A549 cells and BALB/c mice infected with PR8, whereas IGF1 regulated the expression of inflammatory cytokines induced by PR8 infection. Overexpression of IGF1 aggravated the IAV-mediated inflammatory response, whereas the inhibition of IGF1 receptor reduced such inflammatory response. The phosphorylation of IGF1 receptor triggered the PI3K/AKT and MAPK signaling pathways to induce an inflammatory response after IAV infection. Therefore, IGF1 plays an important immune function in IAV-mediated acute inflammatory lung injury. IGF1 may provide a therapeutic target for humans in response to an influenza outbreak, and inhibition of IGF1 or IGF1 receptor may represent a novel approach to influenza treatment.

negative: Viral etiology and seasonality of influenza-like illness in Gabon, March 2010 to June 2011 BACKGROUND: Surveillance of influenza-like illness (ILI) in Central Africa began only recently, and few data are therefore available on the circulation of influenza virus and other respiratory viruses. In Gabon, a Central African country, we established a surveillance network in four major towns in order to analyze cases of ILI among patients who visited health centers between March 2010 and June 2011, and to determine the viral etiology. METHODS: Nasal swabs were sent for analysis to the Centre International de Recherches Médicales de Franceville, where they were screened for 17 respiratory viruses in a multiplex real-time reverse transcription polymerase chain reaction for all pathogens according the following pairs: adenovirus/parainfluenza virus 4, respiratory syncytial virus/human metapneumovirus, parainfluenza virus 1/parainfluenza virus 2, pandemic influenza virus A/seasonal influenza virus A (H1N1, H3N2)/seasonal influenza virus B, human coronaviruses 229E/OC43, human coronaviruses NL63/HKU1, rhinovirus/human parechovirus, and enterovirus/parainfluenza virus 3. RESULTS: We analyzed a total of 1041 specimens, of which 639 (61%) were positive for at least one virus. Three-quarters of the patients were children under five years old. We therefore focused on this age group, in which 68.1% of patients were positive for at least one virus. The most common viruses were adenoviruses (17.5%), followed by parainfluenza viruses (PIVs) 1–4 (16.8%), enteroviruses (EV) (14.7%), respiratory syncytial virus (RSV) (13.5%), and influenza virus (11.9%). The prevalence of some viruses was subject to geographic and seasonal variations. One-third of positive samples contained more than one virus. CONCLUSIONS: Like most studies in the world, the virus PIVs, EV, RSV, Influenza virus, HRV were predominant among children under five years old in Gabon. An exception is made for adenoviruses which have a high prevalence in our study. However adenoviruses can be detected in asymptomatic persons. These finding gave a better knowledge of the circulation and the seasonality of the viruses involved in ILI in Gabon.

negative: Crouching Tiger, Hidden Dragon: The Laboratory Diagnosis of Severe Acute Respiratory Syndrome

negative: A SARS-CoV-2 serological assay to determine the presence of blocking antibodies that compete for human ACE2 binding As SARS-CoV-2 continues to spread around the world, there is an urgent need for new assay formats to characterize the humoral response to infection. Convalescent serum is being used for treatment and for isolation of patient-derived antibodies. However, currently there is not a simple means to estimate serum bulk neutralizing capability. Here we present an efficient competitive serological assay that can simultaneously determine an individual’s seropositivity against the SARS-CoV-2 Spike protein and estimate the neutralizing capacity of anti-Spike antibodies to block interaction with the human angiotensin converting enzyme 2 (ACE2) required for viral entry. In this ELISA-based assay, we present natively-folded viral Spike protein receptor binding domain (RBD)-containing antigens via avidin-biotin interactions. Sera are then supplemented with soluble ACE2-Fc to compete for RBD-binding serum antibodies, and antibody binding quantified. Comparison of signal from untreated serum and ACE2-Fc-treated serum reveals the presence of antibodies that compete with ACE2 for RBD binding, as evidenced by loss of signal with ACE2-Fc treatment. In our test cohort of nine convalescent SARS-CoV-2 patients, we found all patients had developed anti-RBD antibodies targeting the epitope responsible for ACE2 engagement. This assay provides a simple and high-throughput method to screen patient sera for potentially neutralizing anti-Spike antibodies to enable identification of candidate sera for therapeutic use.

negative: The site of origin of the 1918 influenza pandemic and its public health implications

negative: A double antibody sandwich enzyme-linked immunosorbent assay for detection of soft-shelled turtle iridovirus antigens Abstract A double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) for detection of the soft-shelled turtle iridovirus (STIV) was developed using a specific monoclonal antibody (mAb) against STIV and anti-STIV rabbit serum. Using DAS-ELISA, the detection limit of STIV was found to be 103 PFU/ml. The positive rate of 15 STIV samples was 100%, while the positive rate of 100 other aquatic virus samples was 0%. These data show that DAS-ELISA is highly specific and sensitive for the detection of STIV. In clinical tests, 128 samples isolated from pond-reared turtles were subjected to DAS-ELISA and PCR. The overall agreement between the results obtained by DAS-ELISA and PCR was 98.4%. The results indicate that the DAS-ELISA method could be used for diagnosing diseases caused by STIV.

negative: Efficient and Practical Sample Pooling for High-Throughput PCR Diagnosis of COVID-19 Diagnostic assays using quantitative Polymerase Chain Reaction (qPCR) most commonly process patient samples one by one. While this is usually an effective and reliable method, the current efforts against the COVID-19 pandemic demand more efficient measures. Diagnostic assays can be scaled up by the method of High-Throughput qPCR via sample pooling. Pooling, the action of combining multiple samples into one tube, is most effective when the chance of positive detection of the target, SARS-CoV-2 RNA, is low. In such cases, large groups of samples can be conclusively classified as negative with a single test, with no need to individually test every sample. However, different frequencies of the target-product presence in the samples, require different pool/batch sizes for optimal results. Here, we present two possible optimized pooling strategies for diagnostic SARSCoV-2 testing on large scales, each one better suited for a different range of target frequency. In the first, we employ a simple information-theoretic heuristic to derive a highly efficient re-pooling protocol: an estimate of the target frequency determines the initial pool size, and any subsequent pools found positive are re-pooled at half-size and tested again. In the range of very rare target (<0.05), this approach can reduce the number of necessary tests dramatically. For example, this method achieves a reduction of a factor of 50 for a target frequency of 0.001. The second method is a simpler approach of optimized one-time pooling followed by individual tests on positive pools. We show that this approach is just as efficient for moderate target-product frequencies (0.05<0.2). For example, it reduces the number of tests needed by half if the frequency of positives samples is 0.07. We show that both methods are comparable to the absolute upper-bound efficiency given by Shannon's source coding theorem. Our strategies require no investment at all, and they offer a significant reduction in the amount of equipment and time needed to test large numbers of samples. Both approaches are dynamic; they can be easily implemented in different conditions with various infection rates and sample numbers. We compare our strategies to the naive way of testing and also to alternative matrix methods. Most importantly, we offer practical pooling instructions for laboratories that perform large scale qPCR assays to diagnose SARS-CoV-2 viral particles.

negative: Enzyme-Linked Immunoassays for the Detection of Microbial Antigens and Their Antibodies Antibodies could be labeled with enzymes for use in histochemical staining procedures by enzyme-immunoassay (EIA). The use of EIA is an extension of previously used serological tests, using enzyme-labeled antibody or antigen to determine antibody content. Direct detection of antigen by EIA represents a more dramatic departure from previous methods based on culture. Also, the method has enabled detection of infectious agents that are difficult to cultivate, such as hepatitis A virus and rotavirus, or agents that cannot be cultivated, such as hepatitis B. The use of EIA tests for detection of microbial antigens provides an alternative to culture as a means for direct identification of a specific microbial agent. It also provides a means to detect microbial agents which have not been successfully propagated. The detection of circulating antigen or detection of antigen in other body fluids by EIA is more difficult than detection of antibody because of the sensitivity required, and because of interfering substances in specimens such as feces and respiratory secretions. For this reason, very few antigen detection assays have the sensitivity and specificity required to be used as a primary diagnostic test. The number of tests that have been developed, however, is impressive and because of the possibilities for rapid, specific diagnosis, the interest in antigen detection by EIA remains high.

negative: Epidemiological Concepts Epidemiology is the study of the distribution and determinants of health-related states, conditions, or events in specified populations and the application of the results of this study to the control of health problems.(1) It is a quantitative science concerned in infectious diseases with the circumstances under which disease processes occur, the factors that affect their incidence and the host response to the infectious agent, and the use of this knowledge for control and prevention.(2) It includes the pathogenesis of disease in both the community and the individual. For infectious diseases, one must study the circumstances under which both infection and disease occur, for these may be different. Infection is the consequence of an encounter of a potentially pathogenic microorganism with a susceptible human host through an appropriate portal of entry and usually involves a demonstrable host response to the agent. Exposure is the key factor, and the sources of infection lie mostly outside the individual human host, within the environment, or in other infected hosts. Disease represents one of the possible consequences of infection, and the factors important in its development are mostly intrinsic to the host, although the dosage and virulence of the infecting microbe play a role. These intrinsic factors include the age at the time of infection, the portal of entry, the presence or absence of immunity, the vigor of the primary defense system, the efficiency and nature of humoral and cell-mediated immune responses, the genetic makeup of the host, the state of nutrition, the presence of other diseases, and psychosocial influences. These factors that result in the occurrence of clinical illness among those infected have been called the “clinical illness-promotion factors,”(3) and many of them remain unknown. The host responses can include death, the classic clinical features of the disease, mild or atypical forms, subclinical and inapparent infections, and the carrier state, which may exist in the absence of a detectable host response. While the clinician is primarily concerned with disease, the epidemiologist is interested in both infection and disease. Infection without disease is a common phenomenon, so that a study limited to clinical illness alone would give an incomplete epidemiological picture and would be a poor basis for control and prevention.(4) A full understanding involves the pathogenesis of the process leading to clinical disease both in the community and in the individual.

negative: Respiratory Barrier as a Safeguard and Regulator of Defense Against Influenza A Virus and Streptococcus pneumoniae The primary function of the respiratory system of gas exchange renders it vulnerable to environmental pathogens that circulate in the air. Physical and cellular barriers of the respiratory tract mucosal surface utilize a variety of strategies to obstruct microbe entry. Physical barrier defenses including the surface fluid replete with antimicrobials, neutralizing immunoglobulins, mucus, and the epithelial cell layer with rapidly beating cilia form a near impenetrable wall that separates the external environment from the internal soft tissue of the host. Resident leukocytes, primarily of the innate immune branch, also maintain airway integrity by constant surveillance and the maintenance of homeostasis through the release of cytokines and growth factors. Unfortunately, pathogens such as influenza virus and Streptococcus pneumoniae require hosts for their replication and dissemination, and prey on the respiratory tract as an ideal environment causing severe damage to the host during their invasion. In this review, we outline the host-pathogen interactions during influenza and post-influenza bacterial pneumonia with a focus on inter- and intra-cellular crosstalk important in pulmonary immune responses.

negative: COVID-19 control in China during mass population movements at New Year

negative: COVID19 - The need for Public Health in a time of emergency

negative: Performances of different diagnostic tests for feline infectious peritonitis in challenging clinical cases Objectives: Feline infectious peritonitis (FIP) can be difficult to diagnose. Histopathology is considered the gold standard test but immunohistochemistry (IHC) is mandatory to confirm/exclude the disease. This study aimed to assess the performances of tests carried out in vivo or at postmortem examination in challenging cases in which FIP was confirmed or excluded based on IHC or on adequate follow‐up. Methods: Twelve cases (four without FIP, eight with FIP) were retrospectively studied. Clinical findings, serum protein electrophoresis (SPE), analysis of the effusions (AE), antifeline coronavirus serology, serum concentration of α1‐acid glycoprotein (AGP) and histopathology were classified as consistent, doubtful or non‐consistent with FIP. Sensitivity, specificity and concordance (κ) with the final diagnosis were calculated. Results: Concordance was absent for serology (κ=−0·08) and AE (κ=−0·52), poor for histopathology (κ=0·09), fair for SPE (κ=0·25) and perfect for AGP (κ=1·00). Sensitivity was high for AGP (100%) and low for AE (50%), SPE (37·5%) and histopathology (37·5%). Specificity was high for AGP or histopathology (100%) and low for SPE (50%) and AE (0%). Clinical Significance: IHC must always be performed to confirm FIP. If this is not possible, when histopathology is controversial, elevated AGP concentrations may support the diagnosis of FIP.

negative: Myocardial characteristics as the prognosis for COVID-19 patients Background Amid the crisis of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), front-line clinicians in collaboration with backstage medical researchers analyzed clinical characteristics of COVID-19 patients and reported the prognosis using myocardial data records upon hospitalization. Methods We reported 135 cases of laboratory-confirmed COVID-19 patients admitted in The First People's Hospital of Jiangxia District in Wuhan, China. Demographic data, medical history, and laboratory parameters were taken from inpatient records and compared between patients at the Intensive Care Unit (ICU) and non-ICU isolation wards for prognosis on disease severity. In particular, survivors and non-survivors upon ICU admission were compared for prognosis on disease mortality. Results For COVID-19 patients, blood test results showed more significantly deranged values in the ICU group than those in non-ICU. Among those parameters for ICU patients, myocardial variables including troponin T, creatine kinase isoenzymes, myoglobin, were found significantly higher in non-survivors than in survivors. Conclusions Upon hospitalization abnormal myocardial metabolism in COVID-19 patients could be prognostic indicators of a worsened outcome for disease severity and mortality.

negative: Analytical sensitivity and efficiency comparisons of SARS-COV-2 qRT-PCR primer-probe sets The recent spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exemplifies the critical need for accurate and rapid diagnostic assays to prompt clinical and public health interventions. Currently, several quantitative reverse-transcription polymerase chain reaction (qRT-PCR) assays are being used by clinical, research, and public health laboratories. However, it is currently unclear if results from different tests are comparable. Our goal was to evaluate the primer-probe sets used in four common diagnostic assays available on the World Health Organization (WHO) website. To facilitate this effort, we generated RNA transcripts to be used as assay standards and distributed them to other laboratories for internal validation. We then used (1) RNA transcript standards, (2) full-length SARS-CoV-2 RNA, (3) pre-COVID-19 nasopharyngeal swabs, and (4) clinical samples from COVID-19 patients to determine analytical efficiency and sensitivity of the qRT-PCR primer-probe sets. We show that all primer-probe sets can be used to detect SARS-CoV-2 at 500 virus copies per reaction, except for the RdRp-SARSr (Charite) confirmatory primer-probe set which has low sensitivity. Our findings characterize the limitations of currently used primer-probe sets and can assist other laboratories in selecting appropriate assays for the detection of SARS-CoV-2.

negative: Serologic Detection of Middle East Respiratory Syndrome Coronavirus Functional Antibodies We developed and validated 2 species-independent protein-based assays to detect Middle East respiratory syndrome coronavirus functional antibodies that can block virus receptor-binding or sialic acid-attachment. Antibody levels measured in both assays correlated strongly with virus-neutralizing antibody titers, proving their use for serologic confirmatory diagnosis of Middle East respiratory syndrome.

negative: Detection of enterotoxigenic K99 (F5) and F41 from fecal sample of calves by molecular and serological methods Enterotoxigenic Escherichia coli (ETEC) is one of the major causes of neonatal calf diarrhea. Almost all ETEC bacteria are known to adhere to receptors on the small intestinal epithelium via their fimbriae, (F5 (K99) and F41).This study was undertaken to investigate the phenotypic and genotypic screening of virulence genes in E. coli K99 and F41. During January 2008 to December 2009, 298 diarrheic neonatal calves at 1–30 days old were studied by multiplex PCR, isolation, and serological grouping. Of the 298 diarrheic samples, 268 E. coli were isolated, of which 16 samples (5.3%) were positive for having the F5 (K99) fimbrial gene by PCR while all of the E. coli isolates also carried F41 fimbrial genes. Twenty-five percent of the isolates were proven not to be toxigenic as they did not possess the STa enterotoxin gene.

negative: MMDB: annotating protein sequences with Entrez's 3D-structure database Three-dimensional (3D) structure is now known for a large fraction of all protein families. Thus, it has become rather likely that one will find a homolog with known 3D structure when searching a sequence database with an arbitrary query sequence. Depending on the extent of similarity, such neighbor relationships may allow one to infer biological function and to identify functional sites such as binding motifs or catalytic centers. Entrez's 3D-structure database, the Molecular Modeling Database (MMDB), provides easy access to the richness of 3D structure data and its large potential for functional annotation. Entrez's search engine offers several tools to assist biologist users: (i) links between databases, such as between protein sequences and structures, (ii) pre-computed sequence and structure neighbors, (iii) visualization of structure and sequence/structure alignment. Here, we describe an annotation service that combines some of these tools automatically, Entrez's ‘Related Structure’ links. For all proteins in Entrez, similar sequences with known 3D structure are detected by BLAST and alignments are recorded. The ‘Related Structure’ service summarizes this information and presents 3D views mapping sequence residues onto all 3D structures available in MMDB ().

negative: Smart Pooled sample Testing for COVID-19: A Possible Solution for Sparsity of Test Kits There is an exponential growth of COVID-19. The adaptation of preventive measures to limit the spread of infection among the people is the best solution to this health issue. The identification of infected cases and their isolation from healthy people is one of the most important preventive measures. In this regard, screening of the samples from a large number of people is needed which requires a lot of reagent kits for the detection of SARS-CoV-2. The use of smart pooled sample testing with the help of algorithms may be a quite useful strategy in the current prevailing scenario of the COVID-19 pandemic. With the help of this strategy, the optimum number of samples to be pooled for a single test may be determined based on the total positivity rate of the particular community.

negative: Discovery of a subgenotype of human coronavirus NL63 associated with severe lower respiratory tract infection in China, 2018 Human coronavirus NL63 (HCoV-NL63) is primarily associated with common cold in children, elderly and immunocompromised individuals. Outbreaks caused by HCoV-NL63 are rare. Here we report a cluster of HCoV-NL63 cases with severe lower respiratory tract infection that arose in Guangzhou, China, in 2018. Twenty-three hospitalized children were confirmed to be HCoV-NL63 positive, and most of whom were hospitalized with severe pneumonia or acute bronchitis. Whole genomes of HCoV-NL63 were obtained using next-generation sequencing. Phylogenetic and single amino acid polymorphism analyses showed that this outbreak was associated with two subgenotypes (C3 and B) of HCoV-NL63. Half of patients were identified to be related to a new subgenotype C3. One unique amino acid mutation at I507 L in spike protein receptor binding domain (RBD) was detected, which segregated this subgenotype C3 from other known subgenotypes. Pseudotyped virus bearing the I507 L mutation in RBD showed enhanced entry into host cells as compared to the prototype virus. This study proved that HCoV-NL63 was undergoing continuous mutation and has the potential to cause severe lower respiratory disease in humans.

negative: Transcriptional analysis of avian embryonic tissues following infection with avian infectious bronchitis virus Abstract Avian infectious bronchitis virus (IBV) infection is one of the major viral respiratory diseases of chickens. Better understanding of the molecular basis of viral pathogenesis should contribute significantly towards the development of improved prophylactic, therapeutic and diagnostic reagents to control infections. In the present investigation, transcriptional profiles were analyzed by using RNA recovered from the lung tissue of IBV infected 18-day-old chicken embryos at 6, 24, 48 and 72h post IBV infection. This microarray analysis was completed using avian cDNA arrays comprised of fragments of 1191 unique chicken and turkey gene transcripts. These arrays were generated from normalized cDNA subtraction libraries that were derived from avian pneumovirus (APV) infected chicken embryo fibroblast (CEF) cultures and tissues obtained from APV infected turkeys subtracted with their respective uninfected cultures and tissues. Of the 1191 unique genes represented on the array, the expression of a total of 327 genes (27% of total) were altered by two-fold or more from 6 through 72h post-infection. A comparative analysis of IBV regulated genes with genes previously reported to change in expression following infection with other avian respiratory viruses revealed both conserved and unique changes. Real-time qRT-PCR was used to confirm the regulated expression of genes related to several functional classes including kinases, interferon induced genes, chemokines and adhesion molecules, vesicular trafficking and fusion protein genes, extracellular matrix protein genes, cell cycle, metabolism, cell physiology and development, translation, RNA binding, lysosomal, protein degradation and ubiquitination related genes. Microarray analysis served as an efficient tool in facilitating a comparative analysis of avian respiratory viral infections and provided insight into host transcriptional changes that were conserved as well as those which were unique to individual pathogens.

negative: Ecosystem approaches to the risk for schizophrenia

negative: Severe Acute Respiratory Syndrome Coronavirus 2 Serology in Asymptomatic Healthcare Professionals: Preliminary Experience of a Tertiary Italian Academic Center. We investigated the SARS-CoV-2 specific antibody titers in 133 asymptomatic healthcare providers working at the Department of Laboratory Medicine of our tertiary center. A commercial chemiluminescence immunoassay, validated according to the ISO15189 standard requirements, was used. All the enrolled healthcare professionals underwent, simultaneously to the blood sampling, a nasopharyngeal swab for molecular testing with quantitative reverse-transcriptase-based polymerase chain reaction (RT-PCR). An overall positiveness of 5.25% was found. We strongly promote a wide use of validated serologic assays in asymptomatic, healthy individuals, as a crucial information for epidemiological surveillance.

negative: Association of Personal Protective Equipment Use with Successful Protection Against COVID-19 Infection Among Health Care Workers The coronavirus disease 2019 (COVID-19) pandemic has posed a major challenge for protecting health care workers (HCWs) against the infection. Use of personal protective equipment (PPE) in health care workplace is recommended as a high priority. In order to investigate the relationship between PPE use and the number of COVID-19 cases among HCWs, we conducted a molecular epidemiological study among 142 HCWs who were dispatched from Hefei to work in Wuhan and 284 HCWs who remained in Hefei, China; both provided care for patients with COVID-19. Nucleic acid testing and SARS-CoV-2 specific antibody (IgM, IgG, IgA) detection were performed to confirm SARS-CoV-2 infection among those HCWs. We also extracted publicly released data on daily number of COVID-19 cases among HCWs, daily number of HCWs who were dispatched to Hubei province since January 24, and daily production of PPE in China and daily demand and supply of PPE in Hubei province. Our laboratory testing confirmed that none of the 142 HCWs who were dispatched to work in Wuhan and 284 HCWs who remained in Hefei were infected by SARS-CoV-2. Consistent with these findings, as of April 15, 2020, none of the 42,600 HCWs who were successively dispatched to Hubei province since January 24, 2020 was reported to have COVID-19. These HCWs were provided with adequate supply of PPE as committed by their original institutions or provinces. In contrast, during the early phase of COVID-19 epidemic in Hubei province, a substantial shortage of PPE and an increasing number of COVID-19 infection among HCWs were reported. With the continuing increase in domestic production of PPE in China, the PPE supply started to meet and then exceed the demand. This coincided with a subsequent reduction in the number of reported COVID-19 cases among HCWs. In conclusion, our findings indicate that COVID-19 infection among HCWs could be completely prevented. Appropriate and adequate PPE might play a crucial role in protecting HCWs against COVID-19 infection.

negative: Mapping the Immunodominance Landscape of SARS-CoV-2 Spike Protein for the Design of Vaccines against COVID-19 The ongoing coronavirus disease 2019 (COVID-19) pandemic is a serious threat to global public health, and imposes severe burdens on the entire human society. The severe acute respiratory syndrome (SARS) coronavirus-2 (SARS-CoV-2) can cause severe respiratory illness and death. Currently, there are no specific antiviral drugs that can treat COVID-19. Several vaccines against SARS-CoV-2 are being actively developed by research groups around the world. The surface S (spike) protein and the highly expressed internal N (nucleocapsid) protein of SARS-CoV-2 are widely considered as promising candidates for vaccines. In order to guide the design of an effective vaccine, we need experimental data on these potential epitope candidates. In this study, we mapped the immunodominant (ID) sites of S protein using sera samples collected from recently discharged COVID-19 patients. The SARS-CoV-2 S protein-specific antibody levels in the sera of recovered COVID-19 patients were strongly correlated with the neutralising antibody titres. We used epitope mapping to determine the landscape of ID sites of S protein, which identified nine linearized B cell ID sites. Four out of the nine ID sites were found in the receptor-binding domain (RBD). Further analysis showed that these ID sites are potential high-affinity SARS-CoV-2 antibody binding sites. Peptides containing two out of the nine sites were tested as vaccine candidates against SARS-CoV-2 in a mouse model. We detected epitope-specific antibodies and SARS-CoV-2-neutralising activity in the immunised mice. This study for the first time provides human serological data for the design of vaccines against COVID-19.

negative: Asymptomatic Middle East Respiratory Syndrome coronavirus infection using a serologic survey in Korea OBJECTIVES: The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status. METHODS: Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results. RESULTS: The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis. CONCLUSIONS: The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.

negative: Guidance for rebooting electrophysiology through the COVID-19 pandemic from the Heart Rhythm Society and the American Heart Association Electrocardiography and Arrhythmias Committee of the Council on Clinical Cardiology Endorsed by the American College of Cardiology Abstract Coronavirus disease 2019 (COVID-19) has presented substantial challenges to patient care and impacted health care delivery, including cardiac electrophysiology practice throughout the globe. Based upon the undetermined course and regional variability of the pandemic, there is uncertainty as to how and when to resume and deliver electrophysiology services for arrhythmia patients. This joint document from representatives of the Heart Rhythm Society, American Heart Association, and American College of Cardiology seeks to provide guidance for clinicians and institutions reestablishing safe electrophysiological care. To achieve this aim, we address regional and local COVID-19 disease status, the role of viral screening and serologic testing, return-to-work considerations for exposed or infected health care workers, risk stratification and management strategies based on COVID-19 disease burden, institutional preparedness for resumption of elective procedures, patient preparation and communication, prioritization of procedures, and development of outpatient and periprocedural care pathways.

negative: A serological comparison of bovine coronavirus strains Two bovine coronavirus (BCV) strains from diarrheic calf faeces were adapted to grow in HRT 18 cells and compared in immunofluorescence (IF), haemagglutination inhibition (HAI) and neutralisation (NT) tests with three other strains of BCV and a human coronavirus (HCV) strain obtained from other laboratories. Polyclonal antisera against these 6 viruses were raised in rabbits. No significant differences between viruses were detected by IF. In the HAI test the HCV strain was distinguishable from the 5 BCV strains and serological variation between the BCV strains was shown. HCV could be distinguished by NT test, but all BCV isolates were similar. Two monoclonal antibodies prepared against one of the BCV strains distinguished HCV in all three assays, and detected varying relationships between BCV strains.

negative: Initial evidence of higher morbidity and mortality due to SARS-CoV-2 in regions with lower air quality COVID-19 has spread in all continents in a span of just over three months, escalating into a pandemic that poses several humanitarian as well as scientific challenges. We here investigated the geographical expansion of the infection and correlate it with the annual indexes of air quality observed from the Sentinel-5 satellite orbiting around China, Italy and the U.S.A. Controlling for population size, we find more viral infections in those areas afflicted by Carbon Monoxide (CO) and Nitrogen Dioxide (NO2). Higher mortality was also correlated with poor air quality, namely with high PM2.5, CO and NO2 values. In Italy, the correspondence between poor air quality and SARS-CoV-2 appearance and induced mortality was the starkest. Similar to smoking, people living in polluted areas are more vulnerable to SARS-CoV-2 infections and induced mortality. This further suggests the detrimental impact climate change will have on the trajectory of future epidemics.

negative: Detection of foot-and-mouth disease virus infection-associated antigen antibodies: comparison of the enzyme-linked immunosorbent assay and agar gel immunodiffusion tests A liquid-phase enzyme-linked immunosorbent assay (ELISA) was compared with the standard agar gel immunodiffusion test (AGID) to identify and quantify antibodies against foot-and-mouth disease (FMD) virus infection-associated (VIA) antigen. A total of 3181 cattle sera were tested. Of these sera, 1885 were from cattle which had not been exposed to FMD. A total of 1296 sera were either from cattle which were experimentally exposed to FMD virus or from cattle involved in field outbreaks. The results indicate that the ELISA has the same specificity as the AGID test, but is more efficient in detecting cattle exposed to FMD virus. The ELISA technique will probably prove to be a more satisfactory test in support of the prevention, control and eradication programs for the disease.

negative: The development of antimicrobial agents, past, present and future

negative: Chapter 3.2 Viral Infections of Laboratory Mice Viral infections of laboratory mice have considerable impact on research results, and prevention of such infections is therefore of crucial importance. This chapter covers infections of mice with the following viruses: herpesviruses, mousepox virus, murine adenoviruses, polyomaviruses, parvoviruses, lactate dehydrogenase-elevating virus, lymphocytic choriomeningitis virus, mammalian orthoreovirus serotype 3, murine hepatitis virus, murine norovirus, murine pneumonia virus, murine rotavirus, Sendai virus, and Theiler’s murine encephalomyelitis virus. For each virus, there is a description of the agent, epizootiology, clinical symptoms, pathology, methods of diagnosis and control, and its impact on research.

negative: Human rhinovirus C: a newly discovered human rhinovirus species Although often ignored, human rhinoviruses (HRVs) are the most frequent causes of respiratory tract infections (RTIs). A group of closely related novel rhinoviruses have recently been discovered. Based on their unique phylogenetic position and distinct genomic features, they are classified as a separate species, HRV-C. After their discovery, HRV-C viruses have been detected in patients worldwide, with a reported prevalence of 1.4–30.9% among tested specimens. This suggests that the species contribute to a significant proportion of RTIs that were unrecognized in the past. HRV-C is also the predominant HRV species, often with a higher detection rate than that of the two previously known species, HRV-A and HRV-B. HRV-C infections appear to peak in fall or winter in most temperate or subtropical countries, but may predominate in the rainy season in the tropics. In children, HRV-C is often associated with upper RTIs, with asthma exacerbation and wheezing episodes being common complications. The virus has also been detected in children with bronchitis, bronchiolitis, pneumonia, otitis media, sinusitis and systemic infections complicated by pericarditis. As for adults, HRV-C has been associated with more severe disease such as pneumonia and exacerbation of chronic obstructive pulmonary disease. However, larger clinical studies with asymptomatic controls are required to better define the significance of HRV-C infection in the adult population. On the basis of VP4 sequence analysis, a potential distinct subgroup within HRV-C has also been identified, although more complete genome sequences are needed to better define the genetic diversity of HRV-C.

negative: Inflammation in the Central Nervous System

negative: CRISPR-based surveillance for COVID-19 using genomically-comprehensive machine learning design The emergence and outbreak of SARS-CoV-2, the causative agent of COVID-19, has rapidly become a global concern and has highlighted the need for fast, sensitive, and specific tools to surveil circulating viruses. Here we provide assay designs and experimental resources, for use with CRISPR-based nucleic acid detection, that could be valuable for ongoing surveillance. We provide assay designs for detection of 67 viral species and subspecies, including: SARS-CoV-2, phylogenetically-related viruses, and viruses with similar clinical presentation. The designs are outputs of algorithms that we are developing for rapidly designing nucleic acid detection assays that are comprehensive across genomic diversity and predicted to be highly sensitive and specific. Of our design set, we experimentally screened 4 SARS-CoV-2 designs with a CRISPR-Cas13 detection system and then extensively tested the highest-performing SARS-CoV-2 assay. We demonstrate the sensitivity and speed of this assay using synthetic targets with fluorescent and lateral flow detection. Moreover, our provided protocol can be extended for testing the other 66 provided designs. Assay designs are available at https://adapt.sabetilab.org/.

negative: MERS-CoV at the Animal–Human Interface: Inputs on Exposure Pathways from an Expert-Opinion Elicitation Nearly 4 years after the first report of the emergence of Middle-East respiratory syndrome Coronavirus (MERS-CoV) and nearly 1800 human cases later, the ecology of MERS-CoV, its epidemiology, and more than risk factors of MERS-CoV transmission between camels are poorly understood. Knowledge about the pathways and mechanisms of transmission from animals to humans is limited; as of yet, transmission risks have not been quantified. Moreover the divergent sanitary situations and exposures to animals among populations in the Arabian Peninsula, where human primary cases appear to dominate, vs. other regions in the Middle East and Africa, with no reported human clinical cases and where the virus has been detected only in dromedaries, represents huge scientific and health challenges. Here, we have used expert-opinion elicitation in order to obtain ideas on relative importance of MERS-CoV risk factors and estimates of transmission risks from various types of contact between humans and dromedaries. Fourteen experts with diverse and extensive experience in MERS-CoV relevant fields were enrolled and completed an online questionnaire that examined pathways based on several scenarios, e.g., camels–camels, camels–human, bats/other species to camels/humans, and the role of diverse biological substances (milk, urine, etc.) and potential fomites. Experts believed that dromedary camels play the largest role in MERS-CoV infection of other dromedaries; however, they also indicated a significant influence of the season (i.e. calving or weaning periods) on transmission risk. All experts thought that MERS-CoV-infected dromedaries and asymptomatic humans play the most important role in infection of humans, with bats and other species presenting a possible, but yet undefined, risk. Direct and indirect contact of humans with dromedary camels were identified as the most risky types of contact, when compared to consumption of various camel products, with estimated “most likely” incidence risks of at least 22 and 13% for direct and indirect contact, respectively. The results of our study are consistent with available, yet very limited, published data regarding the potential pathways of transmission of MERS-CoV at the animal–human interface. These results identify key knowledge gaps and highlight the need for more comprehensive, yet focused research to be conducted to better understand transmission between dromedaries and humans.

negative: The Essential Facts of Wuhan Novel Coronavirus Outbreak in China and Epitope-based Vaccine Designing against COVID-19 Wuhan Novel Coronavirus disease (COVID-19) outbreak has become a global outbreak which has raised the concern of scientific community to design and discover a definitive cure against this deadly virus which has caused deaths of numerous infected people upon infection and spreading. To date, no antiviral therapy or vaccine is available which can effectively combat the infection caused by this virus. This study was conducted to design possible epitope-based subunit vaccines against the SARS-CoV-2 virus using the approaches of reverse vaccinology and immunoinformatics. Upon continual computational experimentation three possible vaccine constructs were designed and one vaccine construct was selected as the best vaccine based on molecular docking study which is supposed to effectively act against SARS-CoV-2. Later, molecular dynamics simulation and in silico codon adaptation experiments were carried out in order to check biological stability and find effective mass production strategy of the selected vaccine. Hopefully, this study will contribute to uphold the present efforts of the researches to secure a definitive treatment against this lethal virus.

negative: Molecular Virology This chapter describes common viral pathogens in humans with emphasis on the molecular diagnosis. Each section includes molecular characteristics, clinical presentation, and commonly used diagnostic methods (both conventional and molecular). Commercially available molecular diagnostic kits are preferentially described. Recommendations and guidelines (if available) for result interpretation and clinical approach are also included. For detailed methods, please refer to the chapter “Methodology and Instrumentation” in this book.

negative: A computer based system for collection, storage, retrieval and reporting accession information in a veterinary medical diagnostic laboratory Abstract Substantial data collected from large numbers of accessions, the need for comprehensive reporting of negative as well as positive laboratory findings, and the necessity for obtaining rapid diagnostic correlations prompted the development of a computer based system of accession data management for collection, storage, rapid retrieval, reporting, concording, and administrative compiling in a state-university Veterinary Medical Diagnostic Laboratory.

negative: Early diagnosis of SARS Coronavirus infection by real time RT-PCR Abstract Background: A novel coronavirus was recently identified as the aetiological agent of Severe Acute Respiratory Syndrome (SARS). Molecular assays currently available for detection of SARS-coronavirus (SARS-Cov) have low sensitivity during the early stage of the illness. Objective: To develop and evaluate a sensitive diagnostic test for SARS by optimizing the viral RNA extraction methods and by applying real-time quantitative RT-PCR technology. Study design: 50 nasopharyngeal aspirate (NPA) samples collected from days 1–3 of disease onset from SARS patients in whom SARS CoV infections was subsequently serologically confirmed and 30 negative control samples were studied. Samples were tested by: (1) our first generation conventional RT-PCR assay with a routine RNA extraction method (Lancet 361 (2003) 1319), (2) our first generation conventional RT-PCR assay with a modified RNA extraction method, (3) a real-time quantitative RT-PCR assay with a modified RNA extraction method. Results: Of 50 NPA specimens collected during the first 3 days of illness, 11 (22%) were positive in our first generation RT-PCR assay. With a modification in the RNA extraction protocol, 22 (44%) samples were positive in the conventional RT-PCR assay. By combining the modified RNA extraction method and real-time quantitative PCR technology, 40 (80%) of these samples were positive in the real-time RT-PCR assay. No positive signal was observed in the negative controls. Conclusion: By optimizing RNA extraction methods and applying quantitative real time RT-PCR technologies, the sensitivity of tests for early diagnosis of SARS can be greatly enhanced.

negative: Diagnostic Methods for Feline Coronavirus: A Review Feline coronaviruses (FCoVs) are found throughout the world. Infection with FCoV can result in a diverse range of signs from clinically inapparent infections to a highly fatal disease called feline infectious peritonitis (FIP). FIP is one of the most serious viral diseases of cats. While there is neither an effective vaccine, nor a curative treatment for FIP, a diagnostic protocol for FCoV would greatly assist in the management and control of the virus. Clinical findings in FIP are non-specific and not helpful in making a differential diagnosis. Haematological and biochemical abnormalities in FIP cases are also non-specific. The currently available serological tests have low specificity and sensitivity for detection of active infection and cross-react with FCoV strains of low pathogenicity, the feline enteric coronaviruses (FECV). Reverse transcriptase polymerase chain reaction (RT-PCR) has been used to detect FCoV and is rapid and sensitive, but results must be interpreted in the context of clinical findings. At present, a definitive diagnosis of FIP can be established only by histopathological examination of biopsies. This paper describes and compares diagnostic methods for FCoVs and includes a brief account of the virus biology, epidemiology, and pathogenesis.

negative: The innate antiviral immune system of the cat: Molecular tools for the measurement of its state of activation Abstract The innate immune system plays a central role in host defence against viruses. While many studies portray mechanisms in early antiviral immune responses of humans and mice, much remains to be discovered about these mechanisms in the cat. With the objective of shedding light on early host–virus interactions in felids, we have developed 12 real-time TaqMan® qPCR systems for feline genes relevant to innate responses to viral infection, including those encoding for various IFNα and IFNω subtypes, IFNβ, intracellular antiviral factor Mx, NK cell stimulator IL-15 and effectors perforin and granzyme B, as well as Toll-like receptors (TLRs) 3 and 8. Using these newly developed assays and others previously described, we measured the relative expression of selected markers at early time points after viral infection in vitro and in vivo. Feline embryonic fibroblasts (FEA) inoculated with feline leukemia virus (FeLV) indicated peak levels of IFNα, IFNβ and Mx expression already 6h after infection. In contrast, Crandell-Rees feline kidney (CrFK) cells inoculated with feline herpes virus (FHV) responded to infection with high levels of IFNα and IFNβ only after 24h, and no induction of Mx could be detected. In feline PBMCs challenged in vitro with feline immunodeficiency virus (FIV), maximal expression levels of IFNα, β and ω subtype genes as well as IL-15 and TLRs 3, 7 and 8 were measured between 12 and 24h after infection, whereas expression levels of proinflammatory cytokine gene IL-6 were consistently downregulated until 48h post inoculation. A marginal upregulation of granzyme B was also observed within 3h after infection. In an in vivo experiment, cats challenged with FIV exhibited a 2.4-fold increase in IFNα expression in blood 1 week post infection. We furthermore demonstrate the possibility of stimulating feline immune cells in vitro with various immune response modifiers (IRMs) already known for their immunostimulatory properties in mice and humans, namely Poly IC, Resiquimod (R-848) and dSLIM™, a synthetic oligonucleotide containing several unmethylated CpG motifs. Stimulation of feline PBMCs with dSLIM™ and R-848 effectively enhanced expression of IFNα within 12h by factors of 6 and 12, respectively, and Poly IC induced an increase in Mx mRNA expression of 28-fold. Altogether, we describe new molecular tools and their successful use for the characterization of innate immune responses against viruses in the cat and provide evidence that feline cells can be stimulated by synthetic molecules to enhance their antiviral defence mechanisms.

negative: COVID-19 and pets: When pandemic meets panic Abstract As the novel coronavirus outbreak spreads globally with devastating effects on human health, pets are also becoming unnecessary victims amidst the pandemic panic. Many have been reluctantly left home alone by owners who have been forced to temporarily evacuate their homes. And, although no evidence exists to indicate that they can either transmit the virus or develop its associated coronavirus disease 2019 (COVID-19), fear among the public that pets might play a role in spreading COVID-19 has resulted in pets being abandoned or even killed. This article outlines some of the ways in which the current pandemic has negatively impacted the welfare of pets. It also highlights the relationships between animal, human, and environmental health, as well as the importance of taking a collaborative transdisciplinary One Health approach to help prevent future COVID-19 outbreaks.

negative: Advances in Diagnosis of Respiratory Diseases of Small Ruminants Irrespective of aetiology, infectious respiratory diseases of sheep and goats contribute to 5.6 percent of the total diseases of small ruminants. These infectious respiratory disorders are divided into two groups: the diseases of upper respiratory tract, namely, nasal myiasis and enzootic nasal tumors, and diseases of lower respiratory tract, namely, peste des petits ruminants (PPR), parainfluenza, Pasteurellosis, Ovine progressive pneumonia, mycoplasmosis, caprine arthritis encephalitis virus, caseous lymphadenitis, verminous pneumonia, and many others. Depending upon aetiology, many of them are acute and fatal in nature. Early, rapid, and specific diagnosis of such diseases holds great importance to reduce the losses. The advanced enzyme-linked immunosorbent assays (ELISAs) for the detection of antigen as well as antibodies directly from the samples and molecular diagnostic assays along with microsatellites comprehensively assist in diagnosis as well as treatment and epidemiological studies. The present review discusses the advancements made in the diagnosis of common infectious respiratory diseases of sheep and goats. It would update the knowledge and help in adapting and implementing appropriate, timely, and confirmatory diagnostic procedures. Moreover, it would assist in designing appropriate prevention protocols and devising suitable control strategies to overcome respiratory diseases and alleviate the economic losses.

negative: A Review: Does Complement or the Contact System Have a Role in Protection or Pathogenesis of COVID-19? INTRODUCTION: COVID-19 presentation may include a profound increase in cytokines and associated pneumonia, rapidly progressing to acute respiratory distress syndrome (ARDS). This so-called cytokine storm often leads to refractory edema, respiratory arrest, and death. At present, anti-IL-6, antiviral therapy, convalescent plasma, hydroxychloroquine, and azithromycin among others are being investigated as potential treatments for COVID-19. As the disease etiology and precise therapeutic interventions are still not definitively defined, we wanted to review the roles that complement and the contact system may have in either the treatment or pathogenesis of the disease. METHODS: We searched the recent literature (PubMed) on complement and coronavirus; contact system and coronavirus; bradykinin and coronavirus; and angiotensin receptor and coronavirus. The manuscript complies with ethics guidelines and was deemed exempt from institutional review board approval according to Human Subjects Protection Office guidelines. RESULTS: Mouse models are available for the study of coronavirus and complement. Although complement is effective in protecting against many viruses, it does not seem to be protective against coronavirus. C3 knockout mice infected with SARS-CoV had less lung disease than wild-type mice, suggesting that complement may play a role in coronavirus pathogenesis. Some evidence suggests that the observed pulmonary edema may be bradykinin-induced and could be the reason that corticosteroids, antihistamines, and other traditional interventions for edema are not effective. Angiotensin-converting enzyme 2 (ACE2) is a co-receptor for SARS-CoV-2, and studies thus far have not concluded a benefit or risk associated with the use of either ACE-inhibitors or angiotensin receptor antagonists. Activation of complement and the contact system, through generation of bradykinin, may play a role in the SARS-CoV-2-induced pulmonary edema, and our search suggests that further work is necessary to confirm our suspicions.

negative: Coronavirus-HKU1 Pneumonia and Differential Diagnosis with COVID 19

negative: Henipavirus Neutralising Antibodies in an Isolated Island Population of African Fruit Bats Isolated islands provide valuable opportunities to study the persistence of viruses in wildlife populations, including population size thresholds such as the critical community size. The straw-coloured fruit bat, Eidolon helvum, has been identified as a reservoir for henipaviruses (serological evidence) and Lagos bat virus (LBV; virus isolation and serological evidence) in continental Africa. Here, we sampled from a remote population of E. helvum annobonensis fruit bats on Annobón island in the Gulf of Guinea to investigate whether antibodies to these viruses also exist in this isolated subspecies. Henipavirus serological analyses (Luminex multiplexed binding and inhibition assays, virus neutralisation tests and western blots) and lyssavirus serological analyses (LBV: modified Fluorescent Antibody Virus Neutralisation test, LBV and Mokola virus: lentivirus pseudovirus neutralisation assay) were undertaken on 73 and 70 samples respectively. Given the isolation of fruit bats on Annobón and their lack of connectivity with other populations, it was expected that the population size on the island would be too small to allow persistence of viruses that are thought to cause acute and immunising infections. However, the presence of antibodies against henipaviruses was detected using the Luminex binding assay and confirmed using alternative assays. Neutralising antibodies to LBV were detected in one bat using both assays. We demonstrate clear evidence for exposure of multiple individuals to henipaviruses in this remote population of E. helvum annobonensis fruit bats on Annobón island. The situation is less clear for LBV. Seroprevalences to henipaviruses and LBV in Annobón are notably different to those in E. helvum in continental locations studied using the same sampling techniques and assays. Whilst cross-sectional serological studies in wildlife populations cannot provide details on viral dynamics within populations, valuable information on the presence or absence of viruses may be obtained and utilised for informing future studies.

negative: The landscape of lung bronchoalveolar immune cells in COVID-19 revealed by single-cell RNA sequencing The novel coronavirus SARS-CoV-2, etiological agent of recently named Coronavirus infected disease (COVID-19) by WHO, has caused more than 2, 000 deaths worldwide since its emergency in Wuhan City, Hubei province, China, in December, 2019. The symptoms of COVID-19 varied from modest, mild to acute respiratory distress syndrome (ARDS), and the latter of which is generally associated with deregulated immune cytokine production; however, we currently know little as to the interplay between the extent of clinical symptoms and the compositions of lung immune microenvironment. Here, we comprehensively characterized the lung immune microenvironment with the bronchoalveolar lavage fluid (BALF) from 3 severe and 3 mild COVID-19 patients and 8 previously reported healthy lung controls through single-cell RNA sequence (scRNA-seq) combined with TCR-seq. Our data shows that monocyte-derived FCN1+ macrophages, whereas notFABP4+ alveolar macrophages that represent a predominant macrophage subset in BALF from patients with mild diseases, overwhelm in the severely damaged lungs from patients with ARDS. These cells are highly inflammatory and enormous chemokine producers implicated in cytokine storm. Furthermore, the formation of tissue resident, highly expanded clonal CD8+ T cells in the lung microenvironment of mild symptom patients suggests a robust adaptive immune response connected to a better control of COVID-19. This study first reported the cellular atlas of lung bronchoalveolar immune microenvironment in COVID-19 patients at the single-cell resolution, and unveiled the potential immune mechanisms underlying disease progression and protection in COVID-19.

negative: Community-wide Outbreak of Infection with a 229E-like Coronavirus in Tecumseh, Michigan

negative: Advice on Standardized Diagnosis and Treatment for Spinal Diseases during the Coronavirus Disease 2019 Pandemic Coronavirus disease 2019 (COVID-19) outbreak started in December 2019 that caused difficulties for clinical work. Practical work experience in our spinal outpatient and emergency department during the COVID-19 pandemic is summarized in this article, with combined evidence-based medical evidence to explore a standardized process of diagnosis and treatment for spinal diseases. Outpatient reservation, continuous screening, triage, and isolation, first consultation accountability system, pandemic reporting system, and online revisit were strictly followed. We hope that our experience in prevention and control of COVID-19 can help spine surgeons globally in stopping the spread of COVID-19. Spine surgeons should collaborate with infection control specialists to avoid cross-infection in hospitals and optimize treatment.

negative: A Serological Survey of Selected Pathogens in Wild Boar in Slovenia Serum samples collected from 178 shot wild boars (Sus scrofa) were tested for the presence of antibodies against classical swine fever virus, Aujeszky's disease virus (ADV), porcine reproductive and respiratory syndrome virus, porcine respiratory coronavirus (PRCV), transmissible gastroenteritis virus, swine influenza virus, porcine parvovirus (PPV), swine vesicular disease virus, Actinobacillus pleuropneumoniae (APP), Mycoplasma hyopneumoniae, Salmonella spp., Brucella spp. and Haemophilus parasuis (HPS) throughout Slovenia during the hunting season 2003/2004. The number of samples corresponds to 3% of the total hunting bag. By enzyme‐linked immunosorbent assay (ELISA) antibodies against ADV were detected in 55 sera (31%), against PRCV in five sera (3%), PPV in 87 sera (49%), APP in 93 sera (52%), M. hyopneumoniae in 38 sera (21%), Salmonella spp. in 85 sera (47%) and HPS in 33 sera (18%).

negative: The Potential Role of Th17 Immune Responses in Coronavirus Immunopathology and Vaccine-induced Immune Enhancement Abstract Increasing evidence points to host Th17 inflammatory responses as contributing to the severe lung pathology and mortality of lower respiratory tract infections from coronaviruses. This includes host inflammatory and cytokine responses to COVID-19 caused by the SARS-2 coronavirus (SARS CoV2). From studies conducted in laboratory animals, there are additional concerns about immune enhancement and the role of potential host immunopathology resulting from experimental human COVID-19 vaccines. Here we summarize evidence suggesting there may be partial overlap between the underlying immunopathologic processes linked to both coronavirus infection and vaccination, and a role for Th17 in immune enhancement and eosinophilic pulmonary immunopathology. Such findings help explain the link between viral-vectored coronavirus vaccines and immune enhancement and its reduction through alum adjuvants. Additional research may also clarify links between COVID-19 pulmonary immunopathology and heart disease.

negative: Etiology of Community-Acquired Pneumonia in Hospitalized School-Age Children: Evidence for High Prevalence of Viral Infections Background. Community-acquired pneumonia (CAP) in young children is most commonly associated with viral infections; however, the role of viruses in CAP of school-age children is still inconclusive. Methods. Seventy-five school-age children hospitalized with CAP were prospectively evaluated for the presence of viral and bacterial pathogens. Nasopharyngeal washes were examined by polymerase chain reaction for viruses and atypical bacteria. Antibody assays to detect bacterial pathogens in acute-phase and convalescent-phase serum samples were also performed. Results. A viral infection was identified in 65% of cases. Rhinovirus RNA was detected in 45% of patients; infection with another virus occurred in 31%. The most common bacterial pathogen was Mycoplasma pneumoniae, which was diagnosed in 35% of cases. Chlamydia pneumoniae DNA was not detected in any patient; results of serological tests were positive in only 2 patients (3%). Mixed infections were documented in 35% of patients, and the majority were a viral-bacterial combination. Conclusions. The high prevalence of viral and mixed viral-bacterial infections supports the notion that the presence of a virus, acting either as a direct or an indirect pathogen, may be the rule rather than the exception in the development of CAP in school-age children requiring hospitalization.

negative: Infection and blood transfusion: a guide to donor screening Abstract In recent years, blood-component therapy has become more accessible in veterinary practice. As with human medicine, care must be taken to minimize the risk of disease transmission from donor to recipient. Determining the appropriate diseases to screen for is complicated by regional variations in disease incidence, the existence of chronic carrier states for some diseases, the difficulty in screening-test selection, and testing cost. The feline diseases considered include retroviral infections, feline coronaviruses, ehrlichiosis (Ehrlichia canis-like), anaplasmosis (Anaplasma phagocytophilum), neorickettsiosis (Neorickettsia risticii), hemoplasmosis (Mycoplasma hemofelis and M. hemominutum, previously feline hemobartonellosis), and cytauxzoonosis (Cytauxzoon felis). The canine diseases considered in this paper include babesiosis (Babesia canis and B. gibsonii,) ehrlichiosis (E. canis and E. ewingii), anaplasmosis (A. phagocytophilum), neorickettsiosis (N. risticii var. atypicalis), leishmaniasis (Leishmania donovani complex), brucellosis (Brucella canis), hemoplasmosis (M. hemocanis, previously canine hemobartonellosis), and bartonellosis (Bartonella vinsonii).

negative: A sensitive retroviral pseudotype assay for influenza H5N1‐neutralizing antibodies Background The World Health Organisation (WHO) recommended the development of simple, safe, sensitive and specific neutralization assays for avian influenza antibodies. We have used retroviral pseudotypes bearing influenza H5 hemagglutinin (HA) as safe, surrogate viruses for influenza neutralization assays which can be carried out at Biosafety Level 2. Results Using our assay, sera from patients who had recovered from infection with influenza H5N1, and sera from animals experimentally immunized or infected with H5 tested positive for the presence of neutralizing antibodies to H5N1. Pseudotype neutralizing antibody titers were compared with titers obtained by hemagglutinin inhibition (HI) assays and microneutralization (MN) assays using live virus, and showed a high degree of correlation, sensitivity and specificity. Conclusions The pseudotype neutralization assay is as sensitive as horse erythrocyte HI and MN for the detection of antibodies to H5N1. It is safer, and can be applied in a high‐throughput format for human and animal surveillance and for the evaluation of vaccines.

negative: Persistence of Antibodies against Middle East Respiratory Syndrome Coronavirus To determine how long antibodies against Middle East respiratory syndrome coronavirus persist, we measured long-term antibody responses among persons serologically positive or indeterminate after a 2012 outbreak in Jordan. Antibodies, including neutralizing antibodies, were detectable in 6 (86%) of 7 persons for at least 34 months after the outbreak.

negative: Discovering drugs to treat coronavirus disease 2019 (COVID-19). The SARS-CoV-2 virus emerged in December 2019 and then spread rapidly worldwide, particularly to China, Japan, and South Korea. Scientists are endeavoring to find antivirals specific to the virus. Several drugs such as chloroquine, arbidol, remdesivir, and favipiravir are currently undergoing clinical studies to test their efficacy and safety in the treatment of coronavirus disease 2019 (COVID-19) in China; some promising results have been achieved thus far. This article summarizes agents with potential efficacy against SARS-CoV-2.

negative: Chinese and Italian COVID-19 outbreaks can be correctly described by a modified SIRD model The COVID-19 disease is rapidly spreading in whole globe, affecting millions of people and pushing governments to take drastic measures to contain the outbreaks. The understanding of the dynamics of the epidemic is of great interest for the governments and health authorities that are facing COVID-19 outbreaks. The scarce presence of epidemiologic data, due to the still ongoing outbreaks, makes prediction difficult and mainly based on heuristic (fitting) models. However, these models with non-physical based parameters, can only give limited insight in the evolution of the outbreaks. In this work a SIRD compartmental model was developed to describe and predict the evolution of the Chinese and Italian outbreaks. Exploiting the similarities of the measures taken by the governments to contain the virus and of the total population number of Hubei province and Italy, the model was tuned on the Chinese outbreak (almost extinguished) and by perturbation the Italian outbreak was describe and predicted.

negative: Detection of a group 2 coronavirus in dogs with canine infectious respiratory disease Abstract An investigation into the causes of canine infectious respiratory disease was carried out in a large rehoming kennel. Tissue samples taken from the respiratory tract of diseased dogs were tested for the presence of coronaviruses using RT–PCR with conserved primers for the polymerase gene. Sequence analysis of four positive samples showed the presence of a coronavirus with high similarity to both bovine and human coronavirus (strain OC43) in their polymerase and spike genes, whereas there was a low similarity to comparable genes in the enteric canine coronavirus. This canine respiratory coronavirus (CRCV) was detected by RT–PCR in 32/119 tracheal and 20/119 lung samples, with the highest prevalence being detected in dogs with mild clinical symptoms. Serological analysis showed that the presence of antibodies against CRCV on the day of entry into the kennel decreased the risk of developing respiratory disease.

negative: Any possible role of phosphodiesterase type 5 inhibitors in the treatment of severe COVID19 infections? A lesson from urology

negative: Novel coronavirus disease (COVID-19): a pandemic (epidemiology, pathogenesis and potential therapeutics) The coronavirus disease (COVID-19) is highly pathogenic viral infection caused by SARS-CoV-2. Currently, COVID-19 has caused global health concern. It is assumed that COVID-19 has zoonotic origin based on the large number of infected people who were exposed to the wet market in Wuhan City, China. The phylogenetic analysis has revealed that SARS-CoV-2 has significant sequence similarity with severe acute respiratory syndrome-like (SARS-like) bat viruses, thus bats could be primary possible reservoir. The intermediate host and there subsequent transfer is not known yet, although human to human transfer is widely confirmed. The transmission of COVID-19 infection from one person to another resulted in the isolation of patients who were subsequently given a variety of treatments. To monitor the current outbreak, robust steps have been taken around the globe to reduce the transmission of COVID-19 infection particularly banning international and domestic flights, inducting lockdowns in vulnerable areas, social distancing etc. No clinically approved antiviral drug or vaccine against COVID-19 is reported yet. However, in clinical trials, few broad-spectrum antiviral drugs were evaluated against COVID-19 infection which resulted in clinical recovery. In this article emergence and pathogenicity of COVID-19 infection along with potential therapeutic strategies are analyzed to combat the COVID-19 pandemic.

negative: The Role of Viral Population Diversity in Adaptation of Bovine Coronavirus to New Host Environments The high mutation rate of RNA viruses enables a diverse genetic population of viral genotypes to exist within a single infected host. In-host genetic diversity could better position the virus population to respond and adapt to a diverse array of selective pressures such as host-switching events. Multiple new coronaviruses, including SARS, have been identified in human samples just within the last ten years, demonstrating the potential of coronaviruses as emergent human pathogens. Deep sequencing was used to characterize genomic changes in coronavirus quasispecies during simulated host-switching. Three bovine nasal samples infected with bovine coronavirus were used to infect human and bovine macrophage and lung cell lines. The virus reproduced relatively well in macrophages, but the lung cell lines were not infected efficiently enough to allow passage of non lab-adapted samples. Approximately 12 kb of the genome was amplified before and after passage and sequenced at average coverages of nearly 950×(454 sequencing) and 38,000×(Illumina). The consensus sequence of many of the passaged samples had a 12 nucleotide insert in the consensus sequence of the spike gene, and multiple point mutations were associated with the presence of the insert. Deep sequencing revealed that the insert was present but very rare in the unpassaged samples and could quickly shift to dominate the population when placed in a different environment. The insert coded for three arginine residues, occurred in a region associated with fusion entry into host cells, and may allow infection of new cell types via heparin sulfate binding. Analysis of the deep sequencing data indicated that two distinct genotypes circulated at different frequency levels in each sample, and support the hypothesis that the mutations present in passaged strains were “selected” from a pre-existing pool rather than through de novo mutation and subsequent population fixation.

negative: Seroprevalence of porcine respiratory coronavirus infection in Spanish breeding sows Abstract The seroprevalence of porcine respiratory coronavirus (PRCV) among breeding sows was estimated in Castilla y León, the largest region in Spain, by a cross-sectional study. Serum samples (1247) were taken from sows from 58 different herds for this purpose throughout 1988 and were tested by a monoclonal antibody-capture ELISA (MACELISA), a test which detects antibodies to both transmissible gastroenteritis virus (TGEV) and PRCV. In order to discriminate positive sera to both coronaviruses, a blocking inhibition ELISA was used for all MACELISA-positive sera. By MACELISA, 31.4% of sera tested were positive and all of them were confirmed specifically as PRCV-positive by blocking inhibition ELISA, thus ruling out the presence of TGEV in the sampled area: 64% of the farms had at least one PRCV-seropositive sow, indicating that the infection was widespread Farms were classified into three categories, according to size and management practices. No significant differences were found in the prevalence rates among the three farm types; there was, however, a highly significant correlation between increasing farm size and increasing within-farm seropositivity.

negative: The impact of early social distancing at COVID-19 Outbreak in the largest Metropolitan Area of Brazil. We evaluated the impact of early social distancing on the COVID-19 transmission in the Sao Paulo metropolitan area. Using an age-stratified SEIR model, we determined the time-dependent reproductive number, and forecasted the ICU beds necessary to tackle this epidemic. Within 60 days, these measures might prevent 89,133 deaths.

negative: RT-PCR and Electrospray Ionization Mass Spectrometry (RT-PCR/ESI-MS) for Identifying Acute Viral Upper Respiratory Tract Infections Diagnosis of respiratory viruses traditionally relies on culture or antigen detection.We aimed to demonstrate capacity of the RT-PCR/ESI-MS platform to identify clinical relevant respiratory viruses in nasopharyngeal aspirate (NPA) samples and compare the diagnostic performance characteristics relative to conventional culture- and antigen-based methods. A RT-PCR/ESI-MS respiratory virus surveillance kit designed to detect respiratory syncytial virus, influenza A and B, parainfluenza types 1-4, adenoviridae types A-F, coronaviridae, human bocavirus, and human metapneumovirus was evaluated using both mock-ups and frozen archived NPA (N=280), 95 of which were positive by clinical virology methods. RT-PCR/ESI-MS detected 74/95 (77.9%) known positive samples and identified an additional 13/185 (7%) from culture negative samples. Viruses that are non-detectable with conventional methods were also identified. Viral load was semi-quantifiable and ranged from 2,400 to >320,000copies/ml. Time to results was 8hrs. RT-PCR/ESI-MS showed promise in rapid detection of respiratory viruses, merits further evaluation for use in clinical settings.

negative: Hypoxia-controlled matrix metalloproteinase-9 hyperexpression promotes behavioral recovery after ischemia. Matrix metalloproteinase-9 (MMP-9) plays a beneficial role in the sub-acute phase after ischemic stroke. However, unrestrained MMP-9 may disrupt the blood-brain barrier (BBB), which has limited its use for the treatment of brain ischemia. In the present study, we constructed lentivirus mediated hypoxia-controlled MMP-9 expression and explored its role after stroke. Hypoxia response element (HRE) was used to confine MMP-9 expression only to the hypoxic region of mouse brain after 120-min transient middle cerebral artery occlusion. Lentiviruses were injected into the peri-infarct area on day 7 after transient ischemia. We found hyperexpression of exogenous HRE-MMP-9 under the control of hypoxia, and its expression was mainly located in neurons and astrocytes without aggravation of BBB damage compared to the CMV group. Furthermore, mice in the HRE-MMP-9 group showed the best behavioral recovery compared with the normal saline, GFP, and SB-3CT groups. Therefore, hypoxia-controlled MMP-9 hyperexpression during the sub-acute phase of ischemia may provide a novel promising approach of gene therapy for stroke.

negative: Development of an enzyme-linked immunosorbent assay for the monitoring and surveillance of antibodies to porcine epidemic diarrhea virus based on a recombinant membrane protein Abstract The recent dramatic increase in reported cases of porcine epidemic diarrhea (PED) in pig farms is a potential threat to the global swine industry. Therefore, the accurate diagnosis, serological monitoring, and surveillance of specific antibodies in pigs resulting from porcine epidemic diarrhea virus (PEDV) infection or vaccination would be essential in helping to control the spread of PED. We developed and validated an indirect enzyme-linked immunosorbent assay (ELISA) based on the recombinant membrane (M) protein of PEDV. To detect PEDV antibodies in eight herds, 382 serum samples were collected from sows that had been immunized with a PED vaccine, and screened using the developed ELISA in parallel with a serum neutralization (SN) assay. Of the tested samples, 276 were positive for the presence of PEDV antibodies according to both assays, while 98 were negative. An excellent agreement between the ELISA and the SN assay was observed (kappa=0.947; 95% confidence interval=0.910–0.984; McNemar's test, P =0.727). No cross-reaction was detected for the developed ELISA with other coronaviruses or other common pig pathogens. The developed ELISA could be used for serological evaluation and indirect diagnosis of PED infection.

negative: Screening of Donor and Recipient Prior to Solid Organ Transplantation

negative: Distribution and genetic diversity of adeno-associated viruses in bats from coastal areas of Southeast China Bats are associated with several important zoonotic viruses from different families. One example includes adeno-associated viruses (AAVs), that are extensively detected in several animals, especially primates. To understand AAVs distribution and genetic diversity in the coastal areas of Southeast China, a total of 415 intestine samples were mostly collected from two provinces of southeast China, i.e., Zhejiang and Fujian province. Intestine samples from five bat species were collected for AAVs detection. The average prevalence rate for AAV detection among these samples was 18.6% (77 positives out of 415 samples) and ranged from 11.8 to 28.9% between the five bat species. This suggests that AAVs are widely distributed in diverse bat populations in southeast coastal areas of China. Based on the genome sequence of bat adeno-associated virus-CXC1(BtAAV-CXC1) from one AAV-positive sample, the genetic diversity of the detected AAVs were assessed and analyzed. Phylogenetic analysis revealed that BtAAV-CXC1 was comparatively distant to other major AAVs from mammals and non-mammals, with only a 52.9~64.7% nucleotide identity. However, they were phylogenetically closer to Rhinolophus sinicus bat adeno-associated virus (Rs-BtAAV1), with a 74.5% nt similarity. Partial analysis of the rep and cap overlapping open reading frame (ORF) sequences from bat AAV samples revealed 48 partial rep sequences and 23 partial cap sequences from positive samples shared 86.9 to 100% and 72.3 to 98.8% nucleotide identities among themselves, respectively. This suggests that the detected AAVs had a distinctly high genetic diversity. These findings led us to conclude that diverse AAVs may be widely distributed in bat populations from the southeast regions of China.

negative: Middle east respiratory syndrome corona virus (MERS CoV): The next steps Developing countries are at risk of importing Middle East Respiratory Syndrome Corona Virus (MERS CoV) from the Middle East. Hospitals in the Middle East currently reporting the disease are staffed by immigrants. In the current hot spots for MERS CoV a sizeable portion of the population is from other countries, but many of these countries have yet to detect any importation of MERS CoV. To assess the disease transmission in these countries, supplemental surveillance strategies are urgently needed beyond the currently recommended measures. A few strategies to address the situation are: (i) improving preparedness with enhanced surveillance in particular regions; (ii) targeting certain sentinel groups for surveillance in hot spots; and (iii) limited use of serosurveillance. Recovered, immune patients can be employed to give patient care during outbreaks.

negative: Evaluation of P1 adhesin epitopes for the serodiagnosis of Mycoplasma pneumoniae infections Most glycolipid antigens used for serological tests of Mycoplasma pneumoniae are not M. pneumonia-specific, and can cross-react with other microorganism antigens and body tissues, resulting in false positives. It is important to identify M. pneumonia-specific antigen(s) for serological testing and correct diagnosis. Two epitopes, rP1-534 and rP1-513, of P1 adhesin predicted by bioinformatics were successfully expressed and purified, and could be recognized by serum samples from M. pneumoniae-infected patients and His tag antibodies by Western blot. There was no cross-reactivity between the anti-recombinant proteins serum and other respiratory antigens. A total of 400 patients were investigated, their respiratory specimens tested by PCR, and sera tested by a commercial test kit; 56 with positive sera and positive respiratory specimens were designated as standard positive serum and 63 patients were designated as standard negative serum. The purified recombinant proteins were used as a combination of antigens or separately to test the serum. Serological test demonstrated that rP1-513 of the C terminal of P1 adhesin is a new candidate antigen with greater sensitivity and specificity for IgG and IgM serodiagnosis of M. pneumoniae-infected patients. The results confirmed that rP1-513 could be a useful new antigen for the immunodiagnosis of M. pneumoniae infection.

negative: Epidemiological Identification of A Novel Pathogen in Real Time: Analysis of the Atypical Pneumonia Outbreak in Wuhan, China, 2019–2020 Virological tests have now shown conclusively that a novel coronavirus is causing the 2019–2020 atypical pneumonia outbreak in Wuhan, China. We demonstrate that non-virological descriptive characteristics could have determined that the outbreak is caused by a novel pathogen in advance of virological testing. Characteristics of the ongoing outbreak were collected in real time from two medical social media sites. These were compared against characteristics of eleven pathogens that have previously caused cases of atypical pneumonia. The probability that the current outbreak is due to “Disease X” (i.e., previously unknown etiology) as opposed to one of the known pathogens was inferred, and this estimate was updated as the outbreak continued. The probability (expressed as a percentage) that Disease X is driving the outbreak was assessed as over 29% on 31 December 2019, one week before virus identification. After some specific pathogens were ruled out by laboratory tests on 5 January 2020, the inferred probability of Disease X was over 49%. We showed quantitatively that the emerging outbreak of atypical pneumonia cases is consistent with causation by a novel pathogen. The proposed approach, which uses only routinely observed non-virological data, can aid ongoing risk assessments in advance of virological test results becoming available.

negative: Cutaneous, Subcutaneous and Systemic Mycology The first description of dermatophytosis was recorded by Celsus, a Roman encyclopaedist who described a suppurative infection of scalp (‘porrigo’ or ‘kerion of Celsus’) in De Re Medicina (30 A.D.). Throughout the middle ages, several descriptions of dermatophytosis were produced where it is described as ‘tinea’. The keratin-destroying moths which made circular holes in the woollen garments are known as Tinea. Due to similarity in the structure of circular lesion of dermatophytosis on the smooth skin with the circular hole made by moth, Cassius Felix introduced the term ‘tinea’ to describe the lesions. In 1806, Alibert used the term ‘favus’ to describe the honey-like exudate in some scalp infections. However, the fungal aetiology of tinea was first detected by Robert Remak, a Polish physician who first observed the presence of hyphae in the crusts of favus. This detection is also a landmark in medical history because this is the first description of a microbe causing a human disease. He himself did not publish his work, but he permitted the reference of his observations in a dissertation by Xavier Hube in 1837. Remak gave all the credits of his discovery to his mentor Schoenlein who first published the fungal etiological report of favus in 1839. He observed the infectious nature of the favus by autoinoculation into his own hands and also successfully isolated the fungus later (1945) and named Achorion schoenleinii (Trichophyton schoenleinii) in honour of his mentor. In 1844, Gruby described the etiologic agent of tinea endothrix, later became known as Trichophyton tonsurans. The genus Trichophyton was created and described by Malmsten (1845) with its representative species T. tonsurans. Charles Robin identified T. mentagrophytes in 1847 and T. equinum was identified by Matruchot and Dassonville in 1898. Raymond Jacques Adrien Sabouraud (France) first compiled the description of Trichophyton in his book (Les Teignes) in 1910 which was based on his observation in artificial culture. The sexual state of dermatophyte was described by Nannizzi (1927). Emmons (1934) first reported the classification of dermatophytes based on vegetative structures and conidia. Gentles (1958) established the successful treatment of tinea capitis with griseofulvin.

negative: Could pulmonary arterial hypertension patients be at a lower risk from severe COVID-19?

negative: Molecular study of porcine transmissible gastroenteritis virus after serial animal passages revealed point mutations in S protein Porcine respiratory coronavirus is related genetically to porcine transmissible gastroenteritis virus with a large deletion in S protein. The respiratory virus is a mutated form that may be a consequence of the gastroenteritis virus’s evolution. Intensive passages of the virus in its natural host may enhance the appearance of mutations and therefore may contribute to any attenuated form of the virus. The objective of this study was to characterize the porcine transmissible gastroenteritis virus TMK22 strain after passages in piglets from 1992 until 2007. A typical experimental infection, molecular characterization, and serological analysis were also carried out to further characterize and to evaluate any significant difference between strains. The sequence analysis showed two amino acid deletions and loss of an N-glycosylation site in transmissible gastroenteritis virus S protein after passages in piglets. Although these deletions were positioned at the beginning of the antigenic site B of S protein, no clinical differences were observed in piglets infected experimentally either with the native virus or the mutated one. Serological tests did not show any antibody reactivity difference between the two strains. In this article, we report that the S protein deletion did not affect the virus’s pathogenicity. The variety of the virus’s evolutionary forms may be a result, not only of the multiple passages in natural hosts, but also of other factors, such as different pathogens co-infection, nutrition, immunity, and others. Further studies need to be carried out to characterize the mutated strain.

negative: Perspectives on therapeutic neutralizing antibodies against the Novel Coronavirus SARS-CoV-2 A newly identified novel coronavirus (SARS-CoV-2) is causing pneumonia-associated respiratory syndrome across the world. Epidemiology, genomics, and pathogenesis of the SARS-CoV-2 show high homology with that of SARS-CoV. Current efforts are focusing on development of specific antiviral drugs. Therapeutic neutralizing antibodies (NAbs) against SARS-CoV-2 will be greatly important therapeutic agents for the treatment of coronavirus disease 2019 (COVID-19). Herein, the host immune responses against SARS-CoV discussed in this review provide implications for developing NAbs and understanding clinical interventions against SARS-CoV-2. Further, we describe the benefits, challenges and considerations of NAbs against SARS-CoV-2. Although many challenges exist, NAbs still offer a therapeutic option to control the current pandemic and the possible re-emergence of the virus in the future, and their development therefore remains a high priority.

negative: Nucleotide sequence of the gene encoding the membrane protein of human coronavirus 229 E The sequence of the gene encoding the membrane protein of human coronavirus 229 E (HCV 229 E) has been determined. The primary translation product, deduced from the DNA sequence, is a polypeptide of 225 amino acids with a predicted molecular weight of 26,000. The polypeptide has 3 potential N-glycosylation sites. Many structural similarities with the membrane proteins of other coronaviruses can be recognized.

negative: Human (non‐severe acute respiratory syndrome) coronavirus infections in hospitalised children in France Aim: This study has two objectives: to study the clinical symptoms associated with the detection of the four human coronaviruses (HCoVs), 229E, OC43, NL63 and HKU1 types, in the respiratory specimens sampled from hospitalised children in France between September 2004 and May 2005; and to develop a multiplex reverse transcription polymerase chain reaction (RT‐PCR) assay allowing for the simultaneous detection of the four HCoVs. Methods: 1002 respiratory specimens were tested for HCoVs. The clinical and epidemiological data were compared on the basis of the type HCoV infection. Results: A hundred coronaviruses, 33 NL63, 2229E, 27 OC43 and 38 HKU1, were detected in 97 (9.8%) of 1002 samples negative in routine tests. The clinical and epidemiological characteristics of the study children were compared in three groups, 24 OC43‐, 27 NL63‐ and 34 HKU1‐infected children. HCoVs were identified mainly in children with upper and lower respiratory tract infections (50.5% vs. 29.4%). The significant difference in clinical presentation between the three coronavirus groups was the very low association between lower respiratory tract illness and HKU1 detection. Conclusions: HCoV detection in hospitalised children without any other respiratory virus detection was associated with upper and a significant rate of lower respiratory tract illness. The four types of HCoVs were detected, and new types NL63 and HKU1 represented a substantial portion of detection. The multiplex RT‐PCR enabled a sensitive one‐time detection and the characterisation of all of the known HCoV types with the exception severe acute respiratory syndrome‐coronavirus.

negative: Application of Support Vector Machines in Viral Biology Novel experimental and sequencing techniques have led to an exponential explosion and spiraling of data in viral genomics. To analyse such data, rapidly gain information, and transform this information to knowledge, interdisciplinary approaches involving several different types of expertise are necessary. Machine learning has been in the forefront of providing models with increasing accuracy due to development of newer paradigms with strong fundamental bases. Support Vector Machines (SVM) is one such robust tool, based rigorously on statistical learning theory. SVM provides very high quality and robust solutions to classification and regression problems. Several studies in virology employ high performance tools including SVM for identification of potentially important gene and protein functions. This is mainly due to the highly beneficial aspects of SVM. In this chapter we briefly provide lucid and easy to understand details of SVM algorithms along with applications in virology.

negative: Viral zoonoses in Europe Abstract A number of new virus infections have emerged or re-emerged during the past 15 years. Some viruses are spreading to new areas along with climate and environmental changes. The majority of these infections are transmitted from animals to humans, and thus called zoonoses. Zoonotic viruses are, as compared to human-only viruses, much more difficult to eradicate. Infections by several of these viruses may lead to high mortality and also attract attention because they are potential bioweapons. This review will focus on zoonotic virus infections occurring in Europe.

negative: Surveillance using serological and molecular methods for the detection of infectious agents in captive Brazilian neotropic and exotic felids. The aim of the current study was to investigate the exposure of captive wild felids to various infectious pathogens using serological and molecular methods. One hundred and fifty-nine neotropic felids and 51 exotic felids from 28 captive settings in Brazil were tested. While antibodies against Feline parvovirus and Feline coronavirus (FCoV), Feline calicivirus and Bartonella spp. were frequently detected by serologic tests, antibodies against Felid herpesvirus 1 or infection with hemotropic mycoplasmas were less prevalent. Serologic evidence of exposure to Ehrlichia spp., Feline immunodeficiency virus, and Feline leukemia virus (FeLV) was detected rarely, and infections with FeLV, Ehrlichia spp., and Cytauxzoon spp. were found infrequently. The detected Bartonella sequence was molecularly similar to B. koehlerae and B. henselae; for Cytauxzoon, the sequence resembled those from domestic cats. No Anaplasma phagocytophilum and Theileria spp. infections were detected. The positive test results varied significantly among different facilities and species. Additionally, FCoV seropositivity was more prevalent in captivity than in free-ranging populations. Results suggest that testing is appropriate prior to relocation of felids.

negative: Genetic evolution analysis of 2019 novel coronavirus and coronavirus from other species The Corona Virus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a Public Health Emergency of International Concern. However, so far, there are still controversies about the source of the virus and its intermediate host. Here, we found the novel coronavirus was closely related to coronaviruses derived from five wild animals, including Paguma larvata, Paradoxurus hermaphroditus, Civet, Aselliscus stoliczkanus and Rhinolophus sinicus, and was in the same branch of the phylogenetic tree. However, genome and ORF1a homology show that the virus is not the same coronavirus as the coronavirus derived from these five animals, whereas the virus has the highest homology with Bat coronavirus isolate RaTG13.

negative: Potent neutralization of 2019 novel coronavirus by recombinant ACE2-Ig 2019-nCoV, which is a novel coronavirus emerged in Wuhan, China, at the end of 2019, has caused at least infected 11,844 as of Feb 1, 2020. However, there is no specific antiviral treatment or vaccine currently. Very recently report had suggested that novel CoV would use the same cell entry receptor, ACE2, as the SARS-CoV. In this report, we generated a novel recombinant protein by connecting the extracellular domain of human ACE2 to the Fc region of the human immunoglobulin IgG1. An ACE2 mutant with low catalytic activity was also used in the study. The fusion proteins were then characterized. Both fusion proteins has high affinity binding to the receptor-binding domain (RBD) of SARS-CoV and 2019-nCoV and exerted desired pharmacological properties. Moreover, fusion proteins potently neutralized SARS-CoV and 2019-nCoV in vitro. As these fusion proteins exhibit cross-reactivity against coronaviruses, they could have potential applications for diagnosis, prophylaxis, and treatment of 2019-nCoV.

negative: Serodiagnosis of Human Bocavirus Infection Background. A new human-pathogenic parvovirus, human bocavirus (HBoV), has recently been discovered and associated with respiratory disease in small children. However, many patients have presented with low viral DNA loads, suggesting HBoV persistence and rendering polymerase chain reaction-based diagnosis problematic. Moreover, nothing is known of HBoV immunity. We examined HBoV-specific systemic B cell responses and assessed their diagnostic use in young children with respiratory disease. Patients and methods. Paired serum samples from 117 children with acute wheezing, previously studied for 16 respiratory viruses, were tested by immunoblot assays using 2 recombinant HBoV capsid antigens: the unique part of virus protein 1 and virus protein 2. Results. Virus protein 2 was superior to the unique part of virus protein 1 with respect to immunoreactivity. According to the virus protein 2 assay, 24 (49%) of 49 children who were positive for HBoV according to polymerase chain reaction had immunoglobulin (Ig) M antibodies, 36 (73%) had IgG antibodies, and 29 (59%) exhibited IgM antibodies and/or an increase in IgG antibody level. Of 22 patients with an increase in antibody levels, 20 (91%) had a high load of HBoV DNA in the nasopharynx, supporting the hypothesis that a high HBoV DNA load indicates acute primary infection, whereas a low load seems to be of less clinical significance. In a subgroup of patients who were previously determined to have acute HBoV infection (defined as a high virus load in the nasopharynx, viremia, and absence of other viral infections), 9 (100%) of 9 patients had serological evidence of primary infection. In the control group of 68 children with wheezing who had polymerase chain reaction results negative for HBoV in the nasopharynx, 9 (13%) had IgM antibodies, including 5 who displayed an increase in IgG antibody levels and were viremic. No cross-reactivity with human parvovirus B19 was detected. Conclusions. Respiratory infections due to HBoV are systemic, elicit B cell immune responses, and can be diagnosed serologically. Serological diagnoses correlate with high virus loads in the nasopharynx and with viremia. Serological testing is an accurate tool for disclosing the association of HBoV infection with disease.

negative: Molecular Diagnosis of Viral Respiratory Infections In clinical practice, a rapid and accurate identification of pathogens causing viral respiratory tract infections can be problematic because of nonspecific clinical presentations, lack of rapid and sensitive tests, and the emergence of new and mutating viral pathogens. Nucleic acid-targeted molecular techniques are increasingly being used to provide high sensitivity and specificity, short test turnaround time, and automatic and high-throughput processing. In-house and commercially available molecular methods have been developed to qualitatively and quantitatively detect and identify a single or a panel of clinically encountered respiratory tract viruses in a single reaction. Molecular techniques are being gradually introduced in routine laboratory diagnosis of viral respiratory tract infections. However, their performance characteristics and limitations must be clearly understood by both laboratory personnel and clinicians to ensure proper utilization and interpretation.

negative: Virus PCR Assay Panels: An Alternative to the Mouse Antibody Production Test Antibody production tests have traditionally been used to test biological materials for viral contamination. Now molecular biology techniques have emerged as an alternative. The authors compare MAP testing with PCR-based detection methods, focusing on differences in animal use, laboratory requirements, sample size, and limits of detection.

negative: Socioeconomic, geographic and climatic risk factors for canine parvovirus infection and euthanasia in Australia Abstract Infection of canids with canine parvovirus (CPV) can result in severe, often fatal disease. This study aimed to examine climatic, socioeconomic and geographic risk factors for CPV infection and CPV-associated euthanasia in Australia. Australian veterinary hospital responses (534; 23.5 %) to a national veterinary survey of CPV case occurrences and euthanasias in 2016 were used. Severe caseloads (>40 cases per annum) were reported by 26 (11 %) hospitals (median 60 cases; IQR 50–110). Case reporting, case numbers, and without-treatment euthanasia were significantly associated with disadvantage across all Socio-Economic Index for Areas quintiles (p < 0.0001) – the greater the disadvantage, the more reports. Strong negative correlations were found between case numbers and the Index of Relative Socioeconomic Disadvantage (rSP = –0.3357, p < 0.0001) and also between euthanasia and the Index of Education and Occupation (rSP = –0.3762, p < 0.0001). Hospitals in more remote areas were also more likely to report cases and to euthanize without treatment (p < 0.0001). Of the climate variables, temperature of the hottest month was most strongly positively correlated with case numbers (rSP = 0.421, p < 0.0001), and lower annual rainfall was associated with more case-reporting hospitals (p < 0.0001). These results confirm that socioeconomic disadvantage is a significant risk-factor for CPV infection and outcome, and high temperature may also contribute to risk.

negative: Demonstration of CD13/Aminopeptidase N on Synovial Fluid T Cells from Patients with Different Forms of Joint Effusions Cytofluorometric analysis was performed to characterize the immunophenotype of lymphocytes of the synovial fluid (SF) and the peripheral blood (PB) from patients suffering from juvenile chronic arthritis (JCA) or rheumatoid arthritis (RA). The most obvious difference could be found in expression of the surface protease aminopeptidase N (AP N/CD13). Whereas monoclonal antibodies specific to CD13 failed to reveal surface expression on lymphocytes of the PB; 63 ± 15% of SF T cells gave positive staining for CD 13 using Leu-M7. No correlation between CD13 expression and joint disease could be found in patients who had different types of inflammatory joint effusions. CD13 expression of T cells was also found in synovial tissue and inflammatory serous cavity effusions. Fixation of T cells revealed the presence of intracellular CD13 antigen already located in the PB T cells of healthy individuals. Induction of CD13 expression on PB T cells could be demonstrated after incubation with Con A/IL-2 or SF from patients with RA. Our findings suggest a role for AP N as a new activation-associated molecule of T lymphocytes.

negative: Rhinovirus and Coronavirus Infection-Associated Hospitalizations among Older Adults Rhinoviruses and coronaviruses are recognized as the major causes of the common cold syndrome. The role of these viruses in more serious respiratory illnesses resulting in hospitalization is less well defined. During a winter when influenza A infection was prevalent, 100 elderly adults hospitalized because of cardiopulmonary illnesses were evaluated for rhinovirus and coronavirus infection. Patients who tested negative for influenza or respiratory syncytial virus had nasal swab samples tested for rhinovirus, coronavirus OC43, and coronavirus 229E by reverse-transcription polymerase chain reaction and for coronaviruses by serologic testing. Twelve percent of patients had rhinovirus or coronavirus identified (rhinovirus, 4 patients; coronavirus 229E, 4 patients; coronavirus OC43, 3 patients; and mixed rhinovirus/coronavirus 229E infection, 1 patient). All patients had significant underlying diseases. Although all patients recovered, the mean length of stay was 8 days; 4 persons had pneumonia, and 1 required ventilator support. These data suggest that rhinoviruses and coronaviruses may be associated with serious respiratory illnesses in frail older adults.

negative: Current status and progress of 2019 novel coronavirus pneumonia/ 中华危重病急救医学 Recently, the 2019 novel coronavirus (2019-nCoV) pneumonia outbroke in Wuhan and rapidly spread to all over China and even the world. Because of the strong infectivity and various clinical symptoms, it has brought certain difficulties to the epidemic prevention and control. Currently there is no specific drug for 2019-nCoV. Previous drugs used to treat other coronaviruses may be effective, but further clinical trials remain needed. We reviewed literature on the epidemiology, etiology, clinical manifestations, imaging manifestations, laboratory examination, diagnosis, complications, treatment and outcome of 2019-nCoV pneumonia.

negative: 2019 novel coronavirus disease in hemodialysis (HD) patients: Report from one HD center in Wuhan, China The outbreak of COVID-19 originated in Wuhan has become a global epidemic of contagious diseases, which poses a serious threat to human life and health, especially for those with underlined diseases. However, Impacts of COVID-19 epidemic on HD center and HD patients are still unknown. In this report, we reviewed the whole course of the epidemic emerged in the HD center of Renmin Hospital, Wuhan University from January 14, 2020, the day the first case was confirmed, to February 17, 2020, the day the epidemic extinction. There are totally 37 cases among 230 HD patients and 4 cases among 33 staff being diagnosed with COVID-19. The epidemiology, clinical presentation and immune profile of dialysis patients contracted COVID-19 were further studied. We found that the two key measures we took in response to the epidemic, one was upgrading level of prevention and protection on January 21 and the other one starting universal screening, isolating, and distributing the infected cases on February 4, were effective in the epidemic control. No new COVID-19 case had been diagnosed since February 13. During the epidemic, 7 HD patients died, including 6 with COVID-19 and 1 without COVID-19. The presumed causes of death were not directly related to pneumonia, but due to cardiovascular and cerebrovascular diseases, hyperkalemia, etc. Most of the leukocytes in the peripheral blood of the HD patients infected with COVID-19 decreased, and the CT images of the chest mostly showed the ground glass like changes on the right side. The symptoms of most of the patients were mild, and there were no cases admitted to ICU. The frequency of lymphocytes in PBMCs and the serum level of inflammatory cytokines were assessed in HD patients contracted COVID-19 or not, non-HD COVID-19 patients, as well as healthy volunteers. The results showed that lymphocytes of T cell, Th cells, killer T cells, as well as NK cells in PBMCs of HD patients decreased significantly than other groups. HD patients with COVID-19 also displayed remarkable lower serum level of inflammatory cytokines than other COVID-19 patients. Our study indicates that HD patients are the highly susceptible population and HD centers are high risk area in the outbreak of COVID-19 epidemic. Measures of prevention, protection, screening, isolation, and distribution are essential in the epidemic management and should be taken in the early stage. HD Patients with COVID-19 are mostly clinical mild and unlikely progress to severe pneumonia due to the impaired cellular immune function and incapability of mounting cytokines storm. More attention should be paid to prevent cardiovascular events, which may be the collateral impacts of COVID-19 epidemic on HD patients.

negative: Remdesivir for severe acute respiratory syndrome coronavirus 2 causing COVID-19: An evaluation of the evidence Abstract The novel coronavirus infection that initially found at the end of 2019 has attracted great attention. So far, the number of infectious cases has increased globally to more than 100 thousand and the outbreak has been defined as a pandemic situation, but there are still no “specific drug” available. Relevant reports have pointed out the novel coronavirus has 80% homology with SARS. In the difficulty where new synthesized drug cannot be applied immediately to patients, “conventional drug in new use” becomes a feasible solution. The first medication experience of the recovered patients in the US has led remdesivir to be the “specific drug”. China has also taken immediate action to put remdesivir into clinical trials with the purpose of applying it into clinical therapeutics for Corona Virus Disease 2019 (COVID-19). We started from the structure, immunogenicity, and pathogenesis of coronavirus infections of the novel coronavirus. Further, we analyzed the pharmacological actions and previous trials of remdesivir to identify the feasibility of conducting experiments on COVID-19.

negative: Perspectives on monoclonal antibody therapy as potential therapeutic intervention for Coronavirus disease-19 (COVID-19). Last decade witnessed the outbreak of many life-threatening human pathogens including Nipah, Ebola, Chikungunya, Zika, Middle East respiratory syndrome coronavirus (MERS-CoV), Severe Acute respiratory syndrome coronavirus (SARS-CoV) and more recently novel coronavirus (2019-nCoV or SARS-CoV-2). The disease condition associated with novel coronavirus, referred to as Coronavirus disease (COVID-19). The emergence of novel coronavirus in 2019 in Wuhan, China marked the third highly pathogenic coronavirus infecting humans in the 21st century. The continuing emergence of coronaviruses at regular intervals poses a significant threat to human health and economy. Ironically, even after a decade of research on coronavirus, still there are no licensed vaccines or therapeutic agents to treat coronavirus infection which highlights an urgent need to develop effective vaccines or post-exposure prophylaxis to prevent future epidemics. Several clinical, genetic and epidemiological features of COVID-19 resemble SARS-CoV infection. Hence, the research advancements on SARS-CoV treatment might help scientific community in quick understanding of this virus pathogenesis and develop effective therapeutic/prophylactic agents to treat and prevent this infection. Monoclonal antibodies represent the major class of biotherapeutics for passive immunotherapy to fight against viral infection. The therapeutic potential of monoclonal antibodies has been well recognized in the treatment of many diseases. Here, we summarize the potential monoclonal antibody based therapeutic intervention for COVID-19 by considering the existing knowledge on the neutralizing monoclonal antibodies against similar coronaviruses SARS-CoV and MERS-CoV. Further research on COVID-19 pathogenesis could identify appropriate therapeutic targets to develop specific anti-virals against this newly emerging pathogen.

negative: Chapter 9 Respiratory viral infections Abstract Molecular analysis of respiratory viruses and the host response to both infection and vaccination have transformed our understanding of these ubiquitous pathogens. Polymerase chain reaction for the rapid and accurate diagnosis of viral infections has led to a better understanding of the epidemiology and impact of many common respiratory viruses and resulted in better patient care. Over the past decade a number of new respiratory viruses including human metapneumovirus and new coronaviruses have been discovered using molecular techniques such as random primer amplification, pan-viral array and next generation sequencing. Analysis of the host transcriptional response during respiratory viral infection using in-vitro, animal models and natural and experimental human challenge have furthered the understanding of the mechanisms and predictors of severe disease and may identify potential therapeutic targets to prevent and ameliorate illness.

negative: Dynamic change process of target genes by RT-PCR testing of SARS-Cov-2 during the course of a Coronavirus Disease 2019 patient Abstract We report the dynamic change process of target genes by RT-PCR testing of SARS-Cov-2 during the course of a COVID-19 patient: from successive negative results to successive single positive nucleocapsid gene, to two positive target genes (orf1ab and nucleocapsid) by RT-PCR testing of SARS-Cov-2, and describe the diagnosis, clinical course, and management of the case. In this case, negative results of RT-PCR testing was not excluded to diagnose a suspected COVID-19 patient, clinical signs and symptoms, other laboratory findings, and chest CT images should be taken into account for the absence of enough positive evidence. This case highlights the importance of successive sampling and testing SARS-Cov-2 by RT-PCR as well as the increased value of single positive target gene from pending to positive in two specimens to diagnose laboratory-confirmed COVID-19.

negative: Infectious Diseases of the Gastrointestinal Tract

negative: The modelling of COVID19 pathways sheds light on mechanisms, opportunities and on controversial interpretations of medical treatments. v2 The new coronavirus (2019-nCoV or SARS-CoV2), inducing the current pandemic disease (COVID-19) and causing pneumoniae in humans, is dramatically increasing in epidemic scale since its first appearance in Wuhan, China, in December 2019. The first infection from epidemic coronaviruses in 2003 fostered the spread of an overwhelming amount of related scientific efforts. The manifold aspects that have been raised, as well as their redundancy offer precious information that has been underexploited and needs to be critically re-evaluated, appropriately used and offered to the whole community, from scientists, to medical doctors, stakeholders and common people. These efforts will favour a holistic view on the comprehension, prevention and development of strategies (pharmacological, clinical etc) as well as common intervention against the new coronavirus spreading. Here we describe a model that emerged from our analysis that was focused on the Renin Angiotensin System (RAS) and the possible routes linking it to the viral infection. because the infection is mediated by the viral receptor on human cell membranes Angiotensin Converting Enzyme (ACE2), which is a key component in RAS signalling. The model depicts the main pathways determining the disease and the molecular framework for its establishment, and can help to shed light on mechanisms involved in the infection. It promptly gives an answer to some of the controversial, and still open, issues concerning predisposing conditions and medical treatments that protect from or favour the severity of the disease (such as the use of ACE inhibitors or ARBs/sartans), or to the sex related biases in the affected population. The model highlights novel opportunities for further investigations, diagnosis and appropriate intervention to understand and fight COVID19.

negative: Comparisons of substitution, insertion and deletion probes for resequencing and mutational analysis using oligonucleotide microarrays Although oligonucleotide probes complementary to single nucleotide substitutions are commonly used in microarray-based screens for genetic variation, little is known about the hybridization properties of probes complementary to small insertions and deletions. It is necessary to define the hybridization properties of these latter probes in order to improve the specificity and sensitivity of oligonucleotide microarray-based mutational analysis of disease-related genes. Here, we compare and contrast the hybridization properties of oligonucleotide microarrays consisting of 25mer probes complementary to all possible single nucleotide substitutions and insertions, and one and two base deletions in the 9168 bp coding region of the ATM (ataxia telangiectasia mutated) gene. Over 68 different dye-labeled single-stranded nucleic acid targets representing all ATM coding exons were applied to these microarrays. We assess hybridization specificity by comparing the relative hybridization signals from probes perfectly matched to ATM sequences to those containing mismatches. Probes complementary to two base substitutions displayed the highest average specificity followed by those complementary to single base substitutions, single base deletions and single base insertions. In all the cases, hybridization specificity was strongly influenced by sequence context and possible intra- and intermolecular probe and/or target structure. Furthermore, single nucleotide substitution probes displayed the most consistent hybridization specificity data followed by single base deletions, two base deletions and single nucleotide insertions. Overall, these studies provide valuable empirical data that can be used to more accurately model the hybridization properties of insertion and deletion probes and improve the design and interpretation of oligonucleotide microarray-based resequencing and mutational analysis.

negative: Epidemiological research priorities for public health control of the ongoing global novel coronavirus (2019-nCoV) outbreak

negative: Prevalence of viral, bacterial and parasitological diseases in rats and mice used in research environments in Australasia over a 5-y period Viral, bacterial and parasitological infections in rats and mice used in biomedical research continue to occur despite improved housing and biosurveillance. The presence of disease in laboratory animals can lead to spurious results for research undertaken in universities, research institutes and the pharmaceutical industry. Here the authors report the results of serological, microbiological, parasitological and molecular tests done on mice and rats from Australasia submitted to a rodent health monitoring laboratory (Cerberus Sciences) from 2004 to 2009. In tested mice, norovirus was the most prevalent virus and ectromelia virus was the least prevalent virus. In tested rats, pneumonia virus of mice was the most prevalent virus and adenoviruses 1 and 2 were the least prevalent viruses. In mice, Helicobacter hepaticus was the most prevalent bacterium, and in rats, Proteus spp. were the most prevalent bacteria. The most common positive helminthological finding in mice and rats was the presence of all pinworms (including Aspicularis spp. and Syphacia spp.). The most common positive protozoan findings in mice and rats were Chilomastix spp. and Trichomonads.

negative: Optimized Expression, Purification of Herpes B Virus gD Protein in Escherichia coli, and Production of Its Monoclonal Antibodies BACKGROUND: Herpes B virus (BV) is a zoonotic disease caused by double-stranded enveloped DNA virus with cercopithecidae as its natural host. The mortality rate of infected people could be up to 70% with fatal encephalitis and encephalomyelitis. Up to now, there are no effective treatments for BV infection. Among the various proteins encoded by monkey B virus, gD, a conserved structural protein, harbors important application value for serological diagnosis of frequent variations of the monkey B virus. OBJECTIVES: This study aimed to expressed the gD protein of BV in Escherichia coli by a recombinant vector, and prepare specific monoclonal antibodies against gD of BV to pave the way for effective and quick diagnosis reagent research. MATERIALS AND METHODS: The gD gene of BV was optimized by OptimWiz to improve codon usage bias and synthesis, and the recombinant plasmid, pET32a/gD, was constructed and expressed in E. coli Rosetta (DE3). The expressed fusion protein, His-gD, was purified and the BALB/c mice were immunized by this protein. Spleen cells from the immunized mice and SP2/0 myeloma cells were fused together, and the monoclonal cell strains were obtained by indirect enzyme-linked immunosorbent assay (ELISA) screening, followed by preparation of monoclonal antibody ascetic fluid. RESULTS: The optimized gD protein was highly expressed in E. coli and successfully purified. Five monoclonal antibodies (mAbs) against BV were obtained and named as 4E3, 3F8, 3E7, 1H3 and 4B6, and with ascetic fluid titers of 2 × 10(6), 2 × 10(5), 2 × 10(5), 2 × 10(3) and 2 × 10(2), respectively. The 1H3 and 4E3 belonged to the IgG2b subclass, while 3E7, 3F8 and 4B6 belonged to the IgG1 subclass. CONCLUSIONS: The cell lines obtained in this work secreted potent, stable and specific anti-BV mAbs, which were suitable for the development of herpes B virus diagnosis reagents.

negative: Host Modulators of H1N1 Cytopathogenicity Influenza A virus infects 5–20% of the population annually, resulting in ∼35,000 deaths and significant morbidity. Current treatments include vaccines and drugs that target viral proteins. However, both of these approaches have limitations, as vaccines require yearly development and the rapid evolution of viral proteins gives rise to drug resistance. In consequence additional intervention strategies, that target host factors required for the viral life cycle, are under investigation. Here we employed arrayed whole-genome siRNA screening strategies to identify cell-autonomous molecular components that are subverted to support H1N1 influenza A virus infection of human bronchial epithelial cells. Integration across relevant public data sets exposed druggable gene products required for epithelial cell infection or required for viral proteins to deflect host cell suicide checkpoint activation. Pharmacological inhibition of representative targets, RGGT and CHEK1, resulted in significant protection against infection of human epithelial cells by the A/WS/33 virus. In addition, chemical inhibition of RGGT partially protected against H5N1 and the 2009 H1N1 pandemic strain. The observations reported here thus contribute to an expanding body of studies directed at decoding vulnerabilities in the command and control networks specified by influenza virulence factors.

negative: COVID-19: the gendered impacts of the outbreak

negative: The impact of biosensing in a pandemic outbreak: COVID-19 Abstract COVID-19 pandemic outbreak is the most astounding scene ever experienced in the XXI century. In this opinionated review, we underscore the crucial role of biosensing to handle with such situations. As a matter of fact, testing accelerates life-saving decisions on treatment and isolation of COVID-19 patients in an early stage, and thereby, decelerating or even preventing the spread of such emerging infectious diseases. Meanwhile, it is also proven that a timely and broad application of testing leads to lower mortality rates in countries like Germany or South Korea. Besides, biosensors are also powerful tools for effective assessment of clinical progress and to provide alertness on severity or critical trends of infection. In view hereof, we critically discuss the state-of-the-art biosensing devices for COVID-19 testing. We spot the urgent needs and highlight innovative diagnostic approaches for targeting various COVID-19 related biomarkers. Finally, we outline our recommendations on biosensors and biosensing-related issues towards pandemic outbreaks.

negative: Chapter 15 Biology and Diseases of Ruminants (Sheep, Goats, and Cattle) Ruminants continue to be important in their traditional role in agricultural research and teaching. They are now also extensively used for studies in molecular biology; genetic engineering; and biotechnology for basic science, agricultural and clinical applications. Concern and interest for the welfare for these species and improved understanding of their biology and behavior have continued and are reflected in changing husbandry and management systems. This chapter addresses at high levels basic biology, husbandry, and the more common or important diseases of the three ruminant species used most commonly in the laboratory, namely sheep, goats and cattle.

negative: Coronaviridae, pathogenetic and clinical aspects: An update Abstract A review is given about pathogenetic and clinical aspects of the well-known as well as of recently detected members of the family Coronaviridae. Special attention is paid to coronavirus infections of domestic cattle and pets, whereas avian, murine, rat and human coronaviruses are summarized briefly.

negative: Estimating SARS-CoV-2 seroprevalence and epidemiological parameters with uncertainty from serological surveys Establishing how many people have already been infected by SARS-CoV-2 is an urgent priority for controlling the COVID-19 pandemic. Patchy virological testing has hampered interpretation of confirmed case counts, and unknown rates of asymptomatic and mild infections make it challenging to develop evidence-based public health policies. Serological tests that identify past infection can be used to estimate cumulative incidence, but the relative accuracy and robustness of various sampling strategies has been unclear. Here, we used a flexible framework that integrates uncertainty from test characteristics, sample size, and heterogeneity in seroprevalence across tested subpopulations to compare estimates from sampling schemes. Using the same framework and making the assumption that serological positivity indicates immune protection, we propagated these estimates and uncertainty through dynamical models to assess the uncertainty in the epidemiological parameters needed to evaluate public health interventions. We examined the relative accuracy of convenience samples versus structured surveys to estimate population seroprevalence, and found that sampling schemes informed by demographics and contact networks outperform uniform sampling. The framework can be adapted to optimize the design of serological surveys given particular test characteristics and capacity, population demography, sampling strategy, and modeling approach, and can be tailored to support decision-making around introducing or removing interventions.

negative: Serological and molecular evidence that canine respiratory coronavirus is circulating in Italy Abstract Canine respiratory coronavirus (CRCoV) is a group II coronavirus that was firstly identified in lung samples of dogs with canine infectious respiratory disease (CIRD) in UK in 2003. We report for the first time the identification of CRCoV in Italy, together with serological evidence that the virus has been circulating in the Italian dog population as from 2005. Serological investigations on 216 dog sera, carried out by an ELISA test using the strictly related bovine coronavirus (BCoV) as antigen, revealed an overall CRCoV seroprevalence of 32.06% in the last 2 years. RT-PCR targeting the S-gene of CRCoV was carried out on 109 lung samples collected from carcasses of dogs submitted for diagnostic investigations. Positive results were obtained from the lungs of a dog of the Apulia region that was co-infected with canine parvovirus type 2. Sequence analysis of the S-gene fragment amplified by RT-PCR (595bp) showed similarity to group II coronaviruses, with the highest nucleotide identity (98%) to the only CRCoV strain currently available in the GenBank database (strain T101). The results of the present study show that CRCoV is present also in continental Europe, although further studies are required to determine the real pathogenic potential of the virus.

negative: Liver Disease Associated with Non-Hepatitis Viruses Abstract Hepatitis is commonly associated with certain viruses labeled as “Hepatitis” viruses. However, many other viral infections can also affect the liver ranging from mild asymptomatic elevations of aminotransferases to fulminant hepatic failure. This article will provide a brief overview on a variety of different viral infections that may be associated with significant liver pathology at least under certain conditions, for example, immunosuppression. This overview discusses key virological features, clinical presentation of associated liver disease and provides some information on diagnosis and an outline of treatment options. Thus, the overview can provide first orientation when infectious hepatitis is encountered in a patient that cannot be explained by the usual hepatitis viruses.

negative: Awareness of MERS-CoV among Staff Members of Prince Sultan Military Medical City in Riyadh, Saudi Arabia Background The Middle East respiratory syndrome coronavirus (MERS-CoV) developed infections that caused serious epidemics. Special priority of awareness and prompt initiative involvement of health workers (HW) during such intensified health situation necessitated an assessment of their preparedness, appropriate attitudes and protective strategies for better efficiency modes and acceleration during emergency. Methods HW of Prince Sultan Military Medical city in Riyadh, Saudi Arabia were reviewed through specifically designed questionnaires to acquire the demanded data. It included clinical and demographic information about the viral diseases, associated signs and symptoms, transmission and protection, and attitudes about the MERS-CoV disease. Results The study was accomplished between August and November, 2017 and 477 participants of the medical city, successfully completed the study questionnaire (Appendix I). Females represented a majority and there was an indirectly proportional decrease with the increasing age. Gradual educational increase levels reflected dominance of the university degree holders. Jobs were dominated by nurses and non-Saudis were a majority whilst, the highly experienced, (>10 years) were a minority. A majority recognized the viral transmission methods, popular information sources of MERS-CoV and associated medical terms. Highest scores were observed in dealing with protective aids and recognizing symptoms of disease. High adherence to hand hygiene protocols and correct washing steps were recorded. Correct and high levels were observed in taking preventive measures and avoiding infection. Participants responded correctly to negative and wrong actions that patients should refrain from. High scores were observed in taking appreciable attitudes towards oneself and towards others. Conclusions Expatriates were majority and nurses were dominant which, necessitates Saudization of this sector. Ministry of health pamphlets and seminars were of less impact in invigilating HW, hence, more attention and efforts are demanded. HW were quite aware of the basic and emergent health policies during epidemic episodes of MERS-CoV.

negative: An Evaluation of Publicly Available Deep Learning Based Commercial Information Retrieval Systems to search Biomedical Articles related to COVID-19 The COVID-19 pandemic has resulted in a tremendous need for access to the latest scientific information, primarily through the use of text mining and search tools. This has led to both corpora for biomedical articles related to COVID-19 (such as the CORD-19 corpus (Wang et al., 2020)) as well as search engines to query such data. While most research in search engines is performed in the academic field of information retrieval (IR), most academic search engines--though rigorously evaluated--are sparsely utilized, while major commercial web search engines (e.g., Google, Bing) dominate. This relates to COVID-19 because it can be expected that commercial search engines deployed for the pandemic will gain much higher traction than those produced in academic labs, and thus leads to questions about the empirical performance of these search tools. This paper seeks to empirically evaluate two such commercial search engines for COVID-19, produced by Google and Amazon, in comparison to the more academic prototypes evaluated in the context of the TREC-COVID track (Roberts et al., 2020). To ensure a fair comparison, we limit the number of documents in the retrieved runs and also annotate additional documents. We find that the top-performing system from TREC-COVID on bpref metric performed the best among the different systems evaluated in this study on all the metrics.

negative: A review of feline infectious peritonitis virus infection: 1963–2008

negative: The indirect fluorescent antibody technique as a method for detecting antibodies in aborted fetuses. In this investigation the indirect fluorescent antibody technique was used to titrate antibodies in bovine sera to parainfluenza 3, infectious bovine rhinotracheitis virus and bovine viral diarrhea virus. These results were compared to those determined on the same samples by hemagglutination inhibition for parainfluenza 3 virus and serum neutralization for bovine virus diarrhea and infectious bovine rhinotracheitis virus. The results of the serological methods agreed closely. The indirect fluorescent antibody technique is a rapid and sensitive method for detecting antibodies and the procedure lends itself to use in diagnostic laboratories. In addition to the above viruses the presence or absence of antibodies to bovine coronavirus and bovine adenovirus 3 were determined by the indirect fluorescent antibody technique in thoracic fluids from 100 aborted fetuses and 50 nonaborted fetuses. Results on these samples were not compared to hemagglutination inhibition or serum neutralization as the condition of fluid samples from aborted fetuses renders interpretation of such tests unreliable. Antibodies to one or more viruses were detected in 30 of the 100 aborted fetuses and in seven of the 50 nonaborted fetuses. Antibodies to more than one agent were detected in eleven of the 100 aborted and in one of the 50 nonaborted fetuses. Reasons for this occurrence and application of the test in determination of causes of abortion are discussed.

negative: Broadly targeted multiprobe QPCR for detection of coronaviruses: Coronavirus is common among mallard ducks (Anas platyrhynchos) Abstract Coronaviruses (CoVs) can cause trivial or fatal disease in humans and in animals. Detection methods for a wide range of CoVs are needed, to understand viral evolution, host range, transmission and maintenance in reservoirs. A new concept, “Multiprobe QPCR”, which uses a balanced mixture of competing discrete non- or moderately degenerated nuclease degradable (TaqMan®) probes was employed. It provides a broadly targeted and rational single tube real-time reverse transcription PCR (“NQPCR”) for the generic detection and discovery of CoV. Degenerate primers, previously published, and the new probes, were from a conserved stretch of open reading frame 1b, encoding the replicase. This multiprobe design reduced the degree of probe degeneration, which otherwise decreases the sensitivity, and allowed a preliminary classification of the amplified sequence directly from the QPCR trace. The split probe strategy allowed detection of down to 10 viral nucleic acid equivalents of CoV from all known CoV groups. Evaluation was with reference CoV strains, synthetic targets, human respiratory samples and avian fecal samples. Infectious-Bronchitis-Virus (IBV)-related variants were found in 7 of 35 sample pools, from 100 wild mallards (Anas platyrhynchos). Ducks may spread and harbour CoVs. NQPCR can detect a wide range of CoVs, as illustrated for humans and ducks.

negative: Necessity of a more standardized virological characterization of rodents for aging studies Characterization of the microbiological status is an important facet of a quality assurance program for laboratory animals. This paper addresses basic issues with regard to standardization of the characterization of murine viral status. Methods for such characterization include clinical signs, virus isolation, and serological tests. Significant considerations are screening profiles; sample collection, processing, and s shipment; and sampling schedules. International standardization of programs and methods to control and characterize the microbiological status of laboratory animals is being developed, and will be highly significant in future efforts to produce, control, and maintain laboratory animals free of viral infections.

negative: Acute care issues in internationally adopted children Over the past decade there has been a dramatic increase in international adoptions in the United States. While most adopted children will have common illnesses, others may have unique medical issues as a result of the conditions in their birth country requiring a broadened differential diagnosis. Knowledge of these issues is essential in the management of these patients. This review will predominately focus on infectious disease issues commonly seen in international adoptees but will also discuss other medical conditions and some of the psychosocial issues which may be encountered by caregivers in the emergency department.

negative: The Novel Coronavirus: A Bird's Eye View The novel coronavirus (2019-nCoV) outbreak, which initially began in China, has spread to many countries around the globe, with the number of confirmed cases increasing every day. With a death toll exceeding that of the SARS-CoV outbreak back in 2002 and 2003 in China, 2019-nCoV has led to a public health emergency of international concern, putting all health organizations on high alert. Herein, we present on an overview of the currently available information on the pathogenesis, epidemiology, clinical presentation, diagnosis, and treatment of this virus.

negative: Comparison of risk factors for viral and nonviral asthma exacerbations

negative: Laboratory Diagnosis of Infection Due to Viruses, Chlamydia, Chlamydophila, and Mycoplasma

negative: The expression and antigenicity of a truncated spike-nucleocapsid fusion protein of severe acute respiratory syndrome-associated coronavirus BACKGROUND: In the absence of effective drugs, controlling SARS relies on the rapid identification of cases and appropriate management of the close contacts, or effective vaccines for SARS. Therefore, developing specific and sensitive laboratory tests for SARS as well as effective vaccines are necessary for national authorities. RESULTS: Genes encoding truncated nucleocapsid (N) and spike (S) proteins of SARSCoV were cloned into the expression vector pQE30 and fusionally expressed in Escherichia coli M15. The fusion protein was analyzed for reactivity with SARS patients' sera and with anti-sera against the two human coronaviruses HCoV 229E and HCoV OC43 by ELISA, IFA and immunoblot assays. Furthermore, to evaluate the antigen-specific humoral antibody and T-cell responses in mice, the fusion protein was injected into 6-week-old BALB/c mice and a neutralization test as well as a T-cell analysis was performed. To evaluate the antiviral efficacy of immunization, BALB/c mice were challenged intranasally with SARSCoV at day 33 post injection and viral loads were determined by fluorescent quantitative RT-PCR. Serological results showed that the diagnostic sensitivity and specificity of the truncated S-N fusion protein derived the SARS virus were > 99% (457/460) and 100.00% (650/650), respectively. Furthermore there was no cross-reactivity with other two human coronaviruses. High titers of antibodies to SRASCoV appeared in the immunized mice and the neutralization test showed that antibodies to the fusion protein could inhibit SARSCoV. The T cell proliferation showed that the fusion protein could induce an antigen-specific T-cell response. Fluorescent quantitative RT-PCR showed that BALB/c mice challenged intranasally with SARSCoV at day 33 post injection were completely protected from virus replication. CONCLUSION: The truncated S-N fusion protein is a suitable immunodiagnostic antigen and vaccine candidate.

negative: A novel coronavirus capable of lethal human infections: an emerging picture SUMMARY: In September 2012, a novel coronavirus was isolated from a patient in Saudi Arabia who had died of an acute respiratory illness and renal failure. The clinical presentation was reminiscent of the outbreak caused by the SARS-coronavirus (SARS-CoV) exactly ten years ago that resulted in over 8000 cases. Sequence analysis of the new virus revealed that it was indeed a member of the same genus as SARS-CoV. By mid-February 2013, 12 laboratory-confirmed cases had been reported with 6 fatalities. The first 9 cases were in individuals resident in the Middle East, while the most recent 3 cases were in family members resident in the UK. The index case in the UK family cluster had travel history to Pakistan and Saudi Arabia. Although the current evidence suggests that this virus is not highly transmissible among humans, there is a real danger that it may spread to other parts of the world. Here, a brief review of the events is provided to summarize the rapidly emerging picture of this new virus.

negative: Sequential serological surveys in the early stages of the coronavirus disease epidemic: limitations and perspectives INTRODUCTION: Estimates of the number of individuals infected by severe acute respiratory syndrome coronavirus 2 are important for health planning and establishment of expectations regarding herd immunity. METHODS: Seven testing rounds of a serological survey were conducted at 1-week intervals between April 19 and May 31, 2020 in Teresina municipality. RESULTS: Over the 7 weeks, serological positivity increased from 0.56% (95% confidence interval [CI]: 0.18%-1.30%) to 8.33% (95% CI: 6.61%-10.33%), representing 33-53 persons infected for each reported case. CONCLUSIONS: Serological screening may be an important tool for understanding the immunity of a population and planning community interventions.

negative: Is COVID-19 receiving ADE from other coronaviruses? Abstract One of the most perplexing questions regarding the current COVID-19 coronavirus epidemic is the discrepancy between the severity of cases observed in the Hubei province of China and those occurring elsewhere in the world. One possible answer is antibody dependent enhancement (ADE) of SARS-CoV-2 due to prior exposure to other coronaviruses. ADE modulates the immune response and can elicit sustained inflammation, lymphopenia, and/or cytokine storm, one or all of which have been documented in severe cases and deaths. ADE also requires prior exposure to similar antigenic epitopes, presumably circulating in local viruses, making it a possible explanation for the observed geographic limitation of severe cases and deaths.

negative: Relative rates of non-pneumonic SARS coronavirus infection and SARS coronavirus pneumonia Summary Background Although the genome of severe acute respiratory syndrome coronavirus (SARS-CoV) has been sequenced and a possible animal reservoir identified, seroprevalence studies and mass screening for detection of subclinical and non-pneumonic infections are still lacking. Methods We cloned and purified the nucleocapsid protein and spike polypeptide of SARS-CoV and examined their immunogenicity with serum from patients with SARS-CoV pneumonia. An ELISA based on recombinant nucleocapsid protein for IgG detection was tested with serum from 149 healthy blood donors who donated 3 years previously and with serum positive for antibodies against SARS-CoV (by indirect immunofluorescence assay) from 106 patients with SARS-CoV pneumonia. The seroprevalence of SARS-CoV was studied with the ELISA in healthy blood donors who donated during the SARS outbreak in Hong Kong, non-pneumonic hospital inpatients, and symptom-free health-care workers. All positive samples were confirmed by two separate western-blot assays (with recombinant nucleocapsid protein and recombinant spike polypeptide). Findings Western-blot analysis showed that the nucleocapsid protein and spike polypeptide of SARS-CoV are highly immunogenic. The specificity of the IgG antibody test (ELISA with positive samples confirmed by the two western-blot assays) was 100%, and the sensitivity was 94·3%. Three of 400 healthy blood donors who donated during the SARS outbreak and one of 131 non-pneumonic paediatric inpatients were positive for IgG antibodies, confirmed by the two western-blot assays (total, 0·48% of our study population). Interpretation Our findings support the existence of subclinical or non-pneumonic SARS-CoV infections. Such infections are more common than SARS-CoV pneumonia in our locality.

negative: [A preliminary investigation on the serological and epidemiological characteristics of severe acute respiratory syndrome in children]. OBJECTIVE The severe acute respiratory syndrome (SARS) is a highly contagious infection caused by a newly discovered strain of coronavirus (SARS-CoV). During the outbreak of SARS in the first half of 2003, children appeared to be less susceptible to the SARS coronavirus and pediatric patients presented with a less aggressive clinical course than adult patients did, demonstrating the traits which were rarely observed in other viral contagious disease. The present study aimed to preliminarily examine the presence of serum specific antibodies against severe acute respiratory syndrome (SARS)-associated coronavirus virus (SARS-CoV) in pediatric SARS patients and explore the possibility of subclinical infection in children/adults through close association with SARS cases. METHODS (1) Clinicians and nurses visited families and collected general and epidemiological information about the subjects using a standard questionnaire and took serum specimens. (2) Specific antibodies against SARS-CoV were assayed with two methods, indirect immunofluorescence assay (IFA) for detecting IgG antibodies and enzyme linked immunosorbent assay (ELISA) for mixed antibodies. Serum specimens tested included those from 21 clinically confirmed pediatric SARS cases (aged from 8 months to 14 years, 11 male and 10 female) and their 23 parents who had close contact with the children, 36 adult patients in convalescence stage of SARS, 24 children (aged 1.5 to 14 years) and other 34 adults who had close contact with infected adults. RESULTS (1) The positive rates of specific IgG and mixed antibodies against SARS-CoV were 38% (8/21) and 33% (7/21) in pediatric cases; whereas the rates were 75% (27/36) and 69% (25/36) in adult patients. (2) The proportion of the patients who had close contact to SARS patients was 7/8 among the antibody-positive group vs. 1/13 for the antibody-negative group (P < 0.05). (3) The IgG antibody emerged in one of 24 children, whose mother, a nurse, had suffered from SARS (4%). (4) Among 23 parents of children with SARS, one was positive for IgG and the mixed antibodies, whose grandson and husband suffered from SARS; The IgG antibody and the mixed antibodies were also positive in another adult who had close contact with adult SARS cases (3%). CONCLUSIONS (1) SARS-CoV infection was confirmed by serological methods in 38.1% of clinically diagnosed pediatric SARS cases, which leads to the assumption that correct diagnosis of pediatric SARS requires more accurate and efficient ways, for example, screening for antigen or gene of SARS-CoV. (2) The proportion of the patients who had close contact to SARS patients among antibody-positive cases was higher than that in antibody-negative cases. (3) It is possible that subclinical SARS CoV infection exists in children and adults, although the rate of occurrence is low. The data of the present study did not confirm that SARS had subclinical infection among adults who had close contact to pediatric SARS cases.

negative: Antigenic relationships amongst coronaviruses Several serological interrelationships between various members of the corona-virus group have been revealed in neutralization, complement fixation, and gel-diffusion tests, using human and hyperimmune animal sera. Several members of this group of human and animal pathogens are shown to cross-react in one or more type of test, but one member, avian infectious bronchitis virus, was shown to be unrelated. Mouse hepatitis virus (MHV(3)) was found to be antigenically related to a number of human types of coronavirus. Difficulties were encountered in the investigation of paired human sera in demonstrating the specificity of antibody rises, placing doubt on the values of some serological studies. The significance of these interrelationships is discussed in the light of other investigations.

negative: COVID-19 Pandemic: the long and difficult way back to work

negative: Emergence of a Novel Coronavirus, Severe Acute Respiratory Syndrome Coronavirus 2: Biology and Therapeutic Options The new decade of the 21(st) century (2020) started with the emergence of a novel coronavirus known as SARS-CoV-2 that caused an epidemic of coronavirus disease (COVID-19) in Wuhan, China. It is the third highly pathogenic and transmissible coronavirus after severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in humans. The source of origin, transmission to humans, and mechanisms associated with the pathogenicity of SARS-CoV-2 are not yet clear, however, its resemblance to SARS-CoV and several other bat coronaviruses was recently confirmed through genome sequencing-related studies. The development of therapeutic strategies is necessary in order to prevent further epidemics and cure infections. In this review, we summarize current information about the emergence, origin, diversity, and epidemiology of three pathogenic coronaviruses with a specific focus on the current outbreak in Wuhan, China. Furthermore, we discuss the clinical features and potential therapeutic options that may be effective against SARS-CoV-2.

negative: MIDDLE EAST RESPIRATORY SYNDROME CORONAVIRUS – MERS, MERS CoV

negative: The outlook for diagnostic purposes of the 2019‐novel coronavirus disease At the end of December 2019, a novel acute respiratory syndrome coronavirus 2 (SARS‐CoV2) appeared as the third unheard of outbreak of human coronavirus infection in the 21st century. First, in Wuhan, China, the novel SARS‐CoV2 was named by the World Health Organization (WHO), as 2019‐nCOV (COVID‐19), and spread extremely all over the world. SARS‐CoV2 is transmitted to individuals by human‐to‐human transmission leading to severe viral pneumonia and respiratory system injury. SARS‐CoV2 elicits infections from the common cold to severe conditions accompanied by lung injury, acute respiratory distress syndrome, and other organ destruction. There is a possibility of virus transmission from asymptomatic cases as active carriers, in addition to symptomatic ones, which is a crucial crisis of COVID‐19 that should be considered. Hence, paying more attention to the accurate and immediate diagnosis of suspected and infected cases can be a great help in preventing the rapid spread of the virus, improving the disease prognosis, and controlling the pandemic. In this review, we provide a comprehensive and up‐to‐date overview of the different types of Clinical and Para‐clinical diagnostic methods and their practical features, which can help understand better the applications and capacities of various diagnostic approaches for COVID‐19 infected cases.

negative: Assay Techniques and Test Development for COVID-19 Diagnosis An ongoing theme of the COVID-19 pandemic is the need for widespread availability of accurate and eﬃcient diagnostic testing for detection of SARS-CoV-2 and antiviral antibodies in infected individuals. This report describes various assay techniques and tests for COVID-19 diagnosis. Most tests for early detection of SARS-CoV-2 RNA rely on the reverse transcription-polymerase chain reaction, but isothermal nucleic acid ampliﬁcation assays, including transcription-mediated ampliﬁcation and CRISPR-based methodologies, are promising alternatives. Identiﬁcation of individuals who have developed antibodies to the SARS-CoV-2 virus requires serological tests, including enzyme-linked immunosorbent assay (ELISA) and lateral ﬂow immunoassay. This report also provides an overview of current development in COVID-19 diagnostic techniques and products to facilitate future improvement and innovation.

negative: Production and Characterization of Monoclonal Antibodies Against the Nucleocapsid Protein of SARS-COV

negative: Hepatitis A Outbreak in a Residential School Summary: Hepatitis A outbreak in a residential school. C. R. Boughton, R. A. Hawkes, N. I. Lehmann and G. S. Grohmann, Aust. N.Z. J. Med., 1980, 10, pp. 4–6. Outbreaks of hepatitis A occurred sequentially in two wards for children in a residential institution for the mentally retarded in Sydney. Twenty‐six of 47 children were initially susceptible to hepatitis A. In the first ward affected, 77 of 13 susceptible children (85%), and in the second ward, four of 13 susceptible (31%), were infected. Of the 15 showing serological evidence of infection, five (33%) were clinically jaundiced.

negative: Chapter 59 Respiratory Virus Vaccines Abstract This chapter reviews the main viral pathogens of the respiratory tract, the immune responses they induce, currently available vaccines, and vaccines that are in development to control them. The main viruses responsible for acute respiratory infection in people include respiratory syncytial, influenza, human parainfluenza, human metapneumo-, human rhino-, corona-, and adenoviruses. Licensed vaccines are available only for influenza virus, with vaccines against the other pathogens either in clinical trials or in preclinical stages of development. The majority of studies evaluating respiratory virus vaccines measure serum antibody responses, because, although both cellular and humoral responses contribute to the clearance of a primary infection, neutralizing antibodies are known to protect against secondary infection. Humoral responses can be readily detected after vaccination with inactivated or subunit vaccines; however, fewer individuals seroconvert after vaccination with live vaccines. Alternative immune mechanisms such as mucosal antibody responses are probably responsible for protection by live attenuated vaccines, and immune correlates of protection are under investigation.

negative: Chapter 8 Infectious Complications of Transfusion of Blood Components Abstract Transfusions are lifesaving but are not without some risks. During the middle of the last century, infectious complications were common from transfusions. By the mid 1980s the risk of transfusion transmission of infections became much lower. With the advent of emerging diseases, however, infectious risks became more prominent for a period of time. Now we live in a time where death from transfusion transmission is 10%–15% of all transfusion-associated deaths and is the lowest in history. As the risks are identified and new screens or processes are put in place, the associated transfusion transmission of infection will continue to have reducing risks and blood supply will continue to be safer still.

negative: Severe Acute Respiratory Syndrome–associated Coronavirus in Lung Tissue Efforts to contain severe acute respiratory syndrome (SARS) have been limited by the lack of a standardized, sensitive, and specific test for SARS-associated coronavirus (CoV). We used a standardized reverse transcription-polymerase chain reaction assay to detect SARS-CoV in lung samples obtained from well-characterized patients who died of SARS and from those who died of other reasons. SARS-CoV was detected in all 22 postmortem lung tissues (to 10(9) viral copies/g) from 11 patients with probable SARS but was not detected in any of the 23 lung control samples (sample analysis was blinded). The sensitivity and specificity (95% confidence interval) were 100% (84.6% to 100%) and 100% (85.1% to 100%), respectively. Viral loads were significantly associated with a shorter course of illness but not with the use of ribavirin or steroids. CoV was consistently identified in the lungs of all patients who died of SARS but not in control patients, supporting a primary role for CoV in deaths.

negative: SEROEPIDEMIOLOGIC STUDIES OF CORONAVIRUS INFECTION IN ADULTS AND CHILDREN(1) McIntosh, K. A. Z. Kapikian, H. C Turner, J. W. Hartley, R. H. Parrott and R. M. Chanock. (Lab. of Infectious Diseases, NIAID, NIH, Bethesda, Md. 20014) Sero-epidemiologic studies of coronavirus infection in adults and children. Amer. J. Epid., 1970, 97: 585–592-A seroepidemiologic study of infection by coronavirus strains 229E, OC38, OC43, and mouse hepatitis virus (MHV) strain A-59, is described. In adults with upper respiratory disease, two “outbreaks” of coronavirus infection occurred, one during the winter of 1965–1966 associated with complement fixing (CF) antibody responses to OC38, OC43 and MHV, and the other during the following winter associated with CF antibody responses to 229E. In hospitalized children, infection with 229E was rare; infection with OC38, OC43, and MHV occurred less often in hospitalized children with lower respiratory tract disease (3.5%) than in a control group with non-respiratory tract disease (8.2%). The limitations of the CF test using available coronavirus antigens are discussed.

negative: Vaccination strategies to combat novel corona virus SARS-CoV-2 The 2019-novel coronavirus disease (COVID-19) is caused by SARS-CoV-2 is transmitted from human to human has recently reported in China. Now COVID-19 has been spread all over the world and declared epidemics by WHO. It has caused a Public Health Emergency of International Concern. The elderly and people with underlying diseases are susceptible to infection and prone to serious outcomes, which may be associated with acute respiratory distress syndrome (ARDS) and cytokine storm. Due to the rapid increase of SARS-CoV-2 infections and unavailability of antiviral therapeutic agents, developing an effective SAR-CoV-2 vaccine is urgently required. SARS-CoV-2 which is genetically similar to SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV) is an enveloped, single and positive-stranded RNA virus with a genome comprising 29,891 nucleotides, which encode the 12 putative open reading frames responsible for the synthesis of viral structural and nonstructural proteins which are very similar to SARS-CoV and MERS-CoV proteins. In this review we have summarized various vaccine candidates i.e., nucleotide, subunit and vector based as well as attenuated and inactivated forms, which have already been demonstrated their prophylactic efficacy against MERS-CoV and SARS-CoV, so these candidates could be used as a potential tool for the development of a safe and effective vaccine against SARS-CoV-2.

negative: The serostatus approach to fighting COVID-19

negative: Intervention Serology and Interaction Substitution: Modeling the Role of ‘Shield Immunity’ in Reducing COVID-19 Epidemic Spread The COVID-19 pandemic has precipitated a global crisis, with more than 690,000 confirmed cases and more than 33,000 confirmed deaths globally as of March 30, 2020 [1–4]. At present twOfficentral public health control strategies have emerged: mitigation and suppression (e.g, [5]). Both strategies focus on reducing new infections by reducing interactions (and both raise questions of sustainability and long-term tactics). Complementary to those approaches, here we develop and analyze an epidemiological intervention model that leverages serological tests [6, 7] to identify and deploy recovered individuals as focal points for sustaining safer interactions via interaction substitution, i.e., to develop what we term ‘shield immunity’ at the population scale. Recovered individuals, in the present context, represent those who have developed protective, antibodies to SARS-CoV-2 and are no longer shedding virus [8]. The objective of a shield immunity strategy is to help sustain the interactions necessary for the functioning of essential goods and services (including but not limited to tending to the elderly [9], hospital care, schools, and food supply) while decreasing the probability of transmission during such essential interactions. We show that a shield immunity approach may significantly reduce the length and reduce the overall burden of an outbreak, and can work synergistically with social distancing. The present model highlights the value of serological testing as part of intervention strategies, in addition to its well recognized roles in estimating prevalence [10, 11] and in the potential development of plasma-based therapies [12–15].

negative: Human immunopathogenesis of severe acute respiratory syndrome (SARS) Abstract Progressive immune-associated injury is a hallmark of severe acute respiratory syndrome (SARS). Viral evasion of innate immunity, hypercytokinemia and systemic immunopathology in the SARS coronavirus (SARS CoV) infected host have been suggested as possible mechanisms for the cause of severe pathology and morbidity in SARS patients. The molecular and cellular basis for how SARS CoV impacts the host immune system resulting in severe SARS, however, has not been elucidated. The variable clinical course of SARS may be the result of complex programs of host responses against the infectious agent. Therefore, the systematic analysis of innate and adaptive immune responses to SARS CoV is imperative in building as complete an immunological model as possible of host immunity and inflammatory responses during illness. Here we review recent advances in SARS immunopathogenesis research and present a summary of our findings regarding host responses in SARS patients. We contend that dysregulated type I and II interferon (IFN) responses during SARS may culminate in a failure of the switch from hyper-innate immunity to protective adaptive immune responses in the human host.

negative: Evaluating the risk of transmission of infection from donor to recipient of a solid organ transplantation Abstract In the context of solid organ transplantation, screening of potential organ donors is crucial, and should be performed with great rigor to minimize the risk of transmission of certain infectious processes. This review aims to update understanding of the possible pathologies involved, as well as of emerging infections that, as a result of globalization, are gaining increasing prominence on a daily basis.

negative: Serological evidence of coronavirus infections in native hamadryas baboons (Papio hamadryas hamadryas) of the Kingdom of Saudi Arabia The hamadryas baboon (Papio hamadryas hamadryas) is the only indigenous species of non-human primates (NHP) found in the Kingdom of Saudi Arabia (KSA). There are no peer-reviewed publications on viral infections of the baboons of KSA. Apart from camels, other animals are likely sources of the novel Middle East Respiratory Syndrome coronavirus (MERSCoV) for humans. We investigated evidence of highly pathogenic coronavirus infections including MERSCoV in a large group of commensal baboons accompanied by feral dogs, on the outskirts of Ta'if city, KSA, in February 2013. Fifty baboons (16 juveniles and 34 adults) were screened for serum antibodies to human coronaviruses (HCoV-043/-NL63/-229) and canine coronaviruses (CCoV-1-3) using direct Enzyme-linked Immunosorbent Assay (ELISA) technique and for MERSCoV antibodies using Serum Neutralization Test (SNT). Of the 50 sampled baboons, 22% (n = 11) were seropositive to HCoVs, 10% (n = 5) were seropositive to CCoVs, while none had detectable MERSCoV antibodies. These findings bear potentially significant implications for public health, canine health and baboon conservation efforts, necessitating follow-up investigations and preventive measures at locations where baboons frequent human habitations, or are regarded as tourist attractions, in KSA.

negative: Non-animal replacement methods for human vaccine potency testing: state of the science and future directions Abstract NICEATM and ICCVAM convened an international workshop to review the state of the science of human and veterinary vaccine potency and safety testing methods, and to identify opportunities to advance new and improved methods that can further reduce, refine, and replace animal use. This report addresses methods and strategies identified by workshop participants for replacement of animals used for potency testing of human vaccines. Vaccines considered to have the highest priority for future efforts were (1) vaccines for which antigen quantification methods are already developed but not validated, (2) vaccines/components that require the largest number of animals, (3) vaccines that require an in vivo challenge test, and (4) vaccines with in vivo tests that are highly variable and cause a significant number of invalid tests. Vaccine potency tests identified as the highest priorities for replacement were those for diphtheria and tetanus, pertussis (whole cell and acellular), rabies, anthrax, polio vaccine (inactivated) and complex combination vaccines based on DT or DTwP/aP. Research into understanding the precise mechanism of protection afforded by vaccines and the identification of clinically relevant immunological markers are needed to facilitate the successful implementation of in vitro testing alternatives. This report also identifies several priority human vaccines and associated research objectives that are necessary to successfully implement in vitro vaccine potency testing alternatives.

negative: Use of the COOH portion of the nucleocapsid protein in an antigen-capturing enzyme-linked immunosorbent assay for specific and sensitive detection of severe acute respiratory syndrome coronavirus. Antibody detection with a recombinant COOH portion of the severe acute respiratory syndrome (SARS) coronavirus nucleocapsid (N) protein, N13 (amino acids 221 to 422), was demonstrated to be more specific and sensitive than that with the full-length N protein, and an N13-based antigen-capturing enzyme-linked immunosorbent assay providing a convenient and specific test for serodiagnosis and epidemiological study of SARS was developed.

negative: Establishment and development of national community-based collaborative innovation demonstration areas to achieve the control target of hepatitis B in China BACKGROUND: The major infectious diseases of hepatitis B has constituted an acute public health challenge in China. An effective and affordable HBV control model is urgently needed. A national project of Community-based Collaborative Innovation HBV (CCI-HBV) demonstration areas has optimized the existing community healthcare resources and obtained initial results in HBV control. METHODS: Based on the existing community healthcare network, CCI-HBV project combined the community health management and health contract signing service for long-staying residents in hepatitis B screening. Moreover, HBV field research strategy was popularized in CCI-HBV areas. After screening, patients with seropositive results were enrolled in corresponding cohorts and received treatment at an early stage. And the uninfected people received medical supports including health education through new media, behavior intervention and HBV vaccinations. In this process, a cloud-based National Information Platform (NIP) was established to collect and store residents’ epidemiological data. In addition, a special quality control team was set up for CCI project. RESULTS: After two rounds of screening, HBsAg positive rate dropped from 5.05% (with 5,173,003 people screened) to 4.57% (with 3,819,675 people screened), while the rate of new HBV infections was 0.28 per 100 person-years in the fixed cohorts of 2,584,322 people. The quality control team completed PPS sampling simultaneously and established the serum sample database with 2,800,000 serum samples for unified testing. CONCLUSIONS: CCI-HBV project has established a large-scale field research to conduct whole-population screening and intervention. We analyzed the HBsAg prevalence and new infection rate of HBV in the fixed population for the epidemic trend and intervention effect. The purpose of CCI-HBV project is to establish and evaluate a practical model of grid management and field strategy, to realize the new goal to control hepatitis B in China. To provide policymakers with a feasible model, our results are directly applicable. TRIAL REGISTRATION: The project was funded by the Major Projects of Science Research for the 11th and 12th five-year plans of China, entitled “The prevention and control of AIDS, viral hepatitis and other major infectious diseases”, Grant Nos. 2009ZX10004901, 2011ZX10004901, 2013ZX10004904, 2014ZX10004007 and 2014ZX10004008.

negative: Cluster of COVID-19 in northern France: A retrospective closed cohort study Background: The Oise department in France has been heavily affected by COVID-19 in early 2020. Methods: Between 30 March and 4 April 2020, we conducted a retrospective closed cohort study among pupils, their parents and siblings, as well as teachers and non-teaching staff of a high-school located in Oise. Participants completed a questionnaire that covered history of fever and/or respiratory symptoms since 13 January 2020 and had blood tested for the presence of anti-SARS-CoV-2 antibodies. The infection attack rate (IAR) was defined as the proportion of participants with confirmed SARS-CoV-2 infection based on antibody detection. Blood samples from two blood donor centres collected between 23 and 27 March 2020 in the Oise department were also tested for presence of anti-SARS-CoV-2 antibodies. Findings: Of the 661 participants (median age: 37 years), 171 participants had anti-SARS-CoV-2 antibodies. The overall IAR was 25.9% (95% confidence interval (CI) = 22.6-29.4), and the infection fatality rate was 0% (one-sided 97.5% CI = 0-2.1). Nine of the ten participants hospitalised since mid-January were in the infected group, giving a hospitalisation rate of 5.3% (95% CI = 2.4-9.8). Anosmia and ageusia had high positive predictive values for SARS-CoV-2 infection (84.7% and 88.1%, respectively). Smokers had a lower IAR compared to non-smokers (7.2% versus 28.0%, P <0.001). The proportion of infected individuals who had no symptoms during the study period was 17.0% (95% CI = 11.2-23.4). The proportion of donors with anti-SARS-CoV-2 antibodies in two nearby blood banks of the Oise department was 3.0% (95% CI = 1.1-6.4). Interpretation: The relatively low IAR observed in an area where SARS-CoV-2 actively circulated weeks before confinement measures indicates that establishing herd immunity will take time, and that lifting these measures in France will be long and complex.

negative: Abstract Presentations from the AABB Annual Meeting Boston, MA, October 13–16, 2018

negative: Editorial Commentary: Still Learning From the Earliest Known MERS Outbreak, Zarqa, Jordan, April 2012

negative: COVID-19 Antibody Test / Vaccination Certification: There's an app for that Goal: As the Coronavirus Pandemic of 2019/2020 unfolds, a COVID-19 'Immunity Passport' has been mooted as a way to enable individuals to return back to work. While the quality of antibody testing, the availability of vaccines, and the likelihood of even attaining COVID-19 immunity continue to be researched, we address the issues involved in providing tamper-proof and privacy-preserving certification for test results and vaccinations. Methods: We developed a prototype mobile phone app and requisite decentralized server architecture that facilitates instant verification of tamper-proof test results. Personally identifiable information is only stored at the user's discretion, and the app allows the end-user selectively to present only the specific test result with no other personal information revealed. The architecture, designed for scalability, relies upon (a) the 2019 World Wide Web Consortium standard called 'Verifiable Credentials', (b) Tim Berners-Lee's decentralized personal data platform 'Solid', and (c) a Consortium Ethereum-based blockchain. Results: Our mobile phone app and decentralized server architecture enable the mixture of verifiability and privacy in a manner derived from public/private key pairs and digital signatures, generalized to avoid restrictive ownership of sensitive digital keys and/or data. Benchmark performance tests show it to scale linearly in the worst case, as significant processing is done locally on each app. For the test certificate Holder, Issuer (e.g. healthcare staff, pharmacy) and Verifier (e.g. employer), it is 'just another app' which takes only minutes to use. Conclusions: The app and decentralized server architecture offer a prototype proof of concept that is readily scalable, applicable generically, and in effect 'waiting in the wings' for the biological issues, plus key ethical issues raised in the discussion section, to be resolved.

negative: Serological Evidence of Bat SARS-Related Coronavirus Infection in Humans, China

negative: Kinetics of severe acute respiratory syndrome (SARS) coronavirus-specific antibodies in 271 laboratory-confirmed cases of SARS. The sensitivities and specificities of an immunofluorescence assay and an enzyme immunoassay for detection of antibodies specific for severe acute respiratory syndrome coronavirus (SARS-CoV) were compared for 148 laboratory-confirmed SARS cases. The appearance and persistence of SARS-CoV-specific antibodies were assessed, with immunoglobulin G detected in 59% of samples collected within 14 days and persisting for 60 to 95 days after the onset of illness.

negative: Betacoronavirus Adaptation to Humans Involved Progressive Loss of Hemagglutinin-Esterase Lectin Activity Human beta1-coronavirus (β1CoV) OC43 emerged relatively recently through a single zoonotic introduction. Like related animal β1CoVs, OC43 uses 9-O-acetylated sialic acid as receptor determinant. β1CoV receptor binding is typically controlled by attachment/fusion spike protein S and receptor-binding/receptor-destroying hemagglutinin-esterase protein HE. We show that following OC43’s introduction into humans, HE-mediated receptor binding was selected against and ultimately lost through progressive accumulation of mutations in the HE lectin domain. Consequently, virion-associated receptor-destroying activity toward multivalent glycoconjugates was reduced and altered such that some clustered receptor populations are no longer cleaved. Loss of HE lectin function was also observed for another respiratory human coronavirus, HKU1. This thus appears to be an adaptation to the sialoglycome of the human respiratory tract and for replication in human airways. The findings suggest that the dynamics of virion-glycan interactions contribute to host tropism. Our observations are relevant also to other human respiratory viruses of zoonotic origin, particularly influenza A virus.

negative: Setting healthcare priorities in hospitals: a review of empirical studies Priority setting research has focused on the macro (national) and micro (bedside) level, leaving the meso (institutional, hospital) level relatively neglected. This is surprising given the key role that hospitals play in the delivery of healthcare services and the large proportion of health systems resources that they absorb. To explore the factors that impact upon priority setting at the hospital level, we conducted a thematic review of empirical studies. A systematic search of PubMed, EBSCOHOST, Econlit databases and Google scholar was supplemented by a search of key websites and a manual search of relevant papers’ reference lists. A total of 24 papers were identified from developed and developing countries. We applied a policy analysis framework to examine and synthesize the findings of the selected papers. Findings suggest that priority setting practice in hospitals was influenced by (1) contextual factors such as decision space, resource availability, financing arrangements, availability and use of information, organizational culture and leadership, (2) priority setting processes that depend on the type of priority setting activity, (3) content factors such as priority setting criteria and (4) actors, their interests and power relations. We observe that there is need for studies to examine these issues and the interplay between them in greater depth and propose a conceptual framework that might be useful in examining priority setting practices in hospitals.

negative: Effective chemical virus inactivation of patient serum compatible with accurate serodiagnosis of infections Abstract Objectives Highly pathogenic viruses such as EBOV are a threat to routine laboratory workers. Inactivation procedures with Triton X-100 0.1% and/or heat are currently recommended, but have unknown effects on the accuracy of serological testing. Furthermore, virus inactivation by Triton X-100 0.1% was shown to be ineffective in serum. This study aimed to demonstrate virus inactivation in serum by Triton X-100 1% and maintained accuracy of serological testing. Methods A panel of 19 serological tests was run on patient serum samples after treatment with Triton X-100 1%, 0.1%, and 0.1% + heat inactivation at 60°C for 1 h. Mean differences between measurements (bias) were calculated applying the Bland–Altman method. To determine effectiveness of virus inactivation, herpes simplex virus 1 (HSV-1) was spiked into medium containing 90% or 1% serum, and treated with Triton X-100 0.1% or 1%. Infectious titres were then determined on Vero cells. Results Serological measurements showed good agreement between controls and samples treated with Triton X-100 0.1% and 1%, with an estimated bias of 0.6 ± 9.2% (n = 258) and –0.1 ± 18.6% (n = 174), respectively. Discordant qualitative results were rare. Conversely, heat inactivation alone and combined with Triton X-100 0.1% triggered a bias of 17.5 ± 66.4% (n = 200) and 37.9 ± 79.8% (n = 160), respectively. Triton X-100 1% completely inactivated HSV-1 in 1% and 90% serum while Triton X-100 0.1% failed to do so in 90% serum. Conclusions Unlike heat inactivation, Triton X-100 1% enabled accurate serological testing and completely inactivated HSV-1 in serum. This simple method could allow safe routine serological diagnostics in high-risk patients.

negative: SARS-CoV-2 and gastrointestinal tract: the dark side of the pandemic

negative: Chapter 24 Nanosensor networks for health-care applications Abstract Functionalized transistors provide effective sensors for a variety of viruses (Zika, severe acute respiratory syndrome), toxins (botulinum), cancers (breast and prostate), and disease or injury biomarkers (troponin, cerebrospinal fluid). A hallmark of this approach is high specificity, rapid response (<5minutes), and ability to be integrated with wireless data transmission capabilities. The ultimate goal is hand-held point-of-care detection that can streamline patient diagnosis.

negative: In vitro assessment of the feline cell-mediated immune response against feline panleukopeniavirus, calicivirus and felid herpesvirus 1 using 5-bromo-2′-deoxyuridine labeling Abstract In this study an in vitro assay was optimized to detect feline proliferating lymphocytes as an assessment for the cell-mediated immune response. For this purpose, 5-bromo-2′-deoxyuridine (BrdU) labeling was chosen because of its sensitivity and the possibility of further characterization of proliferating cells. The assay was optimized by selecting the best batch and concentration of fetal bovine serum, β-mercaptoethanol concentration, cell density, BrdU incubation time and antigen presenting cell type. Cats were vaccinated with the attenuated Nobivac vaccine Tricat and the peripheral blood lymphocyte proliferation responses were quantified upon in vitro restimulation with inactivated and infectious feline panleukopenia virus (FPV), feline calicivirus (FCV) and felid herpesvirus 1 (FeHV-1). Proliferation signals were detected with inactivated FeHV-1 in the CD8+ but not in the CD8− T lymphocyte population, with inactivated FCV and FPV in both CD8− and CD8+ T lymphocyte populations. Restimulation with infectious FCV caused significant proliferation in the CD8− T lymphocyte population only while infectious FPV and FeHV-1 seemed to suppress lymphocyte proliferation in both T cell populations. Additional IFN-γ quantification in the culture supernatant revealed a large correlation between the proliferation signals and IFN-γ production, indicating that BrdU labeling is a very reliable technique to assess and characterize feline lymphoproliferative responses to viral antigens in vitro.

negative: The important role of serology for COVID-19 control

negative: The relationship between the feline coronavirus antibody titre and the age, breed, gender and health status of Australian cats. OBJECTIVES To investigate the relationship between Feline Coronavirus (FCoV) antibody titres and age, breed, gender and health status of Australian cats DESIGN Retrospective study PROCEDURE Results from two serological tests that measure FCoV antibody levels, the Coronase test and the 7B Feline Infectious Peritonitis (FIP) test, were recorded over a 2-year period, with patient signalment, history, presenting complaint and the reason for ordering the test (as available). Results from each antibody test were related to four explanatory variables (breed, age, gender and health status at the time of blood collection) using univariate ordinal logistic regression analyses, Mann Whitney U tests, one-sample sign tests or Kruskal-Wallis analyses, as appropriate. RESULTS Results from 637 Coronase and 191 7B FIP antibody tests were recorded. There were significant differences in median Coronase antibody titres between breeds of cats (P < 0.0005). Specifically, the median Coronase antibody titres of Siamese, Persians, Domestic Shorthairs and Bengal cats (100) were significantly lower than that of British Shorthairs, Cornish Rex and Burmese cats (400, P < 0.0005). There was no statistical relationship between the Coronase or 7B FIP antibody titres and age, gender or overall health status, even when considering only those cats in which clinical signs suggestive of FIP were present. CONCLUSION This study reinforces the complexity of interpreting serological tests for FCoV in both healthy cats and patients with signs compatible with FIR Unique to this study is the detection of a significant relationship between breed and median FCoV antibody titre. This supports the theory that breed related differences exist in response to FCoV infection. The distribution of median Coronase antibody titres by breed was very similar to the pattern of breed predisposition to FIP recently reported in Sydney.

negative: Docetaxel induces moderate ovarian toxicity in mice, primarily affecting granulosa cells of early growing follicles Advances in cancer therapy have focused attention on the quality of life of cancer survivors. Since infertility is a major concern following chemotherapy, it is important to characterize the drug-specific damage to the reproductive system to help find appropriate protective strategies. This study investigates the damage on neonatal mouse ovary maintained in vitro for 6 days, and exposed for 24 h (on Day 2) to clinically relevant doses of Docetaxel (DOC; low: 0.1 µM, mid: 1 µM, high: 10 µM). Furthermore, the study explores the putative protective action exerted by Tri-iodothyronine (T3; 10(−7) M). At the end of culture, morphological analyses and follicle counts showed that DOC negatively impacts on early growing follicles, decreasing primary follicle number and severely affecting health at the transitional and primary stages. Poor follicle health was mainly due to effects on granulosa cells, indicating that the effects of DOC on oocytes were likely to be secondary to granulosa cell damage. DOC damages growing follicles specifically, with no direct effect on the primordial follicle reserve. Immunostaining and western blotting showed that DOC induces activation of intrinsic, type II apoptosis in ovarian somatic cells; increasing the levels of cleaved caspase 3, cleaved caspase 8, Bax and cleaved poly(ADP-ribose) polymerase, while also inducing movement of cytochrome C from mitochondria into the cytosol. T3 did not prevent the damage induced by the low dose of DOC. These results demonstrated that DOC induces a gonadotoxic effect on the mouse ovary through induction of somatic cell apoptosis, with no evidence of direct effects on the oocyte, and that the damaging effect is not mitigated by T3.

negative: COVID-19 excess deaths in the United States during April 2020 Background: Some have claimed that the number of COVID-19 deaths is not much greater than would be experienced in the usual course of events. We sought to estimate the number of deaths due to COVID-19 in the United States during April 2020 and compare that to the number of expected deaths in the same time period. Methods: The Institute for Health Metrics and Evaluation (IHME) predicts that 67,212 COVID-19 deaths will occur during April 2020. To obtain the number of excess COVID-19 deaths, we multiplied published infection fatality rates by age by population numbers to obtain assumed infection rates. We then subtracted the expected number of deaths calculated using life table mortality rates. Results: During April 2020 there may be 61,690 to 62,526 excess deaths. Population infection rates of 3.6% to 4.3% by mid-April 2020 would generate the number of COVID-19 deaths predicted by IHME. Conclusions: During April 2020 over 90% of the COVID-19 deaths can be classified as excess deaths. These deaths would normally occur over 11.2 to 13.3 months instead of being concentrated in 1 month.

negative: Physical inactivity and cardiovascular disease at the time of coronavirus disease 2019 (COVID-19)

negative: Use of Multiple Imputation to Estimate the Proportion of Respiratory Virus Detections Among Patients Hospitalized With Community-Acquired Pneumonia BACKGROUND: Real-time polymerase chain reaction (PCR) on respiratory specimens and serology on paired blood specimens are used to determine the etiology of respiratory illnesses for research studies. However, convalescent serology is often not collected. We used multiple imputation to assign values for missing serology results to estimate virus-specific prevalence among pediatric and adult community-acquired pneumonia hospitalizations using data from an active population-based surveillance study. METHODS: Presence of adenoviruses, human metapneumovirus, influenza viruses, parainfluenza virus types 1–3, and respiratory syncytial virus was defined by positive PCR on nasopharyngeal/oropharyngeal specimens or a 4-fold rise in paired serology. We performed multiple imputation by developing a multivariable regression model for each virus using data from patients with available serology results. We calculated absolute and relative differences in the proportion of each virus detected comparing the imputed to observed (nonimputed) results. RESULTS: Among 2222 children and 2259 adults, 98.8% and 99.5% had nasopharyngeal/oropharyngeal specimens and 43.2% and 37.5% had paired serum specimens, respectively. Imputed results increased viral etiology assignments by an absolute difference of 1.6%–4.4% and 0.8%–2.8% in children and adults, respectively; relative differences were 1.1–3.0 times higher. CONCLUSIONS: Multiple imputation can be used when serology results are missing, to refine virus-specific prevalence estimates, and these will likely increase estimates.

negative: Diagnostic Testing for the Novel Coronavirus.

negative: A Major Role of Macrophage Activation by Interferon-Gamma during Mouse Hepatitis Virus Type 3 Infection. I. Genetically Dependent Resistance() Resistance of mice to mouse hepatitis virus type 3 (MHV3) infection is genetically determined. Normal adult A/J mice are resistant, and BALB/c mice are susceptible. Higher titers of virus and interferon (IFN) in vivo were found in MHV3-infected BALB/c mice compared with A/J mice. In vitro activation of macrophages (MФ) by lipopolysaccharide (LPS) delayed MHV3 replication only in cells that originated from A/J mice, although cell populations from both A/J, and BALB/c mice were able to synthesize comparable amounts of IFN-α/β. Using specific antibodies, we have shown that the delayed MHV3 replication in LPS-activated A/J MФ was due, in part, to IFN-α/β. A/J MФ were found to be more sensitive to IFN-γ than to IFN-α/β, and BALB/c MФ did not develop an antiviral state to either IFN. Cultured spleen cells from A/J mice synthesized more IFN-γ than BALB/c spleen cells after specific or non-specific stimulation. The results indicate that IFN-activated MФ may play a crucial role in the resistance to MHV3 infection. Since IFN-γ is produced in large amounts by A/J spleen cells after specific stimulation with MHV3 and is efficient in activating the A/J MФ, a T cell-dependent mechanism- is likely to be involved.

negative: Fetal tissue ban blocks study of potential coronavirus therapies The Trump administration’s 2019 ban on the use of human fetal tissue by scientists at the National Institutes of Health (NIH) is preventing a leading researcher from using special mice to test potential therapies for coronavirus disease 2019 (COVID-19), The Washington Post reports According to the Post, Kim Hasenkrug, an immunologist at NIH’s Rocky Mountain Laboratories, has spent nearly 1 month appealing to the Trump administration to grant him an exemption to the administration’s strict policy Federal restrictions imposed in June 2019 ban NIH scientists from using human fetal tissue donated after elective abortions

negative: Serological Diagnosis of Flavivirus-Associated Human Infections Arthropod-borne viruses (arboviruses) belonging to the Flavivirus genus of the Flaviviridae family, are a major public health threat in tropical and subtropical regions, and have recently become a medical concern in temperate zones. Most flaviviruses are classified as zoonotic viruses. Human flavivirus infections can be asymptomatic, responsible for unspecific symptoms in the first few days following infection, or responsible for severe complications potentially resulting in death. During the first days following symptom onset, laboratory diagnosis of acute human flavivirus infection is mainly based on molecular detection of the viral genome by RT-PCR methods, followed by the capture of specific antibodies using serological tests after the first week of infection. The detection of antibodies that have virus neutralizing activity can be used to confirm flavivirus infection. However, human flavivirus infections induce the production of cross-reactive antibodies, often making serology inconclusive. Indeed, serological diagnosis of flavivirus infection can be hampered by a patient’s history of flavivirus exposure, particularly in regions where multiple antigenically related flaviviruses co-circulate. We focus our mini review on conventional immunoassays that allow the diagnosis of major flavivirus-associated human infections in basic, routine and high-profile central health centers; and the interpretation of diagnostic serology tests for patients living within different epidemiological situations.

negative: Antibody tests for COVID-19: drawing attention to the importance of analytical specificity.

negative: The epidemic of 2019-novel-coronavirus (2019-nCoV) pneumonia and insights for emerging infectious diseases in the future Abstract At the end of December 2019, a novel coronavirus, 2019-nCoV, caused an outbreak of pneumonia spreading from Wuhan, Hubei province, to the whole country of China, which has posed great threats to public health and attracted enormous attention around the world. To date, there are no clinically approved vaccines or antiviral drugs available for these human coronavirus infections. Intensive research on the novel emerging human infectious coronaviruses is urgently needed to elucidate their route of transmission and pathogenic mechanisms, and to identify potential drug targets, which would promote the development of effective preventive and therapeutic countermeasures. Herein, we describe the epidemic and etiological characteristics of 2019-nCoV, discuss its essential biological features, including tropism and receptor usage, summarize approaches for disease prevention and treatment, and speculate on the transmission route of 2019-nCoV.

negative: Comparative Genomic Analysis of Rapidly Evolving SARS-CoV-2 Viruses Reveal Mosaic Pattern of Phylogeographical Distribution The Coronavirus Disease-2019 (COVID-19) that started in Wuhan, China in December 2019 has spread worldwide emerging as a global pandemic. The severe respiratory pneumonia caused by the novel SARS-CoV-2 has so far claimed more than 60,000 lives and has impacted human lives worldwide. However, as the novel SARS-CoV-2 displays high transmission rates, their underlying genomic severity is required to be fully understood. We studied the complete genomes of 95 SARS-CoV-2 strains from different geographical regions worldwide to uncover the pattern of the spread of the virus. We show that there is no direct transmission pattern of the virus among neighboring countries suggesting that the outbreak is a result of travel of infected humans to different countries. We revealed unique single nucleotide polymorphisms (SNPs) in nsp13-16 (ORF1b polyprotein) and S-Protein within 10 viral isolates from the USA. These viral proteins are involved in RNA replication, indicating highly evolved viral strains circulating in the population of USA than other countries. Furthermore, we found an amino acid addition in nsp16 (mRNA cap-1 methyltransferase) of the USA isolate (MT188341) leading to shift in amino acid frame from position 2540 onwards. Through the construction of SARS-CoV-2-human interactome, we further revealed that multiple host proteins (PHB, PPP1CA, TGF-β, SOCS3, STAT3, JAK1/2, SMAD3, BCL2, CAV1 & SPECC1) are manipulated by the viral proteins (nsp2, PL-PRO, N-protein, ORF7a, M-S-ORF3a complex, nsp7-nsp8-nsp9-RdRp complex) for mediating host immune evasion. Thus, the replicative machinery of SARS-CoV-2 is fast evolving to evade host challenges which need to be considered for developing effective treatment strategies.

negative: A recombinant nucleocapsid protein-based indirect enzyme-linked immunosorbent assay to detect antibodies against porcine deltacoronavirus Recently, porcine deltacoronavirus (PDCoV) has been proven to be associated with enteric disease in piglets. Diagnostic tools for serological surveys of PDCoV remain in the developmental stage when compared with those for other porcine coronaviruses. In our study, an indirect enzyme-linked immunosorbent assay (ELISA) (rPDCoV-N-ELISA) was developed to detect antibodies against PDCoV using a histidine-tagged recombinant nucleocapsid (N) protein as an antigen. The rPDCoV-N-ELISA did not cross-react with antisera against porcine epidemic diarrhea virus, swine transmissible gastroenteritis virus, porcine group A rotavirus, classical swine fever virus, porcine circovirus-2, porcine pseudorabies virus, and porcine reproductive and respiratory syndrome virus; the receiver operating characteristic (ROC) curve analysis revealed 100% sensitivity and 90.4% specificity of the rPDCoV-N-ELISA based on samples of known status (n=62). Analyses of field samples (n=319) using the rPDCoV-N-ELISA indicated that 11.59% of samples were positive for antibodies against PDCoV. These data demonstrated that the rPDCoV-N-ELISA can be used for epidemiological investigations of PDCoV and that PDCoV had a low serum prevalence in pig population in Heilongjiang province, northeast China.

negative: In Vitro Diagnostic Assays for COVID-19: Recent Advances and Emerging Trends There have been tremendous advances in in vitro diagnostic (IVD) assays for coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The main IVD assays used for COVID-19 employ real-time reverse transcriptase polymerase chain reaction (RT-PCR) that takes a few hours. But the assay duration has been shortened to 45 min by Cepheid. Of interest is the point-of-care (POC) molecular assay by Abbott that decreased the assay duration to just 5 min. Most molecular tests have been approved by the United States Food and Drug Administration (FDA) under emergency use authorization (EUA) and are Conformité Européenne (CE) marked. A wide range of serology immunoassays (IAs) have also been developed that complement the molecular assays for the diagnosis of COVID-19. The most prominent IAs are automated chemiluminescent IA (CLIA), manual ELISA, and rapid lateral flow IA (LFIA), which detect the immunoglobulin M (IgM) and immunoglobulin G (IgG) produced in persons in response to SARS-CoV-2 infection. The ongoing research efforts and advances in complementary technologies will pave the way to new POC IVD assays in the coming months. However, the performance of IVD assays needs to be critically evaluated before they are employed for the clinical diagnosis of COVID-19.

negative: Non-specific Effect of Vaccines: Immediate Protection against Respiratory Syncytial Virus Infection by a Live Attenuated Influenza Vaccine The non-specific effects (NSEs) of vaccines have been discussed for their potential long-term beneficial effects beyond direct protection against a specific pathogen. Cold-adapted, live attenuated influenza vaccine (CAIV) induces local innate immune responses that provide a broad range of antiviral immunity. Herein, we examined whether X-31ca, a donor virus for CAIVs, provides non-specific cross-protection against respiratory syncytial virus (RSV). The degree of RSV replication was significantly reduced when X-31ca was administered before RSV infection without any RSV-specific antibody responses. The vaccination induced an immediate release of cytokines and infiltration of leukocytes into the respiratory tract, moderating the immune perturbation caused by RSV infection. The potency of protection against RSV challenge was significantly reduced in TLR3(-/-) TLR7(-/-) mice, confirming that the TLR3/7 signaling pathways are necessary for the observed immediate and short-term protection. The results suggest that CAIVs provide short-term, non-specific protection against genetically unrelated respiratory pathogens. The additional benefits of CAIVs in mitigating acute respiratory infections for which vaccines are not yet available need to be assessed in future studies.

negative: Measurement of neutralizing antibody responses against H5N1 clades in immunized mice and ferrets using pseudotypes expressing influenza hemagglutinin and neuraminidase Abstract Neutralizing antibody is associated with the prevention and clearance of influenza virus infection. Microneutralization (MN) and hemagglutination inhibition (HI) assays are currently used to evaluate neutralizing antibody responses against human and avian influenza viruses, including H5N1. The MN assay is somewhat labor intensive, while HI is a surrogate for neutralization. Moreover, use of replication competent viruses in these assays requires biosafety level 3 (BSL-3) containment. Therefore, a neutralization assay that does not require BSL-3 facilities would be advantageous. Toward this goal, we generated a panel of pseudotypes expressing influenza hemagglutinin (HA) and neuraminidase (NA) and developed a pseudotype-based neutralization (PN) assay. Here we demonstrate that HA/NA pseudotypes mimic release and entry of influenza virus and that the PN assay exhibits good specificity and reveals quantitative difference in neutralizing antibody titers against different H5N1 clades and subclades. Using immune ferret sera, we demonstrated excellent correlation between the PN, MN, and HI assays. Thus, we conclude that the PN assay is a sensitive and quantifiable method to measure neutralizing antibodies against diverse clades and subclades of H5N1 influenza virus.

negative: Projecting the transmission dynamics of SARS-CoV-2 through the post-pandemic period There is an urgent need to project how transmission of the novel betacoronavirus SARS-CoV-2 will unfold in coming years. These dynamics will depend on seasonality, the duration of immunity, and the strength of cross-immunity to/from the other human coronaviruses. Using data from the United States, we measured how these factors affect transmission of human betacoronaviruses HCoV-OC43 and HCoV-HKU1. We then built a mathematical model to simulate transmission of SARS-CoV-2 through the year 2025. We project that recurrent wintertime outbreaks of SARS-CoV-2 will probably occur after an initial pandemic wave. We summarize the full range of plausible transmission scenarios and identify key data still needed to distinguish between them, most importantly longitudinal serological studies to determine the duration of immunity to SARS-CoV-2.

negative: Mycoplasma pneumoniae: Current Knowledge on Nucleic Acid Amplification Techniques and Serological Diagnostics Mycoplasma pneumoniae (M. pneumoniae) belongs to the class Mollicutes and has been recognized as a common cause of respiratory tract infections (RTIs), including community-acquired pneumonia (CAP), that occur worldwide and in all age groups. In addition, M. pneumoniae can simultaneously or sequentially lead to damage in the nervous system and has been associated with a wide variety of other acute and chronic diseases. During the past 10 years, the proportion of LRTI in children and adults, associated with M. pneumoniae infection has ranged from 0 to more than 50%. This variation is due to the age and the geographic location of the population examined but also due to the diagnostic methods used. The true role of M. pneumoniae in RTIs remains a challenge given the many limitations and lack of standardization of the applied diagnostic tool in most cases, with resultant wide variations in data from different studies. Correct and rapid diagnosis and/or management of M. pneumoniae infections is, however, critical to initiate appropriate antibiotic treatment and is nowadays usually done by PCR and/or serology. Several recent reviews, have summarized current methods for the detection and identification of M. pneumoniae. This review will therefore provide a look at the general principles, advantages, diagnostic value, and limitations of the most currently used detection techniques for the etiological diagnosis of a M. pneumoniae infection as they evolve from research to daily practice.

negative: Early epidemiological analysis of the coronavirus disease 2019 outbreak based on crowdsourced data: a population-level observational study Summary Background As the outbreak of coronavirus disease 2019 (COVID-19) progresses, epidemiological data are needed to guide situational awareness and intervention strategies. Here we describe efforts to compile and disseminate epidemiological information on COVID-19 from news media and social networks. Methods In this population-level observational study, we searched DXY.cn, a health-care-oriented social network that is currently streaming news reports on COVID-19 from local and national Chinese health agencies. We compiled a list of individual patients with COVID-19 and daily province-level case counts between Jan 13 and Jan 31, 2020, in China. We also compiled a list of internationally exported cases of COVID-19 from global news media sources (Kyodo News, The Straits Times, and CNN), national governments, and health authorities. We assessed trends in the epidemiology of COVID-19 and studied the outbreak progression across China, assessing delays between symptom onset, seeking care at a hospital or clinic, and reporting, before and after Jan 18, 2020, as awareness of the outbreak increased. All data were made publicly available in real time. Findings We collected data for 507 patients with COVID-19 reported between Jan 13 and Jan 31, 2020, including 364 from mainland China and 143 from outside of China. 281 (55%) patients were male and the median age was 46 years (IQR 35–60). Few patients (13 [3%]) were younger than 15 years and the age profile of Chinese patients adjusted for baseline demographics confirmed a deficit of infections among children. Across the analysed period, delays between symptom onset and seeking care at a hospital or clinic were longer in Hubei province than in other provinces in mainland China and internationally. In mainland China, these delays decreased from 5 days before Jan 18, 2020, to 2 days thereafter until Jan 31, 2020 (p=0·0009). Although our sample captures only 507 (5·2%) of 9826 patients with COVID-19 reported by official sources during the analysed period, our data align with an official report published by Chinese authorities on Jan 28, 2020. Interpretation News reports and social media can help reconstruct the progression of an outbreak and provide detailed patient-level data in the context of a health emergency. The availability of a central physician-oriented social network facilitated the compilation of publicly available COVID-19 data in China. As the outbreak progresses, social media and news reports will probably capture a diminishing fraction of COVID-19 cases globally due to reporting fatigue and overwhelmed health-care systems. In the early stages of an outbreak, availability of public datasets is important to encourage analytical efforts by independent teams and provide robust evidence to guide interventions. Funding Fogarty International Center, US National Institutes of Health.

negative: Nonpharmaceutical interventions and epidemic intensity during the 2019 novel coronavirus disease pandemic

negative: Tools to therapeutically harness the human antibody response The natural human antibody response is a rich source of highly specific, neutralizing and self-tolerant therapeutic reagents. Recent advances have been made in isolating and characterizing monoclonal antibodies that are generated in response to natural infection or vaccination. Studies of the human antibody response have led to the discovery of crucial epitopes that could serve as new targets in vaccine design and in the creation of potentially powerful immunotherapies. With a focus on influenza virus and HIV, herein we summarize the technological tools used to identify and characterize human monoclonal antibodies and describe how these tools might be used to fight infectious diseases.

negative: Chapter 14 Middle East Respiratory Syndrome-Coronavirus (MERS-CoV) Infection MERS-CoV infection is an emerging infectious disease with a high mortality rate. The exact incidence and prevalence of the disease is not known as we do not have yet reliable serologic tests. The diagnosis of MERS-CoV infection relies on detection of the virus using real-time RT-PCR. Currently, the origin of the virus and the source is not known and future studies are needed to elucidate possible sources and the best therapeutic options.

negative: Infection of a calf with the enteric coronavirus strain Paris A tissue-culture-grown enteric coronavirus infected the whole of the gastrointestinal tract and caused enteritis and diarrhoea in a 10-day-old gnotobiotic Friesian calf. Diarrhoea occurred 2 days after inoculation and excretion of virus in faeces and rectal swabs increased until necropsy at 3 days. Virus growth, as detected by indirect immunofluorescence, virus isolation, and thin section electron microscopy, was most extensive in the epithelium of the colon and rectum at 3 days after inoculation. No virus was detected in other organs or in the pleural, peritoneal and oropharyngeal cavities. The origin and host specificity of this coronavirus is discussed.

negative: Diagnostic electron microscopy is still a timely and rewarding method Abstract Background: Parallel to its technical development starting in the 1930s, electron microscopy (EM) became an important tool in basic and clinical virology. First utilized in the rapid diagnosis of smallpox, it developed to a diagnostic routine in the early 1960s using the negative staining technique. EM was applied to infected cell-cultures and also to ‘dirty’ specimens including urine, feces, vesicle fluid, liquor. With the implementation of molecular biological and genetic techniques, the use of diagnostic EM decreased. Objectives: (1) To give a perspective on future indications and possible uses by discussing the past and the present of diagnostic EM, (2) To describe the system of External Quality Assessment on EM virus diagnosis (EQA-EMV) established in 1994 by our laboratory and its achievements. Study design: EQA-EMV is run to evaluate, to confirm and to improve the quality of diagnostic EM. Two different types of specimen are sent out: (1) prepared grids to assess and train the diagnostic skills of the participants, (2) stabilized virus particle suspensions to assess preparation efficiency. Results: Diagnostic EM differs from other diagnostic tests in its rapidity and its undirected ‘open view’. To emphasize these advantages, the indications for diagnostic EM are discussed, fundamental for a continuing future adaptation. Besides appropriate techniques, quality control measures are required to achieve and keep high diagnostic standards. The results from 6 years of EQA-EMV are presented. Conclusions: In the history of diagnostic EM in virology, a change in use has been seen. Starting in the 1990s and coincident with the broad introduction of ‘modern’ diagnostic techniques, the number of EM diagnostic labs has decreased considerably—in spite of the obvious advantages of this technique. To guarantee the continuing performance of diagnostic EM in the future, EQA runs have to be performed as with other techniques in the diagnostic armament. The growing number of participants and participating countries indicates an interest in as well as a need for this program.

negative: Simultaneous detection of antibodies to mouse hepatitis virus recombinant structural proteins by a microsphere-based multiplex fluorescence immunoassay. We describe a new microsphere-based multiplex fluorescent immunoassay (MFI) using recombinant mouse hepatitis virus (MHV) proteins to detect antibodies to coronaviruses in mouse and rat sera. All the recombinant proteins, including nucleocapsid (N) and 3 subunits of spike protein, S1, S2, and Smid, showed positive reactivity in MFI with mouse antisera to 4 MHV strains (MHV-S, -A59, -JHM, and -Nu67) and rat antiserum to a strain of sialodacryoadenitis virus (SDAV-681). The MFI was evaluated for its diagnostic power, with panels of mouse sera classified as positive or negative for anti-MHV antibodies by enzyme-linked immunosorbent assay (ELISA) using MHV virion antigen and indirect fluorescent antibody assay. The reactivities of 236 naturally infected mouse sera were examined; 227 samples were positive by MFI using S2 antigen (96% sensitivity), and 208 samples were positive using N antigen (88% sensitivity). Based on the assessment by MFI using the S2 and N antigens, only 3 serum samples showed double-negative results, indicating a false-negative rate of 1.3%. In 126 uninfected mouse sera, including 34 ELISA false-positive sera, only 7 samples showed false-positive results by MFI using either the S2 or N antigen (94% specificity). Similarly, the S2 and N antigen-based MFI was 98% sensitive and 100% specific in detecting anticoronavirus antibodies in rat sera. Thus, this MFI-based serologic assay using the S2 and N antigens promises to be a reliable diagnostic method, representing a highly sensitive and specific alternative to traditional ELISA for detection of coronavirus infections in laboratory mouse and rat colonies.

negative: Virus-specific RNA and Antibody from Convalescent-phase SARS Patients Discharged from Hospital Severe acute respiratory syndrome (SARS) is caused by a novel coronavirus (SARS-CoV). In a longitudinal cross-sectional study, we determined the prevalence of virus in bodily excretions and time of seroconversion in discharged patients with SARS. Conjunctival, throat, stool, and urine specimens were collected weekly from 64 patients and tested for SARS-CoV RNA by real-time polymerase chain reaction; serum samples were collected weekly and tested for SARS-CoV antibody with indirect enzyme immunoassay and immunofluorescence assay. In total, 126 conjunctival, 124 throat swab, 116 stool, and 124 urine specimens were analyzed. Five patients had positive stool samples, collected in weeks 5–9. Two patients seroconverted in weeks 7 and 8; the others were seropositive at the first serum sample collection. In this study, 5 (7.8%) of 64 patients continued to shed viral RNA in stool samples only, for up to week 8 of illness. Most seroconversions occurred by week 6 of illness.

negative: Suggested new breakpoints of anti-MERS-CoV antibody ELISA titers: performance analysis of serologic tests To provide optimal cut-off values of anti-Middle East respiratory syndrome coronavirus (MERS-CoV) serologic tests, we evaluated performance of ELISA IgG, ELISA IgA, IFA IgM, and IFA IgG using 138 serum samples of 49 MERS-CoV-infected patients and 219 serum samples of 219 rRT-PCR-negative MERS-CoV-exposed healthcare personnel and patients. The performance analysis was conducted for two different purposes: (1) prediction of neutralization activity in MERS-CoV-infected patients, and (2) epidemiologic surveillance of MERS-CoV infections among MERS-CoV-exposed individuals. To evaluate performance according to serum collection time, we used ‘days post onset of illness (dpoi)’ and ‘days post exposure (dpex)’ assessing neutralization activity and infection diagnosis, respectively. Performance of serologic tests improved with delayed sampling time, being maximized after a seroconversion period. In predicting neutralization activity, ELISA IgG tests showed optimal performance using sera collected after 21 dpoi at cut-off values of OD ratio 0.4 (sensitivity 100% and specificity 100%), and ELISA IgA showed optimal performance using sera collected after 14 dpoi at cut-off value of OD ratio 0.2 (sensitivity 85.2% and specificity 100%). In diagnosis of MERS-CoV infection, ELISA IgG exhibited optimal performance using sera collected after 28 dpex, at a cut-off value of OD ratio 0.2 (sensitivity 97.3% and specificity 92.9%). These new breakpoints are markedly lower than previously suggested values (ELISA IgG OD ratio 1.1, sensitivity 34.8% and specificity 100% in the present data set), and the performance data help serologic tests to be practically used in the field of MERS management. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10096-017-3043-3) contains supplementary material, which is available to authorized users.

negative: The aetiology, origins, and diagnosis of severe acute respiratory syndrome Summary Severe acute respiratory syndrome (SARS) is a new infectious disease that first emerged in Guangdong province, China, in November, 2002. A novel coronavirus was later identified in patients with SARS. The detection of the virus in these patients, its absence in healthy controls or other patients with atypical pneumonia, and the reproduction of a similar disease in a relevant animal model fulfilled Koch's postulates for implicating this coronavirus as the causal agent of SARS. The full genome sequence was determined within weeks of the virus's identification. The rapid progress in the aetiology, the development of laboratory diagnostic tests, and the defining of routes of viral transmission were facilitated through a unique WHO-coordinated virtual network of laboratories, which shared information on a real-time basis through daily teleconferences. Subsequent studies have indicated that the SARS coronavirus is of animal origin, that its precursor is still present in animal populations within the region, and that live-animal markets in southern China may have provided the animal-human interphase that allowed this precursor virus to adapt to human-human transmission. These findings underscore the potential for the re-emergence of SARS and the need for laboratory tests for early diagnosis. However, the low viral load in the respiratory tract makes early diagnosis of SARS a diagnostic challenge, although improvements in the sensitivity of molecular diagnostic methods continue to be made.

negative: 2018 international meeting of the Global Virus Network Abstract The Global Virus Network (GVN) was established in 2011 to strengthen research and responses to emerging viral causes of human disease and to prepare against new viral pandemics. There are now 45 GVN Centers of Excellence and 7 Affiliate laboratories in 29 countries. The 10th International GVN meeting was held from November 28–30, 2018 in Veyrier du Lac, France and was co-hosted by the two GVN Centers of Excellence, the Mérieux Foundation and the University of Veterinary Medicine Hannover (TiHo). The theme of this 10th International GVN meeting was “Eradication and control of (re-) emerging viruses”. This report highlights the recent accomplishments of GVN researchers in several important areas of medical virology, including strategies for the eradication of smallpox, measles, polio, SARS and vector-borne or zoonotic infections, emergence and intervention strategies for retroviruses and arboviruses, preparedness for outbreaks of Filo- and other hemophilic viruses, pathogenesis, impact and prevention of respiratory viruses, as well as, viruses affecting the central and peripheral nervous system. Also threats in crisis settings like refugee camps were presented.

negative: Potential Neutralizing Antibodies Discovered for Novel Corona Virus Using Machine Learning The fast and untraceable virus mutations take lives of thousands of people before the immune system can produce the inhibitory antibody. Recent outbreak of novel coronavirus infected and killed thousands of people in the world. Rapid methods in finding peptides or antibody sequences that can inhibit the viral epitopes of COVID-19 will save the life of thousands. In this paper, we devised a machine learning (ML) model to predict the possible inhibitory synthetic antibodies for Corona virus. We collected 1933 virus-antibody sequences and their clinical patient neutralization response and trained an ML model to predict the antibody response. Using graph featurization with variety of ML methods, we screened thousands of hypothetical antibody sequences and found 8 stable antibodies that potentially inhibit COVID-19. We combined bioinformatics, structural biology, and Molecular Dynamics (MD) simulations to verify the stability of the candidate antibodies that can inhibit the Corona virus.

negative: Retrospective serological investigation of severe acute respiratory syndrome coronavirus antibodies in recruits from mainland China. Different assays were used to analyze 1,621 serum specimens collected from military recruits from the People's Republic of China in 2002 for severe acute respiratory syndrome (SARS) coronavirus antibodies. The results demonstrated that the subjects either had rarely been exposed to the virus before the 2003 SARS outbreak or had not been exposed but the nucleocapsid protein cross-reacted with other antibodies in humans.

negative: Case-finding: Fast, Available, and Efficient Font-line Diagnostics for SARS-CoV-2

negative: Quantitative Detection and Viral Load Analysis of SARS-CoV-2 in Infected Patients BACKGROUND: Coronavirus disease 2019 (COVID-19) has become a public health emergency. The widely used reverse transcription PCR (RT-PCR) method has limitations for clinical diagnosis and treatment. METHODS: A total of 323 samples from 76 COVID-19 confirmed patients were analyzed by droplet digital PCR (ddPCR) and RT-PCR based two target genes (ORF1ab and N). Nasal swabs, throat swabs, sputum, blood, and urine were collected. Clinical and imaging data were obtained for clinical staging. RESULTS: In 95 samples tested positive by both methods, the cycle threshold (Ct) of RT-PCR was highly correlated with the copy numbed of ddPCR (ORF1ab gene, R(2) = 0.83; N gene, R(2) = 0.87). 4 (4/161) negative and 41 (41/67) single-gene positive samples tested by RT-PCR were positive according to ddPCR with viral load ranging from 11.1 to 123.2 copies/test. Then the viral load of respiratory samples was compared and the average viral load in sputum (17429 ± 6920 copies/test) was found to be significantly higher than in throat swabs (2552 ± 1965 copies/test, p < 0.001) and nasal swabs (651 ± 501 copies/test, p < 0.001). Furthermore, the viral load in the early and progressive stages were significantly higher than that in the recovery stage (46800 ± 17272 vs 1252 ± 1027, p < 0.001) analyzed by sputum samples. CONCLUSIONS: Quantitative monitoring of viral load in lower respiratory tract samples helps to evaluate disease progression, especially in cases of low viral load.

negative: [Health protection guideline of mobile cabin hospitals during Novel Coronavirus Pneumonia (NPC) outbreak]. This guideline is applicable to the health protection requirements of large indoor stadiums which are reconstructed as treatment sites for the Novel Coronavirus Pneumonia (NPC) patients with mild symptoms during the outbreak. Focusing on the health emergency scenario of severe virus infectious diseases and atypical places where NPC patients with mild symptom gather, from perspectives of functional zones, hygiene facilities, personal protection, and management system, health risk protection recommendations and countermeasures are comprehensively proposed to mainly protect staffs and surrounding environment. The implementation of this guideline will provide technique support for emergency requirements of indoor stadiums reconstructed as mobile cabin hospitals.

negative: Molecular Techniques for Blood and Blood Product Screening The Food and Drug Administration (FDA) is responsible for ensuring the safety of the more than 15 million units of blood and blood components donated each year in the United States. “Blood banking has become a manufacturing industry, an industry that must conform to high standards and quality control requirements comparable to those of pharmaceutical companies or other regulated industries,” said David A. Kessler, MD, former FDA commissioner [1]. Screening donated blood for infectious diseases that can be transmitted through blood transfusion is a very important step in ensuring safety. The United States has the safest blood supply in the world [1] and the FDA is striving to keep it safe by decreasing the risk of infectious disease transmission. The regulatory agency is continuously updating its requirements and standards for collecting and processing blood. As mentioned earlier, an important step in ensuring safety is the screening of donated blood for infectious diseases. In the United States, tests for infectious diseases are routinely conducted on each unit of donated blood, and these tests are designed to comply with regulatory requirements (Table 28.1). The field of clinical microbiology and virology are now focusing on molecular technology. Currently, nucleic acid testing techniques have been developed to screen blood and plasma products for evidence of very recent viral infections that could be missed by conventional serologic tests. It is time for all blood safety procedures to include molecular detection techniques. This approach can significantly aid in blood safety to reduce the risk of transmission of serious disease by transfusion. This chapter reviews the current antigen/antibody-based technology, molecular biological technology, and published regulatory policy data for blood safety.

negative: High‐cell‐passage canine coronavirus vaccine providing sterilising immunity Objectives: To evaluate the ability of a high‐cell‐passage canine coronavirus vaccine to immunise dogs against challenge with a field isolate of the virus. Methods: Three dogs that had previously tested seronegative and virus‐negative for canine coronavirus were inoculated twice, at 21‐day intervals, with the vaccine and kept under observation. Two seronegative and virus‐negative dogs served as unvaccinated controls. For safety tests, two additional dogs were inoculated oronasally with 10 times the vaccinal dose and no reactions were observed. Faecal samples were collected daily from the vaccinated dogs after the first and second inoculations. Both vaccinated and control dogs were challenged two weeks after the second vaccination with a field canine coronavirus strain. Blood samples were collected for serological tests before vaccination and at weekly intervals after vaccinations and challenge. Results: Virus was not detected in faecal samples after the first or second vaccinations by virus isolation assays and PCR. Significantly, the vaccinated dogs did not have clinical signs after challenge and no virus shedding was observed. The two unvaccinated control dogs had moderate enteritis, and virus was detected in cell cultures starting from three days postchallenge (dog 1) and two days postchallenge (dog 2), and by PCR for 23 median days. Clinical Significance: This study showed the efficacy of a high‐cell‐passage canine coronavirus vaccine in preventing infection of dogs by virulent virus and, specifically, its ability to induce sterilising immunity.

negative: Modeling Exit Strategies from COVID-19 Lockdown with a Focus on Antibody Tests This paper presents two epidemiological models that have been developed in order to study the disease dynamics of the COVID-19 pandemic and exit strategies from the lockdown which has been imposed on many countries world-wide. A strategy is needed such that both the health system is not overloaded letting people die in an uncontrolled way and also such that the majority of people can get back their social contacts as soon as possible. We investigate the potential effects of a combination of measures such as continuation of hygienic constraints after leaving lockdown, isolation of infectious persons, repeated and adaptive short-term contact reductions and also large-scale use of antibody tests in order to know who can be assumed to be immune and participate at public life without constraints. We apply two commonly used modeling approaches: extended SEIR models formulated both as System Dynamics and Agent-Based Simulation, in order to get insight into the disease dynamics of a complete country like Germany and also into more detailed behavior of smaller regions. We confirm the findings of other models that without intervention the consequences of the pandemic can be catastrophic and we extend such findings with effective strategies to overcome the challenge. Based on the modeling assumptions it can be expected that repeated short-term contact reductions will be necessary in the next years to avoid overload of the health system and that on the other side herd immunity can be achieved and antibody tests are an effective way to mitigate the contact reductions for many.

negative: Coronavirus infection in mink (Mustela vision). Serological evidence of infection with a coronavirus related to transmissible gastroenteritis virus and porcine epidemic diarrhea virus Abstract Antibodies to a transmissible gastroenteritis virus (TGEV)-related coronavirus have been demonstrated in mink sera by indirect immunofluorescence, peroxidase-linked antibody assays and immunoblotting. This is the first serological evidence of a specific coronavirus infection in mink. The putative mink coronavirus (MCV) seems to be widespread in the Danish mink population with a prevalence approaching 100%. Analysis by immunoblotting has shown that MCV is closely related to TGEV by the spike (S), matrix (M) and nucleoprotein (N) polypeptides. Furthermore, antibodies to MCV also cross-reacted with N and M polypeptides of porcine epidemic diarrhea virus (PEDV). Thus MCV may occupy an intermediate position between the TGEV group of coronaviruses and PEDV. The possibility that MCV may be associated with syndromes of acute enteritis in preweaning mink is discussed.

negative: Utility of Substandard Face Mask Options for Health Care Workers During the COVID-19 Pandemic

negative: Advanced Immunotechnological Methods for Detection and Diagnosis of Viral Infections: Current Applications and Future Challenges Diagnosis and identification of viruses is an important component of diagnostic virology laboratory. Although various modes of diagnostic methods are now available at disposal, a vast majority of the diseases across the globe remain undiagnosed. This is largely due to the overlapping undifferentiated set of symptoms across myriad set of RNA and DNA viral diseases. As such, it becomes critical to take into consideration several factors for viral diagnosis ranging from the type and quality of specimen collected, time of specimen collection, mode of transport, accuracy, specificity, sensitivity, and the type of diagnostic method used. This chapter broadly emphasizes various methods on diagnostic virology ranging from the classical methods of diagnosis to the most recently developed molecular methods of detection of virus.

negative: Singapore claims first use of antibody test to track coronavirus infections ;Science ;AAAS In what appears to be a first, disease trackers in Singapore have used an experimental antibody test for COVID-19 to confirm that a suspected patient was infected with the coronavirus The patient was one of two people who together formed a missing link between two clusters of cases that each occurred in a Singaporean church Researchers around the world are racing to develop antibody tests, also called serological tests, that can confirm whether someone was infected even after their immune system has cleared the virus that causes COVID-19 The group that developed the test, at Duke-NUS Medical School in Singapore, is among the front-runners, although its assay has to be validated before it is taken into production and deployed widely

negative: Voice from China: nomenclature of the novel coronavirus and related diseases

negative: Infectious Disease Diagnostic Assays Dogs and cats are commonly exposed to infectious disease agents. The following article is an update on the most common infectious disease assays used in small animal practice. In some situations, results of pathogen-specific molecular diagnostic assays can be used to assist the practicing veterinarian in the management of patients with infectious diseases. However, with some infectious disease agents, the assays are positive in healthy and ill animals and can be falsely negative and so the predictive values of the assays vary.

negative: Infections with Viruses and Mycoplasma pneumoniae during Exacerbations of Chronic Bronchitis The association of viral and Mycoplasma pneumoniae infections with acute exacerbations of chronic bronchitis was studied by serologic or isolation techniques in 46 adult men during the five years from 1964 through 1968. Serologic evidence of viral or M. pneumoniae infection was detected in 25% of 166 episodes of exacerbation and 14% of 138 remission periods (P = 0.02). Influenza A virus, parainfluenza virus type 3, and coronavirus OC43 predominated; infections with other viruses were infrequent. Infection with M. pneumoniae was detected serologically in four patients, but this organism was never isolated from sputum specimens. Rhinoviruses were isolated from frozen-stored sputum specimens in 2.7% of the episodes of exacerbation and from 0.55% of the remission intervals (P not significant). These data suggest that although exacerbations of chronic bronchitis may be accompanied by viral and M. pneumoniae infections, patients with chronic bronchitis also acquire such infections without a worsening of their respiratory status.

negative: Astrovirus Diagnostics Various methods exist to detect an astrovirus infection. Current methods include electron microscopy (EM), cell culture, immunoassays, polymerase chain reaction (PCR) and various other molecular approaches that can be applied in the context of diagnostic or in surveillance studies. With the advent of metagenomics, novel human astrovirus (HAstV) strains have been found in immunocompromised individuals in association with central nervous system (CNS) infections. This work reviews the past and current methods for astrovirus detection and their uses in both research laboratories and for medical diagnostic purposes.

negative: Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, China: a descriptive study Summary Background A cluster of patients with coronavirus disease 2019 (COVID-19) pneumonia caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were successively reported in Wuhan, China. We aimed to describe the CT findings across different timepoints throughout the disease course. Methods Patients with COVID-19 pneumonia (confirmed by next-generation sequencing or RT-PCR) who were admitted to one of two hospitals in Wuhan and who underwent serial chest CT scans were retrospectively enrolled. Patients were grouped on the basis of the interval between symptom onset and the first CT scan: group 1 (subclinical patients; scans done before symptom onset), group 2 (scans done ≤1 week after symptom onset), group 3 (>1 week to 2 weeks), and group 4 (>2 weeks to 3 weeks). Imaging features and their distribution were analysed and compared across the four groups. Findings 81 patients admitted to hospital between Dec 20, 2019, and Jan 23, 2020, were retrospectively enrolled. The cohort included 42 (52%) men and 39 (48%) women, and the mean age was 49·5 years (SD 11·0). The mean number of involved lung segments was 10·5 (SD 6·4) overall, 2·8 (3·3) in group 1, 11·1 (5·4) in group 2, 13·0 (5·7) in group 3, and 12·1 (5·9) in group 4. The predominant pattern of abnormality observed was bilateral (64 [79%] patients), peripheral (44 [54%]), ill-defined (66 [81%]), and ground-glass opacification (53 [65%]), mainly involving the right lower lobes (225 [27%] of 849 affected segments). In group 1 (n=15), the predominant pattern was unilateral (nine [60%]) and multifocal (eight [53%]) ground-glass opacities (14 [93%]). Lesions quickly evolved to bilateral (19 [90%]), diffuse (11 [52%]) ground-glass opacity predominance (17 [81%]) in group 2 (n=21). Thereafter, the prevalence of ground-glass opacities continued to decrease (17 [57%] of 30 patients in group 3, and five [33%] of 15 in group 4), and consolidation and mixed patterns became more frequent (12 [40%] in group 3, eight [53%] in group 4). Interpretation COVID-19 pneumonia manifests with chest CT imaging abnormalities, even in asymptomatic patients, with rapid evolution from focal unilateral to diffuse bilateral ground-glass opacities that progressed to or co-existed with consolidations within 1–3 weeks. Combining assessment of imaging features with clinical and laboratory findings could facilitate early diagnosis of COVID-19 pneumonia. Funding None.

negative: Severe atypical pneumonia in critically ill patients: a retrospective multicenter study BACKGROUND: Chlamydophila pneumoniae (CP) and Mycoplasma pneumoniae (MP) patients could require intensive care unit (ICU) admission for acute respiratory failure. METHODS: Adults admitted between 2000 and 2015 to 20 French ICUs with proven atypical pneumonia were retrospectively described. Patients with MP were compared to Streptococcus pneumoniae (SP) pneumonia patients admitted to ICUs. RESULTS: A total of 104 patients were included, 71 men and 33 women, with a median age of 56 [44–67] years. MP was the causative agent for 76 (73%) patients and CP for 28 (27%) patients. Co-infection was documented for 18 patients (viruses for 8 [47%] patients). Median number of involved quadrants on chest X-ray was 2 [1–4], with alveolar opacities (n = 61, 75%), interstitial opacities (n = 32, 40%). Extra-pulmonary manifestations were present in 34 (33%) patients. Mechanical ventilation was required for 75 (72%) patients and vasopressors for 41 (39%) patients. ICU length of stay was 16.5 [9.5–30.5] days, and 11 (11%) patients died in the ICU. Compared with SP patients, MP patients had more extensive interstitial pneumonia, fewer pleural effusion, and a lower mortality rate [6 (8%) vs. 17 (22%), p = 0.013]. According MCA analysis, some characteristics at admission could discriminate MP and SP. MP was more often associated with hemolytic anemia, abdominal manifestations, and extensive chest radiograph abnormalities. SP-P was associated with shock, confusion, focal crackles, and focal consolidation. CONCLUSION: In this descriptive study of atypical bacterial pneumonia requiring ICU admission, mortality was 11%. The comparison with SP pneumonia identified clinical, laboratory, and radiographic features that may suggest MP or CP pneumonia. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13613-018-0429-z) contains supplementary material, which is available to authorized users.

negative: Multihospital Outbreak of a Middle East Respiratory Syndrome Coronavirus Deletion Variant, Jordan: A Molecular, Serologic, and Epidemiologic Investigation BACKGROUND: An outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) in Jordan in 2015 involved a variant virus that acquired distinctive deletions in the accessory open reading frames. We conducted a molecular and seroepidemiologic investigation to describe the deletion variant’s transmission patterns and epidemiology. METHODS: We reviewed epidemiologic and medical chart data and analyzed viral genome sequences from respiratory specimens of MERS-CoV cases. In early 2016, sera and standardized interviews were obtained from MERS-CoV cases and their contacts. Sera were evaluated by nucleocapsid and spike protein enzyme immunoassays and microneutralization. RESULTS: Among 16 cases, 11 (69%) had health care exposure and 5 (31%) were relatives of a known case; 13 (81%) were symptomatic, and 7 (44%) died. Genome sequencing of MERS-CoV from 13 cases revealed 3 transmissible deletions associated with clinical illness during the outbreak. Deletion variant sequences were epidemiologically clustered and linked to a common transmission chain. Interviews and sera were collected from 2 surviving cases, 23 household contacts, and 278 health care contacts; 1 (50%) case, 2 (9%) household contacts, and 3 (1%) health care contacts tested seropositive. CONCLUSIONS: The MERS-CoV deletion variants retained human-to-human transmissibility and caused clinical illness in infected persons despite accumulated mutations. Serology suggested limited transmission beyond that detected during the initial outbreak investigation.

negative: Sub-national variation in measles vaccine coverage and outbreak risk: a case study from a 2010 outbreak in Malawi BACKGROUND: Despite progress towards increasing global vaccination coverage, measles continues to be one of the leading, preventable causes of death among children worldwide. Whether and how to target sub-national areas for vaccination campaigns continues to remain a question. We analyzed three metrics for prioritizing target areas: vaccination coverage, susceptible birth cohort, and the effective reproductive ratio (R(E)) in the context of the 2010 measles epidemic in Malawi. METHODS: Using case-based surveillance data from the 2010 measles outbreak in Malawi, we estimated vaccination coverage from the proportion of cases reporting with a history of prior vaccination at the district and health facility catchment scale. Health facility catchments were defined as the set of locations closer to a given health facility than to any other. We combined these estimates with regional birth rates to estimate the size of the annual susceptible birth cohort. We also estimated the effective reproductive ratio, R(E), at the health facility polygon scale based on the observed rate of exponential increase of the epidemic. We combined these estimates to identify spatial regions that would be of high priority for supplemental vaccination activities. RESULTS: The estimated vaccination coverage across all districts was 84%, but ranged from 61 to 99%. We found that 8 districts and 354 health facility catchments had estimated vaccination coverage below 80%. Areas that had highest birth cohort size were frequently large urban centers that had high vaccination coverage. The estimated R(E) ranged between 1 and 2.56. The ranking of districts and health facility catchments as priority areas varied depending on the measure used. CONCLUSIONS: Each metric for prioritization may result in discrete target areas for vaccination campaigns; thus, there are tradeoffs to choosing one metric over another. However, in some cases, certain areas may be prioritized by all three metrics. These areas should be treated with particular concern. Furthermore, the spatial scale at which each metric is calculated impacts the resulting prioritization and should also be considered when prioritizing areas for vaccination campaigns. These methods may be used to allocate effort for prophylactic campaigns or to prioritize response for outbreak response vaccination.

negative: Differentiation of feline coronavirus type I and II infections by virus neutralization test Abstract Feline coronavirus (FCoV) is divided into two types I and II, based on their growth in vitro and antigenicity. In this study, virus neutralization (VN) test was applied for type differentiation of FCoV infections. Sera of cats which were clinically and serologically diagnosed as feline infectious peritonitis (FIP) possessed significantly higher VN titers to type I FCoV, and sera from cats experimentally infected with FIPV type II had high VN titers to type II but not type I viruses. A total of 79 cat sera collected in the years between 2004 and 2005 were examined to evaluate seroprevalence by the VN test, showing the following results: (1) 50 cats (63.3%) were sero-positive to FCoV; (2) of the 50 FCoV positive cat serum samples, 49 (98%) showed significantly higher titers to type I virus and only one (2%) for type II virus. These results indicate that the VN test described here can be used for serological differentiation of FCoV infections of cats, and that FCoV type I is a dominant type in recent years of Japan.

negative: Detection by radioimmunoassay and enzyme-linked immunosorbent assay of coronavirus antibodies in bovine serum and lacteal secretions. The sensitivity of a radioimmunoassay (RIA), an enzyme-linked immunosorbent assay (ELISA), and a serum neutralization assay (SN) for detecting antibodies to bovine coronavirus in serum and colostrum were compared. Although there proved to be a good correlation among all three assays (r = 0.915 and 0.964 for RIA with SN and ELISA, respectively), RIA and ELISA proved to be at least 10 times more sensitive than neutralization tests. By using these techniques, it was possible to detect a time-dependent decrease in antibody levels in bovine colostrum after parturition. Using ELISA, we demonstrated that 12 of 12 herds in Saskatchewan, and 109 of 110 animals tested, and antibody to bovine coronavirus. There was no elevated antibody response in serum or lacteal secretions of cows vaccinated once or twice with a commercially available modified live rota-coronavirus vaccine. In addition to being more sensitive than SN, ELISA and RIA proved to have other advantages for measuring antibody levels to bovine coronavirus and therefore warrant wider use as tools in diagnostic virology.

negative: Utilización adecuada del lenguaje médico: principales problemas y soluciones Resumen El lenguaje médico debe caracterizarse por su precisión, neutralidad emocional y estabilidad. La comunicación efectiva de los resultados de los trabajos científicos depende del cumplimiento de las normas vigentes de redacción y estilo, de manera que en un texto con defectos formales puede quedar mermado el interés de los hallazgos. En este trabajo se comentan algunos de los problemas y defectos más habituales del lenguaje médico; entre ellos, el abuso de siglas y de extranjerismos, la utilización de palabras impropias, los errores sintácticos o solecismos, los defectos más frecuentes en los títulos, y el abuso de mayúsculas y del gerundio. Frente a estos problemas, el investigador dispone de armas eficaces para superarlos, como la consulta de textos de calidad, los diccionarios críticos de dudas y dificultades de la lengua española y los manuales de redacción y estilo. Abstract Medical language should be characterized by its precision, emotional neutrality and stability. The effective communication of results of scientific studies depends on compliance with current standards of drafting and style; texts with defects can hinder interest in the findings. In this study, we discuss some of the most common problems and errors in medical language, including the abuse of abbreviations and foreign words, the use of improper words, syntax errors and solecisms, the most common errors in titles and the abuse of capital letters and the gerund. Investigators have effective tools for dealing with these problems, such as quality texts, critical dictionaries of questions and difficulties with the Spanish language and various drafting and style manuals.

negative: Covert COVID-19 and false-positive dengue serology in Singapore

negative: Development and validation of an enzyme-linked immunosorbent assay for human metapneumovirus serology based on a recombinant viral protein. The human metapneumovirus (hMPV) is a newly reported respiratory virus belonging to the Paramyxoviridae family that has been associated with bronchiolitis and pneumonia in young children. We developed a simple enzyme-linked immunosorbent assay (ELISA) for hMPV serological testing using the nucleoprotein (N) from group A or B (N-A or N-B) as the antigen, and we evaluated it in both children and adults. The N proteins were first used in a Western immunoblot assay to identify hMPV-negative sera, which were then used to determine the cutoff value of the ELISA test. Subsequent evaluation of the ELISA-N test revealed that the mean reciprocal antibody titer of 20 randomly selected seropositive children was 143, compared to 69 for 20 seropositive adults. In a prospective evaluation of 71 adults with acute exacerbations of chronic obstructive pulmonary disease, 58 (81.6%) had prior hMPV antibodies and 3 (4.2%) had evidence of recent hMPV infection. In testing paired sera from adults (n = 4) with recent hMPV group A infection confirmed by reverse transcriptase PCR (RT-PCR), ELISAs using the N-A or N-B proteins were able to detect hMPV seroconversion. Moreover, testing of paired sera from three adults with a recent infection by the human respiratory syncytial virus confirmed by RT-PCR and serology did not reveal any increase in hMPV antibodies over time. The ELISA-N is a simple, objective, and specific serological test useful for detecting anti-hMPV antibodies following group A or B viral infections, which should permit a better understanding of the epidemiology of this virus.

negative: The Effect of Large-Scale Anti-Contagion Policies on the Coronavirus (COVID-19) Pandemic Governments around the world are responding to the novel coronavirus (COVID-19) pandemic with unprecedented policies designed to slow the growth rate of infections. Many actions, such as closing schools and restricting populations to their homes, impose large and visible costs on society. In contrast, the benefits of these policies, in the form of infections that did not occur, cannot be directly observed and are currently understood through process-based simulations. Here, we compile new data on 1,659 local, regional, and national anti-contagion policies recently deployed in the ongoing pandemic across localities in China, South Korea, Iran, Italy, France, and the United States (US). We then apply reduced-form econometric methods, commonly used to measure the effect of policies on economic growth, to empirically evaluate the effect that these anti-contagion policies have had on the growth rate of infections. In the absence of any policy actions, we estimate that early infections of COVID-19 exhibit exponential growth rates of roughly 42% per day. We find that anti-contagion policies collectively have had significant effects slowing this growth. Our results suggest that similar policies may have different impacts on different populations, but we obtain consistent evidence that the policy packages now deployed are achieving large, beneficial, and measurable health outcomes. We estimate that, to date, current policies have already prevented or delayed on the order of 62 million infections across these six countries. These findings may help inform whether or when these ongoing policies should be lifted or intensified, and they can support decision-making in the other 180+ countries where COVID-19 has been reported.

negative: Longitudinally Profiling Neutralizing Antibody Response to SARS Coronavirus with Pseudotypes The severe acute respiratory syndrome–associated coronavirus (SARS-CoV) spike protein (S) is a major target for neutralizing antibodies. Retroviral SARS-CoV S pseudotypes have been constructed and used to develop an in vitro microneutralization assay that is both sensitive and specific for SARS-CoV neutralizing antibodies. Neutralization titers measured by this assay are highly correlated to those measured by an assay using replication-competent SARS-CoV. No cross-neutralization occurred with human sera known to contain antibodies to coronavirus strains OC43 and 229E. The pseudotype assay was used to profile neutralizing antibody responses against SARS-CoV S in sequential serum samples taken from 41 confirmed SARS patients during the 2003 outbreak in Hong Kong and shows long-lasting immunity in most recovered patients. The pseudotype assay does not require handling live SARS virus; it is a useful tool to determine neutralizing titers during natural infection and the preclinical evaluation of candidate vaccines.

negative: Potential effect of blood purification therapy in reducing cytokine storm as a late complication of critically ill COVID-19

negative: Antiviral immunity is impaired in COPD patients with frequent exacerbations Patients with frequent exacerbations represent a chronic obstructive pulmonary disease (COPD) subgroup requiring better treatment options. The aim of this study was to determine the innate immune mechanisms that underlie susceptibility to frequent exacerbations in COPD. We measured sputum expression of immune mediators and bacterial loads in samples from patients with COPD at stable state and during virus-associated exacerbations. In vitro immune responses to rhinovirus infection in differentiated primary bronchial epithelial cells (BECs) sampled from patients with COPD were additionally evaluated. Patients were stratified as frequent exacerbators (≥2 exacerbations in the preceding year) or infrequent exacerbators (<2 exacerbations in the preceding year) with comparisons made between these groups. Frequent exacerbators had reduced sputum cell mRNA expression of the antiviral immune mediators type I and III interferons and reduced interferon-stimulated gene (ISG) expression when clinically stable and during virus-associated exacerbation. A role for epithelial cell-intrinsic innate immune dysregulation was identified: induction of interferons and ISGs during in vitro rhinovirus (RV) infection was also impaired in differentiated BECs from frequent exacerbators. Frequent exacerbators additionally had increased sputum bacterial loads at 2 wk following virus-associated exacerbation onset. These data implicate deficient airway innate immunity involving epithelial cells in the increased propensity to exacerbations observed in some patients with COPD. Therapeutic approaches to boost innate antimicrobial immunity in the lung could be a viable strategy for prevention and treatment of frequent exacerbations.

negative: The common cold: a review of the literature Abstract Respiratory viral infections, also known as the common cold, are the most common infections in humans. Despite their benign nature, they are a major cause of morbidity and mortality on a worldwide basis. Several viruses have been associated with such illness, of which rhinovirus is the most common. Symptom production is a combination of viral cytopathic effect and the activation of inflammatory pathways. Therefore, antiviral treatment alone may not be able to prevent these events. The optimal use of such agents also requires earlier initiation; therefore, it is important to develop accurate and rapid diagnostic techniques for respiratory viruses. Before any reliable and effective treatment is available, symptomatic therapies may remain the only possible choice of management.

negative: Executive summary of imported infectious diseases after returning from foreign travel: Consensus document of the Spanish Society for Infectious Diseases and Clinical Microbiology (SEIMC) In a global world, knowledge of imported infectious diseases is essential in daily practice, both for the microbiologist–parasitologist and the clinician who diagnoses and treats infectious diseases in returned travelers. Tropical and subtropical countries where there is a greater risk of contracting an infectious disease are among the most frequently visited tourist destinations. The SEIMC considers it appropriate to produce a consensus document that will be useful to primary care physicians as well as specialists in internal medicine, infectious diseases and tropical medicine who help treat travelers returning from tropical and sub-tropical areas with infections. Preventive aspects of infectious diseases and infections imported by immigrants are explicitly excluded here, since they have been dealt with in other SEIMC documents. Various types of professionals (clinicians, microbiologists, and parasitologists) have helped produce this consensus document by evaluating the available evidence-based data in order to propose a series of key facts about individual aspects of the topic. The first section of the document is a summary of some of the general aspects concerning the general assessment of travelers who return home with potential infections. The main second section contains the key facts (causative agents, diagnostic procedures and therapeutic measures) associated with the major infectious syndromes affecting returned travelers [gastrointestinal syndrome (acute or persistent diarrhea); febrile syndrome with no obvious source of infection; localized cutaneous lesions; and respiratory infections]. Finally, the characteristics of special traveler subtypes, such as pregnant women and immunocompromised travelers, are described.

negative: Exploring the Linkages Between Ecosystems and Human Health The linkages between human health and ecosystems are complex, dynamic, and political. For millennia ecosystems have provided humans with essential services such as food, water, shelter and medicine. At the same time, they have mediated the transmission of many diseases and posed a number of health risks. The vitality of ecosystem services for human health and well-being is well captured by Bernard Abraham, President of Weskit-Chi Aboriginal Trappers Association, when he commented on the importance of forest ecosystems to Aboriginal people. He observed that many Aboriginal people consider the forest as: “their food bank, drugstore, meat market, bakery, fruit and vegetable stand, building material centre, beverage supply, and the habitat for all of the creator’s creatures.”(1)

negative: Estimating the COVID-19 infection rate: Anatomy of an inference problem As a consequence of missing data on tests for infection and imperfect accuracy of tests, reported rates of cumulative population infection by the SARS CoV-2 virus are lower than actual rates of infection. Hence, reported rates of severe illness conditional on infection are higher than actual rates. Understanding the time path of the COVID-19 pandemic has been hampered by the absence of bounds on infection rates that are credible and informative. This paper explains the logical problem of bounding these rates and reports illustrative findings, using data from Illinois, New York, and Italy. We combine the data with assumptions on the infection rate in the untested population and on the accuracy of the tests that appear credible in the current context. We find that the infection rate might be substantially higher than reported. We also find that the infection fatality rate in Illinois, New York, and Italy is substantially lower than reported.

negative: Early Reflection on the Global Impact of COVID19, and Implications for Physiotherapy

negative: Using common spatial distributions of atoms to relate functionally divergent influenza virus N10 and N11 protein structures to functionally characterized neuraminidase structures, toxin cell entry domains, and non-influenza virus cell entry domains. The ability to identify the functional correlates of structural and sequence variation in proteins is a critical capability. We related structures of influenza A N10 and N11 proteins that have no established function to structures of proteins with known function by identifying spatially conserved atoms. We identified atoms with common distributed spatial occupancy in PDB structures of N10 protein, N11 protein, an influenza A neuraminidase, an influenza B neuraminidase, and a bacterial neuraminidase. By superposing these spatially conserved atoms, we aligned the structures and associated molecules. We report spatially and sequence invariant residues in the aligned structures. Spatially invariant residues in the N6 and influenza B neuraminidase active sites were found in previously unidentified spatially equivalent sites in the N10 and N11 proteins. We found the corresponding secondary and tertiary structures of the aligned proteins to be largely identical despite significant sequence divergence. We found structural precedent in known non-neuraminidase structures for residues exhibiting structural and sequence divergence in the aligned structures. In N10 protein, we identified staphylococcal enterotoxin I-like domains. In N11 protein, we identified hepatitis E E2S-like domains, SARS spike protein-like domains, and toxin components shared by alpha-bungarotoxin, staphylococcal enterotoxin I, anthrax lethal factor, clostridium botulinum neurotoxin, and clostridium tetanus toxin. The presence of active site components common to the N6, influenza B, and S. pneumoniae neuraminidases in the N10 and N11 proteins, combined with the absence of apparent neuraminidase function, suggests that the role of neuraminidases in H17N10 and H18N11 emerging influenza A viruses may have changed. The presentation of E2S-like, SARS spike protein-like, or toxin-like domains by the N10 and N11 proteins in these emerging viruses may indicate that H17N10 and H18N11 sialidase-facilitated cell entry has been supplemented or replaced by sialidase-independent receptor binding to an expanded cell population that may include neurons and T-cells.

negative: Proteome-wide analysis of differentially-expressed SARS-CoV-2 antibodies in early COVID-19 infection Rapid and accurate tests that detect IgM and IgG antibodies to SARS-CoV-2 proteins are essential in slowing the spread of COVID-19 by identifying patients who are infected with COVID-19. Using a SARS-CoV-2 proteome microarray developed in our lab, we comprehensively profiled both IgM and IgG antibodies in forty patients with early-stage COVID-19, influenza, or non-influenza who had similar symptoms. The results revealed that the SARS-CoV-2 N protein is not an ideal biomarker for COVID-19 diagnosis because of its low immunogenicity, thus tests that rely on this marker alone will have a high false negative rate. Our data further suggest that the S protein subunit 1 receptor binding domain (S1-RBD) might be the optimal antigen for IgM antibody detection, while the S protein extracellular domain (S1+S2ECD) would be the optimal antigen for both IgM and IgG antibody detection. Notably, the combination of all IgM and IgG biomarkers can identify 87% and 73.3% COVID-19 patients, respectively. Finally, the COVID-19-specific antibodies are significantly correlated with the clinical indices of viral infection and acute myocardial injury (p≤0.05). Our data may help understand the function of anti-SARS-CoV-2 antibodies and improve serology tests for rapid COVID-19 screening.

negative: Testing recommendation for COVID-19 (SARS-CoV-2) in patients planned for surgery - continuing the service and ‘suppressing’ the pandemic

negative: XMRV as a Human Pathogen? XMRV has been proposed to be associated with Prostate Cancer and Chronic Fatigue Syndrome. This proposition has been controversial because many investigators have failed to replicate the reported associations. Here, we explore whether XMRV is an authentic human pathogen in the light of recent findings that indicate otherwise.

negative: Recent apprise on coronavirus and its terrible insinuations Epidemically increased evidence reveals that the link between the 2019-nCoV and other similar strain of coronaviruses circulating in bats and specifically the Rhinopodous bat sub-species. These sub-species are ample and widely present in Southern China, Middle East Africa and Europe. Recent studies show that more than 500 CoV have been identified in bats in China. The Center for Diseases Control and Prevention and the World Health Organization maintains a website that is updated frequently with new cases of MERS-CoV infection. As per WHO Situation report 16th, 24,554 number of cases confirmed globally out of which 99.22% cases from china. A new coronavirus (2019-nCoV) is causing respiratory syndrome mostly in Hubei Province, China. Corona Virus spread over 24 countries including Japan, India, Korea, and other countries 2019-CoV infection vary from mild, moderate or severe illness; the later includes severe pneumonia, ARDS, sepsis and septic shock. There are two diagnostic tests for coronavirus infection i.e. molecular test and serology test. In this review article there are the various recent cases of the patients that are suffering from the corona virus, the outcome of these studies is that corona virus infection is an epidemic disease which affects Central Nervous System (CNS).

negative: Seroprevalence of turkey coronavirus in North American turkeys determined by a newly developed enzyme-linked immunosorbent assay based on recombinant antigen. Turkey coronavirus (TCoV) causes diarrhea in young turkey poults, but little is known about its prevalence in the field. To address this, the complete nucleocapsid gene was cloned and expressed in Escherichia coli. Expressed nucleocapsid gene produced two distinct proteins (52 and 43 kDa); their specificity was confirmed by Western blotting using two different monoclonal antibodies. Recombinant N protein was purified and used as an antigen to develop an enzyme-linked immunosorbent assay (ELISA) for the serological detection of TCoV that was then validated using experimentally derived turkey serum. The N-based ELISA showed (97%) sensitivity and (93%) specificity for TCoV, which was significantly higher than an infectious bronchitis coronavirus-based commercial test for TCoV. To assess the utility of this recombinant ELISA, 360 serum samples from turkey farms in Ontario, Canada, and 81 serum samples from farms in Arkansas were tested for TCoV-specific antibodies. A high seroprevalence of TCoV was found in turkeys from the Ontario farms with 73.9% of breeders and 60.0% of meat turkeys testing seropositive using the N-based ELISA. Similarly, a high field prevalence was found in the turkeys from Arkansas, for which 64.2% of the serum samples tested seropositive.

negative: Canine and Feline Blood Donor Screening for Infectious Disease Consensus Statements of the American College of Veterinary Internal Medicine (ACVIM) provide veterinarians with guidelines regarding the pathophysiology, diagnosis, or treatment of animal diseases. The foundation of the Consensus Statement is evidence‐based medicine, but if such evidence is conflicting or lacking, the panel provides interpretive recommendations on the basis of their collective expertise. The Consensus Statement is intended to be a guide for veterinarians, but it is not a statement of standard of care or a substitute for clinical judgment. Topics of statements and panel members to draft the statements are selected by the Board of Regents with input from the general membership. A draft prepared and input from Diplomates is solicited at the Forum and via the ACVIM Web site and incorporated in a final version. This Consensus Statement was approved by the Board of Regents of the ACVIM before publication.

negative: Duration of Maternal Antibodies against Canine Distemper Virus and Hendra Virus in Pteropid Bats Old World frugivorous bats have been identified as natural hosts for emerging zoonotic viruses of significant public health concern, including henipaviruses (Nipah and Hendra virus), Ebola virus, and Marburg virus. Epidemiological studies of these viruses in bats often utilize serology to describe viral dynamics, with particular attention paid to juveniles, whose birth increases the overall susceptibility of the population to a viral outbreak once maternal immunity wanes. However, little is understood about bat immunology, including the duration of maternal antibodies in neonates. Understanding duration of maternally derived immunity is critical for characterizing viral dynamics in bat populations, which may help assess the risk of spillover to humans. We conducted two separate studies of pregnant Pteropus bat species and their offspring to measure the half-life and duration of antibodies to 1) canine distemper virus antigen in vaccinated captive Pteropus hypomelanus; and 2) Hendra virus in wild-caught, naturally infected Pteropus alecto. Both of these pteropid bat species are known reservoirs for henipaviruses. We found that in both species, antibodies were transferred from dam to pup. In P. hypomelanus pups, titers against CDV waned over a mean period of 228.6 days (95% CI: 185.4–271.8) and had a mean terminal phase half-life of 96.0 days (CI 95%: 30.7–299.7). In P. alecto pups, antibodies waned over 255.13 days (95% CI: 221.0–289.3) and had a mean terminal phase half-life of 52.24 days (CI 95%: 33.76–80.83). Each species showed a duration of transferred maternal immunity of between 7.5 and 8.5 months, which was longer than has been previously estimated. These data will allow for more accurate interpretation of age-related Henipavirus serological data collected from wild pteropid bats.

negative: A comparison study between GeXP-based multiplex-PCR and serology assay for Mycoplasma pneumoniae detection in children with community acquired pneumonia BACKGROUND: Diagnosis of community-acquired pneumonia (CAP) caused by Mycoplasma pneumoniae (Mp) in children has been hampered by difficulty in obtaining convalescent serum and time constraints. In this study, the two diagnostic assays that targeted respectively on Mp-antibody and Mp-DNA were retrospectively investigated. METHODS: A total of 3146 children were clinically diagnosed to have CAP and were confirmed by chest X-ray during March 2015 to February 2016 in Children’s hospital of Hebei Province (China). Both of the sera and sputum samples were collected in 24 h after their admission. The Mp-antibody was examined by the passive particle agglutination assay and a fourfold or greater increase of antibody titers of paired sera or≧1:160 titer of single serum was set as the serology positive. Mp-DNA in the sputum samples was tested by a multiplex-PCR method named GeXP assay (multiplex PCR combined with automated capillary electrophoresis). In order to eliminate the false positive results caused by the asymptomatic carriage after infected by M. pneumoniae, the inconsistent samples were tested by the real-time isothermal transcription-mediated RNA amplification assay (SAT). RESULTS: The inter-rated agreement test was performed in 3146 CAP patients, with a highest kappa value in the school-age children as 0.783. There were 6.29% (198/3146) cases showed inconsistent results determined by GeXP and serology assay. All of the 19 GeXP(+)/Serology (−) samples and a randomly chosen 27 from 179 GeXP(−)/Serology (+) samples were tested by SAT assay, and a 97.8% diagnosis agreement was observed between SAT and GeXP assay, but not with the serology assay. In addition, patients who were detected only by serology or only by multiplex-PCR were significantly younger than those with both methods positive (3.0 and 1.5 years vs. 5.0 years, p < 0.01). The Viral-Mp coinfection accounted for 37.0% (97/262), which was more common in winter and spring (p < 0.05) and in the infantile group (p < 0.01), compared to the pure Mp positive ones. CONCLUSION: In some children CAP cases, the Mp laboratory diagnosis was inconsistent between serology and multiplex-PCR assay. Verified by the SAT assay, the GeXP showed a more sensitive and reliable performance compared with the serology assay. Furthermore, employing the multiplex-PCR could provide more information on the associated pathogens for clinical assessment of CAP. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12879-017-2614-3) contains supplementary material, which is available to authorized users.

negative: Bioinformatics After reading this chapter, you should know the answers to these questions:

negative: The Diagnosis of Pandemic Coronavirus Pneumonia: A Review of Radiology Examination and Laboratory Test Abstract Since the outbreak of novel coronavirus disease 2019 (COVID-19), epidemic prevention strategies have been implemented worldwide. For the sake of controlling the infectious coronavirus pneumonia, early diagnosis and quarantine play an imperative role. Currently, the mainstream diagnostic methods are imaging and laboratory diagnosis, which differ in their efficacy of diagnosis. To compare the detection rate, we reviewed numerous literature on pneumonia caused by coronaviruses (SARS, MERS, and SARS-CoV-2) and analyzed two different ways of diagnosis. The results showed that the detection rate of computed tomography (CT) diagnosis was significantly higher than that of real-time quantitative polymerase chain reaction (qPCR) (P = 0.00697). Still, clinicians should combine radiology and laboratory methods to achieve a higher detection rate, so that instant isolation and treatment could be effectively conducted to curb the rampant spread of the epidemic.

negative: Diagnostic Testing for Severe Acute Respiratory Syndrome–Related Coronavirus-2: A Narrative Review Diagnostic testing to identify persons infected with severe acute respiratory syndrome–related coronavirus-2 (SARS–CoV-2) infection is central to control the global pandemic of COVID-19 that began in late 2019. In a few countries, the use of diagnostic testing on a massive scale has been a cornerstone of successful containment strategies. In contrast, the United States, hampered by limited testing capacity, has prioritized testing for specific groups of persons. Real-time reverse transcriptase polymerase chain reaction–based assays performed in a laboratory on respiratory specimens are the reference standard for COVID-19 diagnostics. However, point-of-care technologies and serologic immunoassays are rapidly emerging. Although excellent tools exist for the diagnosis of symptomatic patients in well-equipped laboratories, important gaps remain in screening asymptomatic persons in the incubation phase, as well as in the accurate determination of live viral shedding during convalescence to inform decisions to end isolation. Many affluent countries have encountered challenges in test delivery and specimen collection that have inhibited rapid increases in testing capacity. These challenges may be even greater in low-resource settings. Urgent clinical and public health needs currently drive an unprecedented global effort to increase testing capacity for SARS–CoV-2 infection. Here, the authors review the current array of tests for SARS–CoV-2, highlight gaps in current diagnostic capacity, and propose potential solutions.

negative: Enzyme-linked immunosorbent assay for detection of antibody in volunteers experimentally infected with human coronavirus strain 229 E. An enzyme-linked immunosorbent assay was developed for detecting antibody rises to human coronavirus strain 229E and related strains in paired sera from infected volunteers. There was a close correlation between development of colds infected volunteers. There was a close correlation between development of colds and significant antibody rises detected by the enzyme-linked immunosorbent assay. Furthermore, the assay was more sensitive than a neutralization assay. This enzyme-linked immunosorbent assay is an easy, accurate, and sensitive assay for measuring significant antibody rises to human coronavirus strain 229E group viruses, and it could be useful in the clinical diagnosis of these infections.

negative: Diagnosis of Feline Viral Infection The methods of diagnosis of the common feline viral infections are discussed. Specific diagnosis involves a combination of an accurate history, careful observation of disease signs, demonstration of characteristic clinicopathologic changes, and isolation or identification of the etiologic agent. The laboratory tests for virus identification—including virus isolation, cytology, electron microscopy, virus neutralization, immunofluorescent microscopy, and enzyme-linkedimmunosorbent-assay (ELISA)—are briefly described.

negative: Chapter 6 Public Health, Communicable Diseases and Global Health Public health professionals are considering how molecular medicine applications can impact on preventive medicine and health provision enabling interventions to start earlier. There is the potential for molecular medicine to improve the workplace although inappropriate use will lead to discrimination. The public health issue of communicable diseases is being addressed through molecular medicine in more effective and early detection and a better understanding of pathogenesis. A threat from emerging and re-emerging infections requires multiple approaches but early and definitive detection will need nucleic acid based approaches. The non-communicable diseases are now a global world problem, particularly obesity. While molecular medicine is still to make a significant impact on this disorder some interesting findings are emerging about the role of genes in obesity. Ultimately, global health issues must include more efficient and environmentally sustainable strategies. Molecular technologies provide a promising approach for the way forward. Keywords Epidemiology, workplace, diagnostics, resistance, virulence, emerging and re-emerging infections, obesity, bioeconomy

negative: Evaluation of a French ELISA for the detection of Salmonella Enteritidis and Salmonella Typhimurium in flocks of laying and breeding hens Abstract In France, the regular and compulsory detection of Salmonella Enteritidis (SE) and Salmonella Typhimurium (ST) in flocks of breeding and laying hens is based on bacteriological examination of environmental swabs and faeces samples. The aim of this study was to compare this bacteriological examination with a serological method (ELISA) developed in our laboratory. This ELISA was first evaluated by use of artificially infected hens. During these experimental infection studies, several groups of hens were inoculated with SE, ST, different vaccines and different Salmonella serovars to calculate the experimental parameters of our ELISA. Then, in a field study, 43 flocks were followed monthly using two bacteriological samples (environmental swab and pool of faeces) and 20 serological samples (sera or yolks). Twenty-seven flocks without SE or ST gave a negative serological response throughout their surveillance. Among the 10 various serovars different from SE and ST isolated in this study, S. Heidelberg, S. Agona and S. Hadar gave seropositive results in seven flocks. Consequently, this ELISA was not specific of SE and ST as it detected serovars sharing or not common antigens with SE and ST. Seropositive results were also obtained each month for two flocks where no Salmonella could be isolated. Finally, in seven flocks found infected with SE or ST, the positive ELISA results appeared later than the bacteriological detection. Therefore, for the detection of chicken flocks recently infected with SE or ST, bacteriological examination currently used in France seems to be more appropriate than this ELISA.

negative: Unveiling patterns of viral pathogen infection in free-ranging carnivores of northern Portugal using a complementary methodological approach Abstract Pathogen surveillance in free-ranging carnivores presents challenges due to their low densitie and secretive nature. We combined molecular and serological assays to investigate infections by viral pathogens (Canine parvovirus (CPV), Canine distemper virus (CDV) and Canine coronavirus (CCoV)) in Portuguese carnivores (Canis lupus, Vulpes vulpes, Lutra lutra, Martes foina, M. martes, Meles meles, and Genetta genetta) over a period of 16 years. Additionally we explored spatio-temporal patterns of virus occurrence in Canis lupus. Our study identified CPV DNA in all carnivore species with an overall prevalence of 91.9 %. CPV was detected in all sampled years and seasons in Canis lupus, supporting its enzootic nature. CDV RNA was mainly detected in the Canidae family, with viral nucleic acid recorded between 2005 and 2008 with a peak prevalence of 67 % among the wolf population, followed by a sharp decline, suggesting an epizootic behaviour of the virus. Antibodies show that mustelids and viverrids were often exposed to CDV. CCoV was first recorded by molecular methods in wolf samples in 2002, remaining in the wolf populations with marked fluctuations over time. The dual serological and molecular approach provided important epidemiological data on pathogens of wild carnivores in Portugal. These programmes should also include monitoring of other potential reservoir hosts such as domestic cats and dogs.

negative: Travel health risk perceptions and preparations among travelers at Hong Kong International Airport. Four levels of pre-travel health preparations were defined to allow the measurement of general travel health preparations by the traveling public. A cross-sectional survey of 770 travelers using Hong Kong International Airport was conducted. Important gaps were found in the self-preparation domain. Length of travel was the only factor associated with higher levels of health preparations after adjusting for potential confounders. Targeted health education should be considered to improve health risk perceptions among travelers in Hong Kong and other similar metropolitan cities that are critical hubs for commercial air transport.

negative: Kinetics of Serologic Responses to MERS Coronavirus Infection in Humans, South Korea We investigated the kinetics of serologic responses to Middle East respiratory syndrome coronavirus (MERS-CoV) infection by using virus neutralization and MERS-CoV S1 IgG ELISA tests. In most patients, robust antibody responses developed by the third week of illness. Delayed antibody responses with the neutralization test were associated with more severe disease.

negative: Potential inhibitors against 2019-nCoV coronavirus M protease from clinically approved medicines

negative: Response to “Novel Middle East respiratory syndrome coronavirus”

negative: The role of laboratory diagnostics in emerging viral infections: the example of the Middle East respiratory syndrome epidemic Rapidly emerging infectious disease outbreaks place a great strain on laboratories to develop and implement sensitive and specific diagnostic tests for patient management and infection control in a timely manner. Furthermore, laboratories also play a role in real-time zoonotic, environmental, and epidemiological investigations to identify the ultimate source of the epidemic, facilitating measures to eventually control the outbreak. Each assay modality has unique pros and cons; therefore, incorporation of a battery of tests using traditional culture-based, molecular and serological diagnostics into diagnostic algorithms is often required. As such, laboratories face challenges in assay development, test evaluation, and subsequent quality assurance. In this review, we describe the different testing modalities available for the ongoing Middle East respiratory syndrome (MERS) epidemic including cell culture, nucleic acid amplification, antigen detection, and antibody detection assays. Applications of such tests in both acute clinical and epidemiological investigation settings are highlighted. Using the MERS epidemic as an example, we illustrate the various challenges faced by laboratories in test development and implementation in the setting of a rapidly emerging infectious disease. Future directions in the diagnosis of MERS and other emerging infectious disease investigations are also highlighted.

negative: Literature-related discovery and innovation — update Abstract Literature-Related Discovery and Innovation (LRDI — formerly LRD — literature-related discovery) integrates 1) discovery generation from disparate literatures with 2) the wealth of knowledge contained in prior art to 3) potentially reverse chronic and infectious diseases and/or 4) potentially solve technical problems that appear intractable. This article describes the evolution of LRDI by the author and the insights gained/lessons learned over the past decade. To illustrate the potential power of LRDI, the article emphasizes the relationship between the results of our 2008 LRDI multiple sclerosis (MS) study and a recent demonstration of MS reversal. Lessons learned from the six LRDI medical studies done so far include: ⁎ The main operational problem in the author's LRDI approach is selecting the most important concepts from extremely large volumes of potential discovery retrieval. This is contrary to most published LRDI research, where the discovery focus is searching for rare events. ⁎ It is important to have topical specialist(s) working closely with information technologist(s); the topical specialist(s) applies judgment in selecting the most important concepts. ⁎ A functional form of the information retrieval query with proximity searching capability provides highly selective filtering for discovery retrieval and core prevention/treatment retrieval; the functional form of the query with proximity searching capability allows the use of full-text for discovery and core prevention/treatment. ⁎ Bibliographic coupling (identifying papers that share common references) combined with text-based relationships strengthens selection for potential discovery further. ⁎ Having ‘skin-in-the-game’ (being affected personally) relative to the medical outcome is a strong incentive to do whatever is necessary to solve the research problem. ⁎ Hormesis is critical to healing; relatively modest doses of stimuli tend to be beneficial, whereas relatively large doses may be harmful. The synergy of hormetic treatment doses produces effects larger than combinations of individual doses and requires smaller doses when combined; the synergy of hormetic doses allows conversion of megadoses of nutrients typically reported in lab/clinical studies to physiological (food-level) doses and associated increased safety. ⁎ Co-promoters (combinations of toxic stimuli required to produce disease symptoms) are extremely important for explaining seemingly conflicting results; if true co-promotion is present, elimination of one of the co-promoters may be adequate for removing symptoms, even though the overall problem persists. ⁎ Prior art (potential treatments already published in the literature but not pursued by mainline medicine) may have much to contribute to potentially solve many serious medical problems; much of prior art is overlooked, especially low-tech prior art (e.g., foods, food extracts, herbs, etc.). ⁎ Systemic and focused treatments are both necessary components of healing, but neither will be fully, or many times even partially, effective until the cause(s) is identified and removed. Any medical approach that involves administering treatments for chronic and infectious diseases without addressing the cause(s) results in a broad range of outcomes mainly involving substitution of one set of symptoms for another. ⁎ Past results of LRDI medical studies showed much overlap among preventatives/systemic treatments for different diseases. Differences will arise mainly in focused treatments, especially those involving high technology. ⁎ The central parameters to healing in much medical research are never identified nor reported. Many treatments require a combination of skilled practitioners, cause removal, and immune/neural/endocrine/circulatory systems to be healthy for full effectiveness, yet practitioner skill, degree of cause removal, and immune system et al. health are never reported. A lack of this information does not allow efficacy of different treatments to be compared. Reviews and meta-analyses that compare and draw conclusions about the effectiveness of these different treatments without the above critical information being reported are of extremely limited value and credibility. ⁎ Finally, the most important deficiency for fully reversing chronic and infectious diseases, as well as rapidly accelerating healing of injuries and wounds, is the credibility and integrity of the medical literature itself, especially in areas that concern commercial and government/political sensitivities. In the evaluation of many concepts that deviated from the norm, it was difficult to ascertain whether the difference was based on solid high-quality research, poor research, or deliberately skewed research.

negative: Middle East Respiratory Syndrome Coronavirus Antibodies in Bactrian and Hybrid Camels from Dubai So far, dromedary camels are the only known animal reservoir for Middle East respiratory syndrome (MERS) coronavirus (MERS-CoV). Previous published serological studies showed that sera of Bactrian camels were all negative for MERS-CoV antibodies. However, a recent study revealed that direct inoculation of Bactrian camels intranasally with MERS-CoV can lead to infection with abundant virus shedding and seroconversion. In this study, we examined the presence of MERS-CoV antibodies in Bactrian and hybrid camels in Dubai, the United Arab Emirates (where dromedaries are also present), and Bactrian camels in Xinjiang, China (where dromedaries are absent). For the 29 serum samples from Bactrian camels in Dubai tested by the MERS-CoV spike (S) protein-based enzyme-linked immunosorbent assay (S-ELISA) and neutralization antibody test, 14 (48%) and 12 (41%), respectively, were positive for MERS-CoV antibodies. All the 12 serum samples that were positive with the neutralization antibody test were also positive for the S-ELISA. For the 11 sera from hybrid camels in Dubai tested with the S-ELISA and neutralization antibody test, 6 (55%) and 9 (82%), respectively, were positive for MERS-CoV antibodies. All the 6 serum samples that were positive for the S-ELISA were also positive with the neutralization antibody test. There was a strong correlation between the antibody levels detected by S-ELISA and neutralizing antibody titers, with a Spearman coefficient of 0.6262 (P < 0.0001; 95% confidence interval, 0.5062 to 0.7225). All 92 Bactrian camel serum samples from Xinjiang were negative for MERS-CoV antibodies tested using both S-ELISA and the neutralization antibody test. Bactrian and hybrid camels are potential sources of MERS-CoV infection. IMPORTANCE Since its first appearance in 2012, Middle East respiratory syndrome (MERS) has affected >25 countries, with >2,400 cases and an extremely high fatality rate of >30%. The total number of mortalities due to MERS is already greater than that due to severe acute respiratory syndrome. MERS coronavirus (MERS-CoV) has been confirmed to be the etiological agent. So far, dromedaries are the only known animal reservoir for MERS-CoV. Previously published serological studies showed that sera of Bactrian camels were all negative for MERS-CoV antibodies. In this study, we observed that 41% of the Bactrian camel sera and 55% of the hybrid camel sera from Dubai (where dromedaries are also present), but none of the sera from Bactrian camels in Xinjiang (where dromedaries are absent), were positive for MERS-CoV antibodies. Based on these results, we conclude that in addition to dromedaries, Bactrian and hybrid camels are also potential sources of MERS-CoV infection.

negative: Schweres akutes respiratorisches Syndrom (SARS) The sudden appearance of the severe acute respiratory syndrome (SARS) in 2003 demonstrated to the world at large that despite the high standard of medical care in affected countries, a highly contagious emerging infectious disease could spread rapidly worldwide. By application and improvement of stringent infection control measures, a further spread of SARS could be stopped and the disease could so far be defeated. In the meantime, decisive progress in the knowledge about the structure and further characteristics of the SARS coronavirus (SARS-CoV) have been made, including the likely virus reservoir and the ways of spread. Validated diagnostic tests are now available and are further being improved. Effective vaccines and antiviral agents are being developed. Of imminent importance to prepare against a resurgence of SARS, remain, besides an exact knowledge about the viral pathogen and its possible further behavior, constant vigilance, early recognition, and instant isolation of suspected cases of SARS.

negative: Difference in immune response in vaccinated and unvaccinated Swedish individuals after the 2009 influenza pandemic BACKGROUND: Previous exposures to flu and subsequent immune responses may impact on 2009/2010 pandemic flu vaccine responses and clinical symptoms upon infection with the 2009 pandemic H1N1 influenza strain. Qualitative and quantitative differences in humoral and cellular immune responses associated with the flu vaccination in 2009/2010 (pandemic H1N1 vaccine) and natural infection have not yet been described in detail. We designed a longitudinal study to examine influenza- (flu-) specific immune responses and the association between pre-existing flu responses, symptoms of influenza-like illness (ILI), impact of pandemic flu infection, and pandemic flu vaccination in a cohort of 2,040 individuals in Sweden in 2009–2010. METHODS: Cellular flu-specific immune responses were assessed by whole-blood antigen stimulation assay, and humoral responses by a single radial hemolysis test. RESULTS: Previous seasonal flu vaccination was associated with significantly lower flu-specific IFN-γ responses (using a whole-blood assay) at study entry. Pandemic flu vaccination induced long-lived T-cell responses (measured by IFN-γ production) to influenza A strains, influenza B strains, and the matrix (M1) antigen. In contrast, individuals with pandemic flu infection (PCR positive) exhibited increased flu-specific T-cell responses shortly after onset of ILI symptoms but the immune response decreased after the flu season (spring 2010). We identified non-pandemic-flu vaccinated participants without ILI symptoms who showed an IFN-γ production profile similar to pandemic-flu infected participants, suggesting exposure without experiencing clinical symptoms. CONCLUSIONS: Strong and long-lived flu-M1 specific immune responses, defined by IFN-γ production, in individuals after vaccination suggest that M1-responses may contribute to protective cellular immune responses. Silent flu infections appeared to be frequent in 2009/2010. The pandemic flu vaccine induced qualitatively and quantitatively different humoral and cellular immune responses as compared to infection with the 2009 H1N1 pandemic H1N1 influenza strain.

negative: COVID-19 and ART: the view of the Italian Society of Fertility and Sterility and Reproductive Medicine Abstract The COVID-19 pandemic is an unprecedented global situation. As ART specialists we should be cautious, carefully monitoring the situation whilst contributing by sharing novel evidence to counsel our patients, both pregnant women and would-be mothers. Time to egg collection and drop-out rates are parameters critical to scheduling treatments once the curve of infections has peaked and plateaued in each country. In order to reduce both parameters, infertile patients now require even more support from their IVF team: urgent oocyte collection for oncologic patients must be guaranteed, and oocyte retrievals for women of advanced maternal age and/or reduced ovarian reserve cannot be postponed indefinitely. This document represents the position of the Italian Society of Fertility and Sterility and Reproductive Medicine (SIFES-MR) in outlining ART priorities during and after this emergency.

negative: Probiotics and prebiotics potential for the care of skin, female urogenital tract, and respiratory tract The prebiotics and probiotics market is constantly growing due to the positive effects of its consumption on human health, which extends beyond the digestive system. In addition, the synbiotic products market is also expanding due to the synergistic effects between pre- and probiotics that provide additional benefits to consumers. Pre- and probiotics are being evaluated for their effectiveness to treat and prevent infectious diseases in other parts of the human body where microbial communities exist. This review examines the scientific data related to the effects of pre- and probiotics on the treatment of diseases occurring in the skin, female urogenital tract, and respiratory tract. The evidence suggests that probiotics consumption can decrease the presence of eczema in children when their mothers have consumed probiotics during pregnancy and lactation. In women, probiotics consumption can effectively prevent recurrent urinary tract infections. The consumption of synbiotic products can reduce respiratory tract infections and their duration and severity. However, the outcomes of the meta-analyses are still limited and not sufficiently conclusive to support the use of probiotics to treat infectious diseases. This is largely a result of the limited number of studies, lack of standardization of the studies, and inconsistencies between the reported results. Therefore, it is advisable that future studies consider these shortcomings and include the evaluation of the combined use of pre- and probiotics.

negative: Virus Neutralization Assay for Turkey Coronavirus Infection Turkey coronavirus (TCoV) infection induces the production of protective antibodies against the sequent exposure of TCoV. Serological tests to determine TCoV-specific antibodies are critical to evaluate previous exposure to TCoV in the turkey flocks and differentiate serotypes from different isolates or strains. A specific virus neutralization assay using embryonated turkey eggs and immunofluorescent antibody assay for determining TCoV-specific neutralizing antibodies is described in this chapter. Virus neutralization titer of turkey serum from turkeys infected with TCoV is the dilution of serum that can inhibit TCoV infection in 50 % of embryonated turkey eggs. Virus neutralization assay for TCoV is useful to monitor the immune status of turkey flocks infected with TCoV for the control of the disease.

negative: Low serum 25-hydroxyvitamin D levels are associated with increased risk of viral coinfections in wheezing children

negative: Porcine epidemic diarrhea virus: An overview of current virological and serological diagnostic methods Abstract Porcine epidemic diarrhea virus (PEDV) is the causative agent of an acute, highly contagious, and severe enteric disease that leads to high mortality rates in suckling piglets. Therefore, accurate diagnosis of PEDV infection is critical for the implementation of control measures for the virus. Many diagnostic tests have been recently developed and are currently available for the detection of PEDV, its proteins or nucleic acid, including virus isolation, immunofluorescence (IF) or immunohistochemistry (IHC), polymerase chain reaction (PCR) and isothermal amplification assays. Additionally, several serological assays have been developed and are currently used for the detection of antibodies against PEDV. Molecular assays such as real-time reverse transcriptase-PCR (rRT-PCR) became the methods of choice for the diagnosis of PEDV infection, providing sensitive, specific and rapid detection of the virus RNA in clinical samples. Whereas serological assays have been widely used to monitor prior exposure to the virus and to evaluate the efficacy of novel vaccine candidates or vaccination strategies. Here we discuss the properties of current PEDV diagnostic assays and prospects for improving diagnostic strategies in the future.

negative: A Stable Calcium Alumanyl A seven‐membered N,N′‐heterocyclic potassium alumanyl nucleophile is introduced and utilised in the metathetical synthesis of Mg−Al and Ca−Al bonded derivatives. Both species have been characterised by experimental and theoretical means, allowing a rationalisation of the greater reactivity of the heavier group 2 species implied by an initial assay of their reactivity.

negative: Multidose intramuscular allogeneic adipose stem cells decrease the severity of canine atopic dermatitis: A pilot study AIM: The aim of this pilot study was to evaluate the therapeutic and safety performance of an intramuscular treatment protocol of multidose of allogeneic adipose stem cells (ASCs) isolated, characterized, and expanded ex vivo from a healthy canine donor. MATERIALS AND METHODS: Twelve dogs diagnosed with canine atopic dermatitis (CAD) were intramuscularly treated with 0.5×10(6) of cryopreserved ASCs from a healthy immunized young canine Ehrlichia canis free donor weekly for 6 weeks. Treatment efficacy was evaluated by the pruritus index and the CAD Lesion Index (CADLI) test. Safety and adverse effects were determined by injection site reaction, weight, blood chemistry, liver function, and whole blood count. RESULTS: Canine ASCs obtained from a donor met the minimum qualities required for this type of cells and showed viability of 90% after thawing. The efficacy of the CADLI score and the pruritus index in 12 dogs with atopic dermatitis was statistically significant efficacy. No adverse reactions were observed at the intramuscular application site, or in relation to animal weight, blood cell populations, or liver and renal function. CONCLUSION: These results suggest that intramuscular administration of cryopreserved ASCs to dogs with atopic dermatitis is a promising cellular therapeutic product for the relief of the symptoms of this disease; however, the duration of the effects obtained with this dose and with other doses should be evaluated, as well as possible immune reactions. As far as we know, this is the first report of the use of multiple intramuscular doses cryopreserved ASCs to treat atopic dermatitis.

negative: Coronavirus: Hotspot on coronavirus disease 2019 in India The novel coronavirus disease (COVID-19) or also known as the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been recognized as the cause of respiratory infection in Wuhan, Hubei Province, China, in late December 2019. As of April 5, 2020, this epidemic had spread to worldwide with 12,03,485 confirmed cases, including 62,000 deaths. The World Health Organization has declared it a Global Public Health Crisis. Coronavirus causes respiratory illness coughing, sneezing, breathlessness, and fever including pneumonia. The disease is transmitted person to person through infected droplets. At present, the research on novel coronavirus is still in the primary stage. Based on the published study, we thoroughly summarize the history and origin, microbiology and taxonomy, mode of transmissions, target receptor, clinical features, diagnosis, prevention, and treatment about COVID-19. This short report writes in hope for providing platform to community and researcher dealings against with the novel coronavirus and providing a reference for further studies.

negative: United States strains to act as cases set record

negative: Detection and Identification by Immune Electron Microscopy of Fastidious Agents Associated with Respiratory Illness, Acute Nonbacterial Gastroenteritis, and Hepatitis A This chapter discusses detection and identification by immune electron microscopy (IEM) of fastidious agents associated with respiratory illness, acute nonbacterial gastroenteritis, and hepatitis A. For Norwalk gastroenteritis and hepatitis A, the IEM technique enabled not only the definitive visualization and identification for the first time of virus-like particles from individuals with these diseases but also enabled researchers to demonstrate for the first time the serological association of an identifiable virus-like agent with each of these diseases. The chapter also explains that a mixture of tobacco mosaic virus (TMV) and anti-TMV rabbit serum resulted in aggregation of the virus particles, whereas by contrast, such aggregation did not occur when the virus reacted with a control normal rabbit serum. T. F. Anderson and W. M. Stanley demonstrated the electron-microscopic specificity of the reaction by observing the lack of such reactivity between TMV and rabbit antiserum to tomato bushy stunt virus; and between tomato bushy stunt virus and anti-TMV rabbit serum.

negative: Emerging Pathogens: Challenges and Successes of Molecular Diagnostics More than 50 emerging and reemerging pathogens have been identified during the last 40 years. Until 1992 when the Institute of Medicine issued a report that defined emerging infectious diseases, medicine had been complacent about such infectious diseases despite the alarm bells of infections with human immunodeficiency virus. Molecular tools have proven useful in discovering and characterizing emerging viruses and bacteria such as Sin Nombre virus (hantaviral pulmonary syndrome), hepatitis C virus, Bartonella henselae (cat scratch disease, bacillary angiomatosis), and Anaplasma phagocytophilum (human granulocytotropic anaplasmosis). The feasibility of applying molecular diagnostics to dangerous, fastidious, and uncultivated agents for which conventional tests do not yield timely diagnoses has achieved proof of concept for many agents, but widespread use of cost-effective, validated commercial assays has yet to occur. This review presents representative emerging viral respiratory infections, hemorrhagic fevers, and hepatitides, as well as bacterial and parasitic zoonotic, gastrointestinal, and pulmonary infections. Agent characteristics, epidemiology, clinical manifestations, and diagnostic methods are tabulated for another 22 emerging viruses and five emerging bacteria. The ongoing challenge to the field of molecular diagnostics is to apply contemporary knowledge to facilitate agent diagnosis as well as to further discoveries of novel pathogens.

negative: Laboratory diagnosis of emerging human coronavirus infections – the state of the art The three unprecedented outbreaks of emerging human coronavirus (HCoV) infections at the beginning of the twenty-first century have highlighted the necessity for readily available, accurate and fast diagnostic testing methods. The laboratory diagnostic methods for human coronavirus infections have evolved substantially, with the development of novel assays as well as the availability of updated tests for emerging ones. Newer laboratory methods are fast, highly sensitive and specific, and are gradually replacing the conventional gold standards. This presentation reviews the current laboratory methods available for testing coronaviruses by focusing on the coronavirus disease 2019 (COVID-19) outbreak going on in Wuhan. Viral pneumonias typically do not result in the production of purulent sputum. Thus, a nasopharyngeal swab is usually the collection method used to obtain a specimen for testing. Nasopharyngeal specimens may miss some infections; a deeper specimen may need to be obtained by bronchoscopy. Alternatively, repeated testing can be used because over time, the likelihood of the SARS-CoV-2 being present in the nasopharynx increases. Several integrated, random-access, point-of-care molecular devices are currently under development for fast and accurate diagnosis of SARS-CoV-2 infections. These assays are simple, fast and safe and can be used in the local hospitals and clinics bearing the burden of identifying and treating patients.

negative: A case of COVID-19 and pneumonia returning from Macau in Taiwan: Clinical course and anti-SARS-CoV-2 IgG dynamic A 46-year-old woman presented to the emergency department with 2-day fever and cough at seven days after returning from Macau. COVID-19 and pneumonia was diagnosed based on the positive real-time RT-PCR tests for oropharyngeal swab samples and the presence of anti-SARS-COV-2 IgG starting from the illness day 11 and post-exposure 18–21 days.

negative: Respiratory virus infections Summary The respiratory tract is a frequent site of infection with a wide range of viruses. Each family of viruses can cause differing clinical syndromes depending on the age of the patient and the immune response. As a corollary, different clinical syndromes can be caused by different families of viruses.

negative: Human Saliva: Non-Invasive Fluid for Detecting Novel Coronavirus (2019-nCoV) The breakthrough of novel coronavirus (2019-nCoV) in Wuhan, a city of China, has damaged the status of health and quality of life. In the sequel of this epidemic or contagious disease, the patient experiences fever, chest paint, chills, a rapid heartbeat, breathing difficulties, pneumonia, and kidney failure. It has been suggested that this disease can spread through human-to-human transmission or by super spreading. By the help of the non-invasive fluid “saliva”, it is easy to detect the virus. This can help with the comfort of the patient as well as healthcare personnel. Under this perspective, we discuss the epidemic situation of 2019-nCOV and its relationship with human saliva.

negative: Zinc Supplementation Promotes a Th1 Response and Improves Clinical Symptoms in Fewer Hours in Children With Pneumonia Younger Than 5 Years Old. A Randomized Controlled Clinical Trial Background: Pneumonia caused 704,000 deaths in children younger than 5 years in 2015. Zinc is an important micronutrient due to its role in immune function. Since 2004, WHO recommends zinc supplementation for children with diarrhea to shorten the duration and decrease severity. Zinc supplementation for children with pneumonia is controversial. Methods: A randomized controlled clinical trial was conducted, and 103 children 1 month to 5 years old with pneumonia were included. Zinc or placebo was given during hospitalization. Clinical symptoms were recorded, and a blood draw was obtained to determine serum zinc levels, lymphoproliferation, and cytokines at hospitalization and at discharge of the patient; a nasal wash was obtained to detect viral or bacterial pathogens by multiplex RT-PCR. Results: Zinc supplementation improved in fewer hours the clinical status (76 ± 7 vs. 105 ± 8, p = 0.01), the respiratory rate (37 ± 6 vs. 57 ± 7, p = 0.04), and the oxygen saturation (53 ± 7 vs. 87 ± 9, p = 0.007) compared to the placebo group. An increase in IFNγ and IL-2 after treatment in the zinc group was observed. Conclusions: Zinc supplementation improved some clinical symptoms in children with pneumonia in fewer hours and induced a cellular immune response. Clinical Trial Registration: The trial was retrospectively registered in ClinicalTrials.gov, identifier NCT03690583, URL https://clinicaltrials.gov/ct2/show/NCT03690583?term=zinc+children&cond=Pneumonia&draw=2&rank=1.

negative: Preventive measures and management of COVID-19 in pregnancy

negative: Cats, coronaviruses and coronavirus antibody tests Feline infectious peritonitis and other coronavirus infections of cats are briefly reviewed. Interpretation and applications of feline coronavirus antibody tests are described, and general recommendations are provided for practitioners. Some of the major unresolved questions regarding coronavirus infections of cats are delineated.

negative: Rapid Metagenomic Diagnostics for Suspected Outbreak of Severe Pneumonia

negative: A consideration of publication-derived immune-related associations in Coronavirus and related lung damaging diseases The severe acute respiratory syndrome virus SARS-CoV-2, a close relative of the SARS-CoV virus, is the cause of recent COVID-19 pandemic affecting, to date, over a 2 million individuals across the globe and demonstrating relatively high rates of infection and mortality. A third virus, the H5N1, responsible for avian influenza, has caused infection with some clinical similarities to those in COVID-19 infections. Cytokines, small proteins that modulate immune responses, have been directly implicated in some of the severe responses seen in COVID-19 patients, e.g. cytokine storms. Understanding the immune processes related to COVID-19, and other similar infections, could help identify diagnostic markers and therapeutic targets. Here we examine data of cytokine, immune cell types, and disease associations captured from biomedical literature associated with coronavirus, SARS, and H5N1 influenza, with the objective of identifying potentially useful relationships and areas for future research. Cytokine and cell-type associations captured from MeSH terms linked to thousands of PubMed abstracts, has identified differing patterns of associations between the three corpuses of abstracts (coronavirus, SARS, or H5N1 influenza). Clustering of cytokine-disease co-occurrences in the context of coronavirus has identified compelling clusters of co-morbidities and symptoms, some of which already known to be linked to COVID-19. Finally, network analysis identified sub-networks of cytokines and immune cell types associated with different manifestations, co-morbidities and symptoms of coronavirus, SARS, and H5N1. Systematic review of research in medicine is essential to facilitate evidence-based choices about health interventions. In a fast moving pandemic the approach taken here will identify trends and enable rapid comparison to the literature of related diseases.

negative: Lung Infections A review of pulmonary infections of all types with diagnostic and morphological features.

negative: Prevalence of canine coronavirus antibodies by an enzyme-linked immunosorbent assay in dogs in the south of Italy Abstract An enzyme-linked immunosorbent assay (Elisa), using as antigen canine coronavirus-infected CrFK cell supernatant, was developed to detect antibodies against canine coronavirus (CCoV). Out of a total of 109 dog serum samples, 80 which were positive by routine virus neutralisation test were also Elisa positive. Seventeen samples which were negative by the virus neutralisation test, were positive by Elisa and by the confirmatory Western blotting test. The Elisa was substantially more sensitive than the virus neutralisation test in detecting antibodies to CCoV and may be used as an alternative technique to virus neutralisation.

negative: An update on feline infectious peritonitis: Diagnostics and therapeutics Abstract This review is concerned with what has been learned about feline infectious peritonitis (FIP) diagnostics and therapeutics since the publication of an extensive overview of literature covering the period 1963–2009. Although progress has been made in both areas, obtaining a definitive diagnosis of FIP remains a problem for those veterinarians and/or cat owners who require absolute certainty. This review will cover both indirect and direct diagnostic tests for the disease and will emphasize their limitations, as well as their specificity and sensitivity. There is still no effective treatment for FIP, although there are both claims that such therapies exist and glimmers of hope coming from new therapies that are under research. FIP has also been identified in wild felids and FIP-like disease is now a growing problem among pet ferrets.

negative: Connecting clusters of COVID-19: an epidemiological and serological investigation Summary Background Elucidation of the chain of disease transmission and identification of the source of coronavirus disease 2019 (COVID-19) infections are crucial for effective disease containment. We describe an epidemiological investigation that, with use of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological assays, established links between three clusters of COVID-19. Methods In Singapore, active case-finding and contact tracing were undertaken for all COVID-19 cases. Diagnosis for acute disease was confirmed with RT-PCR testing. When epidemiological information suggested that people might have been nodes of disease transmission but had recovered from illness, SARS-CoV-2 IgG serology testing was used to establish past infection. Findings Three clusters of COVID-19, comprising 28 locally transmitted cases, were identified in Singapore; these clusters were from two churches (Church A and Church B) and a family gathering. The clusters in Church A and Church B were linked by an individual from Church A (A2), who transmitted SARS-CoV-2 infection to the primary case from Church B (F1) at a family gathering they both attended on Jan 25, 2020. All cases were confirmed by RT-PCR testing because they had active disease, except for A2, who at the time of testing had recovered from their illness and tested negative. This individual was eventually diagnosed with past infection by serological testing. ELISA assays showed an optical density of more than 1·4 for SARS-CoV-2 nucleoprotein and receptor binding domain antigens in titres up to 1/400, and viral neutralisation was noted in titres up to 1/320. Interpretation Development and application of a serological assay has helped to establish connections between COVID-19 clusters in Singapore. Serological testing can have a crucial role in identifying convalescent cases or people with milder disease who might have been missed by other surveillance methods. Funding National Research Foundation (Singapore), National Natural Science Foundation (China), and National Medical Research Council (Singapore).

negative: AI-Driven Tools for Coronavirus Outbreak: Need of Active Learning and Cross-Population Train/Test Models on Multitudinal/Multimodal Data The novel coronavirus (COVID-19) outbreak, which was identified in late 2019, requires special attention because of its future epidemics and possible global threats. Beside clinical procedures and treatments, since Artificial Intelligence (AI) promises a new paradigm for healthcare, several different AI tools that are built upon Machine Learning (ML) algorithms are employed for analyzing data and decision-making processes. This means that AI-driven tools help identify COVID-19 outbreaks as well as forecast their nature of spread across the globe. However, unlike other healthcare issues, for COVID-19, to detect COVID-19, AI-driven tools are expected to have active learning-based cross-population train/test models that employs multitudinal and multimodal data, which is the primary purpose of the paper.

negative: Glial cell activation, recruitment, and survival of B-lineage cells following MCMV brain infection BACKGROUND: Chemokines produced by reactive glia drive migration of immune cells and previous studies from our laboratory have demonstrated that CD19(+) B cells infiltrate the brain. In this study, in vivo and in vitro experiments investigated the role of reactive glial cells in recruitment and survival of B-lineage cells in response to (murine cytomegalovirus) MCMV infection. METHODS: Flow cytometric analysis was used to assess chemokine receptor expression on brain-infiltrating B cells. Real-time RT-PCR and ELISA were used to measure chemokine levels. Dual-immunohistochemical staining was used to co-localize chemokine production by reactive glia. Primary glial cell cultures and migration assays were used to examine chemokine-mediated recruitment. Astrocyte: B cell co-cultures were used to investigate survival and proliferation. RESULTS: The chemokine receptors CXCR3, CXCR5, CCR5, and CCR7 were detected on CD19(+) cells isolated from the brain during MCMV infection. In particular, CXCR3 was found to be elevated on an increasing number of cells over the time course of infection, and it was the primary chemokine receptor expressed at 60 days post infection Quite different expression kinetics were observed for CXCR5, CCR5, and CCR7, which were elevated on the highest number of cells early during infection and decreased by 14, 30, and 60 days post infection Correspondingly, elevated levels of CXCL9, CXCL10, and CXCL13, as well as CCL5, were found within the brains of infected animals, and only low levels of CCL3 and CCL19 were detected. Differential expression of CXCL9/CXCL10 and CXCL13 between microglia and astrocytes was apparent, and B cells moved towards supernatants from MCMV-infected microglia, but not astrocytes. Pretreatment with neutralizing Abs to CXCL9 and CXCL10 inhibited this migration. In contrast, neutralizing Abs to the ligand of CXCR5 (i.e., CXCL13) did not significantly block chemotaxis. Proliferation of brain-infiltrating B cells was detected at 7 days post infection and persisted through the latest time tested (60 days post infection). Finally, astrocytes produce BAFF (B cell activating factor of the TNF family) and promote proliferation of B cells via cell-to-cell contact. CONCLUSIONS: CXCR3 is the primary chemokine receptor on CD19(+) B cells persisting within the brain, and migration to microglial cell supernatants is mediated through this receptor. Correspondingly, microglial cells produce CXCL9 and CXCL10, but not CXCL13. Reactive astrocytes promote B cell proliferation.

negative: Broad anti-coronaviral activity of FDA approved drugs against SARS-CoV-2 in vitro and SARS-CoV in vivo SARS-CoV-2 emerged in China at the end of 2019 and has rapidly become a pandemic with roughly 2.7 million recorded COVID-19 cases and greater than 189,000 recorded deaths by April 23rd, 2020 (www.WHO.org). There are no FDA approved antivirals or vaccines for any coronavirus, including SARS-CoV-2. Current treatments for COVID-19 are limited to supportive therapies and off-label use of FDA approved drugs. Rapid development and human testing of potential antivirals is greatly needed. A quick way to test compounds with potential antiviral activity is through drug repurposing. Numerous drugs are already approved for human use and subsequently there is a good understanding of their safety profiles and potential side effects, making them easier to fast-track to clinical studies in COVID-19 patients. Here, we present data on the antiviral activity of 20 FDA approved drugs against SARS-CoV-2 that also inhibit SARS-CoV and MERS-CoV. We found that 17 of these inhibit SARS-CoV-2 at a range of IC50 values at non-cytotoxic concentrations. We directly follow up with seven of these to demonstrate all are capable of inhibiting infectious SARS-CoV-2 production. Moreover, we have evaluated two of these, chloroquine and chlorpromazine, in vivo using a mouse-adapted SARS-CoV model and found both drugs protect mice from clinical disease.

negative: Coronavirus disease 2019 (COVID-19): current status and future perspectives ABSTRACT Coronavirus disease 2019 (COVID-19) originated in the city of Wuhan, Hubei Province, Central China, and has spread quickly to 72 countries to date. COVID-19 is caused by a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [previously provisionally known as 2019 novel coronavirus (2019-nCoV)]. At present, the newly identified SARS-CoV-2 has caused a large number of deaths with tens of thousands of confirmed cases worldwide, posing a serious threat to public health. However, there are no clinically approved vaccines or specific therapeutic drugs available for COVID-19. Intensive research on the newly emerged SARS-CoV-2 is urgently needed to elucidate the pathogenic mechanisms and epidemiological characteristics and to identify potential drug targets, which will contribute to the development of effective prevention and treatment strategies. Hence, this review will focus on recent progress regarding the structure of SARS-CoV-2 and the characteristics of COVID-19, such as the aetiology, pathogenesis and epidemiological characteristics.

negative: Clinical characteristics of COVID-19 infection in pregnant women: a systematic review and meta-analysis Background: On December 2019, Novel coronavirus disease (COVID-19) was detected in Wuhan, China, and then spread around the world. There is little information about effects of COVID-19 on Pregnant women and newborns as a sensitive population. The current study is a systemic review and Meta-analysis to measure the risks and determine the presentations of COVID-19 in pregnant women and newborn. Methods: online data bases were searched on march 20. Heterogeneity of the included studies was assessed using the Cochran Q test and Higgins I2 statistic and expressed as percentage. All data were analyzed with 95% confidence intervals. Results: A total of 7 studies involving 50 participants with Positive test of COVID-19 were enrolled. Mean age of pregnant women was 30.57 years old and the Mean Gestational age was 36.9 weeks. Other variables such as Apgar score, birth weight, Sign and symptoms, Complications and Laboratory data were Analyzed. Conclusion: Our findings showed same clinical characteristics in pregnant women as in non-pregnant adults, with the main symptoms being cough and fever. No vertical transmission was seen and all patients delivered healthy neonates. Our findings would be of great help to the decision making process, regarding the management of pregnant women diagnosed with COVID-19.

negative: Colostrum Antibodies, Egg Antibodies and Monoclonal Antibodies Providing Passive Immunity for Animals Passive immunity can be provided to animals by several sources of antibodies including from colostrum, avian eggs, and monoclonal sources. These antibodies have been shown protect production and companion animals from a number of pathogens. This chapter reviews the immune system for the principles of immune response to antigens and the synthesis of immunoglobulins of the five classes of antibodies in the body. Colostrum antibodies are described for passive immunity protection in animals such as calves. Chicken egg antibodies are another source of antibodies for passive immunity. Therapeutic monoclonal antibodies are also used to provide passive immunity in the veterinary field.

negative: Seroepidemiology of Middle East respiratory syndrome (MERS) coronavirus in Saudi Arabia (1993) and Australia (2014) and characterisation of assay specificity. The pseudoparticle virus neutralisation test (ppNT) and a conventional microneutralisation (MN) assay are specific for detecting antibodies to Middle East respiratory syndrome coronavirus (MERS-CoV) when used in seroepidemiological studies in animals. Genetically diverse MERS-CoV appear antigenically similar in MN tests. We confirm that MERS-CoV was circulating in dromedaries in Saudi Arabia in 1993. Preliminary data suggest that feral Australian dromedaries may be free of MERS-CoV but larger confirmatory studies are needed.

negative: Coronaviruses Coronaviruses of humans were first identified more than 60 years ago from individuals with respiratory infections, mainly mild. Two different viruses, 229E and OC43 were initially recognized. Because of difficulty in isolating them using standard techniques, many of the early studies of their occurrence were seroepidemiologic. They were confirmed to be worldwide in distribution, and, in the North Temperate Zone, mainly occurring in the winter season. With the development of the reverse transcriptase polymerase chain reaction (PCR) technique, two additional distinct viruses have been identified, HKU1 and NL63. The four viruses have now been recognized as important in the etiology of common respiratory infections, second only to the rhinoviruses. In 2002, a previously unrecognized betacoronavirus emerged from a zoonotic reservoir in Southern China and spread during the following year to several major cities of the world. The resulting illness was termed Severe Acute Respiratory Syndrome (SARS) because of its potential lethality. More than 8,000 probable cases were reported during 2003, mainly from Hong Kong and mainland China, producing social and economic disruption in those areas affected. A constant feature of the outbreak was the importance of nosocomial spread. In spite of an estimated basic reproductive number higher than influenza, the outbreak was ended, in large part because of control of in-hospital transmission. In 2012, another betacoronavirus has emerged in the Arabian peninsula which is producing a somewhat similar illness, termed Middle East Respiratory Syndrome (MERS), also marked by extensive nosocomial transmission. The outcome of this emergence is currently unknown.

negative: Radiological Findings in Patients with COVID-19 After its origin in Wuhan, China, coronavirus related respiratory illness spread across the globe, being declared as a pandemic by WHO on March 13, 2020. Because it is acquired via respiratory droplets, community spread is responsible for the recent global crisis. The current diagnostic options include real-time polymerase chain reaction (RT-PCR) and a few serology tests, including but not limited to the recently approved five minutes serology tests. The disease presents as a lower respiratory tract illness. Anecdotal experiences have shown that imaging characteristics are crucial to diagnosis as radiological evidence of disease appears prior to clinical manifestations and tends to evolve over time, which can be useful in predicting the stage of the disease. CT scan is more sensitive than a chest X-ray in highlighting these changes.

negative: Inflammatory response in mixed viral-bacterial community-acquired pneumonia BACKGROUND: The role of mixed pneumonia (virus + bacteria) in community-acquired pneumonia (CAP) has been described in recent years. However, it is not known whether the systemic inflammatory profile is different compared to monomicrobial CAP. We wanted to investigate this profile of mixed viral-bacterial infection and to compare it to monomicrobial bacterial or viral CAP. METHODS: We measured baseline serum procalcitonin (PCT), C reactive protein (CRP), and white blood cell (WBC) count in 171 patients with CAP with definite etiology admitted to a tertiary hospital: 59 (34.5%) bacterial, 66 (39.%) viral and 46 (27%) mixed (viral-bacterial). RESULTS: Serum PCT levels were higher in mixed and bacterial CAP compared to viral CAP. CRP levels were higher in mixed CAP compared to the other groups. CRP was independently associated with mixed CAP. CRP levels below 26 mg/dL were indicative of an etiology other than mixed in 83% of cases, but the positive predictive value was 45%. PCT levels over 2.10 ng/mL had a positive predictive value for bacterial-involved CAP versus viral CAP of 78%, but the negative predictive value was 48%. CONCLUSIONS: Mixed CAP has a different inflammatory pattern compared to bacterial or viral CAP. High CRP levels may be useful for clinicians to suspect mixed CAP.

negative: Isolation of a Coronavirus from Urinary Tract Tumours of Endemic Balkan Nephropathy Patients

negative: Systems-based candidate genes for human response to influenza infection Abstract Influenza A is a serious respiratory illness that can be debilitating and may cause complications leading to hospitalization and death. The outcome of infection with the influenza A virus is determined by a complex interplay of viral and host factors. With the ongoing threat of seasonal influenza and the potential emergence of new, more virulent strains of influenza viruses, we need to develop a better understanding of genetic variation in the human population and its association with severe outcomes from influenza infection. We propose a list of approximately 100 systems-based candidate genes for future study of the genetic basis of influenza disease and immunity in humans, based on evidence in the published literature for their potential role in the pathogenesis of this infection: binding of the virus to receptors on the host cell surface; cleavability of HA by host proteases; virus replication in host cells; destruction of host cells by apoptosis; state of immunocompetence of the individual host; and viral infections predisposing to bacterial infection.

negative: The Use of Convalescent Sera in Immune-Electron Microscopy to Detect Non-Suspected/New Viral Agents Negative staining electron microscopy methods can be employed for the diagnosis of viral particles in animal samples. In fact, negative staining electron microscopy methods are used to identify viruses, especially in minor species and wild animals, when no other methods are available and in cases of rare, emerging or re-emerging infections. In particular, immune-electron-microscopy with convalescent sera is employed to detect etiological agents when there are undiagnosed clinical outbreaks, when alternative diagnostic methods fail due to the lack of immunological reagents and primers, and when there is no indicative clinical suspect. An overview of immune-electron-microscopy with convalescent sera’s use in the diagnosis of new and unsuspected viruses in animals of domestic and wild species is provided through the descriptions of the following four diagnostic veterinary cases: (I) enteric viruses of pigs: Porcine Rotavirus, Porcine Epidemic Diarrhea Virus, Porcine Circovirus and Porcine Torovirus; (II) Rotavirus and astrovirus in young turkeys with enteritis; (III) Parvovirus-like particles in pheasants; and (IV) Lagoviruses: Rabbit Hemorrhagic Disease Virus and European Brown Hare Syndrome Virus.

negative: Diagnóstico microbiológico de las infecciones gastrointestinales Acute gastrointestinal tract infections are among the most common infectious diseases. In the present review, the different methods of diagnosing gastrointestinal infections caused by bacteria, viruses, and parasites are examined. Stool culture is the method of choice for diagnosing bacterial intestinal infections; however, infections caused by Clostridium difficile can be diagnosed by detection of toxins A and B in stools, and infections caused by diarrheagenic Escherichia coli by PCR detection of specific virulence factor genes harbored by several E. coli pathotypes. The techniques used to diagnose viral gastrointestinal infections include detection of viral antigens and nucleic acids. Finally, gastrointestinal infections caused by parasites can be diagnosed by testing for trophozoites and cysts of protozoa, or larvae and eggs of helminths in stools by direct microscopic examination, with concentration techniques, or by specific stains.

negative: Preparation and characterization of SARS in-house reference antiserum A reference antiserum for SARS is in urgent need in the development of SARS vaccine and other serological test of SARS research. Convalescent serum was collected from clinical confirmed patient. ELISA, Western-blotting and neutralization assay detected specific antibody against SARS coronavirus. This antiserum was prepared as in-house reference antiserum, freeze-dried and sealed in ampoules. The potency of this reference antiserum is defined to be 52.7 U after extensive calibration. Further, collaborative studies for the evaluation of this serum are needed in order to satisfy the requirements for international reference antiserum.

negative: The interface of animal and human vaccines

negative: Diversity of Dromedary Camel Coronavirus HKU23 in African Camels Revealed Multiple Recombination Events among Closely Related Betacoronaviruses of the Subgenus Embecovirus Genetic recombination has frequently been observed in coronaviruses. Here, we sequenced multiple complete genomes of dromedary camel coronavirus HKU23 (DcCoV-HKU23) from Nigeria, Morocco, and Ethiopia and identified several genomic positions indicative of cross-species virus recombination events among other betacoronaviruses of the subgenus Embecovirus (clade A beta-CoVs). Recombinant fragments of a rabbit coronavirus (RbCoV-HKU14) were identified at the hemagglutinin esterase gene position. Homolog fragments of a rodent CoV were also observed at 8.9-kDa open reading frame 4a at the 3′ end of the spike gene. The patterns of recombination differed geographically across the African region, highlighting a mosaic structure of DcCoV-HKU23 genomes circulating in dromedaries. Our results highlighted active recombination of coronaviruses circulating in dromedaries and are also relevant to the emergence and evolution of other betacoronaviruses, including Middle East respiratory syndrome coronavirus (MERS-CoV). IMPORTANCE Genetic recombination is often demonstrated in coronaviruses and can result in host range expansion or alteration in tissue tropism. Here, we showed interspecies events of recombination of an endemic dromedary camel coronavirus, HKU23, with other clade A betacoronaviruses. Our results supported the possibility that the zoonotic pathogen MERS-CoV, which also cocirculates in the same camel species, may have undergone similar recombination events facilitating its emergence or may do so in its future evolution.

negative: Analyzing Vaccine Trials in Epidemics With Mild and Asymptomatic Infection Vaccine efficacy against susceptibility to infection (VE(S)), regardless of symptoms, is an important endpoint of vaccine trials for pathogens with a high proportion of asymptomatic infection, because such infections may contribute to onward transmission and long-term sequelae, such as congenital Zika syndrome. However, estimating VE(S) is resource-intensive. We aimed to identify approaches for accurately estimating VE(S) when limited information is available and resources are constrained. We modeled an individually randomized vaccine trial by generating a network of individuals and simulating an epidemic. The disease natural history followed a “susceptible-exposed-infectious/symptomatic (or infectious/asymptomatic)-recovered” model. We then used 7 approaches to estimate VE(S), and we also estimated vaccine efficacy against progression to symptoms (VE(P)). A corrected relative risk and an interval-censored Cox model accurately estimate VE(S) and only require serological testing of participants once, while a Cox model using only symptomatic infections returns biased estimates. Only acquiring serological endpoints in a 10% sample and imputing the remaining infection statuses yields unbiased VE(S) estimates across values of the basic reproduction number (R(0)) and accurate estimates of VE(P) for higher R(0) values. Identifying resource-preserving methods for accurately estimating VE(S) and VE(P) is important in designing trials for diseases with a high proportion of asymptomatic infection.

negative: A serological survey on neutralizing antibody titer of SARS convalescent sera A seroepidemiologic study was conducted in North China in 2003 to determine the neutralizing antibody titer of severe acute respiratory syndrome (SARS) convalescent sera. A total of 99 SARS convalescent serum samples were collected from patients from the Inner Mongolia Autonomous Region, Hebei Province, and Beijing 35–180 days after the onset of symptoms. The anti‐SARS antibodies were detected by enzyme‐linked immunosorbent assay (ELISA), neutralization assay, and Western blot. Eighty‐seven serum samples were confirmed to be positive for SARS antibodies. The neutralizing antibody titer of the 87 positive sera was analyzed quantitatively by neutralization assay. The geometric mean titer (GMT) of the 87 convalescent sera was 1:61. The Kolmogorov–Smirnov test showed that the neutralizing antibody titers conform to normal distribution, which suggests that the average anti‐SARS antibody level in this study was representative of the convalescent antibody level of the SARS population. This result could be useful for the development and quality control of SARS vaccines. J. Med. Virol. 77:147–150, 2005. © 2005 Wiley‐Liss, Inc.

negative: A Peptide-Based Magnetic Chemiluminescence Enzyme Immunoassay for Serological Diagnosis of Coronavirus Disease 2019 BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel ß-coronavirus, causes severe pneumonia and has spread throughout the globe rapidly. The disease associated with SARS-CoV-2 infection is named coronavirus disease 2019 (COVID-19). To date, real-time reverse-transcription polymerase chain reaction (RT-PCR) is the only test able to confirm this infection. However, the accuracy of RT-PCR depends on several factors; variations in these factors might significantly lower the sensitivity of detection. METHODS: In this study, we developed a peptide-based luminescent immunoassay that detected immunoglobulin (Ig)G and IgM. The assay cutoff value was determined by evaluating the sera from healthy and infected patients for pathogens other than SARS-CoV-2. RESULTS: To evaluate assay performance, we detected IgG and IgM in the sera from confirmed patients. The positive rate of IgG and IgM was 71.4% and 57.2%, respectively. CONCLUSIONS: Therefore, combining our immunoassay with real-time RT-PCR might enhance the diagnostic accuracy of COVID-19.

negative: Middle East respiratory syndrome coronavirus (MERS-CoV) neutralising antibodies in a high-risk human population, Morocco, November 2017 to January 2018 BACKGROUND: Middle East respiratory syndrome coronavirus (MERS-CoV) remains a major concern for global public health. Dromedaries are the source of human zoonotic infection. MERS-CoV is enzootic among dromedaries on the Arabian Peninsula, the Middle East and in Africa. Over 70% of infected dromedaries are found in Africa. However, all known zoonotic cases of MERS have occurred in the Arabian Peninsula with none being reported in Africa. AIM: We aimed to investigate serological evidence of MERS-CoV infection in humans living in camel-herding areas in Morocco to provide insights on whether zoonotic transmission is taking place. METHODS: We carried out a cross sectional seroprevalence study from November 2017 through January 2018. We adapted a generic World Health Organization MERS-CoV questionnaire and protocol to assess demographic and risk factors of infection among a presumed high-risk population. ELISA, MERS-CoV spike pseudoparticle neutralisation tests (ppNT) and plaque neutralisation tests (PRNT) were used to assess MERS-CoV seropositivity. RESULTS: Serum samples were collected from camel slaughterhouse workers (n = 137), camel herders (n = 156) and individuals of the general population without occupational contact with camels but living in camel herding areas (n = 186). MERS-CoV neutralising antibodies with ≥ 90% reduction of plaque numbers were detected in two (1.5%) slaughterhouse workers, none of the camel herders and one individual from the general population (0.5%). CONCLUSIONS: This study provides evidence of zoonotic transmission of MERS-CoV in Morocco in people who have direct or indirect exposure to dromedary camels.

negative: Diagnostic Testing of Mouse and Rat Colonies for Infectious Agents Rodent health monitoring programs make an essential contribution to biomedical research by identifying the presence of infectious agents that might confound animal research. The authors discuss the types of diagnostic tests available, which agents deserve monitoring, and the appropriate frequency for such interventions.

negative: First known person-to-person transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the USA BACKGROUND: Coronavirus disease 2019 (COVID-19) is a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first detected in China in December, 2019. In January, 2020, state, local, and federal public health agencies investigated the first case of COVID-19 in Illinois, USA. METHODS: Patients with confirmed COVID-19 were defined as those with a positive SARS-CoV-2 test. Contacts were people with exposure to a patient with COVID-19 on or after the patient's symptom onset date. Contacts underwent active symptom monitoring for 14 days following their last exposure. Contacts who developed fever, cough, or shortness of breath became persons under investigation and were tested for SARS-CoV-2. A convenience sample of 32 asymptomatic health-care personnel contacts were also tested. FINDINGS: Patient 1—a woman in her 60s—returned from China in mid-January, 2020. One week later, she was hospitalised with pneumonia and tested positive for SARS-CoV-2. Her husband (Patient 2) did not travel but had frequent close contact with his wife. He was admitted 8 days later and tested positive for SARS-CoV-2. Overall, 372 contacts of both cases were identified; 347 underwent active symptom monitoring, including 152 community contacts and 195 health-care personnel. Of monitored contacts, 43 became persons under investigation, in addition to Patient 2. These 43 persons under investigation and all 32 asymptomatic health-care personnel tested negative for SARS-CoV-2. INTERPRETATION: Person-to-person transmission of SARS-CoV-2 occurred between two people with prolonged, unprotected exposure while Patient 1 was symptomatic. Despite active symptom monitoring and testing of symptomatic and some asymptomatic contacts, no further transmission was detected. FUNDING: None.

negative: Rapid and accurate identification of COVID-19 infection through machine learning based on clinical available blood test results Since the sudden outbreak of coronavirus disease 2019 (COVID-19), it has rapidly evolved into a momentous global health concern. Due to the lack of constructive information on the pathogenesis of COVID-19 and specific treatment, it highlights the importance of early diagnosis and timely treatment. In this study, 11 key blood indices were extracted through random forest algorithm to build the final assistant discrimination tool from 49 clinical available blood test data which were derived by commercial blood test equipments. The method presented robust outcome to accurately identify COVID-19 from a variety of suspected patients with similar CT information or similar symptoms, with accuracy of 0.9795 and 0.9697 for the cross-validation set and test set, respectively. The tool also demonstrated its outstanding performance on an external validation set that was completely independent of the modeling process, with sensitivity, specificity, and overall accuracy of 0.9512, 0.9697, and 0.9595, respectively. Besides, 24 samples from overseas infected patients with COVID-19 were used to make an in-depth clinical assessment with accuracy of 0.9167. After multiple verification, the reliability and repeatability of the tool has been fully evaluated, and it has the potential to develop into an emerging technology to identify COVID-19 and lower the burden of global public health. The proposed tool is well-suited to carry out preliminary assessment of suspected patients and help them to get timely treatment and quarantine suggestion. The assistant tool is now available online at http://lishuyan.lzu.edu.cn/COVID2019_2/.

negative: Interrupting transmission of COVID-19: lessons from containment efforts in Singapore Despite multiple importations resulting in local chains of transmission, Singapore has been able to control the COVID-19 outbreak without major disruption to daily living. In this article, we describe the combination of measures taken by Singapore to contain COVID-19 and share some early lessons learnt from the experience.

negative: Seroprevalence of hepatitis E virus in dromedary camels, Bedouins, Muslim Arabs and Jews in Israel, 2009–2017 Hepatitis E virus (HEV) is an emerging cause of viral hepatitis worldwide. Recently, HEV-7 has been shown to infect camels and humans. We studied HEV seroprevalence in dromedary camels and among Bedouins, Arabs (Muslims, none-Bedouins) and Jews and assessed factors associated with anti-HEV seropositivity. Serum samples from dromedary camels (n = 86) were used to determine camel anti-HEV IgG and HEV RNA positivity. Human samples collected between 2009 and 2016 from >20 years old Bedouins (n = 305), non-Bedouin Arabs (n = 320) and Jews (n = 195), were randomly selected using an age-stratified sampling design. Human HEV IgG levels were determined using Wantai IgG ELISA assay. Of the samples obtained from camels, 68.6% were anti-HEV positive. Among the human populations, Bedouins and non-Bedouin Arabs had a significantly higher prevalence of HEV antibodies (21.6% and 15.0%, respectively) compared with the Jewish population (3.1%). Seropositivity increased significantly with age in all human populations, reaching 47.6% and 34.8% among ⩾40 years old, in Bedouins and non-Bedouin Arabs, respectively. The high seropositivity in camels and in ⩾40 years old Bedouins and non-Bedouin Arabs suggests that HEV is endemic in Israel. The low HEV seroprevalence in Jews could be attributed to higher socio-economic status.

negative: Cross-sectional surveillance of Middle East respiratory syndrome coronavirus (MERS-CoV) in dromedary camels and other mammals in Egypt, August 2015 to January 2016 A cross-sectional study was conducted in Egypt to determine the prevalence of Middle East respiratory syndrome coronavirus (MERS-CoV) in imported and resident camels and bats, as well as to assess possible transmission of the virus to domestic ruminants and equines. A total of 1,031 sera, 1,078 nasal swabs, 13 rectal swabs, and 38 milk samples were collected from 1,078 camels in different types of sites. In addition, 145 domestic animals and 109 bats were sampled. Overall, of 1,031 serologically-tested camels, 871 (84.5%) had MERS-CoV neutralising antibodies. Seroprevalence was significantly higher in imported (614/692; 88.7%) than resident camels (257/339; 5.8%) (p < 0.05). Camels from Sudan (543/594; 91.4%) had a higher seroprevalence than those from East Africa (71/98; 72.4%) (p < 0.05). Sampling site and age were also associated with MERS-CoV seroprevalence (p < 0.05). All tested samples from domestic animals and bats were negative for MERS-CoV antibodies except one sheep sample which showed a 1:640 titre. Of 1,078 camels, 41 (3.8%) were positive for MERS-CoV genetic material. Sequences obtained were not found to cluster with clade A or B MERS-CoV sequences and were genetically diverse. The presence of neutralising antibodies in one sheep apparently in contact with seropositive camels calls for further studies on domestic animals in contact with camels.

negative: The Emergence of Human Coronavirus EMC: How Scared Should We Be? A novel betacoronavirus, human coronavirus (HCoV-EMC), has recently been detected in humans with severe respiratory disease. Further characterization of HCoV-EMC suggests that this virus is different from severe acute respiratory syndrome coronavirus (SARS-CoV) because it is able to replicate in multiple mammalian cell lines and it does not use angiotensin-converting enzyme 2 as a receptor to achieve infection. Additional research is urgently needed to better understand the pathogenicity and tissue tropism of this virus in humans. In their recent study published in mBio, Kindler et al. shed some light on these important topics (E. Kindler, H. R. Jónsdóttir, M. Muth, O. J. Hamming, R. Hartmann, R. Rodriguez, R. Geffers, R. A. Fouchier, C. Drosten, M. A. Müller, R. Dijkman, and V. Thiel, mBio 4[1]:e00611-12, 2013). These authors report the use of differentiated pseudostratified human primary airway epithelial cells, an in vitro model with high physiological relevance to the human airway epithelium, to characterize the cellular tropism of HCoV-EMC. More importantly, the authors demonstrate the potential use of type I and type III interferons (IFNs) to control viral infection.

negative: Viral Pneumonia in Older Adults Viruses account for a substantial portion of respiratory illnesses, including pneumonia, in the elderly population. Presently, influenza virus A H3N2 and respiratory syncytial virus are the most commonly identified viral pathogens in older adults with viral pneumonia. As diagnostic tests such as reverse-transcription polymerase chain reaction become more widely used, the relative importance of additional viruses (such as parainfluenza, rhinoviruses, coronaviruses, and human metapneumovirus) will likely increase. Influenza virus should be considered as a cause of pneumonia during the winter months, especially during periods of peak activity. Patients with high-grade fever, myalgias, and cough should arouse the highest suspicion. Respiratory syncytial virus pneumonia should also be suspected during the winter in patients with coryza, wheezing, low-grade fever, and patchy infiltrates, especially if negative for influenza on rapid testing. Because clinical features and periods of activity for many viruses overlap, laboratory confirmation of influenza is recommended for cases involving seriously ill or institutionalized patients.

negative: Exploiting the Legacy of the Arbovirus Hunters In recent years, it has become evident that a generational gap has developed in the community of arbovirus research. This apparent gap is due to the dis-investment of training for the next generation of arbovirologists, which threatens to derail the rich history of virus discovery, field epidemiology, and understanding of the richness of diversity that surrounds us. On the other hand, new technologies have resulted in an explosion of virus discovery that is constantly redefining the virosphere and the evolutionary relationships between viruses. This paradox presents new challenges that may have immediate and disastrous consequences for public health when yet to be discovered arboviruses emerge. In this review we endeavor to bridge this gap by providing a historical context for the work being conducted today and provide continuity between the generations. To this end, we will provide a narrative of the thrill of scientific discovery and excitement and the challenges lying ahead.

negative: Breadth of concomitant immune responses underpinning viral clearance and patient recovery in a non-severe case of COVID-19 We report the kinetics of the immune response in relation to clinical and virological features of a patient with mild-to-moderate coronavirus disease-19 (COVID-19) requiring hospitalisation. Increased antibody-secreting cells, follicular T-helper cells, activated CD4+ and CD8+ T-cells and IgM/IgG SARS-CoV-2-binding antibodies were detected in blood, prior to symptomatic recovery. These immunological changes persisted for at least 7 days following full resolution of symptoms, indicating substantial anti-viral immunity in this non-severe COVID-19.

negative: Enzyme‐Linked lmmunosorbent assay: A rapid reproducible test for the measurement of rabies antibody An enzyme‐linked immunosorbent assay (ELISA) was developed for detecting IgG antibodies to the Pitman Moore strain of rabies virus in sera from subjects immunised with HDCS vaccine. End‐point titres of antibody were determined using a pocket calculator preprogrammed to analyse absorbence values of test sera and negative controls. The assay was highly reproducible, and very close agreement was achieved when the results were compared with those of the mouse neutralization test. Rabies enzyme‐linked immunosorbent assay is easy to perform, the results are obtained within 48 hours, and because it employs inactivated virus, the test can be used safely without special containment facilities.

negative: Etude épidémiologique de gastroentérites infantiles d'origine virale dans la région amienoise Summary A systematic survey was carried on stools from 130 children suffering of acute gastroenteritis. Electron microscopy, enzymo-linked immunosorbent assay (ELISA) and counter electrophoresis were employed. This survey allowed to the detection by electron microscopy of Rotavirus (40 cases), Coronaviruses (3 cases), Astroviruses (2 cases), Adenoviruses (2 cases) and Small Round Viruses (1 case). Serological tests (complement fixation, ELISA and counter electrophoresis) done with 86 sera showed a good correlation with results obtained with electron microscopy.

negative: Localization to the nucleolus is a common feature of coronavirus nucleoproteins, and the protein may disrupt host cell division. The subcellular localization of transmissible gastroenteritis virus (TGEV) and mouse hepatitis virus (MHV) (group I and group II coronaviruses, respectively) nucleoproteins (N proteins) were examined by confocal microscopy. The proteins were shown to localize either to the cytoplasm alone or to the cytoplasm and a structure in the nucleus. This feature was confirmed to be the nucleolus by using specific antibodies to nucleolin, a major component of the nucleolus, and by confocal microscopy to image sections through a cell expressing N protein. These findings are consistent with our previous report for infectious bronchitis virus (group III coronavirus) (J. A. Hiscox et al., J. Virol. 75:506-512, 2001), indicating that nucleolar localization of the N protein is a common feature of the coronavirus family and is possibly of functional significance. Nucleolar localization signals were identified in the domain III region of the N protein from all three coronavirus groups, and this suggested that transport of N protein to the nucleus might be an active process. In addition, our results suggest that the N protein might function to disrupt cell division. Thus, we observed that approximately 30% of cells transfected with the N protein appeared to be undergoing cell division. The most likely explanation for this is that the N protein induced a cell cycle delay or arrest, most likely in the G(2)/M phase. In a fraction of transfected cells expressing coronavirus N proteins, we observed multinucleate cells and dividing cells with nucleoli (which are only present during interphase). These findings are consistent with the possible inhibition of cytokinesis in these cells.

negative: Serologic and behavioral risk survey of workers with wildlife contact in China We report on a study conducted in Guangdong Province, China, to characterize behaviors and perceptions associated with transmission of pathogens with pandemic potential in highly exposed human populations at the animal-human interface. A risk factor/exposure survey was administered to individuals with high levels of exposure to wildlife. Serological testing was performed to evaluate prior infection with several wildlife viral pathogens. Follow up serology was performed on a subset of the cohort as well as close contacts of individuals. 1,312 individuals were enrolled in the study. Contact with a wide range of wildlife species was reported in both occupational and occasional contexts. The overall proportion of individuals seropositive to any of the tested wildlife pathogens was approximately 4.0%. However, persons employed as butchers demonstrated a seropositivity of 9.0% to at least one pathogen of interest. By contrast, individuals working as hunters had lower rates of seropositivity. Among the study population, a number of other behaviors showed correlation with seropositivity, including contact with particular wildlife species such as field rats. These results demonstrate the need to further explore zoonotic risks of particular activities regarding wildlife contact, and to better understand risks of persons working as butchers with wildlife species.

negative: COVID-19 pneumonia manifestations at the admission on chest ultrasound, radiographs, and CT: single-center study and comprehensive radiologic literature review PURPOSE: To investigate the imaging features of emerging COVID-19 pneumonia on chest ultrasound (US), radiographs (CXR) and computed tomography (CT) examinations performed at admission and to provide a comprehensive radiological literature review on ongoing radiological data from recent publications. MATERIALS AND METHODS: In this retrospective single-center study, we enrolled consecutive patients from February 15, 2020, to March 15, 2020, with laboratory-confirmed SARS-CoV-2 hospitalized in Valduce Hospital (Como, Italy). Multi-modality imaging findings were evaluated and compared. Literature research was conducted through a methodical search on Pubmed and Embase databases. RESULTS: Fifty-eight patients (36 men, 22 women; age range, 18–98 years) were included in the study. Among these, chest US, CXR, and CT were performed respectively in twenty-two, thirty-two and forty-two patients. Lung US findings were consistent with diffuse B lines (100%) and subpleural consolidations (27.3%). CXR showed prevalent manifestations of consolidations (46.9%) and hazy increased opacities (37.5%). Typical CT features included bilateral and multilobar ground-glass opacities (GGO) with (59.5%) and without (35.7%) consolidations having a predominantly peripheral distribution (64.3%). Other imaging features included crazy paving pattern (57.1%), fibrous stripes (50%), subpleural lines (35.7%), architectural distortion (28.6%), air bronchogram sign (26.2%), vascular thickening (23.8%) and nodules (2.4%). Also, enlarged lymph nodes (14.3 %) and pleural effusion (7.1%) were observed. The literature review identified twenty-six original studies supporting our imaging chest findings. CONCLUSION: The spectrum of chest imaging manifestations of COVID-19 pneumonia upon admission includes B-lines and consolidations on US, consolidations and hazy increased opacities on CXR, and multifocal GGO with consolidations on CT.

negative: A novel severe acute respiratory syndrome coronavirus protein, U274, is transported to the cell surface and undergoes endocytosis. The severe acute respiratory syndrome coronavirus (SARS-CoV) genome contains open reading frames (ORFs) that encode for several genes that are homologous to proteins found in all known coronaviruses. These are the replicase gene 1a/1b and the four structural proteins, nucleocapsid (N), spike (S), membrane (M), and envelope (E), and these proteins are expected to be essential for the replication of the virus. In addition, this genome also contains nine other potential ORFs varying in length from 39 to 274 amino acids. The largest among these is the first ORF of the second longest subgenomic RNA, and this protein (termed U274 in the present study) consists of 274 amino acids and contains three putative transmembrane domains. Using antibody specific for the C terminus of U274, we show U274 to be expressed in SARS-CoV-infected Vero E6 cells and, in addition to the full-length protein, two other processed forms were also detected. By indirect immunofluorescence, U274 was localized to the perinuclear region, as well as to the plasma membrane, in both transfected and infected cells. Using an N terminus myc-tagged U274, the topology of U274 and its expression on the cell surface were confirmed. Deletion of a cytoplasmic domain of U274, which contains Yxxphi and diacidic motifs, abolished its transport to the cell surface. In addition, U274 expressed on the cell surface can internalize antibodies from the culture medium into the cells. Coimmunoprecipitation experiments also showed that U274 could interact specifically with the M, E, and S structural proteins, as well as with U122, another protein that is unique to SARS-CoV.

negative: Gastrointestinal Infection Could Be New Focus for Coronavirus Diagnosis It's not news to tell you that the coronavirus, known as COVID-19, is a worldwide pandemic. The initial outbreak of this novel virus in Wuhan in the Hubei province of China, first described in December 2019, has since moved on to being declared a pandemic by the World Health Organization. The classic description of COVID-19 is a respiratory illness that manifests with fever, dry cough, and dyspnea on exertion. However, gastrointestinal (GI) complication of COVID-19 is emerging as well. This was observed with similar viral respiratory illnesses, such as severe acute respiratory syndrome (SARS), which emerged in 2003, and the Middle East respiratory syndrome (MERS), which emerged in 2012. In a recently published, single-center case series of 138 consecutive hospitalized patients with confirmed COVID-19, investigators reported that approximately 10% of patients initially presented with GI symptoms, prior to the subsequent development of respiratory symptoms. Common and often very subtle symptoms included diarrhea, nausea, and abdominal pain, with a less common symptom being nonspecific GI illness. New studies are expanding our understanding of the possible fecal transmission of COVID-19. Assessment by polymerase chain reaction (PCR) has provided evidence of the virus in the stool and the oropharynx outside the nasopharynx and respiratory tract. Virus in the stool may be evident on presentation and last throughout the course of illness resolution for up to 12 days after the respiratory virus evidence is gone. In fact, in one of the most recent studies looking at 73 patients, approximately 24% remained positive in their stool for evidence of the virus, though not necessarily infection, after showing negative in respiratory samples. The Centers for Disease Control and Prevention (CDC) recommends that after two negative respiratory tests separated by ≥ 24 hours, patients can be dismissed from having transmissibility infection risk for COVID-19. The potential for fecal-oral transmission of COVID-19 needs to be strongly considered. Considering these cases and the lessons from SARS, many authors recommend that real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from feces should be performed routinely in SARS-CoV-2 patients.

negative: Testing the Donor The transplantation of tissues from donor to recipient is a fundamental part of medicine today. A range of tissues including bone, skin, tendons, heart valves, corneas etc. are collected from suitable donors and transplanted into those patients for whom tissue transplant would have clinical benefit.

negative: NUEVOS VIRUS RESPIRATORIOS EN PEDIATRÍA RESUMEN Las infecciones respiratorias continúan siendo la mayor causa de morbimortalidad en pediatría. Los virus constituyen los agentes infecciosos más frecuentes, actualmente con los avances en las técnicas diagnósticas se han sumado “nuevos virus” entre los que destacan Metapneumovirus (MPVh), Bocavirus (BoVh) y Coronavirus (CoVh), que son el objetivo de este artículo. SUMMARY Acute lower respiratory infection is still the leading cause of global morbility and mortality in children. Viruses are the most frequent pathogen, currently the most common viral etiology VRS, although recently due to advances in diagnostic techniques new viruses have been added, that includes Metapneumovirus (hMPV), Bocavirus (hBoV) and Coronavirus (hCoV), which are the purpose of this review.

negative: Lack of Innate Interferon Responses during SARS Coronavirus Infection in a Vaccination and Reinfection Ferret Model In terms of its highly pathogenic nature, there remains a significant need to further define the immune pathology of SARS-coronavirus (SARS-CoV) infection, as well as identify correlates of immunity to help develop vaccines for severe coronaviral infections. Here we use a SARS-CoV infection-reinfection ferret model and a functional genomics approach to gain insight into SARS immunopathogenesis and to identify correlates of immune protection during SARS-CoV-challenge in ferrets previously infected with SARS-CoV or immunized with a SARS virus vaccine. We identified gene expression signatures in the lungs of ferrets associated with primary immune responses to SARS-CoV infection and in ferrets that received an identical second inoculum. Acute SARS-CoV infection prompted coordinated innate immune responses that were dominated by antiviral IFN response gene (IRG) expression. Reinfected ferrets, however, lacked the integrated expression of IRGs that was prevalent during acute infection. The expression of specific IRGs was also absent upon challenge in ferrets immunized with an inactivated, Al(OH)(3)-adjuvanted whole virus SARS vaccine candidate that protected them against SARS-CoV infection in the lungs. Lack of IFN-mediated immune enhancement in infected ferrets that were previously inoculated with, or vaccinated against, SARS-CoV revealed 9 IRG correlates of protective immunity. This data provides insight into the molecular pathogenesis of SARS-CoV and SARS-like-CoV infections and is an important resource for the development of CoV antiviral therapeutics and vaccines.

negative: Can we contain the COVID-19 outbreak with the same measures as for SARS? Summary The severe acute respiratory syndrome (SARS) outbreak in 2003 resulted in more than 8000 cases and 800 deaths. SARS was eventually contained by means of syndromic surveillance, prompt isolation of patients, strict enforcement of quarantine of all contacts, and in some areas top-down enforcement of community quarantine. By interrupting all human-to-human transmission, SARS was effectively eradicated. By contrast, by Feb 28, 2020, within a matter of 2 months since the beginning of the outbreak of coronavirus disease 2019 (COVID-19), more than 82 000 confirmed cases of COVID-19 have been reported with more than 2800 deaths. Although there are striking similarities between SARS and COVID-19, the differences in the virus characteristics will ultimately determine whether the same measures for SARS will also be successful for COVID-19. COVID-19 differs from SARS in terms of infectious period, transmissibility, clinical severity, and extent of community spread. Even if traditional public health measures are not able to fully contain the outbreak of COVID-19, they will still be effective in reducing peak incidence and global deaths. Exportations to other countries need not result in rapid large-scale outbreaks, if countries have the political will to rapidly implement countermeasures.

negative: Evaluation of candidate vaccine approaches for MERS-CoV The emergence of Middle East respiratory syndrome coronavirus (MERS-CoV) as a cause of severe respiratory disease highlights the need for effective approaches to CoV vaccine development. Efforts focused solely on the receptor-binding domain (RBD) of the viral Spike (S) glycoprotein may not optimize neutralizing antibody (NAb) responses. Here we show that immunogens based on full-length S DNA and S1 subunit protein elicit robust serum-neutralizing activity against several MERS-CoV strains in mice and non-human primates. Serological analysis and isolation of murine monoclonal antibodies revealed that immunization elicits NAbs to RBD and, non-RBD portions of S1 and S2 subunit. Multiple neutralization mechanisms were demonstrated by solving the atomic structure of a NAb-RBD complex, through sequencing of neutralization escape viruses and by constructing MERS-CoV S variants for serological assays. Immunization of rhesus macaques confers protection against MERS-CoV-induced radiographic pneumonia, as assessed using computerized tomography, supporting this strategy as a promising approach for MERS-CoV vaccine development.

negative: Reassessing therapeutic antibodies for neglected and tropical diseases In the past two decades there has been a significant expansion in the number of new therapeutic monoclonal antibodies (mAbs) that are approved by regulators. The discovery of these new medicines has been driven primarily by new approaches in inflammatory diseases and oncology, especially in immuno-oncology. Other recent successes have included new antibodies for use in viral diseases, including HIV. The perception of very high costs associated with mAbs has led to the assumption that they play no role in prophylaxis for diseases of poverty. However, improvements in antibody-expression yields and manufacturing processes indicate this is a cost-effective option for providing protection from many types of infection that should be revisited. Recent technology developments also indicate that several months of protection could be achieved with a single dose. Moreover, new methods in B cell sorting now enable the systematic identification of high-quality antibodies from humanized mice, or patients. This Review discusses the potential for passive immunization against schistosomiasis, fungal infections, dengue, and other neglected diseases.

negative: How will country-based mitigation measures influence the course of the COVID-19 epidemic?

negative: COVID-19 coronavirus vaccine design using reverse vaccinology and machine learning To ultimately combat the emerging COVID-19 pandemic, it is desired to develop an effective and safe vaccine against this highly contagious disease caused by the SARS-CoV-2 coronavirus. Our literature and clinical trial survey showed that the whole virus, as well as the spike (S) protein, nucleocapsid (N) protein, and membrane protein, have been tested for vaccine development against SARS and MERS. We further used the Vaxign reverse vaccinology tool and the newly developed Vaxign-ML machine learning tool to predict COVID-19 vaccine candidates. The N protein was found to be conserved in the more pathogenic strains (SARS/MERS/COVID-19), but not in the other human coronaviruses that mostly cause mild symptoms. By investigating the entire proteome of SARS-CoV-2, six proteins, including the S protein and five non-structural proteins (nsp3, 3CL-pro, and nsp8–10) were predicted to be adhesins, which are crucial to the viral adhering and host invasion. The S, nsp3, and nsp8 proteins were also predicted by Vaxign-ML to induce high protective antigenicity. Besides the commonly used S protein, the nsp3 protein has not been tested in any coronavirus vaccine studies and was selected for further investigation. The nsp3 was found to be more conserved among SARS-CoV-2, SARS-CoV, and MERS-CoV than among 15 coronaviruses infecting human and other animals. The protein was also predicted to contain promiscuous MHC-I and MHC-II T-cell epitopes, and linear B-cell epitopes localized in specific locations and functional domains of the protein. Our predicted vaccine targets provide new strategies for effective and safe COVID-19 vaccine development.

negative: Enzyme-linked immunosorbent assay for the detection of canine coronavirus and its antibody in dogs Abstract Two methods of enzyme-linked immunosorbent assay (ELISA) were developed for the diagnosis of canine coronavirus (CCV) infection in dogs. One ELISA, in which CCV-infected CRFK cell lysate is used as antigen, is for the detection and titration of antibody against CCV, and the other ELISA uses the double antibody sandwich method for the detection of CCV antigen. The first ELISA procedure demonstrated antibody responses in dogs inoculated with CCV, as did the virus neutralization test; the second ELISA detected specific CCV antigen in feces and organ homogenates of inoculated dogs.

negative: The impact of gestational age on targeted amniotic cell profiling in experimental neural tube defects. PURPOSE The proportions of select stem cells in term amniotic fluid have been shown to correlate with the type and size of experimental neural tube defects (NTDs). We sought to determine the impact of gestational age upon this form of targeted amniotic cell profiling. METHODS Sprague-Dawley fetuses with retinoic acid-induced NTDs (n = 110) underwent amniotic fluid procurement at four time points in gestation. Samples were analyzed by flow cytometry for the presence of cells concomitantly expressing Nestin and Sox-2 (neural stem cells, aNSCs) and cells concomitantly expressing CD29 and CD44 (mesenchymal stem cells, aMSCs). Statistical analysis was by nonparametric Kruskal-Wallis ANOVA (p < 0.05). RESULTS There was a statistically significant impact of gestational age on the proportions of both aMSCs (p = 0.01) and aNSCs (p < 0.01) in fetuses with isolated spina bifida. No such impact was noted in normal fetuses (p > 0.10 for both cells), in isolated exencephaly (p > 0.10 for both cells), or in combination defects (p > 0.10 for both cells). Gestational age had no effect on aNSC/aMSC ratios. CONCLUSIONS Targeted quantitative amniotic cell profiling varies with gestational age in experimental isolated spina bifida. This finding should be considered prior to the eventual translation of this diagnostic adjunct into the prenatal evaluation of these anomalies. © 2014 S. Karger AG, Basel.

negative: Development and validation of a monoclonal antibody-based competitive ELISA for detection of antibodies against porcine epidemic diarrhoea virus (PEDV) Abstract Porcine epidemic diarrhoea virus (PEDV), belongs to the genus Alphacoronavirus in the family Coronaviridae and causes severe diarrhoea, vomiting, dehydration and high mortality in seronegative newborn piglets. Thus, a precise and rapid diagnosis of PEDV infection is important for the application of control measures to limit viral dissemination. In this investigation, a monoclonal antibodies (MAbs)-based competitive enzyme-linked immunosorbent assay (ELISA) for detecting antibodies against PEDV was developed and validated. The diagnostic performance of the test was evaluated by receiver operating characteristic (ROC) analysis using a panel of 829 known sera collected from different commercial pig farms, with or without a history of PED presence and from experimentally infected pigs. The competitive ELISA showed excellent diagnostic performance and discriminatory power with high sensitivity (Se) and specificity (Sp) values (Se = 96.5%, 95% IC 94.1–98.1; Sp = 98.2%, 95% IC 96.3–99.3). Moreover, this competitive ELISA method has other properties, such as high feasibility of testing sera without pre-treatment and automatic and instrument-mediated revealing, that makes it appropriate for large-scale screenings of affected pig farms in endemic regions or for monitoring plans in PEDV-free areas.

negative: Severe Acute Respiratory Syndrome (SARS) Severe acute respiratory syndrome (SARS) is caused by a novel coronavirus (SARS-CoV), spread largely via droplets. Patients present with rapidly progressive pneumonia and respiratory failure. Diagnosis requires the demonstration of epidemiological linkage, clinical profiles, and virological evidence of SARS-CoV infection. Treatment of SARS is largely anecdotal. High-dose corticosteroid therapy might be useful for critically ill patients, but previous use of ribavirin (a broad-spectrum antiviral agent) was probably not efficacious. Some survivors of SARS suffer from avascular necrosis of hip and knee joints. Poor prognostic factors include advanced age, comorbidities, and high serum lactate dehydrogenase and neutrophil levels.

negative: A novel luciferase immunosorbent assay performs better than a commercial enzyme-linked immunosorbent assay to detect MERS-CoV specific IgG in humans and animals Abstract The Middle East respiratory syndrome (MERS) is a lethal zoonosis caused by MERS coronavirus (MERS-CoV) and poses a significant threat to public health worldwide. Therefore, a rapid, sensitive, and specific serologic test for detecting anti-MERS-CoV antibodies in both humans and animals is urgently needed for the successful management of this illness. Here, we evaluated various novel luciferase immunosorbent assays (LISA) based on nucleocapsid protein (NP) as well as fragments derived from spike protein (S) including subunit 1 (S1), N terminal domain (NTD), receptor-binding domain (RBD) and subunit 2 (S2) of S for the detection of MERS-CoV-specific IgG. Fusion proteins, including nanoluciferase (NLuc) and various fragments derived from the NP or S protein of MERS-CoV, were expressed in human embryonic kidney 293 T cells. LISAs that detected anti-MERS-CoV IgG were further developed using cell lysates expressing various fusion proteins. Panels of human or animal samples infected with MERS-CoV were used to analyze the sensitivity and specificity of various LISAs in reference to a MERS-CoV RT-PCR, commercial S1-based ELISA, and pseudovirus particle neutralization test (ppNT). Our results showed that the S1-, RBD-, and NP-LISAs were more sensitive than the NTD- and S2-LISAs for the detection of anti-MERS-CoV IgG. Furthermore, the S1-, RBD-, and NP-LISAs were more sensitive (by at least 16-fold) than the commercially available S1-ELISA. Moreover, the S1-, RBD-, and NP-LISA specifically recognized anti-MERS-CoV IgG and did not cross-react with samples derived from other human CoV (OC43, 229E, HKU1, NL63)-infected patients. More importantly, these LISAs proved their applicability and reliability for detecting anti-MERS-CoV IgG in samples from camels, monkeys, and mice, among which the RBD-LISA exhibited excellent performance. The results of this study suggest that the novel MERS-CoV RBD- and S1- LISAs are highly effective platforms for the rapid and sensitive detection of anti-MERS-CoV IgG in human and animal samples. These assays have the potential to be used as serologic tests for the management and control of MERS-CoV infection.

negative: Mapping the Landscape of Artificial Intelligence Applications against COVID-19 COVID-19, the disease caused by the SARS-CoV-2 virus, has been declared a pandemic by the World Health Organization, with over 2.5 million confirmed cases as of April 23, 2020. In this review, we present an overview of recent studies using Machine Learning and, more broadly, Artificial Intelligence, to tackle many aspects of the COVID-19 crisis at different scales including molecular, clinical, and societal applications. We also review datasets, tools, and resources needed to facilitate AI research. Finally, we discuss strategic considerations related to the operational implementation of projects, multidisciplinary partnerships, and open science. We highlight the need for international cooperation to maximize the potential of AI in this and future pandemics.

negative: CHAPTER 14 Microbial Forensics Host Factors Publisher Summary This chapter presents the elements of the host response in a simplified fashion. Microbial forensics aims at identifying: the biological agent, its source, and the individuals responsible for a biothreat event. Analytic approaches differ when the suspected biothreat agent is encountered in a container or the environment, as opposed to a human or an animal. However, once the microbe or its toxin is in the living host, all the preceding items except the microbial nucleic acid cannot be analyzed. Nevertheless, the host response to the biological agent is available for analysis. The host response to a foreign substance is often a well orchestrated series of events designed to protect the individual from any harm. Modern techniques help to elucidate the pathways and components of the host response. Similar to a live microbe, vaccines can also provoke an antibody response. A vaccine can compose of: a live or attenuated microbe, a whole nonproliferating microbe, or an antigenic part of the microbe. Regardless, the intent of the vaccine is to produce protection, often by protective antibodies. It is likely that the future understanding of the immune system and evolving technologies; such as microarrays will enhance analytic power.

negative: 2019-novel coronavirus outbreak: A new challenge OBJECTIVES: Following the public health emergency declared by the World Health Organization and the recent outbreak by 2019-nCoV in China and through other 29 countries, we aimed to summarize the clinical aspects of novel beta-coronavirus infection and its possible clinical presentations together with suggested therapeutic algorithms for patients who may require antibiotic treatment. METHODS: We reviewed the currently available literature of microbiologically confirmed infections by 2019-ConV (or COVID-19) occurred at the time of writing (13 February 2020). A literature search was performed using the PubMed database and the Cochrane library. Search terms included "novel coronavirus" or "2019-nCoV" or “COVID-19”. RESULTS: Published cases occurred mostly in males (age ranged from 8 to 92). Cardiovascular, digestive and endocrine system diseases were commonly reported, except previous chronic pulmonary diseases (e.g., COPD, asthma, bronchiectasis) that were surprisingly underreported. Fever was presented in all the case series available, flanked by cough, dyspnea, myalgias and fatigue. Multiple bilateral lobular and subsegmental areas of consolidation or bilateral ground-glass opacities were the main reported radiological features of 2019-nCoV, at least in the early phases of disease. CONCLUSIONS: The new 2019-nCoV epidemics is mainly associated with respiratory disease and few extrapulmonary signs. However, there is a low rate of associated pre-existing respiratory comorbidities.

negative: From SARS to COVID-19: A previously unknown SARS- related coronavirus (SARS-CoV-2) of pandemic potential infecting humans – Call for a One Health approach Human coronaviruses continue to pose a threat to human health. The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019 which causes coronavirus disease-2019 (COVID-19), an acute respiratory disease marked the third introduction of a highly pathogenic coronavirus into the human population in the twenty-first century. This recent emergence of a previously unknown coronavirus in China leads to huge impacts on humans globally. Covid-19 is a challenge to global public health. Here, we discuss the COVID-19 outbreak in a one health context, highlighting the need for the implementation of one health measures and practices to improve human health and reduce the emergence of pandemic viruses.

negative: A cell phone data driven time use analysis of the COVID-19 epidemic Transmission of the SAR-COV-2 virus that causes COVID-19 is largely driven by human behavior and person-to-person contact. By staying home, people reduce the probability of contacting an infectious individual, becoming infected, and passing on the virus. One of the most promising sources of data on time use is smartphone location data. We develop a time use driven proportional mixing SEIR model that naturally incorporates time spent at home measured using smartphone location data and allows people of different health statuses to behave differently. We simulate epidemics in almost every county in the United States. The model suggests that Americans' behavioral shifts have reduced cases in 55%-86% of counties and for 71%-91% of the population, depending on modeling assumptions. Resuming pre-epidemic behavior would lead to a rapid rise in cases in most counties. Spatial patterns of bending and flattening the curve are robust to modeling assumptions. Depending on epidemic history, county demographics, and behavior within a county, returning those with acquired immunity (assuming it exists) to regular schedules generally helps reduce cumulative COVID-19 cases. The model robustly identifies which counties would experience the greatest share of case reduction relative to continued distancing behavior. The model occasionally mischaracterizes epidemic patterns in counties tightly connected to larger counties that are experiencing large epidemics. Understanding these patterns is critical for prioritizing testing resources and back-to-work planning for the United States.

negative: A low density oligonucleotide microarray for the detection of viral and atypical bacterial respiratory pathogens Abstract Acute respiratory tract infections are a major cause of morbidity and mortality worldwide and exert a considerable economic burden on healthcare systems. Acute respiratory tract infections of the upper and lower respiratory tract are caused by a wide variety of viral and bacterial pathogens, which require comprehensive laboratory investigations. Conventional serological and immunofluorescence-based diagnostic methods for acute respiratory tract infections lack sensitivity when compared to polymerase chain reaction (PCR)-based approaches and the development of new diagnostic methodologies is required, to provide accurate, sensitive and rapid diagnoses. In the present study, a PCR-based low density oligonucleotide microarray was developed for the detection of 16 viral and two atypical bacterial pathogens. The performance of this DNA microarray-based analysis exhibited comparable sensitivities and specificities to multiplex real-time reverse transcription polymerase chain reactions (rtPCRs) confirming the potential diagnostic utility of the method. In contrast to routine multiplex PCR, the microarray incorporates an intrinsic redundancy as multiple and non-identical probes per target on the array allow direct intra-assay confirmation of positives. This study demonstrates that microarray technology provides a viable alternative to conventional serological-based approaches and multiplex PCR for pathogen identification in acute respiratory tract infections.

negative: A case of SARS-CoV-2 carrier for 32 days with several times false negative nucleic acid tests In 2019, a novel coronavirus (SARS-CoV-2) was first discovered in Wuhan, Hubei, China, causing severe respiratory disease in humans, and has been identified as a public health emergency of international concern. With the spread of the virus, there are more and more false negative cases of RT-PCR nucleic acid detection in the early stage of potential infection. In this paper, we collected the epidemiological history, clinical manifestations, outcomes, laboratory results and images of a SARS-CoV-2 carrier with no significant past medical history. The patient was quarantined because of her colleague had been diagnosed. After the onset of clinical symptoms, chest CT results showed patchy ground-glass opacity (GGO) in her lungs, but it took a total of nine nucleic acid tests to confirm the diagnosis, among which the first eight RT-PCR results were negative or single-target positive. In addition to coughing up phlegm during her stay in the hospital, she did not develop chills, fever, abdominal pain, diarrhea and other clinical symptoms. Since initial antiviral treatment, the lung lesions were absorbed. But the sputum nucleic acid test was still positive. In combination with antiviral and immune therapy, the patient tested negative for the virus. Notably, SARS-CoV-2 was detected only in the lower respiratory tract samples (sputum) throughout the diagnosis and treatment period. This is a confirmed case of SARS-CoV-2 infection with common symptoms, and her diagnosis has undergone multiple false negatives ,suggesting that it is difficult to identify certain carriers of the virus and that such patients may also increase the spread of the SARS-CoV-2.

negative: ReScan, a Multiplex Diagnostic Pipeline, Pans Human Sera for SARS-CoV-2 Antigens Serologic assays are needed to determine SARS-CoV-2 seroprevalence, but poor specificity can overestimate exposures. Here, we built a pan-human coronavirus proteome-wide programmable phage display assay (VirScan) to profile coronavirus antigens specifically enriched by 20 COVID-19 patient serum IgG. With ReScan, a new diagnostic development workflow which combines the isolation of phage expressing the most immunogenic peptides with paper-based microarrays manufactured via acoustic liquid handling, we identified 9 candidate antigens from a library of 534 SARS-CoV-2 peptides. These arrays could form the basis of a multiplexed COVID-19 serologic assay with enhanced specificity. ReScan has broad applicability for serologic assay development.

negative: Potent binding of 2019 novel coronavirus spike protein by a SARS coronavirus-specific human monoclonal antibody The newly identified 2019 novel coronavirus (2019-nCoV) has caused more than 800 laboratory-confirmed human infections, including 25 deaths, posing a serious threat to human health. Currently, however, there is no specific antiviral treatment or vaccine. Considering the relatively high identity of receptor binding domain (RBD) in 2019-nCoV and SARS-CoV, it is urgent to assess the cross-reactivity of anti-SARS-CoV antibodies with 2019-nCoV spike protein, which could have important implications for rapid development of vaccines and therapeutic antibodies against 2019-nCoV. Here, we report for the first time that a SARS-CoV-specific human monoclonal antibody, CR3022, could bind potently with 2019-nCoV RBD (KD of 6.3 nM). The epitope of CR3022 does not overlap with the ACE2 binding site within 2019-nCoV RBD. Therefore, CR3022 has the potential to be developed as candidate therapeutics, alone or in combination with other neutralizing antibodies, for the prevention and treatment of 2019-nCoV infections. Interestingly, some of the most potent SARS-CoV-specific neutralizing antibodies (e.g., m396, CR3014) that target the ACE2 binding site of SARS-CoV failed to bind 2019-nCoV spike protein, indicating that the difference in the RBD of SARS-CoV and 2019-nCoV has a critical impact for the cross-reactivity of neutralizing antibodies, and that it is still necessary to develop novel monoclonal antibodies that could bind specifically to 2019-nCoV RBD.

negative: Repurposing Therapeutics for COVID-19: Rapid Prediction of Commercially available drugs through Machine Learning and Docking Background The outbreak of the novel coronavirus disease COVID 19, caused by the SARS-CoV-2 virus has spread rapidly around the globe during the past 3 months. As the virus infected cases and mortality rate of this disease is increasing exponentially, scientists and researchers all over the world are relentlessly working to understand this new virus along with possible treatment regimens by discovering active therapeutic agents and vaccines. So, there is an urgent requirement of new and effective medications that can treat the disease caused by SARS CoV 2. Methods and findings We perform the study of drugs that are already available in the market and being used for other diseases to accelerate clinical recovery, in other words repurposing of existing drugs. The vast complexity in drug design and protocols regarding clinical trials often prohibit developing various new drug combinations for this epidemic disease in a limited time. Recently, remarkable improvements in computational power coupled with advancements in Machine Learning (ML) technology have been utilized to revolutionize the drug development process. Consequently, a detailed study using ML for the repurposing of therapeutic agents is urgently required. Here, we report the ML model based on the Naive Bayes algorithm, which has an accuracy of around 73% to predict the drugs that could be used for the treatment of COVID-19. Our study predicts around ten FDA approved commercial drugs that can be used for repurposing. Among all, we suggest that the antiretroviral drug Atazanavir (DrugBank ID DB01072) would probably be one of the most effective drugs based on the selected criterions. Conclusions Our study can help clinical scientists in being more selective in identifying and testing the therapeutic agents for COVID 19 treatment. The ML based approach for drug discovery as reported here can be a futuristic smart drug designing strategy for community applications.

negative: Clinico-epidemiological characteristics of acute respiratory infections by coronavirus OC43, NL63 and 229E Abstract Background and objectives Acute respiratory infection is a very common condition in the general population. The majority of these infections are due to viruses. This study attempted to determine the clinical and epidemiological characteristics of adult patients with respiratory infection by the coronavirus OC43, NL63 and 229E. Patients and methods Between January 2013 and February 2014, we prospectively studied all patients with suspected clinical respiratory infection by taking throat swabs and performing a reverse transcription polymerase chain reaction in search of coronavirus. Results In 48 cases (7.0% of the 686 enrolled patients; 12.6% of the 381 in whom a virus was detected) the presence of a coronavirus demonstrated. In 24 cases, the virus was OC43 (50%); in 14 cases, the virus was NL63 (29%); and in 10 cases, the virus was 229E (21%). The mean age was 54.5 years, with a slight predominance of men. The most common clinical presentations were nonspecific influenza symptoms (43.7%), pneumonia (29.2%) and chronic obstructive pulmonary disease exacerbation (8.3%). Fifty-two percent of the patients required hospitalization, and 2 patients required intensive care. There were no deaths. Conclusion Acute respiratory infections caused by coronavirus mainly affect middle-aged male smokers, who are often affected by previous diseases. The most common clinical picture has been nonspecific influenza symptoms.

negative: B-cell responses in patients who have recovered from severe acute respiratory syndrome target a dominant site in the S2 domain of the surface spike glycoprotein. Severe acute respiratory syndrome (SARS) is a recently emerged infectious disease caused by a novel strain of coronavirus. Examination of the immune responses of patients who have recovered from SARS should provide important information for design of a safe and effective vaccine. We determined the continuous viral epitopes targeted by antibodies in plasma samples from convalescent SARS patients through biopanning with a vast M13 phage display dodecapeptide library. These epitopes converged to very short peptide fragments, one on each of the structural proteins spike and nucleocapsid and the nonstructural proteins 3a, 9b, and nsp 3. Immunoassays found that most of the patients who had recovered from SARS developed complementary antibodies to the epitope-rich region on the spike S2 protein, indicating that this is an immunodominant site on the viral envelope comprising the spike, matrix, and small envelope glycoproteins. These S2-targeting antibodies were shown to effectively neutralize the coronavirus, indicating that they provided protective immunity to help the patients recover from the viral infection. These results suggest that the SARS coronavirus might have an antigenic profile distinct from those of other human or animal coronaviruses. Due to the tested safety and protective effects of the convalescent-phase serological antibodies, identification of their complementary antigens may enable the design of an epitope-based vaccine to prevent potential antibody-mediated immunopathology.

negative: A line immunoassay utilizing recombinant nucleocapsid proteins for detection of antibodies to human coronaviruses Abstract Most coronaviruses infecting humans cause mild diseases, whereas severe acute respiratory syndrome (SARS)-associated coronavirus is an extremely dangerous pathogen. Here, we report the development of a serologic assay for detection of antibodies to human coronaviruses (HCoVs) based on recombinant nucleocapsid (N) proteins of all known pathogenic strains (229E, NL63, OC43, HKU1, SARS). The novel immunoassay is highly useful for epidemiologic surveys, where use of nucleic acid diagnostics often is limited. Purified recombinant antigens were immobilized on nitrocellulose membranes and applied in a line immunoassay, which allows rapid detection of antibodies to 5 different HCoVs in a single experiment. For assay evaluation, serum samples from persons infected with 229E or OC43 (acute/convalescent), recovered SARS patients and healthy donors were analyzed. Screening for nucleocapsid (N)-specific immunoglobulin G (IgG) in convalescent sera reached 100% sensitivity. With this new technique, we found that recently identified NL63 and HKU1 contribute significantly to the overall spectrum of coronavirus infections. Possibly, cross-reactive antibody responses were observed using 229E and OC43 serum pairs. However, the potential of this assay could clearly be demonstrated employing SARS-positive serum samples, where nonspecific binding to nucleocapsids of other HCoVs was not observed. This coronavirus strain-specific line immunoassay represents a powerful tool for serologic diagnostics.

negative: Multiplex method for simultaneous serological detection of porcine reproductive and respiratory syndrome virus and porcine circovirus type 2. Porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) are major contributors to the porcine respiratory disease complex (PRDC). Routine serological diagnosis and surveillance play an important role in the prevention of PRDC, as it is a leading cause of economic losses to the swine industry. We herein describe an advanced microsphere-based immunoassay that permits the simultaneous detection of antibodies to PCV2 and PRRSV, thereby reducing the time and effort involved in testing. Recombinant PRRSV nucleoprotein antigen and the PCV2 capsid antigen were coupled to fluorophore-dyed beads with distinct spectral addresses. Weekly serum samples from 72 pigs that were experimentally exposed to either PCV2, PRRSV, or both PCV2 and PRRSV were used to validate the microbead assay (MBA) in comparison with the "gold standard" enzyme-linked immunosorbent assays. The kinetics of the PCV2- and PRRSV-specific antibody responses measured by the microbead assay were comparable to those of the standard assays; Spearman's rank correlations were 0.72 (P < 0.001) for PRRSV and 0.80 (P < 0.001) for PCV2. Diagnostic sensitivity and specificity were determined using field sera whose positive or negative status was determined by the standard tests. The diagnostic sensitivity and specificity were both 98% for PCV2 and were 91% and 93%, respectively, for PRRSV (kappa coefficients, 0.85 and 0.67 for PCV2 and PRRSV, respectively). Multiplexing did not interfere with assay performance or diagnostic sensitivity. Therefore, the described study demonstrates proof of concept for the development of more versatile and economical microbead array-based multiplex serological test panels for veterinary use.

negative: An epidemiological forecast model and software assessing interventions on COVID-19 epidemic in China We develop a health informatics toolbox that enables public health workers to timely analyze and evaluate the time-course dynamics of the novel coronavirus (COVID-19) infection using the public available data from the China CDC. This toolbox is built upon a hierarchical epidemiological model in which two observed time series of daily proportions of infected and removed cases are emitted from the underlying infection dynamics governed by a Markov SIR infectious disease process. We extend the SIR model to incorporate various types of time-varying quarantine protocols, including government-level macro isolation policies and community-level micro inspection measures. We develop a calibration procedure for under-reported infected cases. This toolbox provides forecast, in both online and offline forms, of turning points of interest, including the time when daily infected proportion becomes smaller than the previous ones and the time when daily infected proportions becomes smaller than that of daily removed proportion, as well as the ending time of the epidemic. An R software is made available for the public, and examples on the use of this software are illustrated. Some possible extensions of our novel epidemiological models are discussed.

negative: Transmission and clinical characteristics of asymptomatic patients with SARS-CoV-2 infection The 2019 novel coronavirus disease, SARS-CoV-2, is now spreading globally and is characterized by person-to-person transmission. However, it has recently been found that individuals infected with SARS-CoV-2 can be asymptomatic, and simultaneously a source of infection in others. The viral load detected in nasopharyngeal swabs of asymptomatic carriers is relatively high, with a great potential for transmission. More attention should be paid to the insidious spread of disease and harm contributed by asymptomatic SARS-CoV-2 carriers. To provide a theoretical basis for the accurate and early clinical identification of asymptomatic patients, this review objectively summarizes the epidemic status, transmission characteristics and clinical features of asymptomatic patients with SARS-CoV-2 infection.

negative: Antibody to human and simian retrovirus, HTLV‐I, HTLV‐II, HIV, STLV‐III, and SRV‐I not increased in patients with multiple sclerosis We have tested sera from patients with multiple sclerosis, matched controls, and those with other neurological diseases, as well as sera from patients with the acquired immunodeficiency syndrome and controls and patients with tropical spastic paraparesis (TSP) and controls for antibody to human T‐lymphotropic virus type I (HTLV‐I), HTLV‐II, human immunodeficiency virus (HIV), simian T‐lymphotropic virus type III, or simian retrovirus type I by immunofluorescent activity test, and for HTLV‐I and HIV by the ELISA method. Sera from patients with multiple sclerosis and matched controls, and from patients with optic neuritis and Parkinson's or other neuromuscular diseases did not have antibody to any of the retroviruses tested. Specimens from TSP patients and some controls contained HTLV‐I antibody. We conclude from our study that only TSP patients had serological evidence of infection with one of the retroviruses studied.

negative: Mikrobiologische Diagnostik und Infektiologie Die erfolgreiche Therapie von Infektionskrankheiten setzt in vielen Fällen eine sachgerecht durchgeführte mikrobiologische Diagnostik voraus. Dabei werden die diagnostischen Möglichkeiten im klinisch-mikrobiologischen Labor entscheidend von der Präanalytik beeinflusst. Sie wird ergänzt durch die Bestimmung klinisch-chemischer Parameter, die häufig erst den Anlass für eine entsprechende weitere Diagnostik geben. Im Rahmen der Infektionsprävention und zur Dokumentation einer einwandfreien Medizinprodukteaufbereitung werden Untersuchungen von unbelebten Materialien wie Wasser, Luft, Oberflächen oder kontaminierten Prüfkörpern durchgeführt. In allen Fällen sollte auf eine standardisierte Probenentnahme geachtet werden. Dies beginnt mit der Auswahl geeigneter Abstrichtupfer und Transportgefäße, setzt sich fort in der korrekten Entnahme und – falls notwendig – Lagerung des Materials und endet mit dem möglichst raschen Transport in das Labor.

negative: COVID-19 randomised trial protocols: rapid publication without barriers

negative: The Outbreak of COVID-19 in Italy: Fighting the Pandemic

negative: Enzyme-linked immunosorbent assay for the detection of the coronavirus-like agent and its antibodies in pigs with porcine epidemic diarrhea Abstract An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of the coronavirus-like agent in feces of pigs naturally affected with porcine epidemic diarrhea (PED) or experimentally infected with the CV777 isolate. The assay was specific and more sensitive than electron microscopy. An ELISA blocking assay is described for the detection and titration of antibodies. Specific antibody formation was demonstrated in pigs experimentally infected with CV777 and in swine naturally affected with PED.

negative: Inclusion of MERS-spike protein ELISA in algorithm to determine serologic evidence of MERS-CoV infection The Centers for Disease Control and Prevention (CDC) algorithm for detecting presence of serum antibodies against Middle East Respiratory Syndrome coronavirus (MERS-CoV) in subjects with potential infections with the virus has included screening by indirect ELISA against recombinant nucleocapsid (N) protein and confirmation by immunofluorescent staining of infected monolayers and/or micro-neutralization titration. Other international groups include indirect ELISA assays using the spike (S) protein, as part of their serological determinations. In the current study, we describe development and validation of an indirect MERS-CoV S ELISA to be used as part of our serological determination for evidence of previous exposure to the virus.

negative: Vaccine against Middle East respiratory syndrome coronavirus

negative: Lack of Transmission among Close Contacts of Patient with Case of Middle East Respiratory Syndrome Imported into the United States, 2014 In May 2014, a traveler from the Kingdom of Saudi Arabia was the first person identified with Middle East respiratory syndrome coronavirus (MERS-CoV) infection in the United States. To evaluate transmission risk, we determined the type, duration, and frequency of patient contact among health care personnel (HCP), household, and community contacts by using standard questionnaires and, for HCP, global positioning system (GPS) tracer tag logs. Respiratory and serum samples from all contacts were tested for MERS-CoV. Of 61 identified contacts, 56 were interviewed. HCP exposures occurred most frequently in the emergency department (69%) and among nurses (47%); some HCP had contact with respiratory secretions. Household and community contacts had brief contact (e.g., hugging). All laboratory test results were negative for MERS-CoV. This contact investigation found no secondary cases, despite case-patient contact by 61 persons, and provides useful information about MERS-CoV transmission risk. Compared with GPS tracer tag recordings, self-reported contact may not be as accurate.

negative: Lianhuaqingwen exerts anti-viral and anti-inflammatory activity against novel coronavirus (SARS-CoV-2) Abstract Purpose Lianhuaqingwen (LH) as traditional Chinese medicine (TCM) formula has been used to treat influenza and exerted broad-spectrum antiviral effects on a series of influenza viruses and immune regulatory effects Ding et al. (2017). The goal of this study is to demonstrate the antiviral activity of LH against the novel SARS-CoV-2 virus and its potential effect in regulating host immune response. Methods The antiviral activity of LH against SARS-CoV-2 was assessed in Vero E6 cells using CPE and plaque reduction assay. The effect of LH on virion morphology was visualized under transmission electron microscope. Pro-inflammatory cytokine expression levels upon SARS-CoV-2 infection in Huh-7 cells were measured by real-time quantitative PCR assays. Results LH significantly inhibited SARS-CoV-2 replication in Vero E6 cells and markedly reduced pro-inflammatory cytokines (TNF-α, IL-6, CCL-2/MCP-1 and CXCL-10/IP-10) production at the mRNA levels. Furthermore, LH treatment resulted in abnormal particle morphology of virion in cells. Conclusions LH significantly inhibits the SARS-COV-2 replication, affects virus morphology and exerts anti-inflammatory activity in vitro. These findings indicate that LH protects against the virus attack, making its use a novel strategy for controlling the COVID-19 disease.

negative: A multicentre collaboration to investigate the cause of severe acute respiratory syndrome Summary Severe Acute respiratory syndrome is a new disease in human beings, first recognised in late February, 2003, in Hanoi, Vietnam. The severity of the disease, combined with its rapid spread along international air-travel routes, prompted WHO to set up a network of scientists from 11 laboratories around the world to try to identify the causal agent and develop a diagnostic test. The network unites laboratories with different methods and capacities to rapidly fulfil all postulates for establishing a virus as the cause of a disease. Results are shared in real time via a secure website, on which microscopy pictures, protocols for testing, and PCR primer sequences are also posted. Findings are discussed in daily teleconferences. Progress is further facilitated through sharing between laboratories of samples and test materials. The network has identified a new coronavirus, consistently detected in samples of SARS patients from several countries, and conclusively named it as the causative agent of SARS; the strain is unlike any other known member of the genus Coronavirus. Three diagnostic tests are now available, but all have limitations.

negative: Viruses in Ixodes Uriae (Acari: Ixodidae) from Seabird Colonies at RøSt Islands, Lofoten, Norway1 A total of 1929 Ixodes uriae collected from Røst Islands, Lofoten, Norway, in July 1974, was divided into 204 pools and inoculated into suckling mice and chick embryo cell cultures for virus isolation. Virus was detected in 6.6% of the laboratory-molted female ticks, 5.4% of the males and 1.8% of the nymphs. No isolates were obtained from 149 unengorged adult ticks. Of 50 viral strains recovered, 30 belonged to the Uukuniemi group, 13 to the Kemerovo group, and I was a strain of Tyuleniy of Group B. Of 6 untyped strains, I was orbiviruslike and I resembled a coronavirus in a negative-staining electron microscopy. The infection rates of I. uria in Lofoten were similar to those reported in the Murmansk area in the northern USSR.

negative: Serological evidence of MERS-CoV and HKU8-related CoV co-infection in Kenyan camels Dromedary camels are important reservoir hosts of various coronaviruses, including Middle East respiratory syndrome coronavirus (MERS-CoV) that cause human infections. CoV genomes regularly undergo recombination during infection as observed in bat SARS-related CoVs. Here we report for the first time that only a small proportion of MERS-CoV receptor-binding domain positive (RBD) of spike protein positive camel sera in Kenya were also seropositive to MERS-CoV nucleocapsid (NP). In contrast, many of them contain antibodies against bat HKU8-related (HKU8r)-CoVs. Among 584 camel samples that were positive against MERS-CoV RBD, we found only 0.48 (8.22%) samples were also positive for NP. Furthermore, we found bat HKU8r-CoV NP antibody in 73 (12.5%) of the MERS-CoV RBD positive and NP negative samples, yet found only 3 (0.43%) of the HKU8r-CoV S1 antibody in the same samples. These findings may indicate co-infection with MERS-CoV and a HKU8r-CoV in camels. It may also raise the possibility of the circulation of a recombinant coronavirus virus with the spike of MERS-CoV and the NP of a HKU8r-CoV in Kenya. We failed to find molecular evidence of an HKU8r-CoV or a putative recombinant virus. Our findings should alert other investigators to look for molecular evidence of HKU8r-CoV or recombinants.

negative: Transmissibility of MERS-CoV Infection in Closed Setting, Riyadh, Saudi Arabia, 2015 To investigate a cluster of Middle East respiratory syndrome (MERS) cases in a women-only dormitory in Riyadh, Saudi Arabia, in October 2015, we collected epidemiologic information, nasopharyngeal/oropharyngeal swab samples, and blood samples from 828 residents during November 2015 and December 2015–January 2016. We found confirmed infection for 19 (8 by reverse transcription PCR and 11 by serologic testing). Infection attack rates varied (2.7%–32.3%) by dormitory building. No deaths occurred. Independent risk factors for infection were direct contact with a confirmed case-patient and sharing a room with a confirmed case-patient; a protective factor was having an air conditioner in the bedroom. For 9 women from whom a second serum sample was collected, antibodies remained detectable at titers >1:20 by pseudoparticle neutralization tests (n = 8) and 90% plaque-reduction neutralization tests (n = 2). In closed high-contact settings, MERS coronavirus was highly infectious and pathogenicity was relatively low.

negative: Molecular Diagnostic Assays for Infectious Diseases in Cats With the advent of more accessible polymerase chain reaction panels, the use of molecular techniques for the detection of infectious organisms has become more routine in veterinary medicine. The use of molecular diagnostics is best reserved for the detection of organisms that are difficult to detect or identify expediently. In this article, the fundamentals of molecular techniques are reviewed along with an examination of specific feline infectious diseases in which diagnosis via molecular techniques is advantageous.

negative: Proceedings of the 42nd annual meeting of the american rheumatism association a section of the arthritis foundation june 1 & 2, 1978 new york city abstracts of papers presented

negative: Chapter 10 Laboratory Diagnosis of Virus Diseases Abstract An accurate virus diagnosis invariably requires laboratory testing of clinical specimens for the presence of virus, viral antigens, or specific antibodies. The past few decades have seen a major revolution in the operation of virus diagnostic laboratories and in their role in clinical patient management. Virus isolation has been largely replaced by sensitive nucleic acid detection assays and the measurement of specific antibodies at a very high level of sensitivity and specificity.

negative: Comparative analysis of serologic cross-reactivity using convalescent sera from filovirus-experimentally infected fruit bats With the exception of Reston and Bombali viruses, the marburgviruses and ebolaviruses (family Filoviridae) cause outbreaks of viral hemorrhagic fever in sub-Saharan Africa. The Egyptian rousette bat (ERB) is a natural reservoir host for the marburgviruses and evidence suggests that bats are also natural reservoirs for the ebolaviruses. Although the search for the natural reservoirs of the ebolaviruses has largely involved serosurveillance of the bat population, there are no validated serological assays to screen bat sera for ebolavirus-specific IgG antibodies. Here, we generate filovirus-specific antisera by prime-boost immunization of groups of captive ERBs with all seven known culturable filoviruses. After validating a system of filovirus-specific indirect ELISAs utilizing infectious-based virus antigens for detection of virus-specific IgG antibodies from bat sera, we assess the level of serological cross-reactivity between the virus-specific antisera and heterologous filovirus antigens. This data is then used to generate a filovirus antibody fingerprint that can predict which of the filovirus species in the system is most antigenically similar to the species responsible for past infection. Our filovirus IgG indirect ELISA system will be a critical tool for identifying bat species with high ebolavirus seroprevalence rates to target for longitudinal studies aimed at establishing natural reservoir host-ebolavirus relationships.

negative: Interhuman transmissibility of Middle East respiratory syndrome coronavirus: estimation of pandemic risk BACKGROUND: The new Middle East respiratory syndrome coronavirus (MERS-CoV) infection shares many clinical, epidemiological, and virological similarities with that of severe acute respiratory syndrome (SARS)-CoV. We aimed to estimate virus transmissibility and the epidemic potential of MERS-CoV, and to compare the results with similar findings obtained for prepandemic SARS. METHODS: We retrieved data for MERS-CoV clusters from the WHO summary and subsequent reports, and published descriptions of cases, and took into account 55 of the 64 laboratory-confirmed cases of MERS-CoV reported as of June 21, 2013, excluding cases notified in the previous 2 weeks. To assess the interhuman transmissibility of MERS-CoV, we used Bayesian analysis to estimate the basic reproduction number (R(0)) and compared it to that of prepandemic SARS. We considered two scenarios, depending on the interpretation of the MERS-CoV cluster-size data. RESULTS: With our most pessimistic scenario (scenario 2), we estimated MERS-CoV R(0) to be 0·69 (95% CI 0·50–0·92); by contrast, the R(0) for prepandemic SARS-CoV was 0·80 (0·54–1·13). Our optimistic scenario (scenario 1) yielded a MERS-CoV R(0) of 0·60 (0·42–0·80). Because of recent implementation of effective contact tracing and isolation procedures, further MERS-CoV transmission data might no longer describe an entire cluster, but only secondary infections directly caused by the index patient. Hence, we calculated that, under scenario 2, eight or more secondary infections caused by the next index patient would translate into a 5% or higher chance that the revised MERS-CoV R(0) would exceed 1—ie, that MERS-CoV might have pandemic potential. INTERPRETATION: Our analysis suggests that MERS-CoV does not yet have pandemic potential. We recommend enhanced surveillance, active contact tracing, and vigorous searches for the MERS-CoV animal hosts and transmission routes to human beings. FUNDING: Agence Nationale de la Recherche (Labex Integrative Biology of Emerging Infectious Diseases), and the European Community's Seventh Framework Programme project PREDEMICS.

negative: Seroepidemiological Study on SARS-CoV IgG Antibodies of Different Populations from Several Areas OBJECTIVE: In order to investigate the clinical and epidemiological rules of severe acute respiratory syndrome (SARS), rates and levels SARS coronavirus (SARS-CoV) IgG antibodies of the patients and community populations from several areas were detected. METHODS: Indirect immunofluorescent assay (IFA) and double-antigen sandwich enzyme-linked immunosorbent assay (ELISA) were used to detect the SARS coronavirus-specific IgG antibodies in sera of 1700, including 1453 general populations from Hongkong, Marco, Guangzhou and Peking and 257 SARS patients from Guangzhou and Peking. The dynamics of the serum antibodies of SARS patients were observed from 3 to 360 days after onset of symptoms. RESULTS: 90% of 257 patient serum specimens after 20 days of disease onset showed positive SARS-CoV IgG either using ELISA or IFA. 257 SARS patients, antibodies titers increased steadily in early 4 to 6 months after onset of SARS. The titers of most cases came to the peak in the 6th month. then antibodies titers declined rapidly in some cases. However, all specimens still were positive for SARS-CoV IgG in the 48th month. CONCLUSIONS: This study suggest that few inapparent infectious patients exist during SARS epidemic. Serum IgG antibodies has diagnostic value for SARS in the late course of disease and the antibodies present more than 48 months.

negative: Detection of selected viral pathogens in dogs with canine infectious respiratory disease in Austria OBJECTIVES: To assess the prevalence of canine parainfluenza virus, canine adenovirus type 2, canine distemper virus, canine respiratory coronavirus and influenza virus A infections in: (1) privately‐owned or, (2) kennelled dogs showing signs consistent with canine infectious respiratory disease and, (3) clinically healthy dogs in Vienna, Austria. MATERIALS AND METHODS: Prospectively, nasal and tonsillar swabs from 214 dogs affected with infectious respiratory disease, and 50 healthy control dogs were tested for nucleic acids specific to the various viral infections. Concurrent bronchoalveolar lavage fluid from 31 dogs with chronic respiratory disease was investigated for the same viral pathogens. Additionally, anti‐canine respiratory coronavirus antibody concentrations were measured in paired blood samples from 30 acutely diseased dogs. RESULTS: Canine respiratory coronavirus (7.5%) and canine parainfluenza virus (6.5%) were the most commonly detected viruses in samples from the upper airways of dogs with respiratory infections. Serological results showed a significant seroconversion in response to coronavirus in 50% of the examined cases. None of the samples was positive for influenza virus A‐specific nucleic acid. Canine coronavirus‐specific nucleic acid was detected in 4.0% of healthy dogs. CLINICAL SIGNIFICANCE: Canine coronavirus should be considered as a clinically relevant cause of infectious respiratory disease in crowded dog populations. For sample collection, the nasal mucosa can be recommended as the favoured site. Analysis of paired serum samples aids verification of canine coronavirus infection in respiratory disease.

negative: Molecular screening and risk factors of enterotoxigenic Escherichia coli and Salmonella spp. in diarrheic neonatal calves in Egypt Abstract The aim of the present study was to carry out molecular epidemiological investigation on enterotoxigenic Escherichia coli (ETEC) K99 and Salmonella spp. in diarrheic neonatal calves. Fecal samples were obtained from 220 diarrheic calves at 9 farms related to four governorates in central and northern Egypt. E. coli and Salmonella spp. isolates were examined for E. coli K99 and Salmonella spp. using PCR. ETEC K99 was recovered from 20 (10.36 %) out of 193 isolates, whereas Salmonella spp. was recovered from nine calves (4.09%). Multivariable logistic regression was used to evaluate the risk factors associated with both infections. ETEC K99 was significantly affected by age (P <0.01; OR: 1.812; CI 95%: 0.566–1.769), colostrum feeding practice (P <0.01; OR: 5.525; CI 95%: 2.025–15.076), rotavirus infection (P <0.001; OR: 2.220; CI 95%: 0.273–1.251), vaccination of pregnant dams with combined vaccine against rotavirus, coronavirus and E. coli (K99) (P <0.001; OR: 4.753; CI 95%: 2.124–10.641), and vitamin E and selenium administration to the pregnant dam (P <0.01; OR: 3.933; CI 95%: 0.703–1.248). Infection with Salmonella spp. was found to be significantly affected by the animal age (P <0.05; OR: 0.376; CI 95%: 0.511–1.369), Hygiene (P <0.05; OR: 0.628; CI 95%: 1.729–5.612), and region (P <0. 01; OR: 0.970; CI 95%: 0.841–1.624). The results of the present study indicate the importance of PCR as rapid, effective and reliable tool for screening of ETEC and Salmonella spp. when confronted with cases of undifferentiated calf diarrhea. Moreover, identification of the risk factors associated with the spreading of bacteria causing diarrhea may be helpful for construction of suitable methods for prevention and control.

negative: Access to Care for Dementia patients suffering from COVID-19

negative: Viral syndromes This chapter focuses on several viral syndromes. The impression that viral infections dominate is strengthened if the abundance of subclinical virus infections is considered, in particular those in children. The most serious medical consequences of viral pneumonia are encountered in the old, the newborn, or the patient with a circulatory or respiratory handicap. Influenza is a cause of increased mortality among the old, while RS virus is the most important respiratory virus infection in small children. Fever and a reddened sore throat are among the most common symptoms of infection, and are seen in association with many virus infections. The predominant number of cases of pharyngitis in children and young adults are because of virus infections. Rotavirus is recognized by its characteristic double-layered capsid with cubical symmetry and by its size, 70 nm in diameter. There are rotaviruses of many different animal species, and some have antigenic and biological properties in common with the three human serotypes.

negative: Serologic responses of 42 MERS-coronavirus-infected patients according to the disease severity Abstract We evaluated serologic response of 42 Middle East respiratory syndrome coronavirus (MERS-CoV)-infected patients according to 4 severity groups: asymptomatic infection (Group 0), symptomatic infection without pneumonia (Group 1), pneumonia without respiratory failure (Group 2), and pneumonia progressing to respiratory failure (Group 3). None of the Group 0 patients showed seroconversion, while the seroconversion rate gradually increased with increasing disease severity (0.0%, 60.0%, 93.8%, and 100% in Group 0, 1, 2, 3, respectively; P = 0.001). Group 3 patients showed delayed increment of antibody titers during the fourth week, while Group 2 patients showed robust increment of antibody titer during the third week. Among patients having pneumonia, 75% of deceased patients did not show seroconversion by the third week, while 100% of the survived patients were seroconverted (P = 0.003).

negative: Serological detection of 2019-nCoV respond to the epidemic: A useful complement to nucleic acid testing Corona Virus Disease 2019 (COVID-19) has spread rapidly to more than 70 countries and regions overseas and over 80000 cases have been infected, resulting in more than three thousand deaths. Rapid diagnosis of patients remains a bottleneck in containing the progress of the epidemic. We used automated chemiluminescent immunoassay to detect serum IgM and IgG antibodies to 2019-nCoV of 736 subjects. COVID-19 patients were becoming reactive(positive) for specific antibodies from 7-12 days after the onset of morbidity. Specific IgM and IgG increased with the progression of the disease. The areas under the ROC curves of IgM and IgG were 0.988 and 1.000, respectively. Specific antibody detection has good sensitivity and specificity. Detection of specific antibodies in patients with fever can be a good distinction between COVID-19 and other diseases, so as to be a complement to nucleic acid diagnosis to early diagnosis of suspected cases.

negative: An ELISA based on recombinant spike protein S for the detection of antibodies to transmissible gastroenteritis virus of swine-like canine coronaviruses Abstract Recombinant canine coronaviruses, resembling the transmissible gastroenteritis virus of swine (TGEV) in a 5′ fragment of the S glycoprotein, have been detected recently and showed to be present in canine populations. The 5′ fragment of the S protein (S′) of a TGEV-like canine coronavirus (CCoV), strain 174/06, was expressed in an Escherichia coli cell-free system. The purified recombinant polypeptide was employed to develop an ELISA test for the detection of TGEV-like CCoV-specific antibodies in dog sera. Four canine sera positive for TGEV-like CCoV, six sera positive to classical CCoV-II strains and 10 negative control sera were examined. The recombinant S′ was not recognized by antibodies to classical CCoV-II, as only sera from dogs infected experimentally with TGEV-like CCoV reacted strongly with the recombinant S′ polypeptide whereas dog sera with antibodies to classical CCoV-II did not react. As classical CCoV-II and TEGV-like CCoVs are related antigenically, the recombinant S′ ELISA is a useful method to investigate serologically the prevalence of TGEV-like CCoVs in dogs.

negative: COVID-19: A critical care perspective informed by lessons learnt from other viral epidemics

negative: Serology characteristics of SARS-CoV-2 infection since the exposure and post symptoms onset Background Timely diagnosis of SARS-CoV-2 infection is the prerequisite for treatment and preventive quarantine. The serology characteristics and complement diagnosis value of antibody test to RNA test needs to be demonstrated. Method A patient cohort study was conducted at the first affiliated hospital of Zhejiang University, China. Serial sera of COVID-19 patients were collected and total antibody (Ab), IgM and IgG antibody against SARS-CoV-2 were detected. The antibody dynamics during the infection were described. Results The seroconversion rate for Ab, IgM and IgG in COVID-19 patients was 98.8% (79/80), 93.8% (75/80) and 93.8% (75/80), respectively. The first detectible serology marker is total antibody and followed by IgM and IgG, with a median seroconversion time of 15, 18 and 20 day post exposure (d.p.e) or 9, 10 and 12 days post onset, separately. The antibody levels increased rapidly since 6 d.p.o and accompanied with the decline of viral load. For patients in the early stage of illness (0-7d.p.o),Ab showed the highest sensitivity (64.1%) compared to the IgM and IgG (33.3% for both, p<0.001). The sensitivities of Ab, IgM and IgG detection increased to 100%, 96.7% and 93.3% two weeks later, respectively. Conclusions Typical acute antibody response is induced during the SARS-CoV-2 infection. The serology testing provides important complementation to RNA test for pathogenic specific diagnosis and helpful information to evaluate the adapted immunity status of patient. It should be strongly recommended to apply well-validated antibody tests in the clinical management and public health practice to improve the control of COVID-19 infection.

negative: Modeling the impact of social distancing, testing, contact tracing and household quarantine on second-wave scenarios of the COVID-19 epidemic The new coronavirus disease 2019 (COVID-19) has required the implementation of severe mobility restrictions and social distancing measures worldwide. While these measures have been proven effective in abating the epidemic in several countries, it is important to estimate the effectiveness of testing and tracing strategies to avoid a potential second wave of the COVID-19 epidemic. We integrate highly detailed (anonymized, privacy-enhanced) mobility data from mobile devices, with census and demographic data to build a detailed agent-based model to describe the transmission dynamics of SARS-CoV-2 in the Boston metropolitan area. We find that enforcing strict social distancing followed by a policy based on a robust level of testing, contact-tracing and household quarantine, could keep the disease at a level that does not exceed the capacity of the health care system. Assuming the identification of 50% of the symptomatic infections, and the tracing of 40% of their contacts and households, which corresponds to about 9% of individuals quarantined, the ensuing reduction in transmission allows the reopening of economic activities while attaining a manageable impact on the health care system. Our results show that a response system based on enhanced testing and contact tracing can play a major role in relaxing social distancing interventions in the absence of herd immunity against SARS-CoV-2.

negative: Dynamic Modeling to Identify Mitigation Strategies for Covid-19 Pandemic Relevant pandemic-spread scenario simulations provide guiding principles for containment and mitigation policy developments. Here we devise a simple model to predict the effectiveness of different mitigation strategies. The model consists of a set of simple differential equations considering the population size, reported and unreported infections, reported and unreported recoveries and the number of Covid-19-inflicted deaths. For simplification, we assume that Covid-19 survivors are immune (e.g. mutations are not considered) and that the virus can only be passed on by persons with undetected infections. While the latter assumption is a simplification (it is neglected that e.g. hospital staff may be infected by detected patients with symptoms), it was introduced here to keep the model as simple as possible. Moreover, the current version of the model does not account for age-dependent differences in the death rates, but considers higher mortality rates due to temporary shortage of intensive care units. Some of the model parameters have been fitted to the reported cases outside of China1 from January 22 to March 12 of the 2020 Covid-19 pandemic. The other parameters were chosen in a plausible range to the best of our knowledge. We compared infection rates, the total number of people getting infected and the number of deaths in six different scenarios. Social distancing or increased testing can contain or drastically reduce the infections and the predicted number of deaths when compared to a situation without mitigation. We find that mass-testing alone and subsequent isolation of detected cases can be an effective mitigation strategy, alone and in combination with social distancing. However, unless one assumes that the virus can be globally defeated by reducing the number of infected persons to zero, testing must be upheld, albeit at reduced intensity, to prevent subsequent waves of infection. The model suggests that testing strategies can be equally effective as social distancing, though at much lower economical costs. We discuss how our mathematical model may help to devise an optimal mix of mitigation strategies against the Covid-19 pandemic. The website corona-lab.ch provides an interactive simulation tool based on the presented model.

negative: Predicting Drug-Target Interaction Networks Based on Functional Groups and Biological Features BACKGROUND: Study of drug-target interaction networks is an important topic for drug development. It is both time-consuming and costly to determine compound-protein interactions or potential drug-target interactions by experiments alone. As a complement, the in silico prediction methods can provide us with very useful information in a timely manner. METHODS/PRINCIPAL FINDINGS: To realize this, drug compounds are encoded with functional groups and proteins encoded by biological features including biochemical and physicochemical properties. The optimal feature selection procedures are adopted by means of the mRMR (Maximum Relevance Minimum Redundancy) method. Instead of classifying the proteins as a whole family, target proteins are divided into four groups: enzymes, ion channels, G-protein- coupled receptors and nuclear receptors. Thus, four independent predictors are established using the Nearest Neighbor algorithm as their operation engine, with each to predict the interactions between drugs and one of the four protein groups. As a result, the overall success rates by the jackknife cross-validation tests achieved with the four predictors are 85.48%, 80.78%, 78.49%, and 85.66%, respectively. CONCLUSION/SIGNIFICANCE: Our results indicate that the network prediction system thus established is quite promising and encouraging.

negative: Liver tests abnormalities in COVID-19: trick or treat?

negative: Development and Validation of a Serologic Test Panel for Detection of Powassan Virus Infection in U.S. Patients Residing in Regions Where Lyme Disease Is Endemic Powassan virus (POWV) is an emerging tick-borne arbovirus presenting a public health threat in North America. POWV lineage II, also known as deer tick virus, is the strain of the virus most frequently found in Ixodes scapularis ticks and is implicated in most cases of POWV encephalitis in the United States. Currently, no commercial tests are available to detect POWV exposure in tick-borne disease (TBD) patients. We describe here the development and analytical validation of a serologic test panel to detect POWV infections. The panel uses an indirect enzyme immunoassay (EIA) to screen. EIA-positive samples reflex to a laboratory-developed, POWV-specific immunofluorescence assay (IFA). The analytical sensitivity of the test panel was 89%, and the limit of detection was a plaque reduction neutralization test (PRNT) titer of 1:20. The analytical specificity was 100% for the IgM assay and 65% for the IgG assay when heterologous-flavivirus-positive samples were tested. On samples collected from regions where Lyme disease is endemic, seroprevalence for POWV in TBD samples was 9.4% (10 of 106) versus 2% when tested with non-TBD samples (2 of 100, P = 0.034). No evidence of POWV infection was seen in samples collected from a region where Lyme disease was not endemic (0 of 22). This test panel provides a sensitive and specific platform for detecting a serologic response to POWV early in the course of infection when neutralizing antibodies may not be detectable. Combined with clinical history, the panel is an effective tool for identifying acute POWV infection. IMPORTANCE Approximately 100 cases of POWV disease were reported in the United States over the past 10 years. Most cases have occurred in the Northeast (52) and Great Lakes (45) regions (https://www.cdc.gov/powassan/statistics.html). The prevalence of POWV in ticks and mammals is increasing, and POWV poses an increasing threat in a greater geographical range. In areas of the Northeast and Midwest where Lyme disease is endemic, POWV testing is recommended for patients with a recent tick bite, patients with Lyme disease who have been treated with antibiotics, or patients with a tick exposure who have tested negative for Lyme disease or other tick-borne illnesses and have persistent symptoms consistent with posttreatment Lyme disease. Testing could also benefit patients with tick exposure and unexplained neurologic symptoms and chronic fatigue syndrome (CFS) patients with known tick exposure. Until now, diagnostic testing for Powassan virus has not been commercially available and has been limited to patients presenting with severe, neurologic complications. The lack of routine testing for Powassan virus in patients with suspected tick-borne disease means that little information is available regarding the overall prevalence of the virus and the full spectrum of clinical symptoms associated with infection. As Ixodes scapularis is the tick vector for Powassan virus and multiple other tick-borne pathogens, including the Lyme disease bacterium, Borrelia burgdorferi, the clinical presentations and long-term outcomes of Powassan virus infection and concurrent infection with other tick-borne disease pathogens remain unknown.

negative: Estimating the presymptomatic transmission of COVID19 using incubation period and serial interval data We estimated the fraction and timing of presymptomatic transmissions of COVID19 with mathematical models combining the available data of the incubation period and serial interval. We found that up to 79.7% transmissions could be presymptomatic among the imported cases in China outside Wuhan. The average timing of presymptomatic transmissions is 3.8 days (SD = 6.1) before the symptom onset, which is much earlier than previously assumed.

negative: Neutralising antibodies to SARS coronavirus 2 in Scottish blood donors - a pilot study of the value of serology to determine population exposure Background. The extent of spread of SARS coronavirus 2 (SARS-CoV-2) in the UK and elsewhere is unknown because typically only symptomatic individuals are diagnosed. We performed a serological study of recent blood donors in Scotland to detect antibodies to SARS-CoV-2 as a marker of past infection. Methods. A pseudotyped SARS-CoV-2 virus microneutralisation assay was used to detect neutralising antibodies to SARS-CoV-2. The study group comprised samples from 1000 blood donors collected in Scotland during March, 2020. Controls were collected from 100 donors in Scotland during 2019. Findings. All samples collected on the 17th March, 2020 (n=500) were negative in the pseudotyped SARS-CoV-2 virus microneutralisation assay. Neutralising antibodies were detected in 5 of the 500 samples collected 21st to 23rd March; one further sample was reactive in an anti-spike ELISA. Interpretation. Although we cannot use the rise in numbers seropositive to infer the contemporary seroprevalence or the growth rate of the epidemic, we note that they are consistent with frequency of reported diagnosed infections and SARS-CoV-2-associated deaths reported in that time period in Scotland, given that seroconversion takes up to 2-3 weeks. It should also be noted that blood donors are not representative of the general population; in particular, those with a history of recent respiratory infections are deferred. Finally, it is unknown what proportion of infected individuals seroconvert and become reactive in the assays used. Serial follow up studies are needed to track infection and seroconversion in this and other similar populations However, these data indicate that sero-surveys of blood banks can serve as a useful tool for tracking the emergence and progression of an epidemic like the current SARS-CoV-2 outbreak.

negative: Recommendations for coronavirus infection in rheumatic diseases treated with biologic therapy Abstract The Coronavirus-associated disease, that was first identified in 2019 in China (CoViD-19), is a pandemic caused by a bat-derived beta-coronavirus, named SARS-CoV2. It shares homology with SARS and MERS-CoV, responsible for past outbreaks in China and in Middle East. SARS-CoV2 spread from China where the first infections were described in December 2019 and is responsible for the respiratory symptoms that can lead to acute respiratory distress syndrome. A cytokine storm has been shown in patients who develop fatal complications, as observed in past coronavirus infections. The management includes ventilatory support and broad-spectrum antiviral drugs, empirically utilized, as a targeted therapy and vaccines have not been developed. Based upon our limited knowledge on the pathogenesis of CoViD-19, a potential role of some anti-rheumatic drugs may be hypothesized, acting as direct antivirals or targeting host immune response. Antimalarial drugs, commonly used in rheumatology, may alter the lysosomal proteases that mediates the viral entry into the cell and have demonstrated efficacy in improving the infection. Anti-IL-1 and anti-IL-6 may interfere with the cytokine storm in severe cases and use of tocilizumab has shown good outcomes in a small cohort. Baricitinib has both antiviral and anti-inflammatory properties. Checkpoints inhibitors such as anti-CD200 and anti-PD1 could have a role in the treatment of CoViD-19. Rheumatic disease patients taking immunosuppressive drugs should be recommended to maintain the chronic therapy, prevent infection by avoiding social contacts and pausing immunosuppressants in case of infection. National and international registries are being created to collect data on rheumatic patients with CoViD-19.

negative: Disease-specific B cell epitopes for serum antibodies from patients with severe acute respiratory syndrome (SARS) and serologic detection of SARS antibodies by epitope-based peptide antigens Severe acute respiratory syndrome (SARS) has emerged as a highly contagious, sometimes fatal disease. To find disease-specific B cell epitopes, phage-displayed random peptide libraries were panned on serum immunoglobulin (Ig) G antibodies from patients with SARS. Forty-nine immunopositive phage clones that bound specifically to serum from patients with SARS were selected. These phageborne peptides had 4 consensus motifs, of which 2 corresponded to amino acid sequences reported for SARS-associated coronavirus (SARSCoV). Synthetic peptide binding and competitive-inhibition assays further confirmed that patients with SARS generated antibodies against SARS-CoV. Immunopositive phage clones and epitope-based peptide antigens demonstrated clinical diagnostic potential by reacting with serum from patients with SARS. Antibody-response kinetics were evaluated in 4 patients with SARS, and production of IgM, IgG, and IgA were documented as part of the immune response. In conclusion, B cell epitopes of SARS corresponded to novel coronavirus. Our epitope-based serologic test may be useful in laboratory detection of the virus and in further study of the pathogenesis of SARS.

negative: Chapter 14 The use of host factors in microbial forensics Abstract Advances have been made in the forensic analysis of microbes and toxins. An underdeveloped and underutilized area in microbial forensics is how the host interacts with microorganisms in a way that provides unique signatures for forensic use. For forensic purposes, an immediate goal is to distinguish a potential victim and innocent person from a perpetrator, and to distinguish between a naturally acquired or intentional infection. Principal methods that are sufficiently developed are characterization of the humoral immune response to microbial antigens including vaccine-induced immunity and detection of antibiotics that may be present in a possible perpetrator. This chapter presents central elements of the host response in a simplified fashion and describes a representative example, which, in the appropriate context, has a high potential of providing evidence that may aid an investigation to distinguish a perpetrator from a victim. This chapter also presents information about the immune system so that the interested reader can have a fuller understanding of the immune response in general.

negative: Serology of Severe Acute Respiratory Syndrome: Implications for Surveillance and Outcome Background. Severe acute respiratory syndrome (SARS) is a novel infectious disease. No information is currently available on host-specific immunity against the SARS coronavirus (CoV), and detailed characteristics of the epidemiology of SARS CoV infection have not been identified. Methods. ELISA was used to detect antibody to SARS CoV. Reverse-transcriptase polymerase chain reaction was used to detect SARS CoV RNA. T cells in peripheral blood of patients were quantified by flow cytometry. Results. Of 36 patients with probable SARS CoV infection, 30 (83.3%) were positive for IgG antibody to SARS CoV; in contrast, only 3 of 48 patients with suspected SARS CoV infection, 0 of 112 patients with fever but without SARS, and 0 of 96 healthy control individuals were positive for it. IgG antibody to SARS CoV was first detected between day 5 and day 47 after onset of illness (mean ± SD, 18.7±10.4). Conclusion. Detection of antibody to SARS CoV is useful in the diagnosis of SARS; however, at the incubation and initial phases of the illness, serological assay is of little value, because of late seroconversion in most patients.

negative: Inter nation social lockdown versus medical care against COVID-19, a mild environmental insight with special reference to India Abstract Infection by coronavirus (CoV-19) has led to emergence of a pandemic called as Coronavirus Disease (COVID-19) that has so far affected about 210 countries. The dynamic data indicate that the pandemic by CoV-19 so far has infected 2,403,963 individuals, and among these 624,698 have recovered while, it has been fatal for 165,229. Without much experience, currently, the medicines that are clinically being evaluated for COVID-19 include chloroquine, hydroxychloroquine, azithromycin, tocilizumab, lopinavir, ritonavir, tocilizumab and corticosteroids. Therefore, countries such as Italy, USA, Spain and France with the most advanced health care system are partially successful to control CoV-19 infection. India being the 2nd largest populous country, where, the healthcare system is underdeveloped, major portion of population follow unhygienic lifestyle, is able to restrict the rate of both infection and death of its citizens from COVID-19. India has followed an early and a very strict social distancing by lockdown and has issued advisory to clean hands regularly by soap and/or by alcohol based sterilizers. Rolling data on the global index of the CoV infection is 13,306, and the index of some countries such as USA (66,148), Italy (175,055), Spain (210,126), France (83,363) and Switzerland (262,122) is high. The index of India has remained very low (161) so far, mainly due to early implementation of social lockdown, social distancing, and sanitizing hands. However, articles on social lockdown as a preventive measure against COVID-19 in PubMed are scanty. It has been observed that social lockdown has also drastic impacts on the environment especially on reduction of NO2 and CO2 emission. Slow infection rate under strict social distancing will offer time to researchers to come up with exact medicines/vaccines against CoV-19. Therefore, it is concluded that stringent social distancing via lockdown is highly important to control COVID-19 and also to contribute for self-regeneration of nature.

negative: Cumulative biological source index: Volumes 1–20

negative: On Viruses, Bats and Men: A Natural History of Food-Borne Viral Infections In this chapter, cross-species infections from bats to humans are reviewed that do or do not use intermediate animal amplification hosts and that lead to human-human transmissions with various efficiencies. Rabies infections, Hendra virus infections in Australia, Nipah virus infections in Malaysia and Bangladesh and SARS coronavirus infection in China are explored from the public health perspective. Factors of bat biology are discussed which make them ideal virus reservoirs for emerging diseases. In line with the book theme, it is asked whether even in these epidemic conditions, viruses can be seen as essential agents of life where host species use their viruses to defend their ecological position against intruders. It is asked whether another essential function of animal viral infections could be the “killing the winning population” phenomenon known from phage biology which would stabilize species diversity in nature.

negative: Clinical characteristics and risk assessment of newborns born to mothers with COVID-19 BACKGROUND: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is causing an outbreak of pneumonia in Wuhan, Hubei Province, China, and other international areas. OBJECTIVE: Here, we report the clinical characteristics of the newborns delivered by SARS-CoV-2 infected pregnant women. METHODS: We prospectively collected and analyzed the clinical features, laboratory data and outcomes of 7 newborns delivered by SARS-CoV-2 infected pregnant women in Zhongnan Hospital of Wuhan University during January 20 to January 29, 2020. RESULTS: 4 of the 7 newborns were late preterm with gestational age between 36 weeks and 37 weeks, and the other 3 were full-term infants. The average birth weight was 2096 ± 660 g. All newborns were born without asphyxia. 2 premature infants performed mild grunting after birth, but relieved rapidly with non-invasive continuous positive airway pressure (nCPAP) ventilation. 3 cases had chest X-ray, 1 was normal and 2 who were supported by nCPAP presented mild neonatal respiratory distress syndrome (NRDS). Samples of pharyngeal swab in 6 cases, amniotic fluid and umbilical cord blood in 4 cases were tested by qRT-PCR, and there was no positive result of SARS-CoV-2 nucleic acid in all cases. CONCLUSIONS: The current data show that the infection of SARS-CoV-2 in late pregnant women does not cause adverse outcomes in their newborns, however, it is necessary to separate newborns from mothers immediately to avoid the potential threats.

negative: Research Communications of the 25th ECVIM‐CA Congress

negative: Molecular Detection of SARS-CoV-2 in Formalin Fixed Paraffin Embedded Specimens Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of human coronavirus disease 2019 (COVID-19), emerged in Wuhan, China in December 2019. The virus rapidly spread globally, resulting in a public-health crisis including more than one million cases and tens of thousands of deaths. Here, we describe the identification and evaluation of commercially available reagents and assays for the molecular detection of SARS-CoV-2 in infected formalin fixed paraffin embedded (FFPE) cell pellets. We identified a suitable rabbit polyclonal anti-SARS-CoV spike protein antibody and a mouse monoclonal anti-SARS-CoV nucleocapsid protein (NP) antibody for cross detection of the respective SARS-CoV-2 proteins by immunohistochemistry (IHC) and immunofluorescence assay (IFA). Next, we established RNAscope in situ hybridization (ISH) to detect SARS-CoV-2 RNA. Furthermore, we established a multiplex fluorescence ISH (mFISH) to detect positive-sense SARS-CoV-2 RNA and negative-sense SARS-CoV-2 RNA (a replicative intermediate indicating viral replication). Finally, we developed a dual staining assay using IHC and ISH to detect SARS-CoV-2 antigen and RNA in the same FFPE section. These reagents and assays will accelerate COVID-19 pathogenesis studies in humans and in COVID-19 animal models.

negative: Antibodies to coronaviruses are higher in older compared with younger adults and binding antibodies are more sensitive than neutralizing antibodies in identifying coronavirus‐associated illnesses Human coronaviruses (HCoV) are common causes of respiratory illnesses (RI) despite preexisting humoral immunity. Sera were obtained near the onset of RI and 3 to 4 weeks later as part of a prospective study of 200 subjects evaluated for RI from 2009 to 2013. Antibodies against common HCoV strains were measured by enzyme‐linked immunosorbent assay and neutralization assay comparing older adults with cardiopulmonary diseases (99 subjects) to younger, healthy adults (101 subjects). Virus shedding was detected in respiratory secretions by polymerase chain reaction. Of 43 HCoV‐associated illnesses, 15 (35%) occurred in 14 older adults (aged ≥60 years) and 28 (65%) in 28 younger adults (aged 21‐40 years). Binding and neutralizing antibodies were higher in older adults. Only 16 (35.7%) of RI with increases in binding antibodies also had increases in neutralizing antibodies to HCoV. Increases in binding antibodies with RI were more frequent than increased neutralizing antibodies and virus shedding, and more frequent in younger compared to older adults. Functional neutralizing antibodies were not stimulated as often as binding antibodies, explaining in part a susceptibility to reinfection with HCoV. Monitoring binding antibodies may be more sensitive for the serologic detection of HCoV infections.

negative: Communicable Disease Surveillance Ethics in the Age of Big Data and New Technology Surveillance is essential for communicable disease prevention and control. Traditional notification of demographic and clinical information, about individuals with selected (notifiable) infectious diseases, allows appropriate public health action and is protected by public health and privacy legislation, but is slow and insensitive. Big data–based electronic surveillance, by commercial bodies and government agencies (for profit or population control), which draws on a plethora of internet- and mobile device–based sources, has been widely accepted, if not universally welcomed. Similar anonymous digital sources also contain syndromic information, which can be analysed, using customised algorithms, to rapidly predict infectious disease outbreaks, but the data are nonspecific and predictions sometimes misleading. However, public health authorities could use these online sources, in combination with de-identified personal health data, to provide more accurate and earlier warning of infectious disease events—including exotic or emerging infections—even before the cause is confirmed, and allow more timely public health intervention. Achieving optimal benefits would require access to selected data from personal electronic health and laboratory (including pathogen genomic) records and the potential to (confidentially) re-identify individuals found to be involved in outbreaks, to ensure appropriate care and infection control. Despite existing widespread digital surveillance and major potential community benefits of extending its use to communicable disease control, there is considerable public disquiet about allowing public health authorities access to personal health data. Informed public discussion, greater transparency and an ethical framework will be essential to build public trust in the use of new technology for communicable disease control.

negative: Chapter 5 Laboratory diagnosis of viral infection Abstract Since the last Handbook of Clinical Neurology volume on this topic, viral diagnosis has made tremendous strides, moving from the margin to the mainstream of clinical care. For many years, conventional virus isolation was the mainstay of viral diagnosis since it was sensitive and “open-minded.” However, growth in conventional cell culture entails an inherent delay that limits its clinical impact. Although rapid culture and viral antigen methods detect fewer pathogens and are less sensitive than conventional culture, both require less expertise and have greatly reduced time to result. Polymerase chain reaction has ushered in a new era in virology, especially in the diagnosis of neurologic diseases. Molecular amplification methods are rapid, highly sensitive, can be automated, quantitative, and detect viruses not amenable to routine culture. User-friendly, walk-away tests with results in an hour, as well as multiplex tests that can detect 20 viruses in a single reaction, are now a reality. As the variety of test methods and commercial products proliferate, the challenges for clinicians and laboratories are selecting which tests to utilize in which clinical scenarios, and understanding how to interpret the results. The advantages and limitations of each method are discussed in this chapter, with special attention to neurologic disease.

negative: Early detection of SARS-CoV-2 antibodies in COVID-19 patients as a serologic marker of infection BACKGROUND: Thousands of medical staff had been infected with SARS-CoV-2 virus with hundreds of deaths reported. Such loss could be prevented if there is a serologic assay for SARS-CoV-2-specific antibodies for serological surveillance of its infection at the early stage of disease. METHODS: Using CHO cell expressed full length SARS-CoV-2 S1 protein as capturing antigen, a COVID-19/SARS-CoV-2 S1 serology ELISA kit was developed and validated with negative samples collected prior to the outbreaks or during the outbreak, and positive samples from patients confirmed with COVID-19. RESULTS: The specificity of the ELISA kit was 97.5%, as examined against total 412 normal human samples. The sensitivity was 97.1% by testing against 69 samples from hospitalized and/or recovered COVID-19 patients. The overall accuracy rate reached 97.3%. The assay was able to detect SARS-CoV-2 antibody on day one after the onset of COVID-19 disease. The average antibody levels increased during the hospitalization and after been discharged for two weeks. SARS-CoV-2 antibodies were detected in 28 out of 276 asymptomatic medical staff and one out of five nucleic acid test-negative "Close contacts" of COVID-19 patient. CONCLUSION: With the assays developed here, we can screen medical staff, in-coming patients, passengers and people who are in close contact with the confirmed patients to identify the "innocent viral spreaders", protect the medical staff and stop the further spreading of the virus.

negative: The association between vitamin D status and infectious diseases of the respiratory system in infancy and childhood PURPOSE: Respiratory tract infections (RTIs) are a major cause of illness worldwide and the most common cause of hospitalization for pneumonia and bronchiolitis. These two diseases are the leading causes of morbidity and mortality among children under 5 years of age. Vitamin D is believed to have immunomodulatory effects on the innate and adaptive immune systems by modulating the expression of antimicrobial peptides, like cathelicidin, in response to both viral and bacterial stimuli. The aim of this review is to summarize the more recently published data with regard to potential associations of 25-hydroxyvitamin D [25(OH)D] with infectious respiratory tract diseases of childhood and the possible health benefits from vitamin D supplementation. METHODS: The literature search was conducted by using the PubMed, Scopus, and Google Scholar databases, with the following keywords: vitamin D, respiratory tract infection, tuberculosis, influenza, infancy, and childhood. RESULTS: Several studies have identified links between inadequate 25(OH)D concentrations and the development of upper or lower respiratory tract infections in infants and young children. Some of them also suggest that intervention with vitamin D supplements could decrease both child morbidity and mortality from such causes. CONCLUSIONS: Most studies agree in that decreased vitamin D concentrations are prevalent among most infants and children with RTIs. Also, normal to high-serum 25(OH)D appears to have some beneficial influence on the incidence and severity of some, but not all, types of these infections. However, studies with vitamin D supplementation revealed conflicting results as to whether supplementation may be of benefit, and at what doses.

negative: Laboratory Diagnosis of Novel Coronavirus Disease 2019 (COVID-19) Infection Coronavirus disease 2019 (COVID-19) is an infection caused by the novel coronavirus severe acute respiratory coronavirus 2 (SARS-CoV-2). The infection manifests as a mild flu to severe acute respiratory infection. The World Health Organization (WHO) declared COVID-19 as a global pandemic on March 11, 2020. The disease spreads by droplet infection from person to person. Early diagnosis is the key for prompt management of cases and control of the spread of the virus. Currently, the laboratory diagnosis of SARS-CoV-2 is based on nucleic acid amplification tests (NAAT) like real-time reverse transcriptase (RT-PCR). Various genes like E, N, S, ORF and RdRp are targeted as a part of screening and confirmation of cases. Furthermore, nucleic acid sequencing may be done for the identification of mutation in the genome of SARS-CoV-2. The development of serological assays and point of care molecular test will further intensify the diagnostic modalities of SARS-CoV-2.

negative: A pneumonia outbreak associated with a new coronavirus of probable bat origin Since the outbreak of severe acute respiratory syndrome (SARS) 18 years ago, a large number of SARS-related coronaviruses (SARSr-CoVs) have been discovered in their natural reservoir host, bats(1–4). Previous studies have shown that some bat SARSr-CoVs have the potential to infect humans(5–7). Here we report the identification and characterization of a new coronavirus (2019-nCoV), which caused an epidemic of acute respiratory syndrome in humans in Wuhan, China. The epidemic, which started on 12 December 2019, had caused 2,794 laboratory-confirmed infections including 80 deaths by 26 January 2020. Full-length genome sequences were obtained from five patients at an early stage of the outbreak. The sequences are almost identical and share 79.6% sequence identity to SARS-CoV. Furthermore, we show that 2019-nCoV is 96% identical at the whole-genome level to a bat coronavirus. Pairwise protein sequence analysis of seven conserved non-structural proteins domains show that this virus belongs to the species of SARSr-CoV. In addition, 2019-nCoV virus isolated from the bronchoalveolar lavage fluid of a critically ill patient could be neutralized by sera from several patients. Notably, we confirmed that 2019-nCoV uses the same cell entry receptor—angiotensin converting enzyme II (ACE2)—as SARS-CoV.

negative: Virological and serological analysis of a recent Middle East respiratory syndrome coronavirus infection case on a triple combination antiviral regimen Abstract Serological, molecular and phylogenetic analyses of a recently imported case of Middle East respiratory syndrome coronavirus (MERS-CoV) in Greece are reported. Although MERS-CoV remained detectable in the respiratory tract secretions of the patient until the fourth week of illness, viraemia was last detected 2 days after initiation of triple combination therapy with pegylated interferon, ribavirin and lopinavir/ritonavir, administered from Day 13 of illness. Phylogenetic analysis of the virus showed close similarity with other human MERS-CoVs from the recent Jeddah outbreak in Saudi Arabia. Immunoglobulin G (IgG) titres peaked 3 weeks after the onset of illness, whilst IgM levels remained constantly elevated during the follow-up period (second to fifth week of illness). Serological testing confirmed by virus neutralisation assay detected an additional case that was a close contact of the patient.

negative: Eleven faces of coronavirus disease 2019 BACKGROUND AND AIMS: The outbreak of coronavirus disease 2019 (COVID‐19) caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection has recently spread worldwide and been declared a pandemic. We aim to describe here the various clinical presentations of this disease by examining eleven cases. METHODS: Electronic medical records of 11 patients with COVID‐19 were collected, and demographics, clinical manifestations, outcomes, key laboratory results, and radiological images are discussed. RESULTS: The clinical course of the eleven cases demonstrated the complexity of the COVID‐19 profile with different clinical presentations. Clinical manifestations range from asymptomatic cases to patients with mild and severe symptoms, with or without pneumonia. Laboratory detection of the viral nucleic acid can yield false‐negative results, and serological testing of virus‐specific IgG and IgM antibodies should be used as an alternative for diagnosis. Patients with common allergic diseases did not develop distinct symptoms and severe courses. Cases with a pre‐existing condition of chronic obstructive pulmonary disease or complicated with a secondary bacterial pneumonia were more severe. CONCLUSION: All different clinical characteristics of COVID‐19 should be taken into consideration to identify patients that need to be in strict quarantine for the efficient containment of the pandemic.

negative: High-throughput Luminex xMAP assay for simultaneous detection of antibodies against rabbit hemorrhagic disease virus, Sendai virus and rabbit rotavirus Rabbits are widely used as models in biological research, and the pathogen status of rabbits used in studies can directly affect the results of experiments. Serological surveillance is the common monitoring method used in laboratory animals. A rapid, sensitive, and cost-effective high-throughput Luminex xMAP assay could be an attractive alternative to labor-intensive enzyme-linked immunosorbent assay (ELISA) methods. In this study, recombinant proteins from rabbit hemorrhagic disease virus and rabbit rotavirus and whole viral lysates of Sendai virus were used as coating antigens in an xMAP assay for the simultaneous detection of antibodies against these pathogens. The xMAP assay showed high specificity, with no cross-reaction with other pathogens. The coefficient of variation for intra-assay and inter-assay comparisons was less than 3% and 4%, respectively, indicating good repeatability and stability of the assay. The xMAP assay exhibited similar limits of detection for rabbit hemorrhagic virus and Sendai virus and was less sensitive for the detection of rabbit rotavirus when compared with commercial ELISA kits. A total of 52 clinical samples were tested simultaneously using both the xMAP assay and ELISA kits. The results obtained using these two methods were 100% coincident. In summary, the novel xMAP assay offers an alternative choice for rapid and sensitive high-throughput detection of antibodies in rabbit serum and can be used as a daily monitoring tool for laboratory animals. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00705-019-04226-9) contains supplementary material, which is available to authorized users.

negative: Nutraceuticals An Alternative Strategy for the Use of Antimicrobials Livestock industries strive to improve the health of their animals and, in the future, they are going to be required to do this with a continued reduction in antimicrobial use. Nutraceuticals represent a group of compounds that may help fill that void because they exert some health benefits when supplemented to livestock. This review is focused on the mechanisms of action, specifically related to the immune responses and health of ruminants. The nutraceutical classes discussed include probiotics, prebiotics, phytonutrients (essential oils and spices), and polyunsaturated fatty acids.

negative: A deep dive into testing and management of COVID-19 for Australian high performance and professional sport Abstract The purpose of testing for any communicable disease is to support clinicians in the diagnosis and management of individual patients and to describe transmission dynamics. The novel coronavirus is formally named SARS-CoV-2 and the clinical disease state resulting from an infection is known as COVID-19. Control of the COVID-19 pandemic requires clinicians, epidemiologists, and public health officials to utilise the most comprehensive, accurate and timely information available to manage the rapidly evolving COVID-19 environment. High performance sport is a unique context that may look towards comprehensive testing as a means of risk mitigation. Characteristics of the common testing options are discussed including the circumstances where additional testing may be of benefit and considerations for the associated risks. Finally, a review of the available technology that could be considered for use by medical staff at the point of care (PoC) in a high-performance sporting context is included.

negative: A Social Network Model of the COVID-19 Pandemic In the COVID-19 coronavirus pandemic, currently vaccines and specific anti-viral treatment are not yet available. Thus, preventing viral transmission by case isolation, quarantine, and social distancing is essential to slowing its spread. Here we model social networks using weighted graphs, where vertices represent individuals and edges represent contact. As public health measures are implemented, connectivity in the graph decreases, resulting in lower effective reproductive numbers, and reduced viral transmission. For COVID-19, model parameters were derived from the coronavirus epidemic in China, validated by epidemic data in Italy, then applied to the United States. We calculate that, in the U.S., the public is able to contain viral transmission by limiting the average number of contacts per person to less than 7 unique individuals over each 5 day period. This increases the average social distance between individuals to 10 degrees of separation.

negative: Serological recognition of feline infectious peritonitis virus spike gene regions expressed as synthetic peptides andE. coli fusion protein Cats exposed to feline infectious peritonitis virus (FIPV) or feline enteric coronavirus (FECV) cannot be differentiated by serological analysis. Three synthetic peptides and anE. coli recombinant fusion protein generated from FIPV 79-1146 spike gene sequence were produced. Coronavirus positive cat sera reacted to peptide aa 950–990 but were non-reactive to aa137–151 and aa 150–180 peptides as demonstrated by ELISA. Amino acid sequence 97–222 expressed as a galk fusion protein inE. coli was tested against coronavirus positive cat sera by western blot analysis. Only sera from cats exposed to the FIPV type-II strains DF-2 or 79–1146 that were exhibiting signs of FIP recognized the fusion protein. Sera from FECV exposed cats did not recognize the 97–222 fusion protein in western blot analysis.

negative: The Usefulness of Lung Ultrasound for the Aetiological Diagnosis of Community-Acquired Pneumonia in Children The aetiology of community-acquired pneumonia (CAP) is not easy to establish. As lung ultrasound (LUS) has already proved to be an excellent diagnostic tool for CAP, we analysed its usefulness for discriminating between the aetiologically different types of CAP in children. We included 147 children hospitalized because of CAP. LUS was performed in all patients at admission, and follow-up LUS was performed in most patients. LUS-detected consolidations in viral CAP were significantly smaller, with a median diameter of 15 mm, compared to 20 mm in atypical bacterial CAP (p = 0.05) and 30 mm in bacterial CAP (p < 0.001). Multiple consolidations were detected in 65.4% of patients with viral CAP and in 17.3% of patients with bacterial CAP (p < 0.001). Bilateral consolidations were also more common in viral CAP than in bacterial CAP (51.9% vs. 8.0%, p < 0.001). At follow-up, a regression of consolidations was observed in 96.6% of patients with bacterial CAP and in 33.3% of patients with viral CAP (p < 0.001). We found LUS to be especially suitable for differentiating bacterial CAP from CAP due to other aetiologies. However, LUS must be interpreted in light of clinical and laboratory findings.

negative: Use of serological surveys to generate key insights into the changing global landscape of infectious disease

negative: Lack of Middle East Respiratory Syndrome Coronavirus Transmission from Infected Camels To determine risk for Middle East respiratory syndrome coronavirus transmission from camels to humans, we tested serum from 191 persons with various levels of exposure to an infected dromedary herd. We found no serologic evidence of human infection, suggesting that zoonotic transmission of this virus from dromedaries is rare.

negative: Molecular Techniques for Blood and Blood Product Screening “Blood banking has become a manufacturing industry, an industry that must conform to high standards and quality control requirements comparable to those of pharmaceutical companies or other regulated industries,” said David A. Kessler, M.D., former FDA commissioner (Revelle, 1995). Screening donated blood for infectious diseases that can be transmitted through blood transfusion is very important in ensuring safety. The United States has the safest blood supply in the world (Revelle, 1995), and the Food and Drug Administration (FDA) is striving to keep it safe by decreasing the risk of infectious disease transmission. The regulatory agency is continuously updating its requirements and standards for collecting and processing blood. An important step in ensuring safety is the screening of donated blood for infectious diseases. In the United States, tests for infectious diseases are routinely conducted on each unit of donated blood, and these tests are designed to comply with regulatory requirements (Table 21.1). The field of clinical microbiology and virology is now moving into the focus of molecular technology. Currently, nucleic acid testing techniques have been developed to screen blood and plasma products for evidence of very recent viral infections that could be missed by conventional serologic tests. It is time for all blood safety staffs to use molecular detection techniques. This approach can significantly aid in blood safety to reduce the risk of transmission of serious disease by transfusion. This chapter will review the current antigen/antibody–based technology, molecular biological technology, and published regulatory policy data for blood safety.

negative: Difference of clinical features in childhood Mycoplasma pneumoniae pneumonia BACKGROUND: M. pneumoniae pneumonia (MP) has been reported in 10-40% of community-acquired pneumonia cases. We aimed to evaluate the difference of clinical features in children with MP, according to their age and chest radiographic patterns. METHODS: The diagnosis of MP was made by examinations at both admission and discharge and by two serologic tests: the indirect microparticle agglutinin assay (≥1:40) and the cold agglutinins titer (≥1:32). A total of 191 children with MP were grouped by age: ≤2 years of age (29 patients), 3-5 years of age (81 patients), and ≥6 years of age (81 patients). They were also grouped by pneumonia pattern: bronchopneumonia group (96 patients) and segmental/lobar pneumonia group (95 patients). RESULTS: Eighty-six patients (45%) were seroconverters, and the others showed increased antibody titers during hospitalization. Among the three age groups, the oldest children showed the longest duration of fever, highest C-reactive protein (CRP) values, and the most severe pneumonia pattern. The patients with segmental/lobar pneumonia were older and had longer fever duration and lower white blood cell (WBC) and lymphocyte counts, compared with those with bronchopneumonia. The patient group with the most severe pulmonary lesions had the most prolonged fever, highest CRP, highest rate of seroconverters, and lowest lymphocyte counts. Thrombocytosis was observed in 8% of patients at admission, but in 33% of patients at discharge. CONCLUSIONS: In MP, older children had more prolonged fever and more severe pulmonary lesions. The severity of pulmonary lesions was associated with the absence of diagnostic IgM antibodies at presentation and lymphocyte count. Short-term paired IgM serologic test may be mandatory for early and definitive diagnosis of MP.

negative: Comparative Serological Study for the Prevalence of Anti-MERS Coronavirus Antibodies in High- and Low-Risk Groups in Qatar Infection with Middle East respiratory syndrome coronavirus (MERS-CoV) could be asymptomatic or cause mild influenza-like illness. Therefore, the prevalence of MERS-CoV infections in the general population could be underestimated, which necessitates active surveillance to determine the epidemiological importance of asymptomatic cases. The aim of this study is to evaluate the performance of various serological assays and to estimate the seroprevalence of anti-MERS-CoV antibodies in high- and low-risk groups in Qatar. A total of 4858 samples were screened, including 4719 samples collected from healthy blood donors (BD) over a period of five years (2012-2016), 135 samples from baseline case contacts (CC) collected from individuals in close contact with three positive PCR-confirmed patients (CP), and four samples from MERS-CoV CP. Initial screening using anti-MERS-CoV IgG (IgG rS1-ELISA kit) revealed ten reactive samples from BD (10/4719, 0.21%), one from CC (1/135, 0.74%), and three from CP (3/4, 75%). Samples from CP but not from BD were also reactive by whole-virus anti-MERS-CoV IgG (n = 3/4) and IgM (n = 1/4) indirect immunefluorescent tests (IIFT) and pseudoparticle neutralization test (ppNT). The reactive sample from CC was also confirmed by ppNT. Surprisingly, one out of thirteen (7.7%) randomly selected IgG rS1-ELISA-negative BD samples from the initial screening was reactive by the IgM-IIFT (but not by the IgG-IIFT) and was subsequently confirmed by ppNT. All IgG rS1-ELISA-reactive samples from BD exhibited considerable reactivity to the four circulating human coronaviruses (HKU1, OC43, 229E, and NL63). Cross-reactivity with SARS was only reported for samples from CP using IgG and IgM-IIFT. In conclusion, we report a low prevalence of anti-MERS antibodies in the general population, which coincides with the low number of all reported cases by the time of our study (2017) in Qatar (n = 21). The false-positive results and the observed cross-reactivity between MERS-CoV and other circulating human coronavirus necessitate more detailed evaluation of available serological assays.

negative: An Overview of the Most Significant Zoonotic Viral Pathogens Transmitted from Animal to Human in Saudi Arabia Currently, there has been an increasing socioeconomic impact of zoonotic pathogens transmitted from animals to humans worldwide. Recently, in the Arabian Peninsula, including in Saudi Arabia, epidemiological data indicated an actual increase in the number of emerging and/or reemerging cases of several viral zoonotic diseases. Data presented in this review are very relevant because Saudi Arabia is considered the largest country in the Peninsula. We believe that zoonotic pathogens in Saudi Arabia remain an important public health problem; however, more than 10 million Muslim pilgrims from around 184 Islamic countries arrive yearly at Makkah for the Hajj season and/or for the Umrah. Therefore, for health reasons, several countries recommend vaccinations for various zoonotic diseases among preventive protocols that should be complied with before traveling to Saudi Arabia. However, there is a shortage of epidemiological data focusing on the emerging and reemerging of zoonotic pathogens transmitted from animal to humans in different densely populated cities and/or localities in Saudi Arabia. Therefore, further efforts might be needed to control the increasing impacts of zoonotic viral disease. Also, there is a need for a high collaboration to enhance the detection and determination of the prevalence, diagnosis, control, and prevention as well as intervention and reduction in outbreaks of these diseases in Saudi Arabia, particularly those from other countries. Persons in the health field including physicians and veterinarians, pet owners, pet store owners, exporters, border guards, and people involved in businesses related to animal products have adopted various preventive strategies. Some of these measures might pave the way to highly successful prevention and control results on the different transmission routes of these viral zoonotic diseases from or to Saudi Arabia. Moreover, the prevention of these viral pathogens depends on socioeconomic impacts, available data, improved diagnosis, and highly effective therapeutics or prophylaxis.

negative: Possible involvement of infection with human coronavirus 229E, but not NL63, in Kawasaki disease Although human coronavirus (HCoV)‐NL63 was once considered a possible causative agent of Kawasaki disease based on RT‐PCR analyses, subsequent studies could not confirm the result. In this study, this possibility was explored using serological tests. To evaluate the role of HCoV infection in patients with Kawasaki disease, immunofluorescence assays and virus neutralizing tests were performed. Paired serum samples were obtained from patients with Kawasaki disease who had not been treated with γ‐globulin. HCoV‐NL63 and two antigenically different isolates of HCoV‐229E (ATCC‐VR740 and a new isolate, Sendai‐H) were examined as controls. Immunofluorescence assays detected no difference in HCoV‐NL63 antibody positivity between the patients with Kawasaki disease and controls, whereas the rate of HCoV‐229E antibody positivity was higher in the patients with Kawasaki disease than that in controls. The neutralizing tests revealed no difference in seropositivity between the acute and recovery phases of patients with Kawasaki disease for the two HCoV‐229Es. However, the Kawasaki disease specimens obtained from patients in recovery phase displayed significantly higher positivity for Sendai‐H, but not for ATCC‐VR740, as compared to the controls. The serological test supported no involvement of HCoV‐NL63 but suggested the possible involvement of HCoV‐229E in the development of Kawasaki disease. J. Med. Virol. 86:2146–2153, 2014. © 2014 Wiley Periodicals, Inc.

negative: Meeting Report: Part I. Notes from the Molecular Virology Workshop 23–24 April, 2004, Clearwater Beach, Florida, USA

negative: STUDIES ON NEW VIRUS ISOLATES RECOVERED IN TRACHEAL ORGAN CULTURE

negative: A Two-Tube Multiplex Reverse Transcription PCR Assay for Simultaneous Detection of Sixteen Human Respiratory Virus Types/Subtypes There is a need for the development of a rapid and sensitive diagnosis of respiratory viral pathogens. With an intended application in provincial Centers for Diseases Control and Prevention, in this study, we present a two-tube multiplex RT-PCR assay (two-tube assay) using automatic electrophoresis to simultaneously detect sixteen common respiratory viruses. The specificity and the sensitivity of the assay were tested. The assay could detect 20–200 copies per reaction when each viral type was assayed individually, 2000 copies with 9 premixed viral targets in the multiplexed assay in tube 1, and 200 copies with 8 premixed templates in tube 2. A total of 247 specimens were used to evaluate the two-tube assay, and the results were compared with those obtained from the Luminex xTAG RVP Fast assay. The discordant results were confirmed by sequencing or by the Seeplex RV15 ACE detection kit. There were no false positives, but six false negatives occurred with the two-tube assay. In conclusion, the two-tube assay is demonstrated to have great potential for routine surveillance of respiratory virus infection in China.

negative: Novel immunofluorescence assay using recombinant nucleocapsid-spike fusion protein as antigen to detect antibodies against severe acute respiratory syndrome coronavirus. Severe acute respiratory syndrome (SARS) is caused by a novel and highly infectious virus named SARS coronavirus (SARS-CoV). Among the serological tests currently available for the detection of SARS-CoV, a whole-virus-based immunofluorescence assay (IFA) was considered one of the most sensitive assays and served as a "gold standard" during the SARS epidemic in Singapore in 2003. However, the need to manipulate live SARS-CoV in the traditional IFA limits its wide application due to the requirement for a biosafety level 3 laboratory and the risk of laboratory infection. Previously, we have identified two immunodominant epitopes, named N195 and Sc, in the two major structural proteins, the N and S proteins, of SARS-CoV (Q. He, K. H. Chong, H. H. Chng, B. Leung, A. E. Ling, T. Wei, S. W. Chan, E. E. Ooi, and J. Kwang, Clin. Diagn. Lab. Immunol., 11:417-422, 2004; L. Lu, I. Manopo, B. P. Leung, H. H. Chng, A. E. Ling, L. L. Chee, E. E. Ooi, S. W. Chan, and J. Kwang, J. Clin. Microbiol. 42:1570-1576, 2004). In the present study, the N195-Sc fusion protein was highly expressed in insect (Sf9) cells infected with a recombinant baculovirus bearing the hybrid gene under the control of a polyhedrin promoter. An IFA based on Sf9 cells producing the fusion protein was standardized with 23 serum samples from patients with SARS, 20 serum samples from patients with autoimmune diseases, and 43 serum samples from healthy blood donors. The detection rates were comparable to those obtained with a commercial SARS-CoV IFA kit (EUROIMMUN, Gross Groenau, Germany) and a conventional IFA performed at the Singapore General Hospital. Our data showed that the newly developed IFA could detect SARS-CoV in 22 of the 23 SARS-CoV-positive serum samples and gave no false-positive results when the sera from patients with autoimmune diseases and healthy individuals were tested. The detection rate was identical to those of the two whole-virus-based IFAs. Thus, the novel N-S fusion antigen-based IFA could be an attractive alternative to present whole-virus-based IFAs for the diagnosis of SARS-CoV infection.

negative: Efficacy of glutathione therapy in relieving dyspnea associated with COVID-19 pneumonia: A report of 2 cases PURPOSE: Infection with COVID-19 potentially can result in severe outcomes and death from “cytokine storm syndrome”, resulting in novel coronavirus pneumonia (NCP) with severe dyspnea, acute respiratory distress syndrome (ARDS), fulminant myocarditis and multiorgan dysfunction with or without disseminated intravascular coagulation. No published treatment to date has been shown to adequately control the inflammation and respiratory symptoms associated with COVID-19, apart from oxygen therapy and assisted ventilation. We evaluated the effects of using high dose oral and/or IV glutathione in the treatment of 2 patients with dyspnea secondary to COVID-19 pneumonia. METHODS: Two patients living in New York City (NYC) with a history of Lyme and tick-borne co-infections experienced a cough and dyspnea and demonstrated radiological findings consistent with novel coronavirus pneumonia (NCP). A trial of 2 g of PO or IV glutathione was used in both patients and improved their dyspnea within 1 h of use. Repeated use of both 2000 mg of PO and IV glutathione was effective in further relieving respiratory symptoms. CONCLUSION: Oral and IV glutathione, glutathione precursors (N-acetyl-cysteine) and alpha lipoic acid may represent a novel treatment approach for blocking NF-κB and addressing “cytokine storm syndrome” and respiratory distress in patients with COVID-19 pneumonia.

negative: An updated roadmap for MERS-CoV research and product development: focus on diagnostics Diagnostics play a central role in the early detection and control of outbreaks and can enable a more nuanced understanding of the disease kinetics and risk factors for the Middle East respiratory syndrome-coronavirus (MERS-CoV), one of the high-priority pathogens identified by the WHO. In this review we identified sources for molecular and serological diagnostic tests used in MERS-CoV detection, case management and outbreak investigations, as well as surveillance for humans and animals (camels), and summarised the performance of currently available tests, diagnostic needs, and associated challenges for diagnostic test development and implementation. A more detailed understanding of the kinetics of infection of MERS-CoV is needed in order to optimise the use of existing assays. Notably, MERS-CoV point-of-care tests are needed in order to optimise supportive care and to minimise transmission risk. However, for new test development, sourcing clinical material continues to be a major challenge to achieving assay validation. Harmonisation and standardisation of laboratory methods are essential for surveillance and for a rapid and effective international response to emerging diseases. Routine external quality assessment, along with well-characterised and up-to-date proficiency panels, would provide insight into MERS-CoV diagnostic performance worldwide. A defined set of Target Product Profiles for diagnostic technologies will be developed by WHO to address these gaps in MERS-CoV outbreak management.

negative: The WHO R&D Blueprint: 2018 review of emerging infectious diseases requiring urgent research and development efforts Abstract The Research and Development (R&D) Blueprint is a World Health Organization initiative to reduce the time between the declaration of a public health emergency and the availability of effective diagnostic tests, vaccines, and treatments that can save lives and avert a public health crisis. The scope of the Blueprint extends to severe emerging diseases for which there are insufficient or no presently existing medical countermeasures or pipelines to produce them. In February 2018, WHO held an informal expert consultation to review and update the list of priority diseases, employing a prioritization methodology which uses the Delphi technique, questionnaires, multi-criteria decision analysis, and expert review to identify relevant diseases. The committee determined that, given their potential to cause a public health emergency and the absence of efficacious drugs and/or vaccines, there is an urgent need for accelerated R&D for (in no order of priority) Crimean-Congo haemorrhagic fever, Ebola virus and Marburg virus disease, Lassa fever, Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS), Nipah and henipaviral diseases, Rift Valley fever and Zika virus disease. The experts also included “Disease X,” representing the awareness that a previously unknown pathogen could cause a major public health emergency. This report describes the methods and results of the 2018 prioritization review.

negative: Comparative study of a blocking enzyme-linked immunosorbent assay and the immunoperoxidase monolayer assay for the detection of antibodies to the porcine reproductive and respiratory syndrome virus in pigs Abstract A blocking enzyme-linked immunosorbent assay (ELISA) for detecting antibodies to the porcine reproductive and respiratory syndrome virus (PRRSV) in pig sera was developed and compared with the immunoperoxidase monolayer assay (IPMA), the most widely used serological diagnostic test in Europe. The blocking ELISA was specific and more sensitive than the IPMA when applied to field sera and to sera which were collected early after an experimental infection with PRRSV. Problems with high background activity as observed in IPMA or indirect ELISA were not encountered.

negative: Chapter 13 Biotechnological innovations in farm and pet animal disease diagnosis Abstract The application of innovative diagnostic technologies for the detection of animal pathogens at an early stage is essential in restricting the economic loss incurred due to emerging infectious animal diseases. The desirable characteristics of such diagnostic methods are easy to use, cost-effective, highly sensitive, and specific, coupled with the high-throughput detection capabilities. The enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) are still the most common assays used for the detection of animal pathogens across the globe. However, utilizing the principles of ELISA and PCR, several serological and molecular technologies have been developed to achieve higher sensitivity, rapid, and point-of-care (POC) detection such as lateral flow assays, biosensors, loop-mediated isothermal amplification, recombinase polymerase amplification, and molecular platforms for field-level detection of animal pathogens. Furthermore, animal disease diagnostics need to be updated regularly to capture new, emerging and divergent infectious pathogens, and biotechnological innovations are helpful in fulfilling the rising demand for such diagnostics for the welfare of the society. Therefore, this chapter primarily describes and discusses in detail the serological, molecular, novel high-throughput, and POC assays to detect pathogens affecting farm and companion animals.

negative: A Review: Does Complement or the Contact System Have a Role in Protection or Pathogenesis of COVID-19? INTRODUCTION: COVID-19 presentation may include a profound increase in cytokines and associated pneumonia, rapidly progressing to acute respiratory distress syndrome (ARDS). This so-called cytokine storm often leads to refractory edema, respiratory arrest, and death. At present, anti-IL-6, antiviral therapy, convalescent plasma, hydroxychloroquine, and azithromycin among others are being investigated as potential treatments for COVID-19. As the disease etiology and precise therapeutic interventions are still not definitively defined, we wanted to review the roles that complement and the contact system may have in either the treatment or pathogenesis of the disease. METHODS: We searched the recent literature (PubMed) on complement and coronavirus; contact system and coronavirus; bradykinin and coronavirus; and angiotensin receptor and coronavirus. The manuscript complies with ethics guidelines and was deemed exempt from institutional review board approval according to Human Subjects Protection Office guidelines. RESULTS: Mouse models are available for the study of coronavirus and complement. Although complement is effective in protecting against many viruses, it does not seem to be protective against coronavirus. C3 knockout mice infected with SARS-CoV had less lung disease than wild-type mice, suggesting that complement may play a role in coronavirus pathogenesis. Some evidence suggests that the observed pulmonary edema may be bradykinin-induced and could be the reason that corticosteroids, antihistamines, and other traditional interventions for edema are not effective. Angiotensin-converting enzyme 2 (ACE2) is a co-receptor for SARS-CoV-2, and studies thus far have not concluded a benefit or risk associated with the use of either ACE-inhibitors or angiotensin receptor antagonists. SUMMARY: Activation of complement and the contact system, through generation of bradykinin, may play a role in the SARS-CoV-2-induced pulmonary edema, and our search suggests that further work is necessary to confirm our suspicions.

negative: Antibody Testing Against Canine Coronavirus by Immunoperoxidase Plaque Staining The application of the immunoperoxidase (IP) plaque staining procedure (IP test) to the diagnosis of canine coronavirus (CCV) infection was investigated. The IP test did not react with sera from either 15 specific pathogen-free (SPF) dogs or 7 SPF dogs immunized with a multivalent vaccine, including canine parvovirus type 2, canine distemper virus, canine adenovirus type 2, and canine parainfluenza virus. To compare the IP test with the neutralizing test (NT), sera from 240 healthy dogs and from 3 experimentally CCV-infected dogs were examined. All 60 sera positive for NT antibody were positive for IP antibody, and all 180 sera negative for NT antibody were negative for IP antibody in the healthy dogs. The IP titres showed similar changes with time after CCV inoculation to those of the NT titres in the experimentally infected dogs. These findings indicate that the IP test specifically detected anti-CCV antibodies. When the IP test and NT were compared in dogs with diarrhoeic signs. 2.1% of 48 sera and 20.3% of 74 sera, which were all negative for NT antibody, were positive for IP antibody in the dogs of under one year of age and at least one year of age, respectively. The difference between the IP and NT titres (log(10) [reciprocal of IP titre] – log(10) [reciprocal of NT titre]) for the diarrhoeic dogs of under one year of age (2.350±0.931) was significantly larger than that for the healthy dogs (0.982±0.447) (p<0.0001), the NT titre being negative or very low, despite a high IP titre in many diarrhoeic dogs. Hence, the IP test is more able to detect anti-CCV antibodies, especially in dogs showing clinical signs. The IP-positivity rate was significantly higher in the diarrhoeic dogs of under one year of age (48.7%) than in the healthy dogs (25.0%) (χ(2) = 19.844, p<0.0001), suggesting that CCV may contribute to diarrhoea in many juvenile dogs.

negative: Research and Development on Therapeutic Agents and Vaccines for COVID-19 and Related Human Coronavirus Diseases Since the outbreak of the novel coronavirus disease COVID-19, caused by the SARS-CoV-2 virus, this disease has spread rapidly around the globe. Considering the potential threat of a pandemic, scientists and physicians have been racing to understand this new virus and the pathophysiology of this disease to uncover possible treatment regimens and discover effective therapeutic agents and vaccines. To support the current research and development, CAS has produced a special report to provide an overview of published scientific information with an emphasis on patents in the CAS content collection. It highlights antiviral strategies involving small molecules and biologics targeting complex molecular interactions involved in coronavirus infection and replication. The drug-repurposing effort documented herein focuses primarily on agents known to be effective against other RNA viruses including SARS-CoV and MERS-CoV. The patent analysis of coronavirusrelated biologics includes therapeutic antibodies, cytokines, and nucleic acid-based therapies targeting virus gene expression as well as various types of vaccines. More than 500 patents disclose methodologies of these four biologics with the potential for treating and preventing coronavirus infections, which may be applicable to COVID-19. The information included in this report provides a strong intellectual groundwork for the ongoing development of therapeutic agents and vaccines.

negative: SARS-CoV-2: an Emerging Coronavirus that Causes a Global Threat An ongoing outbreak of pneumonia caused by a novel coronavirus, currently designated as the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), was reported recently. However, as SARS-CoV-2 is an emerging virus, we know little about it. In this review, we summarize the key events occurred during the early stage of SARS-CoV-2 outbreak, the basic characteristics of the pathogen, the signs and symptoms of the infected patients as well as the possible transmission pathways of the virus. Furthermore, we also review the current knowledge on the origin and evolution of the SARS-CoV-2. We highlight bats as the potential natural reservoir and pangolins as the possible intermediate host of the virus, but their roles are waiting for further investigation. Finally, the advances in the development of chemotherapeutic options are also briefly summarized.

negative: ELM—the database of eukaryotic linear motifs Linear motifs are short, evolutionarily plastic components of regulatory proteins and provide low-affinity interaction interfaces. These compact modules play central roles in mediating every aspect of the regulatory functionality of the cell. They are particularly prominent in mediating cell signaling, controlling protein turnover and directing protein localization. Given their importance, our understanding of motifs is surprisingly limited, largely as a result of the difficulty of discovery, both experimentally and computationally. The Eukaryotic Linear Motif (ELM) resource at http://elm.eu.org provides the biological community with a comprehensive database of known experimentally validated motifs, and an exploratory tool to discover putative linear motifs in user-submitted protein sequences. The current update of the ELM database comprises 1800 annotated motif instances representing 170 distinct functional classes, including approximately 500 novel instances and 24 novel classes. Several older motif class entries have been also revisited, improving annotation and adding novel instances. Furthermore, addition of full-text search capabilities, an enhanced interface and simplified batch download has improved the overall accessibility of the ELM data. The motif discovery portion of the ELM resource has added conservation, and structural attributes have been incorporated to aid users to discriminate biologically relevant motifs from stochastically occurring non-functional instances.

negative: Assessment of the potential relationship between egg quality and infectious bronchitis virus infection in Australian layer flocks OBJECTIVE: This investigation aimed to determine if there was a relationship between the production of eggs with poor internal quality, as measured by poor Haugh units, by Australian layer flocks and the detection of infectious bronchitis virus (IBV) in the hens. Other risk factors including flock size, flock type, flock age, chicken breed and vaccination frequency were also assessed. METHODS: The study group comprised 17 flocks from 14 farms. Data relating to the factors investigated were requested on a regular basis. The Haugh unit data were used to grade eggs as good or poor based on the age and flock at the time of data collection. Cloacal swabs were collected from 20 chickens in each flock approximately every 6 weeks. RESULTS: IBV was detected from a majority of the flocks and in 68% of cases the IBV strain detected was an A‐vaccine‐related field strain. Three variant strains were detected. Detection of IBV in a flock, the farm type and flock size were identified as potential risk factors for the production of eggs with poor Haugh units. CONCLUSION: IBV is prevalent in Australian layer flocks, but infection was primarily subclinical. The results complement previous reports indicating that there are many potential risk factors for the production of eggs with poor Haugh units.

negative: COVID-19: Strategies for Allocation of Test Kits With the increasing spread of COVID-19, it is important to systematically test more and more people. The current strategy for test-kit allocation is mostly rule-based, focusing on individuals having (a) symptoms for COVID-19, (b) travel history or (c) contact history with confirmed COVID-19 patients. Such testing strategy may miss out on detecting asymptomatic individuals who got infected via community spread. Thus, it is important to allocate a separate budget of test-kits per day targeted towards preventing community spread and detecting new cases early on. In this report, we consider the problem of allocating test-kits and discuss some solution approaches. We believe that these approaches will be useful to contain community spread and detect new cases early on. Additionally, these approaches would help in collecting unbiased data which can then be used to improve the accuracy of machine learning models trained to predict COVID-19 infections.

negative: Global epidemiology, pathogenesis, immune response, diagnosis, treatment, economic and psychological impact, challenges, and future prevention of COVID-19: A scoping review Background: Globally, the novel coronavirus, is a public health problem causing respiratory infections. Since the outbreak of severe acute and Middle East respiratory syndromes coronavirus was not reported to cause human infections. Now, it become an epidemic proportion with growing number of cases and deaths. Methods: A scoping review was conducted following the methodological framework. In this scoping review, 50 records published before 28 March, 2020 were included and discussed to better understand the current epidemiology, pathogenesis, immunological response, diagnosis, evasion mechanisms and suggested strategies to boost the immune system, challenges, treatment, and future preventions of the virus. PubMed, BioRxiv, MedRxiv, Global Health and google scholars were searched comprehensively for articles, preprints, grey literatures, reports, websites, conference proceedings and expert information. Studies conducted in human and published in the English language were included in the analysis. All the findings and statements of the review regarding the outbreak are based on published information as listed in citations. Results: We identified 360 records, of which 50 studies met the inclusion criteria. We synthesized the data from the included records and dig out the deep insights of them and pooled into this review. The burden of the outbreak is worsening due to overcrowding, presence of asymptomatic carriers, scarcity of test kits, the immune escaping ability of the virus and lack of awareness. Conclusions and recommendations: Due to the fast-spreading nature of COVID-19 the prevention and control strategies become challenging. It is imposing social, psychological, and socio-economic impacts. We recommended that following social distancing, isolation suspects, using personal protective equipment, health education and introducing handwashing practices, avoiding contact with animals, vaccine development and treatment for controlling and prevention.

negative: Effectiveness and safety of antiviral or antibody treatments for coronavirus: A rapid review Background: To identify safe and effective medical countermeasures (e.g., antivirals/antibodies) to address the current outbreak of a novel coronavirus (COVID-19) Methods: Comprehensive literature searches were developed by an experienced librarian for MEDLINE, EMBASE, the Cochrane Library, and biorxiv.org/medrxiv.org; additional searches for ongoing trials and unpublished studies were conducted in clinicaltrials.gov and the Global Infectious Diseases and Epidemiology Network (GIDEON). Title/abstract and full-text screening, data abstraction, and risk of bias appraisal were carried out by single reviewers. Results: 54 studies were included in the review: three controlled trials, 10 cohort studies, seven retrospective medical record/database studies, and 34 case reports or series. These studies included patients with severe acute respiratory syndrome (SARs, n=33), middle east respiratory syndrome (MERS, n=16), COVID-19 (n=3), and unspecified coronavirus (n=2). The most common treatment was ribavirin (n=41), followed by oseltamivir (n=10) and the combination of lopinavir/ritonavir (n=7). Additional therapies included broad spectrum antibiotics (n=30), steroids (n=39) or various interferons (n=12). No eligible studies examining monoclonal antibodies for COVID-19 were identified. One trial found that ribavirin prophylactic treatment statistically significantly reduced risk of MERS infection in people who had been exposed to the virus. Of the 21 studies reporting rates of ICU admission in hospitalized SARS or MERS patients, none reported statistically significant results in favour of or against antiviral therapies. Of the 40 studies reporting mortality rates in hospitalized SARS or MERS patients, one cohort study (MERS) and one retrospective study (SARS) found a statistically significant increase in the mortality rate for patients treated with ribavirin. Eighteen studies reported potential drug-related adverse effects including gastrointestinal symptoms, anemia, and altered liver function in patients receiving ribavirin. Conclusion: The current evidence for the effectiveness and safety of antiviral therapies for coronavirus is inconclusive and suffers from a lack of well-designed prospective trials or observational studies, preventing any treatment recommendations from being made. However, it is clear that the existing body of evidence is weighted heavily towards ribavirin (41/54 studies), which has not shown conclusive evidence of effectiveness and may cause harmful adverse events so future investigations may consider focusing on other candidates for antiviral therapy.

negative: Prevalence of anti-Toxoplasma gondii antibodies in serum and aqueous humor samples from cats with uveitis or systemic diseases in France Abstract Anti-Toxoplasma gondii antibodies were determined in serum and aqueous humor of two groups of cats in France: cats with uveitis (group 1, n =26) and cats with systemic disease (group 2, n =24) using an agglutination test. Titres above 1:64 were considered positive. IgG antibodies to T. gondii were detected in 10 serum samples from group 1 and in 10 serum samples from group 2, and in 2 aqueous humor samples from group 1 and in 1 aqueous humor samples from group 2. The distribution of ocular lesions according to the serological status of the animals indicated that lens luxation and buphthalmia were more frequent in T. gondii seropositive cats than in seronegative ones. The study reports a similar prevalence of anti-T. gondii antibodies in cats with uveitis and in cats without uveitis in France. Serological results must be analysed carefully and additional diagnostic tools is required.

negative: Development and evaluation of enzyme-linked immunosorbent assay based on recombinant nucleocapsid protein for detection of porcine epidemic diarrhea (PEDV) antibodies Abstract An enzyme-linked immunosorbent assays (ELISA) based on recombinant nucleocapsid (N) protein generated in Escherichia coli was evaluated for its sensitivity and specificity for diagnosis of porcine epidemic diarrhea (PEDV) infection. The N gene encoding the N protein was cloned and expressed as a fusion protein with His tag protein in E. coli. The recombinant N protein was migrated at 48kDa and reacted with six histidine tag specific monoclonal antibody by immunoblotting. Recombinant N protein ELISA (rnELISA) demonstrated 98.7% specificities among (80) PEDV-free individuals, and 98% sensitivity ranging among (103) clinical samples with PEDV. On testing 884 field samples, an overall agreement of 88.3% was generated between the SN and rnELISA. Taken together, these results indicated that nucleocapsid protein may be a useful antigen for the sera-diagnosis of PEDV and it was also suggested that the ELISA is a highly sensitive and specific test for detecting antibodies to PEDV.

negative: Detection of severe acute respiratory syndrome (SARS) coronavirus nucleocapsid protein in sars patients by enzyme-linked immunosorbent assay. We report the development of an enzyme-linked immunosorbent assay (ELISA) for the detection of severe acute respiratory syndrome (SARS) coronavirus (CoV) nucleocapsid protein. The assay was carried out with hyperimmune polyclonal nucleocapsid-specific antibodies from guinea pigs and rabbits immunized with recombinant His(6)-tagged SARS CoV nucleocapsid protein. The assay was used for the detection of SARS CoV nucleocapsid protein in nasopharyngeal aspirate, urine, and fecal samples collected from patients with confirmed SARS between days 2 and 33 after the onset of illness. The ELISA was capable of detecting this protein in SARS CoV cell culture lysates at 15 50% tissue culture infective doses/ml but did not produce positive signals when tested with cell culture lysates of human coronaviruses OC43 and 229E. When tested with 120 nasopharyngeal aspirate, 100 urine, and 100 fecal specimens from hospitalized patients without SARS, the assay was shown to have high specificities-96.7, 99, and 96%, respectively. In an evaluation of clinical specimens from SARS patients, 34 (52%) of 66 nasopharyngeal aspirate samples from 50 patients, 5 (5%) of 94 urine samples from 94 patients, and 36 (55%) of 65 fecal samples from 65 patients tested positive for SARS CoV nucleocapsid protein. Nucleocapsid protein could be detected from days 6 to 24 in nasopharyngeal aspirate specimens, from days 11 to 31 in urine specimens, and from days 8 to 32 in fecal specimens after the onset of illness. Moreover, the protein could be detected in 25 (83%) of 30 nasopharyngeal aspirate specimens obtained from days 11 to 15 and in all 7 fecal specimens obtained from days 21 to 32. Since the present ELISA is more convenient and economical than reverse transcription-PCR, it may serve as an alternative tool for the early diagnosis of SARS CoV infection in laboratories with limited resources and expertise and for mass screening for the reservoir of SARS CoV. Further studies on serial clinical specimens should reveal the duration of nucleocapsid protein shedding and may reveal a higher detection rate in SARS patients.

negative: Detection of SARS-CoV-2 antibodies using commercial assays and seroconversion patterns in hospitalized patients. OBJECTIVES SARS-CoV-2 antibody assays are needed for serological surveys and as a complement to molecular tests to confirm COVID-19. However, the kinetics of the humoral response against SARS-CoV-2 remains poorly described and relies on the performance of the different serological tests. METHODS In this study, we evaluated the performance of six CE-marked point-of-care tests (POC) and three ELISA assays for the diagnosis of COVID-19 by exploring seroconversions in hospitalized patients who tested positive for SARS-CoV-2 RNA. RESULTS Both the ELISA and POC tests were able to detect SARS-CoV-2 antibodies in at least half of the samples collected seven days or more after the onset of symptoms. After 15 days, the rate of detection rose to over 80% but without reaching 100%, irrespective of the test used. More than 90% of the samples collected after 15 days tested positive using the iSIA and Accu-Tell® POC tests and the ID.Vet IgG ELISA assay. Seroconversion was observed 5 to 12 days after the onset of symptoms. Three assays suffer from a specificity below 90% (EUROIMMUN IgG and IgA, UNscience, Zhuhai Livzon). CONCLUSIONS The second week of COVID-19 seems to be the best period for assessing the sensitivity of commercial serological assays. To achieve an early diagnosis of COVID-19 based on antibody detection, a dual challenge must be met: the immunodiagnostic window period must be shortened and an optimal specificity must be conserved.

negative: SARS-CoV Antibody Prevalence in All Hong Kong Patient Contacts A total of 1,068 asymptomatic close contacts of patients with severe acute respiratory (SARS) from the 2003 epidemic in Hong Kong were serologically tested, and 2 (0.19%) were positive for SARS coronavirus immunoglobulin G antibody. SARS rarely manifests as a subclinical infection, and at present, wild animal species are the only important natural reservoirs of the virus.

negative: Teicoplanin potently blocks the cell entry of 2019-nCoV Since December 2019, the outbreak of a new coronavirus, named 2019-nCoV, has greatly threatened the public health in China and raised great concerns worldwide. No specific treatment for this infection is currently available. We previously reported that teicoplanin, a glycopeptide antibiotic which has routinely been used in the clinic to treat bacterial infection with low toxicity, significantly inhibits the invasion of cells by Ebola virus, SARS-CoV and MERS-CoV, via specifically inhibiting the activity of cathepsin L. Here, we tested the efficacy of teicoplanin against 2019-nCoV virus infection and found that teicoplanin potently prevents the entrance of 2019-nCoV-Spike-pseudoviruses into the cytoplasm, with an IC50 of 1.66 μM. Although the inhibitory effect upon the replication of wildtype viruses ex vivo and in vivo remains to be determined, our preliminary result indicates that the potential antiviral activity of teicoplanin could be applied for the treatment of 2019-nCoV virus infection.

negative: Inhibition of protein kinase R activation and upregulation of GADD34 expression play a synergistic role in facilitating coronavirus replication by maintaining de novo protein synthesis in virus-infected cells. A diversity of strategies is evolved by RNA viruses to manipulate the host translation machinery in order to create an optimal environment for viral replication and progeny production. One of the common viral targets is the alpha subunit of eukaryotic initiation factor 2 (eIF-2alpha). In this report, we show that phosphorylation of eIF-2alpha was severely suppressed in human and animal cells infected with the coronavirus infectious bronchitis virus (IBV). To understand whether this suppression is through inhibition of protein kinase R (PKR), the double-stranded-RNA-dependent kinase that is one of the main kinases responsible for phosphorylation of eIF-2alpha, cells infected with IBV were analyzed by Western blotting. The results showed that the level of phosphorylated PKR was greatly reduced in IBV-infected cells. Overexpression of IBV structural and nonstructural proteins (nsp) demonstrated that nsp2 is a weak PKR antagonist. Furthermore, GADD34, a component of the protein phosphatase 1 (PP1) complex, which dephosphorylates eIF-2alpha, was significantly induced in IBV-infected cells. Inhibition of the PP1 activity by okadaic acid and overexpression of GADD34, eIF-2alpha, and PKR, as well as their mutant constructs in virus-infected cells, showed that these viral regulatory strategies played a synergistic role in facilitating coronavirus replication. Taken together, these results confirm that IBV has developed a combination of two mechanisms, i.e., blocking PKR activation and inducing GADD34 expression, to maintain de novo protein synthesis in IBV-infected cells and, meanwhile, to enhance viral replication.

negative: Enteric Viruses Many viruses use the enteric tract as a route of entry to the human, animal, or avian host. The onset of acute enteritis is associated with infection by viruses that replicate at or near the site of entry into the intestinal mucosa, including caliciviruses, rotaviruses, adenoviruses, astroviruses, and coronaviruses. These ‘enteric’ viruses occur globally and share similar features. Most are RNA viruses that replicate in the cytoplasm of mature absorptive epithelial cells lining the villi of the small intestine, leading to inflammation and villus atrophy. Vomiting and diarrhea can result in dehydration and death if untreated. Despite abundant growth in vivo, they initially proved difficult or impossible to grow in vitro. Most are genetically diverse, species specific, highly infectious within species and transmitted by the fecal–oral route. Severe symptoms are most commonly associated with primary infections of young animals, and are followed by short-lived immunity. Reinfections are common throughout life, but are often only mildly symptomatic. Safe and effective vaccines have been developed to prevent severe rotavirus disease in young children. In addition to these enterotropic viruses, enteric disease can also result from spread to the intestine of HIV or cytomegaloviruses during the later stages of systemic disease in immunocompromised hosts.

negative: Isolation of a Coronavirus from Kidney Biopsies of Endemic Balkan Nephropathy Patients Endemic Balkan nephropathy (EBN) is a kidney disease of unknown etiology limited to Bulgaria, Rumania and former Yugoslavia. Primary kidney tissue cultures were established as explants from tissue obtained at operations from 5 EBN patients with urinary tract tumors. Four out of the five biopsy specimens on extended culture incubation at 33°C yielded a coronavirus virus (EBNV) which was cytopathogenic for human fibroblast and Vero cells. In cells inoculated with EBNV, cytoplasmic immunofluorescence was found using antisera for human coronaviruses OC43 and 229E as well as the porcine transmissible gastroenteric virus and avian (chicken) bronchitis virus. In neutralization tests, EBNV failed to react with antisera to these viruses. Using hyperimmune serum raised with EBNV, positive cytoplasmic immunofluorescence was seen with cells infected with OC43, 229E, TGV and significantly with the kidney tissue of the biopsy specimens from the EBN patients. A screen for neutralizing antibody using the EBN virus revealed that 87.2% of EBN patients on dialysis were positive, also 74% of people from an endemic area were also positive, while only 13.5% from outside were positive. It is suggested that a coronavirus is involved in the etiology of the disease and that humans are an incidental host of a coronavirus zoonosis.

negative: Plasmodium vivax Antigen Discovery Based on Alpha-Helical Coiled Coil Protein Motif Protein α-helical coiled coil structures that elicit antibody responses, which block critical functions of medically important microorganisms, represent a means for vaccine development. By using bioinformatics algorithms, a total of 50 antigens with α-helical coiled coil motifs orthologous to Plasmodium falciparum were identified in the P. vivax genome. The peptides identified in silico were chemically synthesized; circular dichroism studies indicated partial or high α-helical content. Antigenicity was evaluated using human sera samples from malaria-endemic areas of Colombia and Papua New Guinea. Eight of these fragments were selected and used to assess immunogenicity in BALB/c mice. ELISA assays indicated strong reactivity of serum samples from individuals residing in malaria-endemic regions and sera of immunized mice, with the α-helical coiled coil structures. In addition, ex vivo production of IFN-γ by murine mononuclear cells confirmed the immunogenicity of these structures and the presence of T-cell epitopes in the peptide sequences. Moreover, sera of mice immunized with four of the eight antigens recognized native proteins on blood-stage P. vivax parasites, and antigenic cross-reactivity with three of the peptides was observed when reacted with both the P. falciparum orthologous fragments and whole parasites. Results here point to the α-helical coiled coil peptides as possible P. vivax malaria vaccine candidates as were observed for P. falciparum. Fragments selected here warrant further study in humans and non-human primate models to assess their protective efficacy as single components or assembled as hybrid linear epitopes.

negative: Virus strain specificity of challenge immunity to coronavirus The resistance of immunized mice to challenge with the same or a different strain of mouse hepatitis virus (MHV) was examined as a model of challenge immunity to coronavirus infection. Genetically susceptible BALB/cByJ mice were given an intranasal immunizing infection of respiratory-type MHV-JHM, MHV-S, or enterotropic MHV-Y. Control mice were sham-immunized with sterile tissue culture fluid. Recovered mice were challenged intranasally with MHV-JHM, MHV-S or sterile tissue culture fluid at 30 days after immunization. Resistance to challenge inoculation was evaluated in groups of mice at 4 and 30 days after challenge. At 4 days, the prevalence of MHV lesions in nose and liver was tabulated and MHV titers in liver were determined. At 30 days, the prevalence of residual brainstem spongiform lesions was tabulated and serum antibody to MHV-JHM and MVH-S was quantified by enzyme immunoassay. Mice immunized with MHV-JHM or MHV-S resisted challenge with the MHV homotype, but MHV-S-immunized mice were fully susceptible to challenge with MVH-JHM. Mice immunized with enterotropic MHV-Y were only partially protected against challenge with antigenically related, but biologically different MHV-S. Serum antibody responses to MHV supported these observations. These data indicate that challenge immunity to coronaviruses is strong, but highly virus strain-specific.

negative: Face mask use in the general population and optimal resource allocation during the COVID-19 pandemic The ongoing novel coronavirus disease (COVID-19) pandemic has rapidly spread in early 2020, causing tens of thousands of deaths, over a million cases and widespread socioeconomic disruption. With no vaccine available and numerous national healthcare systems reaching or exceeding capacity, interventions to limit transmission are urgently needed. While there is broad agreement that travel restrictions and closure of non-essential businesses and schools are beneficial in limiting local and regional spread, recommendations around the use of face masks for the general population are less consistent internationally. In this study, we examined the role of face masks in mitigating the spread of COVID-19 in the general population, using epidemic models to estimate the total reduction of infections and deaths under various scenarios. In particular, we examined the optimal deployment of face masks when resources are limited, and explored a range of supply and demand dynamics. We found that face masks, even with a limited protective effect, can reduce infections and deaths, and can delay the peak time of the epidemic. We consistently found that a random distribution of masks in the population was a suboptimal strategy when resources were limited. Prioritizing coverage among the elderly was more beneficial, while allocating a proportion of available resources for diagnosed infected cases provided further mitigation under a range of scenarios. In summary, face mask use, particularly for a pathogen with relatively common asymptomatic carriage, can effectively provide some mitigation of transmission, while balancing provision between vulnerable healthy persons and symptomatic persons can optimize mitigation efforts when resources are limited.

negative: Isolation and Characterization of Dromedary Camel Coronavirus UAE-HKU23 from Dromedaries of the Middle East: Minimal Serological Cross-Reactivity between MERS Coronavirus and Dromedary Camel Coronavirus UAE-HKU23 Recently, we reported the discovery of a dromedary camel coronavirus UAE-HKU23 (DcCoV UAE-HKU23) from dromedaries in the Middle East. In this study, DcCoV UAE-HKU23 was successfully isolated in two of the 14 dromedary fecal samples using HRT-18G cells, with cytopathic effects observed five days after inoculation. Northern blot analysis revealed at least seven distinct RNA species, corresponding to predicted subgenomic mRNAs and confirming the core sequence of transcription regulatory sequence motifs as 5′-UCUAAAC-3′ as we predicted previously. Antibodies against DcCoV UAE-HKU23 were detected in 58 (98.3%) and 59 (100%) of the 59 dromedary sera by immunofluorescence and neutralization antibody tests, respectively. There was significant correlation between the antibody titers determined by immunofluorescence and neutralization assays (Pearson coefficient = 0.525, p < 0.0001). Immunization of mice using recombinant N proteins of DcCoV UAE-HKU23 and Middle East respiratory syndrome coronavirus (MERS-CoV), respectively, and heat-inactivated DcCoV UAE-HKU23 showed minimal cross-antigenicity between DcCoV UAE-HKU23 and MERS-CoV by Western blot and neutralization antibody assays. Codon usage and genetic distance analysis of RdRp, S and N genes showed that the 14 strains of DcCoV UAE-HKU23 formed a distinct cluster, separated from those of other closely related members of Betacoronavirus 1, including alpaca CoV, confirming that DcCoV UAE-HKU23 is a novel member of Betacoronavirus 1.

negative: Recombinant protein-based assays for detection of antibodies to severe acute respiratory syndrome coronavirus spike and nucleocapsid proteins. Recombinant severe acute respiratory syndrome (SARS) nucleocapsid and spike protein-based immunoglobulin G immunoassays were developed and evaluated. Our assays demonstrated high sensitivity and specificity to the SARS coronavirus in sera collected from patients as late as 2 years postonset of symptoms. These assays will be useful not only for routine SARS coronavirus diagnostics but also for epidemiological and antibody kinetic studies.

negative: Detection of rotavirus in faecal specimens with a monoclonal antibody enzyme-linked immunosorbent assay: Comparison with polyclonal antibody enzyme immuno-assays and a latex agglutination test Monoclonal antibodies have been produced against the 81/36F strain of rotavirus. One of them, was chosen as diagnostic reagent: it showed high ELISA reactivity with all the bovine, human and porcine rotavirus strains tested and reacted with VP6, structural protein product known to support the common rotavirus antigen. A sandwich ELISA procedure using the chosen monoclonal as “capture and detecting” antibody was performed to detect rotavirus in faecal samples from experimentally inoculated newborn calves: it always gave a negative response with meconium and a positive response for the stool specimens which rotavirus have been isolated. This assay was compared with Enzygnost and Slidex Rota Kit tests and with a non-commercial sandwich ELISA test using polyclonal antibodies: it showed more sensitivity than the agglutination test and was as sensitive as the other two tests to detect rotavirus in routine diagnostic material. The test evaluated showed no equivocal results.

negative: Qualitative and Quantitative Determination of MERS-CoV S1-Specific Antibodies Using ELISA Indirect enzyme-linked immunosorbent assay (ELISA) enables detection and quantification of antigen-specific antibodies in biological samples such as human or animal sera. Most current MERS-CoV serological assays such as neutralization, immunofluorescence, or protein microarray rely on handling of live MERS-CoV in high containment laboratories, highly trained personnel as well as the need for expensive and special equipment and reagents representing a hurdle for most laboratories especially when resources are limited. In this chapter, we describe a validated and optimized indirect ELISA protocol based on recombinant S1 subunit (amino acids 1–725) of MERS-CoV for qualitative and quantitative determination of MERS-CoV-binding antibodies.

negative: Molecular Diagnostic Assays for Detection of Viral Respiratory Pathogens in Institutional Outbreaks Outbreaks of viral respiratory disease in institutions may be associated with high morbidity and mortality, depending upon the viral etiology and the age and immune status of the affected patients. Control of outbreaks may include isolation and/or cohorting, and prohylaxis or treatment with specific antiviral agents may be indicated, all dependent upon the specific cause of the outbreak. Conventional methods of viral diagnosis detect only a limited number of the viruses that are known to cause outbreaks. The availability of sensitive and specific molecular assays has facilitated rapid diagnosis of a wider range of viruses from respiratory outbreaks. Molecular methods have distinct advantages over conventional methods, including the ability to rapidly develop assays for emerging viruses and new variants of existing viruses. In addition, molecular testing allows rapid detection of resistance to antiviral agents or mutations leading to increased virulence. However, high-throughput molecular testing requires batch processes that may compromise the ability to respond quickly to urgent testing demands.

negative: Immunological assays for SARS-CoV-2: an analysis of available commercial tests to measure antigen and antibodies The rapid spread of SARS-CoV-2 coronavirus infection has led to the development of molecular and serologic tests in a short period of time. While tests such as RT-PCR have applications in the immediate diagnosis revealing the presence of the virus, serological tests can be used to determine previous exposure to the virus and complement acute diagnosis. Antibody production can occur as early as 5 days post-infection. Both IgM and IgG specific anti-SARS-COV-2 antibodies can be a useful tool to test faster and larger groups of individuals. The objective of this study was to carry out a review of the different serological tests offered to detect antigen or antibodies against SARS-CoV-2. This information should be useful for decision takers in different countries to choose a test according to their needs. Based on web pages that listed serological assays, we found 226 coming from 20 countries, the majority are indirect tests for specific antibodies detection (n 180) and use immunochromatography methods (n 110) with samples coming from blood-derived products (n 105). Measuring IgM/IgG at the same time (n 112) and a procedure time of <20 min (n 83) are the most common. The overall average sensitivity was 91.8% and specificity was 97%. Most of the tests are currently for in vitro diagnosis (IVD). This information gathered could change day by day due to the expedite process of production and emergency of authorization use.

negative: Improving influenza vaccine virus selectionReport of a WHO informal consultation held at WHO headquarters, Geneva, Switzerland, 14–16 June 2010 • For almost 60 years, the WHO Global Influenza Surveillance and Response System (GISRS) has been the key player in monitoring the evolution and spread of influenza viruses and recommending the strains to be used in human influenza vaccines. The GISRS has also worked to continually monitor and assess the risk posed by potential pandemic viruses and to guide appropriate public health responses. • The expanded and enhanced role of the GISRS following the adoption of the International Health Regulations (2005), recognition of the continuing threat posed by avian H5N1 and the aftermath of the 2009 H1N1 pandemic provide an opportune time to critically review the process by which influenza vaccine viruses are selected. In addition to identifying potential areas for improvement, such a review will also help to promote greater appreciation by the wider influenza and policy‐making community of the complexity of influenza vaccine virus selection. • The selection process is highly coordinated and involves continual year‐round integration of virological data and epidemiological information by National Influenza Centres (NICs), thorough antigenic and genetic characterization of viruses by WHO Collaborating Centres (WHOCCs) as part of selecting suitable candidate vaccine viruses, and the preparation of suitable reassortants and corresponding reagents for vaccine standardization by WHO Essential Regulatory Laboratories (ERLs). • Ensuring the optimal effectiveness of vaccines has been assisted in recent years by advances in molecular diagnosis and the availability of more extensive genetic sequence data. However, there remain a number of challenging constraints including variations in the assays used, the possibility of complications resulting from non‐antigenic changes, the limited availability of suitable vaccine viruses and the requirement for recommendations to be made up to a year in advance of the peak of influenza season because of production constraints. • Effective collaboration and coordination between human and animal influenza networks is increasingly recognized as an essential requirement for the improved integration of data on animal and human viruses, the identification of unusual influenza A viruses infecting human, the evaluation of pandemic risk and the selection of candidate viruses for pandemic vaccines. • Training workshops, assessments and donations have led to significant increases in trained laboratory personnel and equipment with resulting expansion in both geographical surveillance coverage and in the capacities of NICs and other laboratories. This has resulted in a significant increase in the volume of information reported to WHO on the spread, intensity and impact of influenza. In addition, initiatives such as the WHO Shipment Fund Project have facilitated the timely sharing of clinical specimens and virus isolates and contributed to a more comprehensive understanding of the global distribution and temporal circulation of different viruses. It will be important to sustain and build upon the gains made in these and other areas. • Although the haemagglutination inhibition (HAI) assay is likely to remain the assay of choice for the antigenic characterization of viruses in the foreseeable future, alternative assays – for example based upon advanced recombinant DNA and protein technologies – may be more adaptable to automation. Other technologies such as microtitre neuraminidase inhibition assays may also have significant implications for both vaccine virus selection and vaccine development. • Microneutralization assays provide an important adjunct to the HAI assay in virus antigenic characterization. Improvements in the use and potential automation of such assays should facilitate large‐scale serological studies, while other advanced techniques such as epitope mapping should allow for a more accurate assessment of the quality of a protective immune response and aid the development of additional criteria for measuring immunity. • Standardized seroepidemiological surveys to assess the impact of influenza in a population could help to establish well‐characterized banks of age‐stratified representative sera as a national, regional and global resource, while providing direct evidence of the specific benefits of vaccination. • Advances in high‐throughput genetic sequencing coupled with advanced bioinformatics tools, together with more X‐ray crystallographic data, should accelerate understanding of the genetic and phenotypic changes that underlie virus evolution and more specifically help to predict the influence of amino acid changes on virus antigenicity. • Complex mathematical modelling techniques are increasingly being used to gain insights into the evolution and epidemiology of influenza viruses. However, their value in predicting the timing and nature of future antigenic and genetic changes is likely to be limited at present. The application of simpler non‐mechanistic statistical algorithms, such as those already used as the basis of antigenic cartography, and phylogenetic modelling are more likely to be useful in facilitating vaccine virus selection and in aiding assessment of the pandemic potential of avian and other animal influenza viruses. • The adoption of alternative vaccine technologies – such as live‐attenuated, quadrivalent or non‐HA‐based vaccines – has significant implications for vaccine virus selection, as well as for vaccine regulatory and manufacturing processes. Recent collaboration between the GISRS and vaccine manufacturers has resulted in the increased availability of egg isolates and high‐growth reassortants for vaccine production, the development of qualified cell cultures and the investigation of alternative methods of vaccine potency testing. WHO will continue to support these and other efforts to increase the reliability and timeliness of the global influenza vaccine supply. • The WHO GISRS and its partners are continually working to identify improvements, harness new technologies and strengthen and sustain collaboration. WHO will continue in its central role of coordinating worldwide expertise to meet the increasing public health need for influenza vaccines and will support efforts to improve the vaccine virus selection process, including through the convening of periodic international consultations.

negative: Intratracheal exposure of common marmosets to MERS-CoV Jordan-n3/2012 or MERS-CoV EMC/2012 isolates does not result in lethal disease Abstract Middle East Respiratory Syndrome Coronavirus (MERS-CoV) continues to be a threat to human health in the Middle East. Development of countermeasures is ongoing; however, an animal model that faithfully recapitulates human disease has yet to be defined. A recent study indicated that inoculation of common marmosets resulted in inconsistent lethality. Based on these data we sought to compare two isolates of MERS-CoV. We followed disease progression in common marmosets after intratracheal exposure with: MERS-CoV-EMC/2012, MERS-CoV-Jordan-n3/2012, media, or inactivated virus. Our data suggest that common marmosets developed a mild to moderate non-lethal respiratory disease, which was quantifiable by computed tomography (CT), with limited other clinical signs. Based on CT data, clinical data, and virological data, MERS-CoV inoculation of common marmosets results in mild to moderate clinical signs of disease that are likely due to manipulations of the marmoset rather than as a result of robust viral replication.

negative: Case series of coronavirus (SARS-CoV-2) in a military recruit school: clinical, sanitary and logistical implications INTRODUCTION: A new coronavirus, called Severe Acute Respiratory Syndrome-CoronaVirus-2 (SARS-CoV-2), has emerged from China in late 2019 and has now caused a worldwide pandemic. The impact of COVID-19 has not been described so far in a military setting. We therefore report a case series of infected patients in a recruit school in Switzerland and the herein associated challenges. METHODS: Retrospective review of COVID-19 cases among Swiss Armed Forces recruits in the early weeks of SARS-CoV-2 pandemic in the canton of Ticino, the southernmost canton of Switzerland. Positive cases were defined with two positive PCR testing for SARS-CoV-2 from nasopharyngeal swabs. Serological testing was performed with a commercially available kit according to manufacturers' instructions. RESULTS: The first case was likely contaminated while skiing during weekend permission. He became symptomatic 4 days later, tested positive for SARS-CoV-2 and was put into isolation. He showed complete symptom resolution after 48 hours. Quarantine was ordered for all recruits with close contact in the past 2 days, a total of 55 persons out of 140 in the company. Seven out of nine recruits in one particular quarantine room became mildly symptomatic. SARS-CoV-2 PCR was positive in one of them. Seven days after initial diagnosis, the index patient and the other one from the quarantine retested positive for SARS-CoV-2, although they had been completely asymptomatic for over 96 hours. Serological testing revealed positive for both patients. All others showed negative IgM and IgG. CONCLUSIONS: Young healthy recruits often showed a mild course of COVID-19 with rapid symptom decline but were persistent SARS-CoV-2 carriers. This illustrates how asymptomatic patients may be responsible for covert viral transmission. An early and prolonged establishment of isolation and quarantine for patients and close contacts is essential to slow down the spread of SARS-CoV-2, especially in the confined space of a military environment.

negative: Coronavirus infections in horses in Saudi Arabia and Oman Equine coronaviruses (ECoV) are the only coronavirus known to infect horses. So far, data on ECoV infection in horses remain limited to the USA, France and Japan and its geographic distribution is not well understood. We carried out RT‐PCR on 306 nasal and 315 rectal swabs and tested 243 sera for antibodies to detect coronavirus infections in apparently healthy horses in Saudi Arabia and Oman. We document evidence of infection with ECoV and HKU23 coronavirus by RT‐PCR. There was no conclusive evidence of Middle East respiratory syndrome coronavirus infection in horses. Serological data suggest that lineage A betacoronavirus infections are commonly infecting horses in Saudi Arabia and Oman but antibody cross‐reactivities between these viruses do not permit us to use serological data alone to identify which coronaviruses are causing these infections.

negative: What are the risks of COVID-19 infection in pregnant women?

negative: The Possible of Immunotherapy for COVID-19: a Systematic Review The novel coronavirus (2019-nCoV) is an emerging pathogen that was first described in late December 2019 and causes a severe respiratory infection in humans. Since the outbreak of COVID-19, international attention has raised to develop treatment and control options such as types of immunotherapies. The immunotherapy is an effective method for fighting against similar viral infections such as SARS-CoV, and MERS-CoV. These methods include several types of vaccines, monoclonal antibody candidates, and etc. This systematic review article was designed to evaluate the existing evidence and experience related to immunotherapy for 2019-nCoV. Web of Science (ISI), PubMed, and Scopus databases were used to search for suitable keywords such as 2019-nCoV, novel coronavirus, Immunotherapy, interleukin, vaccine and the related words for relevant publications up to 24.3.2020. The present systematic review was performed based on PRISMA protocol. Data extraction and quality valuation of articles were performed by two reviewers. 51 articles were the results of the search and based on the inclusions and exclusions criteria, 7 articles were included in the final review. As a conclusion of these studies demonstrated that although no serious research has been done on this subject at the time of writing this article, similar studies on the related viruses showed notable results. So immunotherapy for this virus can also be a suitable option.

negative: Epidemiology of community-acquired pneumonia in adult patients at the dawn of the 21st century: a prospective study on the Mediterranean coast of Spain This study presents data from a prospective study of adult patients with community-acquired pneumonia (CAP). Of 493 patients included in the study, 223 (45.2%) were aged ≥ 65 years, and 265 (53.7%) had one or more underlying diseases, mostly chronic obstructive pulmonary disease, diabetes mellitus or dementia. In total, 281 microorganisms were identified in 250 (50.7%) patients, with two or more pathogens detected in 28 (5.7%) cases. Microbial diagnosis varied according to age, severity, co-morbidity and site-of-care, but there was much overlap among groups. Streptococcus pneumoniae was the single most prevalent organism in outpatients, patients admitted to hospital, and patients who died, either as a single pathogen or combined with another organism. Infections caused by ‘atypical’ pathogens were seen across all groups, including the elderly and patients with co-morbidities. Mortality varied according to the pneumonia severity index (PSI) of the pneumonia patient outcomes research team. Shock (OR 34.48), an age of > 65 years (OR 25) and altered mental status (OR 9.92) were factors associated independently with 30-day mortality. Key findings from this study were the advanced age of the population with CAP, and the high prevalence of dementia as an underlying disease. The study also revealed that microbiological diagnosis of CAP remains problematic. Although certain epidemiological features may help to predict the microbial aetiology, the overlap among groups reduces the usefulness of this information in guiding therapeutic decisions. Greater effort should be made to improve identification methods for microbial pathogens causing CAP.

negative: Topological data analysis to model the shape of immune responses during co-infections Co-infections by multiple pathogens have important implications in many aspects of health, epidemiology and evolution. However, how to disentangle the non-linear dynamics of the immune response when two infections take place at the same time is largely unexplored. Using data sets of the immune response during influenza-pneumococcal co-infection in mice, we employ here topological data analysis to simplify and visualise high dimensional data sets. We identified persistent shapes of the simplicial complexes of the data in the three infection scenarios: single viral infection, single bacterial infection, and co-infection. The immune response was found to be distinct for each of the infection scenarios and we uncovered that the immune response during the co-infection has three phases and two transition points. During the first phase, its dynamics is inherited from its response to the primary (viral) infection. The immune response has an early shift (few hours post co-infection) and then modulates its response to react against the secondary (bacterial) infection. Between 18 and 26 h post co-infection the nature of the immune response changes again and does no longer resembles either of the single infection scenarios.

negative: Diagnosis of human coronavirus infections in children using enzyme‐linked immunosorbent assay An enzyme‐linked immunosorbent assay (ELISA) was developed for diagnosing human coronavirus (HCV) infections in children. One hundred and seventy seven nose swabs, throat swabs, and nasopharyngeal aspirates were collected from 30 children suffering from acute respiratory infections. These samples were tested for HCV antigens by ELISA and 28.2% of the samples were shown to be HCV positive. These results indicate that our ELISA should prove useful in the diagnosis of HCV infections in children. Further studies are in progress to extend the ELISA to detect HCVs in experimentally and naturally acquired infections in adults.

negative: Integrated biological–behavioural surveillance in pandemic-threat warning systems Economically and politically disruptive disease outbreaks are a hallmark of the 21st century. Although pandemics are driven by human behaviours, current surveillance systems for identifying pandemic threats are largely reliant on the monitoring of disease outcomes in clinical settings. Standardized integrated biological–behavioural surveillance could, and should, be used in community settings to complement such clinical monitoring. The usefulness of such an approach has already been demonstrated in studies on human immunodeficiency virus, where integrated surveillance contributed to a biologically based and quantifiable understanding of the behavioural risk factors associated with the transmission dynamics of the virus. When designed according to Strengthening the Reporting of Observational Studies in Epidemiology criteria, integrated surveillance requires that both behavioural risk factors – i.e. exposure variables – and disease-indicator outcome variables be measured in behavioural surveys. In the field of pandemic threats, biological outcome data could address the weaknesses of self-reported data collected in behavioural surveys. Data from serosurveys of viruses with pandemic potential, collected under non-outbreak conditions, indicate that serosurveillance could be used to predict future outbreaks. When conducted together, behavioural surveys and serosurveys could warn of future pandemics, potentially before the disease appears in clinical settings. Traditional disease-outcome surveillance must be frequent and ongoing to remain useful but behavioural surveillance remains informative even if conducted much less often, since behaviour change occurs slowly over time. Only through knowledge of specific behavioural risk factors can interventions and policies that can prevent the next pandemic be developed.

negative: Clinical and Immunologic Responses in Patients with Viral Keratoconjunctivitis

negative: Clinical evaluation of real-time PCR assays for rapid diagnosis of SARS coronavirus during outbreak and post-epidemic periods Abstract Background: The protocols of WHO network laboratories facilitated development of rapid diagnosis for SARS coronavirus (CoV) using reverse transcription (RT)-PCR assays. However, several reports have shown that conventional and real-time PCR assays were very specific for SARS CoV but lack sensitivity depending on the assay, specimen, and time course of disease. Objective: To evaluate an automatic nucleic acid extraction system and two standardized real-time PCR assays for rapid diagnosis of SARS CoV during outbreak and post-epidemic periods in Hong Kong. Study design: Specimens from clinically suspected SARS patients collected during outbreak and post-epidemic periods were tested by an automatic nucleic acid extraction system followed by our first generation conventional RT-PCR and two standardized real-time PCR assays (Artus GmbH, Germany and Roche Diagnostics, Germany). Paired serum samples were assayed for increasing titer against SARS CoV. Results: In the SARS epidemic, Artus and Roche PCR assays exhibited sensitivities of 87% and 85% for respiratory specimens (n =64), 91% and 88% for stool (n =44), and 82% for urine (n =29). A specificity of 100% was exhibited by both PCR assays except Artus attained only a 92% specificity for stool. For post-epidemic period, no SARS CoV was identified among 56 respiratory specimens by all PCR assays. Inhibitors to PCR assays were detected at an average rate of 7–8% among 202 clinical specimens. Conclusion: This study highlights the high throughput and performance of automatic RNA extraction in coordination with standardized real-time PCR assays suitable for large-scale routine diagnosis in case of future SARS epidemic. As no SARS CoV was detected among specimens collected during post-epidemic period, the positive predictive value of real-time PCR assays for detection of SARS CoV during low epidemic requires further evaluation.

negative: Establishment and Characterization of Monoclonal Antibodies Against SARS Coronavirus Immunological detection of viruses and their components by monoclonal antibodies is a powerful method for studying the structure and function of viral molecules. Here we describe detailed methods for establishing monoclonal antibodies against severe acute respiratory syndrome coronavirus (SARS-CoV). B cell hybridomas are generated from mice that are hyperimmunized with inactivated SARS-CoV virions. The hybridomas produce monoclonal antibodies that recognize viral component molecules, including the spike protein (S) and the nucleocapsid protein (N), enabling the immunological detection of SARS-CoV by immunofluorescence staining, immunoblot, or an antigen-capture ELISA system. In addition, several S protein-specific antibodies are shown to have in vitro neutralization activity. Thus the monoclonal antibody approach provides useful tools for rapid and specific diagnosis of SARS, as well as for possible antibody-based treatment of the disease.

negative: Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR BACKGROUND: The ongoing outbreak of the recently emerged novel coronavirus (2019-nCoV) poses a challenge for public health laboratories as virus isolates are unavailable while there is growing evidence that the outbreak is more widespread than initially thought, and international spread through travellers does already occur. AIM: We aimed to develop and deploy robust diagnostic methodology for use in public health laboratory settings without having virus material available. METHODS: Here we present a validated diagnostic workflow for 2019-nCoV, its design relying on close genetic relatedness of 2019-nCoV with SARS coronavirus, making use of synthetic nucleic acid technology. RESULTS: The workflow reliably detects 2019-nCoV, and further discriminates 2019-nCoV from SARS-CoV. Through coordination between academic and public laboratories, we confirmed assay exclusivity based on 297 original clinical specimens containing a full spectrum of human respiratory viruses. Control material is made available through European Virus Archive – Global (EVAg), a European Union infrastructure project. CONCLUSION: The present study demonstrates the enormous response capacity achieved through coordination of academic and public laboratories in national and European research networks.

negative: A longitudinal study of bovine coronavirus enteric and respiratory infections in dairy calves in two herds in Ohio Abstract This prospective longitudinal study examined the epidemiology and disease syndrome associated with bovine coronavirus (BCV) infections in a cohort of 8 conventional calves from 0 to 120 days of age, in two dairy herds in Ohio. The periods of respiratory shedding of BCV were determined by direct immunofluorescent (DIF) staining of nasal epithelial cells and ELISA of nasal swab supernatant fluids. The periods of fecal shedding of BCV were determined by ELISA and immunoelectron microscopy (IEM). The isotype-specific antibody titers to BCV in serum (at selected intervals between 0 and 120 days of age) and the post-suckling (24 to 48 h after birth) total immunoglobulin levels were examined by ELISA and zinc sulfate turbidity tests, respectively. Of the 8 calves studied, 4 had evidence of BCV respiratory (by DIF or ELISA) or enteric infections (by IEM or ELISA) in association with diarrhea or rhinitis, even though 7 or 8 calves showed increases in one or more serum antibody isotypes to BCV and 6 of 8 calves showed BCV respiratory or enteric antigen shedding by ELISA. Serological antibody titer increases occurred in 3 calves before 30 days of age and in 4 calves after 30 days of age; two of the latter calves had a second rise in serum antibody titers to BCV after the initial rise. A serological antibody titer increase was not observed in one calf. This suggests that BCV infections may be very common in a closed herd and may occur in older calves, although many may be subclinical and some may be recurrent. There were no statistically significant correlations between total serum immunoglobulin levels or BCV antibody isotype titers in serum (24–48 h after birth) and clinical disease or infection by BCV; however, calves with low levels of IgA BCV antibodies in serum (24–48 h after birth) had a significantly greater average number of days with diarrhea than those calves having high levels of IgA BCV-specific antibodies in serum.

negative: Serodiagnostic Aids and Management Practice for Feline Retrovirus and Coronavirus Infections

negative: Detection of SARS-CoV-2 RNA and Antibodies in Diverse Samples: Protocol to Validate the Sufficiency of Provider-Observed, Home-Collected Blood, Saliva, and Oropharyngeal Samples BACKGROUND: The response in the United States to the coronavirus disease (COVID-19) pandemic has been hampered by a lack of aggressive testing for the infection. Testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cornerstone of an effective public health response. However, efforts to test have been hampered by limited reagents, limitations in the availability of swabs used for the collection of nasopharyngeal swab (NPS) specimens, limitations in personal protective equipment (PPE) for health care providers collecting the NPS specimens, and limitations in viral transport media for transporting the specimens. Therefore, more flexible options for screening for SARS-CoV-2 RNA and serologic responses are critical to inform clinical and public health responses. OBJECTIVE: We aim to document the ability of patients to self-collect sufficient specimens for SARS-CoV-2 viral detection and serology. METHODS: Patient self-collection of samples will be done with observation by a health care provider during a telemedicine session. Participants will be mailed a specimen collection kit, engage in a telehealth session with a provider through a HIPPA (Health Insurance Portability and Accountability Act of 1996)-compliant video meeting, and collect specimens while being observed by the provider. Providers will record whether they are confident in the suitability of the specimen for laboratory testing that would inform clinical decision making. We will objectively assess the sufficiency of biological material in the mailed-in specimens. RESULTS: The protocol was approved by the Emory University Institutional Review Board (IRB) on March 30, 2020 (Protocol number 371). To date, we have enrolled 159 participants. CONCLUSIONS: Defining a conceptual framework for assessing the sufficiency of patient-collected samples for the detection of SARS-CoV-2 RNA and serologic responses to infection is critical for facilitating public health responses and providing PPE-sparing options to increase testing. Validation of alternative methods of specimen collection should include objective measures of the sufficiency of specimens for testing. A strong evidence base for diversifying testing modalities will improve tools to guide public health responses to the COVID-19 pandemic.

negative: Viral Kinetics and Antibody Responses in Patients with COVID-19 Background A pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading over the world. However, the viral dynamics, host serologic responses, and their associations with clinical manifestations, have not been well described in prospective cohort. Methods We conducted a prospective cohort and enrolled 67 COVID-19 patients admitting between Jan 26 and Feb 5, 2020. Clinical specimens including nasopharyngeal swab, sputum, blood, urine and stool were tested periodically according to standardized case report form with final follow-up on February 27. The routes and duration of viral shedding, antibody response, and their associations with disease severity and clinical manifestations were systematically evaluated. Coronaviral particles in clinical specimens were observed by transmission electron microscopy (TEM). Results The median duration of SARS-CoV-2 RNA shedding were 12 (3-38), 19 (5-37), and 18 (7-26) days in nasopharyngeal swabs, sputum and stools, respectively. Only 13 urines (5.6%) and 12 plasmas (5.7%) were viral positive. Prolonged viral shedding was observed in severe patients than that of non-severe patients. Cough but not fever, aligned with viral shedding in clinical respiratory specimens, meanwhile the positive stool-RNA appeared to align with the proportion who concurrently had cough and sputum production, but not diarrhea. Typical coronaviral particles could be found directly in sputum by TEM. The anti-nucleocapsid-protein IgM started on day 7 and positive rate peaked on day 28, while that of IgG was on day 10 and day 49 after illness onset. IgM and IgG appear earlier, and their titers are significantly higher in severe patients than non-severe patients (p<0.05). The weak responders for IgG had a significantly higher viral clearance rate than that of strong responders (p= 0.011). Conclusions Nasopharyngeal, sputum and stools rather than blood and urine, were the major shedding routes for SARS-CoV-2, and meanwhile sputum had a prolonged viral shedding. Symptom cough seems to be aligned with viral shedding in clinical respiratory and fecal specimens. Stronger antibody response was associated with delayed viral clearance and disease severity.

negative: Evaluation of 10 serological assays for diagnosing Mycoplasma pneumoniae infection Abstract In this study, the performance of 10 serological assays for the diagnosis of Mycoplasma pneumoniae infection was evaluated. A total of 145 sera from 120 patients were tested. They were obtained from patients who were serologically positive for M. pneumoniae infection as well as from patients who were infected with micro-organisms that may cause interstitial pneumonia. The following assays were utilized: SeroMP IgM and IgG, SeroMP recombinant IgM, IgA and IgG, Liaison M. pneumoniae IgM and IgG and M. pneumoniae IgM, IgA and IgG ELISA Medac. The SeroMP Recombinant and Liaison assays both showed low IgM specificity, and crossreactivity was mainly observed in groups of patients with acute cytomegalovirus and Epstein-Barr virus infections. For IgA, the Medac assay was less specific than the SeroMP Recombinant assay. Discrepancies between the four tests were observed in IgG analyses, and due to the lack of a gold standard, 22 results were removed prior to determining the sensitivity and specificity. Therefore, the overall performance of IgG assays may be overstated; nevertheless, the SeroMP assay demonstrated a lack of sensitivity. The seroprevalence of IgG appears to be very low, raising concerns regarding whether the serological techniques can detect IgG levels over time. Serology remains a biological tool of choice for diagnosing M. pneumoniae infection, but improvement and standardization of the assays are needed, particularly for the determination of IgG.

negative: Current treatment options and the role of peptides as potential therapeutic components for Middle East Respiratory Syndrome (MERS): A review Abstract Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a highly pathogenic respiratory virus with mechanisms that may be driven by innate immune responses. Despite the effort of scientific studies related to this virus, Middle East Respiratory Syndrome (MERS) is still a public health concern. MERS-CoV infection has a high mortality rate, and to date, no therapeutic or vaccine has been discovered, that is effective in treating or preventing the disease. In this review, we summarize our understanding of the molecular and biological events of compounds acting as MERS-CoV inhibitors, the outcomes of existing therapeutic options and the various drugs undergoing clinical trials. Currently, several therapeutic options have been employed, such as convalescent plasma (CP), intravenous immunoglobulin (IVIG), monoclonal antibodies and repurposing of existing clinically approved drugs. However, these therapeutic options have drawbacks, thus the need for an alternative approach. The requirement for effective therapeutic treatment has brought the necessity for additional MERS treatments. We suggest that antimicrobial peptides (AMPs) may be used as alternative therapeutic agents against MERS-CoV infection. In addition, we propose the feasibility of developing effective agents by repurposing the existing and clinically approved anti-coronavirus and anti-viral peptide drugs.

negative: Coronavirus HKU15 in respiratory tract of pigs and first discovery of coronavirus quasispecies in 5′-untranslated region Coronavirus HKU15 is a deltacoronavirus that was discovered in fecal samples of pigs in Hong Kong in 2012. Over the past three years, Coronavirus HKU15 has been widely detected in pigs in East/Southeast Asia and North America and has been associated with fatal outbreaks. In all such epidemiological studies, the virus was generally only detected in fecal/intestinal samples. In this molecular epidemiology study, we detected Coronavirus HKU15 in 9.6% of the nasopharyngeal samples obtained from 249 pigs in Hong Kong. Samples that tested positive were mostly collected during winter. Complete genome sequencing of the Coronavirus HKU15 in two nasopharyngeal samples revealed quasispecies in one of the samples. Two of the polymorphic sites involved indels, but the other two involved transition substitutions. Phylogenetic analysis showed that the two nasopharyngeal strains in the present study were most closely related to the strains PDCoV/CHJXNI2/2015 from Jiangxi, China, and CH/Sichuan/S27/2012 from Sichuan, China. The outbreak strains in the United States possessed highly similar genome sequences and were clustered monophyletically, whereas the Asian strains were more diverse and paraphyletic. The detection of Coronavirus HKU15 in respiratory tracts of pigs implies that in addition to enteric infections, Coronavirus HKU15 may be able to cause respiratory infections in pigs and that in addition to fecal-oral transmission, the virus could possibly spread through the respiratory route. The presence of the virus in respiratory samples provides an alternative clinical sample to confirm the diagnosis of Coronavirus HKU15 infection. Quasispecies were unprecedentedly observed in the 5′-untranslated region of coronavirus genomes.

negative: Towards effective diagnostic assays for COVID-19: a review. Countries globally are affected by the COVID-19 pandemic, with nearly two million cases and 120 000 deaths occurring within 4 months of the discovery of the severe acute respiratory syndrome coronavirus-2 in December 2019 in China. Accurate diagnoses of cases is key in managing the pandemic by identification, isolation and treatment of patients and defining the epidemiology of the virus. By mid-January 2020, a scientist from China published the full genome of the virus, which facilitated the development of accurate molecular diagnostic assays. By the end of January 2020, the WHO, in collaboration with laboratories in Asia, Europe and the USA, published several real-time reverse transcriptase PCR (rtRT-PCR) protocols that allowed identification of cases and development of commercial assays. Clinical investigations facilitated development of accurate case definition and guidance for laboratories on the optimum specimens and procedures for diagnoses. Currently, laboratory-based rtRT-PCR is the recommended test for diagnoses of acute cases to ensure patients can be identified and isolated and to facilitate the public health response. However, due to delays in diagnoses, severe shortage of tests and laboratory capacity, point-of-care molecular or antigen tests are becoming more attractive. Although serological tests are not suitable for diagnoses of acute cases, they are important to define epidemiological questions, including attack rate in the population, and to identify immune individuals. This review aimed to summarise the current available information for diagnoses of cases and to aid laboratories and healthcare workers to select the best assays and procedures.

negative: Scoping Review on Search Queries and Social Media for Disease Surveillance: A Chronology of Innovation BACKGROUND: The threat of a global pandemic posed by outbreaks of influenza H5N1 (1997) and Severe Acute Respiratory Syndrome (SARS, 2002), both diseases of zoonotic origin, provoked interest in improving early warning systems and reinforced the need for combining data from different sources. It led to the use of search query data from search engines such as Google and Yahoo! as an indicator of when and where influenza was occurring. This methodology has subsequently been extended to other diseases and has led to experimentation with new types of social media for disease surveillance. OBJECTIVE: The objective of this scoping review was to formally assess the current state of knowledge regarding the use of search queries and social media for disease surveillance in order to inform future work on early detection and more effective mitigation of the effects of foodborne illness. METHODS: Structured scoping review methods were used to identify, characterize, and evaluate all published primary research, expert review, and commentary articles regarding the use of social media in surveillance of infectious diseases from 2002-2011. RESULTS: Thirty-two primary research articles and 19 reviews and case studies were identified as relevant. Most relevant citations were peer-reviewed journal articles (29/32, 91%) published in 2010-11 (28/32, 88%) and reported use of a Google program for surveillance of influenza. Only four primary research articles investigated social media in the context of foodborne disease or gastroenteritis. Most authors (21/32 articles, 66%) reported that social media-based surveillance had comparable performance when compared to an existing surveillance program. The most commonly reported strengths of social media surveillance programs included their effectiveness (21/32, 66%) and rapid detection of disease (21/32, 66%). The most commonly reported weaknesses were the potential for false positive (16/32, 50%) and false negative (11/32, 34%) results. Most authors (24/32, 75%) recommended that social media programs should primarily be used to support existing surveillance programs. CONCLUSIONS: The use of search queries and social media for disease surveillance are relatively recent phenomena (first reported in 2006). Both the tools themselves and the methodologies for exploiting them are evolving over time. While their accuracy, speed, and cost compare favorably with existing surveillance systems, the primary challenge is to refine the data signal by reducing surrounding noise. Further developments in digital disease surveillance have the potential to improve sensitivity and specificity, passively through advances in machine learning and actively through engagement of users. Adoption, even as supporting systems for existing surveillance, will entail a high level of familiarity with the tools and collaboration across jurisdictions.

negative: Update on Canine and Feline Blood Donor Screening for Blood‐Borne Pathogens An update on the 2005 American College of Veterinary Internal Medicine (ACVIM) Consensus Statement on blood donor infectious disease screening was presented at the 2015 ACVIM Forum in Indianapolis, Indiana, followed by panel and audience discussion. The updated consensus statement is presented below. The consensus statement aims to provide guidance on appropriate blood‐borne pathogen testing for canine and feline blood donors in North America.

negative: Antigenic analysis of feline coronaviruses with monoclonal antibodies (MAbs): Preparation of MAbs which discriminate between FIPV strain 79-1146 and FECV strain 79-1683 Abstract We prepared 31 monoclonal antibodies (MAbs) against either FIPV strain 79-1146 or FECV strain 79-1683, and tested them for reactivity with various coronaviruses by indirect flourescent antibody assay (IFA). Sixteen MAbs which reacted with all of the 11 strains of feline coronaviruses, also reacted with canine coronavirus (CCV) and transmissible gastroenteritis virus (TGEV). In many of them, the polypeptide specifity was the recognition of transmembrane (E1) protein of the virus. We succeeded in obtaining MAbs which did not react with eight strains FIPV Type I viruses (showing cell-associated growth) but reacted with FIPV Type II (79-1146, KU-1) and/or FECV Type II (79-1683) viruses (showing non-cell associated growth). These MAbs also reacted with CCV or TGEV. These MAbs recognized peplomer (E2) glycoprotein, and many antigenic differences were found in this E2 protein. These results suggest that FIPV Type II and FECV Type II viruses are antigenically closer to TGEV or CCV than to FIPV Type I viruses. Furthermore, the MAb prepared in this study has enabled discrimination between FIPV strain 79-1146 and FECV strain 79-1683, which was thought to be impossible by the previous serological method.

negative: A serological survey of canine respiratory coronavirus in New Zealand Aims: To determine the seroprevalence of canine respiratory coronavirus (CRCoV) in New Zealand dogs, and to explore associations with age, sex, breed, month, and geographical region of sampling and reported presence of clinical signs suggestive of respiratory disease. Methods: A total of 1,015 canine serum samples were randomly selected from submissions to a diagnostic laboratory between March and December 2014, and were analysed for CRCoV antibodies using a competitive ELISA. Logistic regression analysis was used to determine associations between seroprevalence of CRCoV and breed category, age, sex, sampling month, region, and reported health status of dogs. Results: Overall, 538/1,015 (53.0%) samples were seropositive for CRCoV, with 492/921 (53.4%) positive dogs in the North Island and 46/94 (49%) in the South Island. Age of dog, sampling month, region, and presence of abnormal respiratory signs were included in the initial logistic regression model. Seroprevalence was higher in dogs aged ≥3 compared with ≤2 years (p < 0.01). The lowest seroprevalence was observed in July (30/105; 28.5%) and August (32/100; 32%), and the highest in June (74/100; 74%). Seroprevalence in dogs from Auckland was higher than in dogs from the Hawkes Bay, Manawatu, Marlborough, and Waikato regions (p < 0.05). Abnormal respiratory signs (coughing, nasal discharge, or sneezing) were reported for 28/1,015 (2.8%) dogs sampled. Seroprevalence for CRCoV tended to be higher among dogs with respiratory signs (67.9 (95% CI = 47.6–83.4)%) than dogs with no reported respiratory signs (52.6 (95% CI = 49.5–55.7)%). Conclusions: Serological evidence of infection with CRCoV was present in more than half of the dogs tested from throughout New Zealand. Differences in CRCoV seroprevalence between regions and lack of seasonal pattern indicate that factors other than external temperatures may be important in the epidemiology of CRCoV in New Zealand. Clinical relevance: Our data suggest that CRCoV should be included in investigations of cases of infectious canine tracheobronchitis, particularly if these occur among dogs vaccinated with current vaccines, which do not include CRCoV antigens.

negative: Influenza, influenza‐like symptoms and their association with cardiovascular risks: a systematic review and meta‐analysis of observational studies AIMS: To synthesise the evidence relating influenza and influenza‐like symptoms to the risks of myocardial infarction (MI), heart failure (HF) and stroke. METHODS: We conducted a systematic review and meta‐analysis of the evidence relating influenza and influenza‐like symptoms to the risks of MI, HF and stroke. We systematically searched all MEDLINE and EMBASE entries up to August 2014 for studies of influenza vs. the cardiovascular outcomes above. We conducted random effects meta‐analysis using inverse variance method for pooled odds ratios (OR) and evaluated statistical heterogeneity using the I (2) statistic. RESULTS: We identified 12 studies with a total of 84,003 participants. The pooled OR for risk of MI vs. influenza (serologically confirmed) was 1.27 (95% CI, confidence interval 0.54–2.95), I (2) = 47%, which was significant for the only study that adjusted for confounders (OR 5.50, 95% CI 1.31–23.13). The pooled OR for risk of MI vs. influenza‐like symptoms was 2.17 (95% CI 1.68–2.80), I (2) = 0%, which was significant for both unadjusted (OR 2.23, 95% CI 1.65–3.01, five studies) and adjusted studies (OR 2.01, 95% CI 1.24–3.27, two studies). We found one study that evaluated stroke risk, one study in patients with HF, and one that evaluated mortality from MI – all of these studies suggested increased risks of events with influenza‐like symptoms. CONCLUSIONS: There is an association between influenza‐like illness and cardiovascular events, but the relationship is less clear with serologically diagnosed influenza. We recommend renewed efforts to apply current clinical guidelines and maximise the uptake of annual influenza immunisation among patients with cardiovascular diseases, to decrease their risks of MI and stroke.

negative: Development and application of nsp5-ELISA for the detection of antibody to infectious bronchitis virus Abstract Infectious bronchitis virus (IBV) continues to be one of the most important poultry pathogens worldwide. The current commercially available enzyme-linked immunosorbent assay (ELISA) kits for IBV specific antibody detection are mostly based on the whole virion, and few serological tests based on nonstructural proteins of IBV have been developed. Herein, an alternative indirect ELISA for detection of IBV antibody was developed with IBV nonstructural protein 5 (nsp5) produced by Escherichia coli. Using an indirect immunofluorescence assay (IFA) and a commercial ELISA kit as reference, we optimized the nsp5-ELISA and determined its cut-off as 0.12. The diagnostic sensitivity (DSN), specificity (DSP) and accuracy of the nsp5-ELISA were 93.11%, 95.38% and 93.33%, respectively, compared with IFA in 660 field serum samples, and were 98.11%, 95.00% and 97.62%, respectively, compared with the commercial IBV ELISA kit (IDEXX) in 126 field sera samples. Furthermore, a time course of IBV specific antibody level detected by nsp5-ELISA following IBV infection and vaccination is consistent with that of IBV antibody detected by the commercial ELISA kit. The results presented in this study indicate that nsp5-ELISA has the potential to serve as a rapid, reliable and cost-effective method for IBV antibody detection. This study is the first to report the development of an nsp-based ELISA to detect an antibody to IBV.

negative: Eucaryotic expression of the nucleocapsid protein gene of porcine circovirus type 2 and use of the protein in an indirect immunofluorescence assay for serological diagnosis of postweaning multisystemic wasting syndrome in pigs. The purpose of this study was to develop a sensitive, rapid, and inexpensive immunofluorescence assay (IFA) using a recombinant porcine circovirus type 2 (PCV2) nucleocapsid protein for the serological detection of PCV2-specific antibodies in pig sera. The viral nucleocapsid protein encoded by the PCV2 ORF2 gene has recently been identified as the most immunoreactive viral protein that carries type-specific antigenic determinants. The ORF2 sequence of the IAF-2897 strain of PCV2 has been cloned into a pCEP5 eucaryotic expression vector under the control of the cytomegalovirus promoter, downstream of a polyhistidine sequence tag. The recombinant plasmid was used in transfection experiments with human epithelial kidney 293 cells that were further tested, and positive expression of the viral nucleocapsid protein was confirmed by IFA and Western blotting. Strong, specific fluorescence was observed in the nuclei of transfected cells. Test specificity to PCV2 was verified with several related infectious agents. Sensitivity was compared to that of standard IFA using PCV2-infected cells by evaluating the reactivities of 44 field serum samples from pigs on farms with a porcine population suffering from postweaning multisystemic wasting syndrome. The recombinant nucleocapsid-based test was able to detect 15 more positive-testing pigs than the PCV2-based IFA. Therefore, the relative sensitivity of the latter test was estimated at only 57.1% compared to that of the recombinant nucleocapsid-based test. The recombinant fusion protein has been purified by affinity chromatography and is being used to develop further sensitive serological tests.

negative: Biorisk assessment for infrastructure & biosafety requirements for the laboratories providing coronavirus SARS-CoV-2/(COVID-19) diagnosis Novel coronavirus infection [coronavirus disease 2019 (COVID-19)] has spread to more than 203 countries of various regions including Africa, America, Europe, South East Asia and Western Pacific. The WHO had declared COVID-19 as the global public health emergency and subsequently as pandemic because of its worldwide spread. It is now one of the top-priority pathogens to be dealt with, because of high transmissibility, severe illness and associated mortality, wide geographical spread, lack of control measures with knowledge gaps in veterinary and human epidemiology, immunity and pathogenesis. The quick detection of cases and isolating them has become critical to contain it. To meet the increasing demand of the diagnostic services, it is necessary to enhance and expand laboratory capabilities since existing laboratories cannot meet the emerging demand. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a BSL-2 (Biosafety Level 2) agent and needs to be handled in biosafety cabinet using standard precautions. This review highlights minimum requirements for the diagnostic laboratories opting testing of material for the diagnosis of COVID-19 and associated biorisk to the individuals and to the community.

negative: Chapter 33 Avian Coronavirus: Case of Infectious Bronchitis Virus Pathogenesis, Diagnostic Approaches, and Phylogenetic Relationship Among Emerging Strains in Middle East and North Africa Regions Abstract Infectious bronchitis (IB) virus (IBV) is a very dynamic and evolving virus, causing severe diseases in poultry with significant economic consequences to the poultry industry worldwide, affecting chickens of all ages and possessing a major threat to the poultry industry. IBV is well studied worldwide; nevertheless, in Middle East and North Africa (MENA) regions, epidemiological and scientific data are poor and not updated. In spite of regular vaccination with Massachusetts (Mass) strain has been available to control IB for many decades in MENA regions, which it is most commonly used, the protection is not occurred. However, the continuity of the spread of IBV has shown the emergence of multiple variant strains due to the frequent point of mutations and recombination events in the S1 gene hypervariable regions. All the reported IBV variants circulate in the form of several serotypes/genotypes that can be partially or poorly neutralized by current vaccines. This emergence remains a problem for the poultry industry and vaccine manufacturers. Therefore the objective of this present chapter, which is reported for the first time, aims to establish phylogenic relationship among emerging strains in MENA regions.

negative: A comparative assessment of four serological methods used in the detection and measurement of anti-parasite antibodies in the serum of the amphibian, bufo viridis Abstract Antibodies against Crithidia fasciculata choanomastigotes were detected in green toad (Bufo viridis) sera by direct agglutination, indirect haemagglutination (IHA), complement-fixation test (CFT) and enzyme-linked immunosorbent assay (ELISA), Correlation coefficients (r) were calculated for comparisons between each of the techniques and regression formulae derived in order to convert antibody levels as determined by one immunological method to that of another. The highest mean titre obtained by ELISA was approximately 1.5–3.5 times greater than those obtained by the other techniques whilst CFT gave the lowest values. IHA and ELISA titres were affected by different preparations of the crithidial antigen extracts. Highly significant r values were determined for control sera when IHA was compared to ELISA (r > 0.79), and to both CFT and ELISA with immune animals (r > 0.96). ELISA would seem most applicable for screening other lower vertebrates for anti-parasite antibodies especially in areas of human disease prevalence.

negative: Revisión Narrativa Sobre La Respuesta Inmunitaria Frente A Coronavirus: Descripción General, Aplicabilidad Para Sars-Cov2 E Implicaciones Terapéuticas Abstract The new coronavirus (SARS-CoV2) that causes a severe acute respiratory syndrome emerged in Wuhan, China, in December 2019. It produces the aforementioned disease due to coronavirus 2019 (COVID-19), and has led to a declaration of a world public health emergency by the World Health Organisation. This new SARS-CoV2 virus could share characteristics and an immune response similar to those described for other coronavirus. Given its activity on the interferon pathway, and the manner in which it dysregulates innate immunity, the use of treatments directed at modulating or containing this could be of interest. A narrative review was made of the current evidence about immunity against coronavirus and it applicability to SARS-CoV2. The physiopathogenesis is also described, along with the underlying leucocyte activity, with the intention of clarifying the possible usefulness of inflammatory biomarkers and the development of personalised treatments.

negative: Drug Repurposing for Japanese Encephalitis Virus Infection by Systems Biology Methods Japanese encephalitis is a zoonotic disease caused by the Japanese encephalitis virus (JEV). It is mainly epidemic in Asia with an estimated 69,000 cases occurring per year. However, no approved agents are available for the treatment of JEV infection, and existing vaccines cannot control various types of JEV strains. Drug repurposing is a new concept for finding new indication of existing drugs, and, recently, the concept has been used to discover new antiviral agents. Identifying host proteins involved in the progress of JEV infection and using these proteins as targets are the center of drug repurposing for JEV infection. In this study, based on the gene expression data of JEV infection and the phenome-wide association study (PheWAS) data, we identified 286 genes that participate in the progress of JEV infection using systems biology methods. The enrichment analysis of these genes suggested that the genes identified by our methods were predominantly related to viral infection pathways and immune response-related pathways. We found that bortezomib, which can target these genes, may have an effect on the treatment of JEV infection. Subsequently, we evaluated the antiviral activity of bortezomib using a JEV-infected mouse model. The results showed that bortezomib can lower JEV-induced lethality in mice, alleviate suffering in JEV-infected mice and reduce the damage in brains caused by JEV infection. This work provides an agent with new indication to treat JEV infection.

negative: Biology and Diseases of Ruminants: Sheep, Goats, and Cattle

negative: Evaluation of a combined MxA and CRP point-of-care immunoassay to identify viral and/or bacterial immune response in patients with acute febrile respiratory infection BACKGROUND: Challenges in the clinical differentiation of viral and/or bacterial respiratory infection lead to the misappropriation of antibiotics and increased healthcare costs. A tool to facilitate rapid and accurate point-of-care (POC) differentiation is needed. METHODS AND FINDINGS: A prospective, single center, blinded, observational clinical trial was conducted at Beth Israel Deaconess Medical Center from December 2012 to August 2013 to determine the accuracy of a POC immunoassay to identify a clinically significant immune response to viral and/or bacterial infection. Sixty patients with acute febrile respiratory infection (19 pharyngitis and 41 lower respiratory tract infection [LRTI]) were enrolled. Participants provided fingerstick blood for immunoassay testing (myxovirus A [MxA] and c-reactive protein [CRP]) and four oropharyngeal samples for viral PCR and routine bacterial cell culture. A venous blood sample was collected. An ELISA was used to measure CRP and MxA. Paired serological testing was used to confirm atypical bacteria. A urine sample was provided for Streptococcus and Legionella antigen testing. Patients with suspected LRTI had sputum and blood cultures, chest X-ray, and WBC count measured. Viral infection was confirmed if oropharyngeal PCR was positive for viral pathogens. Bacterial infection was confirmed in positive throat or sputum cultures. Elevated immunoglobulin M antibodies or twofold increase in IgG antibodies between acute and convalescent phase indicated atypical bacteria. Positive Streptococcus or Legionella urine antigen assays also confirmed bacterial infection. The immunoassay correctly categorized subjects as 92% (22/24) negative, 80% (16/20) with bacterial infection, and 70% (7/10) with viral infection. CONCLUSIONS: The interplay between an MxA value and a semi-quantitative CRP value can aid in the differentiation of infectious etiology. In isolation, neither MxA nor CRP alone is sensitive or specific. However, the pattern of results in a rapid immunoassay provides a sensitive and specific method to differentiate acute febrile respiratory infections. This diagnostic information may help reduce antibiotic misuse and resistance and lower healthcare costs.

negative: Infectious Diseases The chapter describes bacerial, viral, parasitic and fungal infections commonly detected in pet birds. The chapter includes history, etiology, susceptible hosts, transmission, pathogenesis, clinical symptoms, lesion, diagnosis, zoonosis, Treatment and control strategy of Tuberculosis, Salmonellosis, Chlamydiosis, Campylobacteriosis, Lyme disease, other bacterial infection, Newcastle disease, Avian Influenza infection, West Nile Virus infection, Usutu virus infection, Avian Borna Virus infection, Beak and feather disease, other viral infection, Toxoplasmosis, Giardiasis, Cryptosporidiosis, other parasitic infection, Cryptococcosis, Aspergillosis, Other fungal infections.

negative: The novel coronavirus 2019 (2019-nCoV) uses the SARS-coronavirus receptor ACE2 and the cellular protease TMPRSS2 for entry into target cells The emergence of a novel, highly pathogenic coronavirus, 2019-nCoV, in China, and its rapid national and international spread pose a global health emergency. Coronaviruses use their spike proteins to select and enter target cells and insights into nCoV-2019 spike (S)-driven entry might facilitate assessment of pandemic potential and reveal therapeutic targets. Here, we demonstrate that 2019-nCoV-S uses the SARS-coronavirus receptor, ACE2, for entry and the cellular protease TMPRSS2 for 2019-nCoV-S priming. A TMPRSS2 inhibitor blocked entry and might constitute a treatment option. Finally, we show that the serum form a convalescent SARS patient neutralized 2019-nCoV-S-driven entry. Our results reveal important commonalities between 2019-nCoV and SARS-coronavirus infection, which might translate into similar transmissibility and disease pathogenesis. Moreover, they identify a target for antiviral intervention. One sentence summary The novel 2019 coronavirus and the SARS-coronavirus share central biological properties which can guide risk assessment and intervention.

negative: Experience with Cidofovir as an adjunctive therapy in a patient of adenovirus-induced macrophage activation syndrome in systemic arthritis A 5-year-old female child, with known systemic juvenile idiopathic arthritis diagnosed at 18 months of age (on low dose Prednisolone + Methotrexate + Leflunomide + Tocilizumab), presented with fever for 1 day, vomiting, drowsiness followed by seizures. On admission to PICU, she was drowsy, tachycardic, tachypneic, with rashes, and hepatosplenomegaly. Lab findings showed thrombocytopenia, leucopenia, low ESR, normal CRP, elevated liver enzymes, high ferritin, LDH, and triglycerides suggestive of macrophage activation syndrome (MAS). Chest X-ray showed left basal pneumonia and DNA PCR of throat swab revealed adenovirus. She was diagnosed as adenovirus-triggered MAS and was initiated on pulse methylprednisolone (6 mg/kg). Because of suboptimal response after 2 doses, manifested by increasing drowsiness, further fall in platelets and rising ferritin, methylprednisolone dosage was increased to 30 mg/kg/day with the addition of oral cyclosporine (4 mg/kg/day). In view of worsening of the chest X-ray and increasing oxygen requirement, Cidofovir infusion (1 mg/kg thrice weekly) was also started simultaneously considering increased activity of the adenoviral infection concurrent to immunosuppression. Within 48 h, the child showed signs of recovery with improved consciousness, lower oxygen requirements, and improving lab parameters. She was discharged after 3 weeks of IV Cidofovir, on oral prednisolone and cyclosporine. To the best of our knowledge, this is the first reported use of Cidofovir in adenovirus-induced MAS. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10067-020-05133-0) contains supplementary material, which is available to authorized users.

negative: Feline coronavirus serotypes 1 and 2: seroprevalence and association with disease in Switzerland. To determine the prevalence of antibodies to feline coronavirus (FCoV) serotypes 1 and 2 in Switzerland and their association with different disease manifestations, a serological study based on immunofluorescence tests was conducted with Swiss field cats using transmissible gastroenteritis virus (TGEV), FCoV type 1 and FCoV type 2 as antigens. A total of 639 serum samples collected in the context of different studies from naturally infected cats were tested. The current study revealed that, with an apparent prevalence of 83%, FCoV serotype 1 is the most prevalent serotype in Switzerland. FCoV type 1 viruses induced higher antibody titers than FCoV type 2, and were more frequently associated with clinical signs and/or feline infectious peritonitis. The antibody development in seven cats experimentally infected with FCoV type 1 revealed that, with progressing duration of infection, antibodies to FCoV type 1 significantly increased over those to FCoV type 2. There was a significant relationship between antibody titers against TGEV, FCoV 1, and FCoV 2 and TGEV antigen detected the highest proportion of seropositive cats. We conclude that a vaccine against FCoV should be based on FCoV type 1-related antigens and that for serodiagnosis of FCoV infection TGEV should be used to attain the highest diagnostic efficiency. When serology is used in addition to clinical signs, hematology, and clinical chemistry results as an aid to diagnose clinical FIP, TGEV shows a diagnostic efficiency equal to that of a FCoV antigen.

negative: A two year serological surveillance of coronavirus infections in Hamburg The occurrence of OC-43 coronavirus-like infections in the population of Hamburg was determined by a monthly serological survey (hemagglutination inhibition test [HI]) undertaken between October 1974 and October 1976. Studies of 3,016 sera revealed a high incidence of HI antibodies (58.2%). The frequency of seropositive reactions (=1:8) and the geometric mean titer were higher in individuals 15 to 24 years old. Treatment of 50 positive sera (titer 1:16 – 1:64) with receptor destroying enzyme, kaolin and ethacridin for elimination of nonspecific inhibitors did not modify the HI-titer of the investigated sera. The serological seasonal pattern suggests that coronaviruses are circulating the whole year in the urban population with a prevalence in the fall-winter period. Of the 331 paired sera examined, 6.6% presented a four- to eightfold rise in titer within eight weeks.

negative: ElaD, a Deubiquitinating Protease Expressed by E. coli BACKGROUND: Ubiquitin and ubiquitin-like proteins (Ubl) are designed to modify polypeptides in eukaryotes. Covalent binding of ubiquitin or Ubls to substrate proteins can be reversed by specific hydrolases. One particular set of cysteine proteases, the CE clan, which targets ubiquitin and Ubls, has homologs in eukaryotes, prokaryotes, and viruses. FINDINGS: We have cloned and analyzed the E. coli protein elaD, which is distantly related to eukaryotic CE clan members of the ULP/SENP protease family that are specific for SUMO and Nedd8. Previously misannotated as a putative sulfatase/phosphatase, elaD is an efficient and specific deubiquitinating enzyme in vitro. Interestingly, elaD is present in all intestinal pathogenic E. coli strains, but conspicuously absent from extraintestinal pathogenic strains (ExPECs). Further homologs of this protease can be found in Acanthamoeba Polyphaga Mimivirus, and in Alpha-, Beta-and Gammaproteobacteria. CONCLUSION: The expression of ULP/SENP-related hydrolases in bacteria therefore extends to plant pathogens and medically relevant strains of Escherichia coli, Legionella pneumophila, Rickettsiae, Chlamydiae, and Salmonellae, in which the elaD ortholog sseL has recently been identified as a virulence factor with deubiquitinating activity. As a counterpoint, our phylogenetic and functional examination reveals that ancient eukaryotic ULP/SENP proteases also have the potential of ubiquitin-specific hydrolysis, suggesting an early common origin of this peptidase clan.

negative: Seroepidemiology of group I human coronaviruses in children BACKGROUND: Recently, several new human coronaviruses have been identified. OBJECTIVES: To define the seroepidemiology of group I human coronaviruses STUDY DESIGN: A recombinant protein enzyme linked immunosorbent assay (ELISA) based on portions of the nucleocapsid protein of group I human coronaviruses was developed and was used to screen serum from 243 children and young adults. RESULTS: For HCoV-229E, the percentages of seropositive individuals were 57.1% for infants < 2 months old; 38.9% for infants 2–3 months old; 4.7% for infants 4–5 months old; 42.9–50.0% for infants 6–12 months old; and 34.8–62.5% for individuals 1–20 years old. For HCoV-NL63, the percentages of seropositive individuals were 45.2% for infants < 2 months old; 11.1% for infants 2–3 months old; 4.7% for infants 4–5 months old; 28.6–40.0% for infants 6–12 months old; and 25.0–70.3% for individuals 1–20 years old. CONCLUSIONS: Infection with these viruses is common in childhood though the prevalence of these viruses may vary from year to year.

negative: COVIEdb: A database for potential immune epitopes of coronaviruses 2019 novel coronavirus (2019-nCoV) has caused large-scale pandemic COVID-19 all over the world. It’s essential to find out which parts of the 2019-nCoV sequence are recognized by human immune system for vaccine development. And for the prevention of the potential outbreak of similar coronaviruses in the future, vaccines against immunogenic epitopes shared by different human coronaviruses are essential. Here we predict all the potential B/T-cell epitopes for SARS-CoV, MERS-CoV, 2019-nCoV and RaTG13-CoV based on the protein sequences. We found YFKYWDQTY in ORF1ab protein, VYDPLQPEL and TVYDPLQPEL in spike (S) protein might be pan-coronavirus targets for vaccine development. All the predicted results are stored in a database COVIEdb (http://biopharm.zju.edu.cn/coviedb/).

negative: Comparison of immunofluorescence with monoclonal antibodies and RT-PCR for the detection of human coronaviruses 229E and OC43 in cell culture Abstract Human coronaviruses, with two known serogroups named 229E and OC43, cause up to one third of common colds and may be associated with serious diseases such as nosocomial respiratory infections, enterocolitis, pericarditis and neurological disorders. Reliable methods of detection in clinical samples are needed for a better understanding of their role in pathology. As a first step in the design of such diagnostic procedures, the sensitivities and specificities of two viral diagnostic assays were compared in an experimental cell culture model: an indirect immuno-fluorescence assay using monoclonal antibodies and reverse transcriptase-polymerase chain reaction amplification of viral RNA from infected cells. Immunofluorescence detected human coronaviruses in cells infected at a MOI as low as 10−2 (log TCID50/ml=4.25 for HCV-229E and 2.0 for HCV-OC43; log PFU/ml=4.83 for HCV-229E and 1.84 for HCV-OC43) versus 10−3 (HCV-OC43) or 10−4 (HCV-229E) for reverse transcriptase-polymerase chain reaction amplification (log TCID50/ml=1.75 for HCV-229E and 1.5 for HCV-OC43; log PFU/ml=2.3 for HCV-229E and 1.34 for HCV-OC43). There were no false positive signals with other human respiratory pathogens: influenza virus, respiratory syncytial virus and adenovirus. Moreover, each assay was coronavirus serogroup-specific. These results demonstrate the potential usefulness of immunofluorescence with monoclonal antibodies and reverse transcriptase-polymerase chain reaction RNA amplification for the rapid detection of human coronaviruses in infected cell cultures. Both methods could be applied to clinical specimens for the diagnosis of human infections.

negative: Evaluation of protection conferred by a vaccination program based on the H120 and CR88 commercial vaccines against a field variant of avian infectious bronchitis virus Abstract Due to serotype variations among different avian infectious bronchitis viruses isolated in Tunisia since 2000, protection of chicks, especially broiler flocks, with Mass H120 vaccine often fails. Therefore, association of CR88 (793B type) with H120 vaccines was used for better response. Challenge experiments were then conducted to evaluate tracheal and renal cross-protection in chickens immunized via nasal and eye drops. Conferred protection was measured by clinical signs and macroscopic lesions observed, based on scores attributed according to their severities. The results showed a low protection conferred by H120 alone, as vaccination did not reduce tracheal and kidney lesions (70% scored as 3) after TN20/00 virus challenge, which also led to 10% mortality. Conversely, the challenge results indicated that the combination of the 2 strains (H120/CR88) allow high protection. Based on the results of the challenge experiments, a vaccination protocol coupling CR88 to H120 was applied for industrial broiler flocks. Clinical observations and serological results confirmed that association of heterologous serotypes (H120 and CR88 vaccines) increased the levels of protection against infectious bronchitis viruses compared with the H120 vaccine given alone.

negative: Evaluation of serological tests for SARS-CoV-2: Implications for serology testing in a low-prevalence setting Background: Robust serological assays are essential for long-term control of the COVID-19 pandemic. Many recently released point-of-care (PoCT) serological assays have been distributed with little pre-market validation. Methods: Performance characteristics for five PoCT lateral flow devices approved for use in Australia were compared to a commercial enzyme immunoassay (ELISA) and a recently described novel surrogate virus neutralisation test (sVNT). Results: Sensitivities for PoCT ranged from 51.8% (95% CI 43.1 to 60.4%) to 67.9% (95% CI 59.4-75.6%), and specificities from 95.6% (95% CI 89.2-98.8%) to 100.0% (95% CI 96.1-100.0%). Overall ELISA sensitivity for either IgA or IgG detection was 67.9% (95% CI 59.4-75.6), increasing to 93.8% (95% CI 85.0-98.3%) for samples >14 days post symptom onset. Overall, sVNT sensitivity was 60.9% (95% CI 53.2-68.4%), rising to 91.2%% (95% CI 81.8-96.7%) for samples collected >14 days post-symptom onset, with a specificity 94.4% (95% CI 89.2-97.5%), Conclusion: Performance characteristics for COVID-19 serological assays were generally lower than those reported by manufacturers. Timing of specimen collection relative to onset of illness or infection is crucial in the reporting of performance characteristics for COVID-19 serological assays. The optimal algorithm for implementing serological testing for COVID-19 remains to be determined, particularly in low-prevalence settings.

negative: Severe Acute Respiratory Syndrome without Respiratory Symptoms or Abnormal Chest Radiograph Findings We report a serologically confirmed case of severe acute respiratory syndrome (SARS) in a 27-year-old health care worker. The patient reported no respiratory complaints, and the findings of serial chest radiographs were normal. This case illustrates the wide spectrum of clinical illness caused by infection with SARS coronavirus.

negative: Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study Summary Background Coronavirus disease 2019 (COVID-19) causes severe community and nosocomial outbreaks. Comprehensive data for serial respiratory viral load and serum antibody responses from patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are not yet available. Nasopharyngeal and throat swabs are usually obtained for serial viral load monitoring of respiratory infections but gathering these specimens can cause discomfort for patients and put health-care workers at risk. We aimed to ascertain the serial respiratory viral load of SARS-CoV-2 in posterior oropharyngeal (deep throat) saliva samples from patients with COVID-19, and serum antibody responses. Methods We did a cohort study at two hospitals in Hong Kong. We included patients with laboratory-confirmed COVID-19. We obtained samples of blood, urine, posterior oropharyngeal saliva, and rectal swabs. Serial viral load was ascertained by reverse transcriptase quantitative PCR (RT-qPCR). Antibody levels against the SARS-CoV-2 internal nucleoprotein (NP) and surface spike protein receptor binding domain (RBD) were measured using EIA. Whole-genome sequencing was done to identify possible mutations arising during infection. Findings Between Jan 22, 2020, and Feb 12, 2020, 30 patients were screened for inclusion, of whom 23 were included (median age 62 years [range 37–75]). The median viral load in posterior oropharyngeal saliva or other respiratory specimens at presentation was 5·2 log10 copies per mL (IQR 4·1–7·0). Salivary viral load was highest during the first week after symptom onset and subsequently declined with time (slope −0·15, 95% CI −0·19 to −0·11; R 2=0·71). In one patient, viral RNA was detected 25 days after symptom onset. Older age was correlated with higher viral load (Spearman's ρ=0·48, 95% CI 0·074–0·75; p=0·020). For 16 patients with serum samples available 14 days or longer after symptom onset, rates of seropositivity were 94% for anti-NP IgG (n=15), 88% for anti-NP IgM (n=14), 100% for anti-RBD IgG (n=16), and 94% for anti-RBD IgM (n=15). Anti-SARS-CoV-2-NP or anti-SARS-CoV-2-RBD IgG levels correlated with virus neutralisation titre (R 2>0·9). No genome mutations were detected on serial samples. Interpretation Posterior oropharyngeal saliva samples are a non-invasive specimen more acceptable to patients and health-care workers. Unlike severe acute respiratory syndrome, patients with COVID-19 had the highest viral load near presentation, which could account for the fast-spreading nature of this epidemic. This finding emphasises the importance of stringent infection control and early use of potent antiviral agents, alone or in combination, for high-risk individuals. Serological assay can complement RT-qPCR for diagnosis. Funding Richard and Carol Yu, May Tam Mak Mei Yin, The Shaw Foundation Hong Kong, Michael Tong, Marina Lee, Government Consultancy Service, and Sanming Project of Medicine.

negative: Respiratory Viruses Abstract This article is an overview of the most clinically important respiratory viruses including the recently emerged highly pathogenic coronaviruses and other viruses that are transmitted via the respiratory tract. In this article, we highlight a description of the agent, its life cycle, epidemiology, pathogenesis, clinical features, diagnosis and management of the infection. The viruses in this article are respiratory syncytial virus, parainfluenza virus, human metapneumovirus, rhinovirus, seasonal and emerging coronaviruses, adenovirus, bocavirus and other viruses associated with the respiratory tract for their life cycle.

negative: Strategies for mapping and imitating viral B-cell epitopes Abstract Identification of viral B-cell epitopes is of importance in the selection of peptides for inclusion into subunit vaccines, the development of virus-specific serological tests and understanding the interaction of antibodies with viruses at a molecular level. B-cell epitopes can often be determined unequivocally by X-ray analyses of antibody-antigen complexes. This technique is, however, time-consuming and alternative strategies have now been developed for identifying epitopes. This article provides an overview of approaches which are currently available for mapping and imitating B-cell epitopes.

negative: Porcine deltacoronavirus: Overview of infection dynamics, diagnostic methods, prevalence and genetic evolution Abstract Porcine deltacoronavirus (PDCoV) was first reported in Hong Kong, China in 2012 and reported in United States swine in February 2014. PDCoV has subsequently been detected in South Korea, mainland China, and Thailand. PDCoV has been experimentally confirmed to cause diarrhea in inoculated pigs and need to be differentially diagnosed from porcine epidemic diarrhea virus and transmissible gastroenteritis virus in the field. Rapid diagnosis is critical for the implementation of efficient control strategies against PDCoV. Developing high-quality diagnostic methods and understanding PDCoV infection dynamics to collect appropriate specimens at the appropriate time window are important to obtain reliable diagnostic results. Among the virological methods, PDCoV-specific RT-PCR remains the method of choice for the detection of PDCoV; immunohistochemistry combined with hematoxylin and eosin staining has also been commonly used to examine histopathological lesions caused by PDCoV. Serological assays can provide information about previous exposure to PDCoV and also determine antibody responses to infection or vaccination. Prevalence of PDCoV is lower compared to that of PEDV. However, among PDCoV-positive samples, co-infection with other enteric pathogen e.g. PEDV is common. It is also important to understand molecular epidemiology of PDCoV and genetic relationships of global PDCoVs. This review discusses PDCoV infection dynamics and appropriate sample collection for diagnostic testing, the commonly used virological and serological methods for PDCoV diagnosis, prevalence and genetic evolution of PDCoVs.

negative: Prevalence of feline coronavirus antibodies in cats in Bursa province, Turkey, by an enzyme-linked immunosorbent assay Feline sera from Bursa province (Turkey) were assayed for coronavirus antibody using an enzyme-linked immunosorbent assay (ELISA). The study was performed on 100 sera collected from cats belonging to catteries or community shelters and to households. The serum samples were initially tested with the virus neutralisation (VN) test and the results were then compared with the ELISA. The VN yielded 79 negative and 21 positive sera but the ELISA confirmed only 74 as negative. The ELISA-negative sera were also found to be free of feline coronoviruses-specific antibodies by Western blotting. Using the VN as the gold standard test, ELISA had a sensitivity of 100% and a specificity of 93.6%, with an overall agreement of 95%. The Kappa (κ) test indicated high association between the two tests (κ =0.86, 95% confidence interval (CI) 0.743–0.980). The positive predictive value (PPV) was 0.8, and the negative predictive value (NPV) was 0.93. The prevalence of FCoV II antibodies in the sampled population based on the gold standard was 62% (95% CI 0.44–0.77) among multi-cat environments, and 4% (95% CI 0.01–0.11) among single cat households.

negative: Geographical tracking and mapping of coronavirus disease COVID-19/severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic and associated events around the world: how 21st century GIS technologies are supporting the global fight against outbreaks and epidemics In December 2019, a new virus (initially called ‘Novel Coronavirus 2019-nCoV’ and later renamed to SARS-CoV-2) causing severe acute respiratory syndrome (coronavirus disease COVID-19) emerged in Wuhan, Hubei Province, China, and rapidly spread to other parts of China and other countries around the world, despite China’s massive efforts to contain the disease within Hubei. As with the original SARS-CoV epidemic of 2002/2003 and with seasonal influenza, geographic information systems and methods, including, among other application possibilities, online real-or near-real-time mapping of disease cases and of social media reactions to disease spread, predictive risk mapping using population travel data, and tracing and mapping super-spreader trajectories and contacts across space and time, are proving indispensable for timely and effective epidemic monitoring and response. This paper offers pointers to, and describes, a range of practical online/mobile GIS and mapping dashboards and applications for tracking the 2019/2020 coronavirus epidemic and associated events as they unfold around the world. Some of these dashboards and applications are receiving data updates in near-real-time (at the time of writing), and one of them is meant for individual users (in China) to check if the app user has had any close contact with a person confirmed or suspected to have been infected with SARS-CoV-2 in the recent past. We also discuss additional ways GIS can support the fight against infectious disease outbreaks and epidemics.

negative: COVID-19: A promising cure for the global panic Abstract The novel Coronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2, which is the causative agent of a potentially fatal disease that is of great global public health concern. The outbreak of COVID-19 is wreaking havoc worldwide due to inadequate risk assessment regarding the urgency of the situation. The COVID-19 pandemic has entered a dangerous new phase. When compared with SARS and MERS, COVID-19 has spread more rapidly, due to increased globalization and adaptation of the virus in every environment. Slowing the spread of the COVID-19 cases will significantly reduce the strain on the healthcare system of the country by limiting the number of people who are severely sick by COVID-19 and need hospital care. Hence, the recent outburst of COVID-19 highlights an urgent need for therapeutics targeting SARS-CoV-2. Here, we have discussed the structure of virus; varying symptoms among COVID-19, SARS, MERS and common flu; the probable mechanism behind the infection and its immune response. Further, the current treatment options, drugs available, ongoing trials and recent diagnostics for COVID-19 have been discussed. We suggest traditional Indian medicinal plants as possible novel therapeutic approaches, exclusively targeting SARS-CoV-2 and its pathways.

negative: The effect of uncontrolled travelers and social distancing on the spread of novel coronavirus disease (COVID-19) in Colombia

negative: The Early Warning and Response System for communicable diseases in the EU: an overview from 1999 to 2005. Under Decision 2119/98/EC of the European Parliament and of the Council, a network for epidemiological surveillance and control of communicable diseases in the Community was set up in 1998. One pillar of Decision 2119/98/EC is the early warning and response system (EWRS). The main objective of the network is to establish permanent communication between European Union (EU) Member States' public health authorities, which are responsible for determining the measures required to control communicable disease-related events. Since 1998, a web based informatics tool has been developed in order to allow information to be shared between the relevant public health authorities. Between 1998 and December 2005, a total of 583 messages were circulated through the EWRS, notifying 396 events. The information shared through the system helped to coordinate public health measures in the EU. However, only few events prompted specific measures at Community level and most of them were controlled with public health measures applied at national level. Major events (such as the Severe Acute Respiratory Syndrome) and the results of simulation exercises prompted the Commission to upgrade the informatics system on the basis of user needs. Since 1 May 2004 the 10 newest Member States have provided information under the current legislation and since April 2005 the European Centre for Disease Prevention and Control (ECDC) is part of the system. Future developments will include a link between the existing EWRS and the communication platform currently developed by the ECDC.

negative: Chapter 8 The Middle East Respiratory Syndrome Coronavirus: An Emerging Virus of Global Threat Abstract Middle East respiratory syndrome (MERS) is a viral respiratory illness caused by a coronavirus (CoV), first identified in Saudi Arabia in 2012. Since then, almost 2000 cases have been reported from 27 countries, with Saudi Arabia being the epicenter. This newly emerging virus is highly pathogenic and has a case mortality rate of 35%. It is similar to the CoV causing severe acute respiratory syndrome CoV (SARS-CoV) in that both belong to the genus beta CoVs that are of zoonotic origin and cause lower respiratory infection. The natural reservoir for MERS-CoV remains unknown. Serological studies indicate that most dromedary camels in the Middle East have been infected with this virus, and they maybe the potential intermediate host. However, the mode of transmission from camels to humans is poorly understood. The majority of confirmed human cases have resulted from human-to-human transmission, most probably via respiratory route. Patients most at risk of developing severe MERS-CoV infection appear to be those with underlying conditions such as diabetes, hypertension, obesity, cardiac diseases, chronic respiratory diseases, and cancer. Unlike SARS-CoV, MERS-CoV is considered an ongoing public health problem, particularly for the Middle East region. In this chapter, we outline the prevailing information regarding the emergence and epidemiology of this virus, its mode of transmission and pathogenicity, its clinical features, and the potential strategies for prevention.

negative: Epidemiology of seasonal coronaviruses: Establishing the context for COVID-19 emergence Public health preparedness for coronavirus disease 2019 (COVID-19) is challenging in the absence of setting-specific epidemiological data. Here we describe the epidemiology of seasonal human coronaviruses (sCoVs) and other cocirculating viruses in the West of Scotland, UK. We analyzed routine diagnostic data for >70,000 episodes of respiratory illness tested molecularly for multiple respiratory viruses between 2005 and 2017. Statistical associations with patient age and sex differed between CoV-229E, CoV-OC43 and CoV-NL63. Furthermore, the timing and magnitude of sCoV outbreaks did not occur concurrently and coinfections were not reported. With respect to other cocirculating respiratory viruses, we found evidence of positive, rather than negative, interactions with sCoVs. These findings highlight the importance of considering cocirculating viruses in the differential diagnosis of COVID-19. Further work is needed to establish the occurrence/degree of cross-protective immunity conferred across sCoVs and with COVID-19, as well as the role of viral coinfection in COVID-19 disease severity.

negative: A phase trial of the oral Lactobacillus casei vaccine polarizes Th2 cell immunity against transmissible gastroenteritis coronavirus infection Transmissible gastroenteritis coronavirus (TGEV) is a member of the genus Coronavirus, family Coronaviridae, order Nidovirales. TGEV is an enteropathogenic coronavirus that causes highly fatal acute diarrhoea in newborn pigs. An oral Lactobacillus casei (L. casei) vaccine against anti-transmissible gastroenteritis virus developed in our laboratory was used to study mucosal immune responses. In this L. casei vaccine, repetitive peptides expressed by L. casei (specifically the MDP and tuftsin fusion protein (MT)) were repeated 20 times and the D antigenic site of the TGEV spike (S) protein was repeated 6 times. Immunization with recombinant Lactobacillus is crucial for investigations of the effect of immunization, such as the first immunization time and dose. The first immunization is more important than the last immunization in the series. The recombinant Lactobacillus elicited specific systemic and mucosal immune responses. Recombinant L. casei had a strong potentiating effect on the cellular immunity induced by the oral L. casei vaccine. However, during TGEV infection, the systemic and local immune responses switched from Th1 to Th2-based immune responses. The systemic humoral immune response was stronger than the cellular immune response after TGEV infection. We found that the recombinant Lactobacillus stimulated IL-17 expression in both the systemic and mucosal immune responses against TGEV infection. Furthermore, the Lactobacillus vaccine stimulated an anti-TGEV infection Th17 pathway. The histopathological examination showed tremendous potential for recombinant Lactobacillus to enable rapid and effective treatment for TGEV with an intestinal tropism in piglets. The TGEV immune protection was primarily dependent on mucosal immunity.

negative: Currently used nucleic acid amplification tests for the detection of viruses and atypicals in acute respiratory infections Abstract For the detection of respiratory viruses conventional culture techniques are still considered as the gold standard. However, results are mostly available too late to have an impact on patient management. The latest developments include appropriate DNA- and RNA-based amplification techniques (both NASBA and PCR) for the detection of an extended number of agents responsible for LRTI. Real time amplification, the latest technical progress, produces, within a considerable shorter time, results with a lower risk of false positives. As results can be obtained within the same day, patient management with appropriate therapy or reduction of unnecessary antibiotic therapy in LRTI will be possible. A number of technical aspects of these amplification assays, and their advantages are discussed. The availability and use of these new diagnostic tools in virology has contributed to a better understanding of the role of respiratory viruses in LRTI. The increasing importance of the viral agents, Mycoplasma pneumoniae and Chlamydophila pneumoniae in ARI is illustrated. A great proportion of ARI are caused by viruses, but their relative importance depends on the spectrum of agents covered by the diagnostic techniques and on the populations studied, the geographical location and the season. The discovery of new viruses is ongoing; examples are the hMPV and the increasing number of coronaviruses. Indications for the use of these rapid techniques in different clinical situations are discussed. Depending on the possibilities, the laboratory could optimize its diagnostic strategy by applying a combination of immunofluorescence for the detection of RSV an IFL, and a combination of real-time amplification tests for other respiratory viruses and the atypical agents. When implementing a strategy, a compromise between sensitivity, clinical utility, turn around time and cost will have to be found.

negative: Laboratory Test for Diagnosis of Parasitic Diseases Parasitic diseases generally develop chronically, and most patients experience non-specific symptoms and show unobvious physical signs. Except medical history and physical examination, the diagnosis is mainly based on the laboratory tests. The commonly applied laboratory tests for the diagnosis of parasitic diseases include etiological examination, immunological assay and molecular biological examination.

negative: Chapter 8.1 Immunoassay Applications in Veterinary Diagnostics This chapter explains the technology and chemistry behind veterinary immunoassays. There is extensive coverage of infectious disease diagnosis and assessment of immune status using immunoassays for feline, canine, porcine, equine, bovine and avian applications, including the assay technology commonly used. There is also a section on the assessment of the reproductive or metabolic status of cats and dogs.

negative: Current status of treatment for 2019 novel coronavirus pneumonia/ 中华微生物学和免疫学杂志 2019 novel coronavirus (2019-nCoV) is a new member of coronavirus family that can cause serious respiratory diseases after the emergence of severe acute respiratory syndrome-coronavirus (SARS-CoV) and middle east respiratory syndrome-coronavirus (MERS-CoV). At present, there is no specific antiviral drug targeting 2019-nCoV. In facing of the increasingly serious epidemic of 2019 novel coronavirus pneumonia and the urgent needs in drug treatment strategies, this paper reviewed the current research situation and progress in antiviral treatment for the newly identified disease.

negative: Evaluation of serological cross-reactivity and cross-neutralization between the United States porcine epidemic diarrhea virus prototype and S-INDEL-variant strains BACKGROUND: At least two genetically different porcine epidemic diarrhea virus (PEDV) strains have been identified in the United States (U.S. PEDV prototype and S-INDEL-variant strains). The current serological assays offered at veterinary diagnostic laboratories for detection of PEDV-specific antibody are based on the U.S. PEDV prototype strain. The objectives of this study were: 1) isolate the U.S. PEDV S-INDEL-variant strain in cell culture; 2) generate antisera against the U.S. PEDV prototype and S-INDEL-variant strains by experimentally infecting weaned pigs; 3) determine if the various PEDV serological assays could detect antibodies against the U.S. PEDV S-INDEL-variant strain and vice versa. RESULTS: A U.S. PEDV S-INDEL-variant strain was isolated in cell culture in this study. Three groups of PEDV-negative, 3-week-old pigs (five pigs per group) were inoculated orally with a U.S. PEDV prototype isolate (previously isolated in our lab), an S-INDEL-variant isolate or virus-negative culture medium. Serum samples collected at 0, 7, 14, 21 and 28 days post inoculation were evaluated by the following PEDV serological assays: 1) indirect fluorescent antibody (IFA) assays using the prototype and S-INDEL-variant strains as indicator viruses; 2) virus neutralization (VN) tests against the prototype and S-INDEL-variant viruses; 3) PEDV prototype strain whole virus based ELISA; 4) PEDV prototype strain S1-based ELISA; and 5) PEDV S-INDEL-variant strain S1-based ELISA. The positive antisera against the prototype strain reacted to and neutralized both prototype and S-INDEL-variant viruses, and the positive antisera against the S-INDEL-variant strain also reacted to and neutralized both prototype and S-INDEL-variant viruses, as examined by IFA antibody assays and VN tests. Antibodies against the two PEDV strains could be detected by all three ELISAs although detection rates varied to some degree. CONCLUSIONS: These data indicate that the antibodies against U.S. PEDV prototype and S-INDEL-variant strains cross-reacted and cross-neutralized both strains in vitro. The current serological assays based on U.S. PEDV prototype strain can detect antibodies against both U.S. PEDV strains.

negative: Ultra-sensitive nanozyme-based chemiluminescence paper test for rapid diagnosis of SARS-CoV-2 infection The recently emerged coronavirus disease COVID-19 has now evolved into a global pandemic. Early detection is crucial for its effective control. Nucleic acid testing for viral pathogen and serological testing for host antibodies are playing important roles in current COVID-19 diagnosis. However, while nucleic acid testing is complicated, facility-restricted and time-consuming, antibody testing may result in high rates of false-negative diagnoses, especially during the early stages of viral infection. Thus, a more rapid and reliable test for both early COVID-19 diagnosis and whole-population screening is urgently needed. Here, we developed a novel nanozyme-based chemiluminescence paper assay for rapid and high-sensitive testing of SARS-CoV-2 spike antigen. Our paper test uses a newly established peroxidase-mimic Co-Fe@hemin nanozyme instead of natural HRP that catalytically amplifies the chemiluminescent signal, allowing for target concentrations to be as low as 0.1 ng/ml. Furthermore, our nanozyme-based chemiluminescence test exhibits a linear range that is 32-fold wider compared to ELISA tests. Importantly, testing is completed in less than 16 min, compared to 1-2 h required for ELISA or nucleic acid tests. Critically, signal detection is feasible using a smartphone camera. Ingredients for our test are simple and readily available, rendering overall cost considerably lower than those used in current diagnoses. In conclusion, our novel test provides a high-sensitive, point-of-care testing (POCT) approach for SARS-CoV-2 antigen detection, which should greatly increase current early screening capacities for suspected infections, and considerably lower demand for national healthcare resources.

negative: Diagnostic Virology Diagnostic virology services are increasingly available and pertinent as the number of useful antiviral agents grows. In this article, current methods of diagnosis are reviewed with special emphasis on rapid procedures. Guidelines for interpretation of cultures and other tests are provided

negative: Abstract Presentations from the AABB Annual Meeting San Diego, CA ctober 7‐10, 2017

negative: The Clinician and the Microbiology Laboratory

negative: Antigenic Relationship between Human Coronavirus Strain DC 43 and Hemagglutinating Encephalomyelitis Virus Strain 67N of Swine: Antibody Responses in Human and Animal Sera Hemagglutinating encephalomyelitis virus of swine (HEV) was adapted to growth in suckling mouse brain. Electron micrographs of HEV-infected suckling mouse brain, prepared by negative staining and thin-section techniques, exhibited typical morphological characteristics shared with other members of the Coronaviridae. The adaptation of HEV to suckling mouse brain facilitated serologic testing by the use of common host reagents and compatible animal systems. With hemagglutination inhibition, complement-fixation, and neutralization tests, an antigenic relationship was demonstrated between human coronavirus OC 43 and HEV in specific immune and hyperimmune animal sera. Children and adults with seroconversion to OC 43 antigen had diagnostic rises in titer of antibody to HEV antigens. Individuals with seroconversion to human coronaviruses 229E and B814 demonstrated antibody to HEV but not diagnostic rises in titer. Swine with titers of antibody to HEV had lower or no detectable titers of antibody to coronavirus OC 43. Although the prevalence and geometric mean titer of antibody to DC 43 were higher than the titer of antibody to HEV in every group of normal humans tested, significant differences in antibody response to coronavirus DC 43 and HEV were seen between populations that did or did not have possible contact with swine. The evidence suggested that antibody to HEV in humans probably represented a heterologous response to infection with coronavirus DC 43. However, a heterotypic response to unknown or uncharacterized strains of coronavirus cannot be excluded.

negative: Chikungunya virus: an update on antiviral development and challenges Chikungunya virus (CHIKV) has re-emerged as a significant public health threat since the 2005 chikungunya fever epidemic in La Réunion. Driven by the medical importance of this virus, as well as the lack of approved antivirals, research into the field of CHIKV antivirals has recently intensified. Potential therapeutics that have been reported to show anti-CHIKV activity in vitro range from known broad-spectrum antivirals like chloroquine to novel strategies involving RNA silencing technology. Although most of the earlier efforts focused on compounds that target host components, some recent studies have reported viral targets such as nonstructural proteins. This article examines the reported in vitro and in vivo efficacies, as well as the therapeutic potential of these antiviral compounds.

negative: Forecasting incidence of hemorrhagic fever with renal syndrome in China using ARIMA model BACKGROUND: China is a country that is most seriously affected by hemorrhagic fever with renal syndrome (HFRS) with 90% of HFRS cases reported globally. At present, HFRS is getting worse with increasing cases and natural foci in China. Therefore, there is an urgent need for monitoring and predicting HFRS incidence to make the control of HFRS more effective. In this study, we applied a stochastic autoregressive integrated moving average (ARIMA) model with the objective of monitoring and short-term forecasting HFRS incidence in China. METHODS: Chinese HFRS data from 1975 to 2008 were used to fit ARIMA model. Akaike Information Criterion (AIC) and Ljung-Box test were used to evaluate the constructed models. Subsequently, the fitted ARIMA model was applied to obtain the fitted HFRS incidence from 1978 to 2008 and contrast with corresponding observed values. To assess the validity of the proposed model, the mean absolute percentage error (MAPE) between the observed and fitted HFRS incidence (1978-2008) was calculated. Finally, the fitted ARIMA model was used to forecast the incidence of HFRS of the years 2009 to 2011. All analyses were performed using SAS9.1 with a significant level of p < 0.05. RESULTS: The goodness-of-fit test of the optimum ARIMA (0,3,1) model showed non-significant autocorrelations in the residuals of the model (Ljung-Box Q statistic = 5.95,P = 0.3113). The fitted values made by ARIMA (0,3,1) model for years 1978-2008 closely followed the observed values for the same years, with a mean absolute percentage error (MAPE) of 12.20%. The forecast values from 2009 to 2011 were 0.69, 0.86, and 1.21per 100,000 population, respectively. CONCLUSION: ARIMA models applied to historical HFRS incidence data are an important tool for HFRS surveillance in China. This study shows that accurate forecasting of the HFRS incidence is possible using an ARIMA model. If predicted values from this study are accurate, China can expect a rise in HFRS incidence.

negative: Coalition: Advocacy for prospective clinical trials to test the post-exposure potential of hydroxychloroquine against COVID-19 Abstract Our coalition of public health experts, doctors, and scientists worldwide want to draw attention to the need for high-quality evaluation protocols of the potential beneficial effect of hydroxychloroquine (HCQ) as a post-exposure drug for exposed people, meaning people with close contact with positive tested patients, including home and medical caregivers. We have reviewed the mechanisms of antiviral effect of HCQ, the risk-benefit ratio taking into consideration the PK/PD of HCQ and the thresholds of efficacy. We have studied its use as an antimalarial, an antiviral, and an immunomodulating drug and concluded that the use of HCQ at does matching that of the standard treatment of Systemic Lupus erythematous, which has proven safety and efficacy in terms of HCQ blood and tissue concentration adapted to bodyweight (2,3), at 6 mg/kg/day 1 (loading dose) followed by 5 mg/kg/day, with a maximum limit of 600 mg/day in all cases should swiftly be clinically evaluated as a post-exposure drug for exposed people.

negative: MERS coronavirus outbreak: Implications for emerging viral infections Abstract In September 2012, a novel coronavirus was isolated from a patient who died in Saudi Arabia after presenting with acute respiratory distress and acute kidney injury. Analysis revealed the disease to be due to a novel virus which was named Middle East Respiratory Coronavirus (MERS-CoV). There have been several MERS-CoV hospital outbreaks in KSA, continuing to the present day, and the disease has a mortality rate in excess of 35%. Since 2012, the World Health Organization has been informed of 2220 laboratory-confirmed cases resulting in at least 790 deaths. Cases have since arisen in 27 countries, including an outbreak in the Republic of Korea in 2015 in which 36 people died, but more than 80% of cases have occurred in Saudi Arabia.. Human-to-human transmission of MERS-CoV, particularly in healthcare settings, initially caused a ‘media panic’, however human-to-human transmission appears to require close contact and thus far the virus has not achieved epidemic potential. Zoonotic transmission is of significant importance and evidence is growing implicating the dromedary camel as the major animal host in spread of disease to humans. MERS-CoV is now included on the WHO list of priority blueprint diseases for which there which is an urgent need for accelerated research and development as they have the potential to cause a public health emergency while there is an absence of efficacious drugs and/or vaccines. In this review we highlight epidemiological, clinical, and infection control aspects of MERS-CoV as informed by the Saudi experience. Attention is given to recommended treatments and progress towards vaccine development.

negative: COVID-19: a meta-analysis of diagnostic test accuracy of commercial assays registered in Brazil Abstract The accuracy of commercially available tests for COVID-19 in Brazil remains unclear. We aimed to perform a meta-analysis to describe the accuracy of available tests to detect COVID-19 in Brazil. We searched at the Brazilian Health Regulatory Agency (ANVISA) online platform to describe the pooled sensitivity (Se), specificity (Sp), diagnostic odds ratio (DOR) and summary receiver operating characteristic curves (SROC) for detection of IgM/IgG antibodies and for tests using naso/oropharyngeal swabs in the random-effects models. We identified 16 tests registered, mostly rapid-tests. Pooled diagnostic accuracy measures [95%CI] were: (i) for IgM antibodies Se=82% [76-87]; Sp=97% [96-98]; DOR=168 [92-305] and SROC=0.98 [0.96-0.99]; (ii) for IgG antibodies Se=97% [90-99]; Sp=98% [97-99]; DOR=1994 [385-10334] and SROC=0.99 [0.98-1.00]; and (iii) for detection of SARS-CoV-2 by antigen or molecular assays in naso/oropharyngeal swabs Se=97% [85-99]; Sp=99% [77-100]; DOR=2649 [30-233056] and SROC=0.99 [0.98-1.00]. These tests can be helpful for emergency testing during the COVID-19 pandemic in Brazil. However, it is important to highlight the high rate of false negative results from tests which detect SARS-CoV-2 IgM antibodies in the initial course of the disease and the scarce evidence-based validation results published in Brazil. Future studies addressing the diagnostic performance of tests for COVID-19 in the Brazilian population are urgently needed.

negative: Development of a Whole-Virus ELISA for Serological Evaluation of Domestic Livestock as Possible Hosts of Human Coronavirus NL63 Known human coronaviruses are believed to have originated in animals and made use of intermediate hosts for transmission to humans. The intermediate hosts of most of the human coronaviruses are known, but not for HCoV-NL63. This study aims to assess the possible role of some major domestic livestock species as intermediate hosts of HCoV-NL63. We developed a testing algorithm for high throughput screening of livestock sera with ELISA and confirmation with recombinant immunofluorescence assay testing for antibodies against HCoV-NL63 in livestock. Optimization of the ELISA showed a capability of the assay to significantly distinguish HCoV-NL63 from HCoV-229E (U = 27.50, p < 0.001) and HCoV-OC43 (U = 55.50, p < 0.001) in coronavirus-characterized sera. Evaluation of the assay with collected human samples showed no significant difference in mean optical density values of immunofluorescence-classified HCoV-NL63-positive and HCoV-NL63-negative samples (F (1, 215) = 0.437, p = 0.509). All the top 5% (n = 8) most reactive human samples tested by ELISA were HCoV-NL63 positive by immunofluorescence testing. In comparison, only a proportion (84%, n = 42) of the top 25% were positive by immunofluorescence testing, indicating an increased probability of the highly ELISA reactive samples testing positive by the immunofluorescence assay. None of the top 5% most ELISA reactive livestock samples were positive for HCoV-NL63-related viruses by immunofluorescence confirmation. Ghanaian domestic livestock are not likely intermediate hosts of HCoV-NL63-related coronaviruses.

negative: A serologic survey of Oklahoma cats for antibodies to feline immunodeficiency virus, coronavirus, and Toxoplasma gondii and for antigen to feline leukemia virus. A serologic survey was done on 618 cat sera submitted to the Oklahoma Animal Disease Diagnostic Laboratory between July 1, 1987 and June 30, 1988. The samples were collected from clinically normal and sick cats. The sera were tested for the presence of antibodies to feline immunodeficiency virus by a commercial immunoassay, to a coronavirus by an indirect fluorescent antibody test, and to Toxoplasma gondii by a commercial latex agglutination test and for the presence of feline leukemia virus antigen with one of 3 different commercial assay kits. Ten percent of the sera had antibodies to feline immunodeficiency virus, 35% had antibodies to a coronavirus, and 22% had antibodies to Toxoplasma gondii. Feline leukemia virus antigen was detected in 15% of the sera. Thirty-two percent of the sera had evidence of exposure to 2 or more of the agents.

negative: Genetic, Transcriptome, Proteomic, and Epidemiological Evidence for Blood-Brain Barrier Disruption and Polymicrobial Brain Invasion as Determinant Factors in Alzheimer’s Disease Diverse pathogens are detected in Alzheimer’s disease (AD) brains. A bioinformatics survey showed that AD genome-wide association study (GWAS) genes (localized in bone marrow, immune locations and microglia) relate to multiple host/pathogen interactomes (Candida albicans, Cryptococcus neoformans, Bornavirus, Borrelia burgdorferri, cytomegalovirus, Ebola virus, HSV-1, HERV-W, HIV-1, Epstein-Barr, hepatitis C, influenza, Chlamydia pneumoniae, Porphyrymonas gingivalis, Helicobacter pylori, Toxoplasma gondii, Trypanosoma cruzi). These interactomes also relate to the AD hippocampal transcriptome and to plaque or tangle proteins. Upregulated AD hippocampal genes match those upregulated by multiple bacteria, viruses, fungi, or protozoa in immunocompetent cells. AD genes are enriched in GWAS datasets reflecting pathogen diversity, suggesting selection for pathogen resistance, as supported by the old age of AD patients, implying resistance to earlier infections. APOE4 is concentrated in regions of high parasitic burden and protects against childhood tropical infections and hepatitis C. Immune/inflammatory gain of function applies to APOE4, CR1, and TREM2 variants. AD genes are also expressed in the blood-brain barrier (BBB), which is disrupted by AD risk factors (age, alcohol, aluminum, concussion, cerebral hypoperfusion, diabetes, homocysteine, hypercholesterolemia, hypertension, obesity, pesticides, pollution, physical inactivity, sleep disruption, smoking) and by pathogens, directly or via olfactory routes to basal-forebrain BBB control centers. The BBB benefits from statins, NSAIDs, estrogen, melatonin, memantine, and the Mediterranean diet. Polymicrobial involvement is supported by upregulation of bacterial, viral, and fungal sensors/defenders in the AD brain, blood, or cerebrospinal fluid. AD serum amyloid-β autoantibodies may attenuate its antimicrobial effects favoring microbial survival and cerebral invasion leading to activation of neurodestructive immune/inflammatory processes, which may also be augmented by age-related immunosenescence. AD may thus respond to antibiotic, antifungal, or antiviral therapy.

negative: Corona Epidemic in Indian context: Predictive Mathematical Modelling The novel Coronavirus pathogen Covid-19 is a cause of concern across the world as the human-to-human infection caused by it is spreading at a fast pace. The virus that first manifested in Wuhan, China has travelled across continents. The increase in number of deaths in Italy, Iran, USA, and other countries has alarmed both the developed and developing countries. Scientists are working hard to develop a vaccine against the virus, but until now no breakthrough has been achieved. India, the second most populated country in the world, is working hard in all dimensions to stop the spread of community infection. Health care facilities are being updated; medical and paramedical staffs are getting trained, and many agencies are raising awareness on the issues related to this virus and its transmission. The administration is leaving no stone unturned to prepare the country to mitigate the adverse effects. However, as the number of infected patients, and those getting cured is changing differently in different states everyday it is difficult to predict the spread of the virus and its fate in Indian context. Different states have adopted measures to stop the community spread. Considering the vast size of the country, the population size and other socio-economic conditions of the states, a single uniform policy may not work to contain the disease. In this paper, we discuss a predictive mathematical model that can give us some idea of the fate of the virus, an indicative data and future projections to understand the further course this pandemic can take. The data can be used by the health care agencies, the Government Organizations and the Planning Commission to make suitable arrangements to fight the pandemic. Though the model is preliminary, it can be used at regional level to manage the health care system in the present scenario. The recommendations can be made, and advisories prepared based on the predictive results that can be implemented at regional levels.

negative: SEROEPIDEMIOLOGIC SURVEY OF CORONAVIRUS (STRAIN OC 43) RELATED INFECTIONS IN A CHILDREN'S POPULATION Kaye, H. S. (CDC, Atlanta, Ga. 30333), H. B. Marsh and W. R. Dowdle. Sero-epidemiologic survey of coronavirus (strain OC 43) related infections in a children's population. Amer J Epid 94: 43–49, 1971.—Acute and convalescent serum pairs and control sera collected from subjects living in a children's home over a 7-year period (1960–1967) were examined by hemagglutination-inhibition (HI) test with coronavirus strain OC 43. Ninety-three serologic conversions were observed; 44 were associated with reported illnesses and 49 with no reported illnesses. In three distinct outbreaks during the winter and spring quarter of 1960–1961, 1964–1965, and 1966–1967, 67 conversions occurred. Seroconversions to strain OC 43 were associated with as much as 19% of the respiratory diseases in a single season. Over the 7-year period coronavirus strain OC 43 accounted for 3% of the total 1328 respiratory illnesses. Evidence of preexisting antibody was apparent in one-third of the children showing seroconversions. The HI test was more sensitive for serodiagnosis than the complement-fixaticn test. The major presenting complaints of the children with respiratory disease associated with coronavirus strain OC 43 were sore throat, cough and coryza; the predominating symptoms were pharyngitis, coryza, fever and cervical adenitis.

negative: A Single Polar Residue and Distinct Membrane Topologies Impact the Function of the Infectious Bronchitis Coronavirus E Protein The coronavirus E protein is a small membrane protein with a single predicted hydrophobic domain (HD), and has a poorly defined role in infection. The E protein is thought to promote virion assembly, which occurs in the Golgi region of infected cells. It has also been implicated in the release of infectious particles after budding. The E protein has ion channel activity in vitro, although a role for channel activity in infection has not been established. Furthermore, the membrane topology of the E protein is of considerable debate, and the protein may adopt more than one topology during infection. We previously showed that the HD of the infectious bronchitis virus (IBV) E protein is required for the efficient release of infectious virus, an activity that correlated with disruption of the secretory pathway. Here we report that a single residue within the hydrophobic domain, Thr16, is required for secretory pathway disruption. Substitutions of other residues for Thr16 were not tolerated. Mutations of Thr16 did not impact virus assembly as judged by virus-like particle production, suggesting that alteration of secretory pathway and assembly are independent activities. We also examined how the membrane topology of IBV E affected its function by generating mutant versions that adopted either a transmembrane or membrane hairpin topology. We found that a transmembrane topology was required for disrupting the secretory pathway, but was less efficient for virus-like particle production. The hairpin version of E was unable to disrupt the secretory pathway or produce particles. The findings reported here identify properties of the E protein that are important for its function, and provide insight into how the E protein may perform multiple roles during infection.

negative: Coronavirus infections of man associated with diseases other than the common cold About 14,000 paired sera, from patients with various types of acute infectious diseases with suspected viral origin, were screened by complement fixation against a wide set of viral antigens, including coronavirus OC43. A significant change in OC43 antibodies was recorded in 33 cases and a constant high titre, defined as a titre occurring in the respective age group in less than 1 % of all sera examined, was found in 45 cases. On the basis of careful retrospective analysis of hospital case records it was concluded that in 28 cases with an increase of OC43 antibody litres, and in two with titre decrease, a disease could be associated with an acute coronavirus infection. In 16 cases the disease was dominated by respiratory symptoms. Eight of these patients, four children and four adults, had pneumonia. Three of the eight pneumonia patients had, however, another concomitant infection, too. Four patients had neurological symptoms, one had severe perimyocarditis, and in five cases fever was the only symptom recorded. Among the patients with a statistically significant high titre of OC43 antibodies, there were 14 cases where a suggestive association with a disease could be envisaged on the basis of hospital records. Five of these patients had pneumonia. These results suggest that human coronaviruses, so far considered only as one group of causative agents of the common cold, may also be associated with other and more severe diseases in all age groups.

negative: COVID-19 experience: first Italian survey on healthcare staff members from a Mother-Child Research hospital using combined molecular and rapid immunoassays test The fast spread of the novel coronavirus (SARS-CoV-2) has become a global threat hitting the worldwide fragile health care system. In Italy, there is a continued COVID-19 growth of cases and deaths that requires control measures for the correct management of the epidemiological emergency. To contribute to increasing the overall knowledge of COVID-19, systematic tests in the general population are required. Here, we describe the first Italian survey performed in 727 employees belonging to a Mother-Child Research hospital tested for both viral (nasopharyngeal and oropharyngeal swabs) and antibody presence. Individuals were divided into three risk categories (high, medium and low) according to their job activity. Only one subject was positive at the swab test while 17.2% of the cohort was positive for the presence of antibodies. Results highlighted that the presence of Positive antibodies is significantly associated with high and medium risk exposure occupation (p-value=0.026) as well as cold and conjunctivitis symptoms (p-value=0.016 and 0.042 respectively). Moreover, among healthcare professionals, the category of medical doctors showed a significant association with the presence of antibodies against SARS-CoV-2 (p-value=0.0127). Finally, we detected a rapid decrease in antibody intensity between two assessments performed within a very short period (p-value=0.009). Overall, the present study increases our knowledge of the epidemiological data of COVID-19 infection in Italy, suggesting a high prevalence of immune individuals (i.e. at least among at-risk categories) and the efficacy of the combined diagnostic protocol to monitor the possible outbreak.

negative: Screening of donor and recipient prior to solid organ transplantation

negative: Understanding Epidemic Data and Statistics: A case study of COVID-19 The 2019-Novel-Coronavirus (COVID-19) has affected 181 countries and out of about 1197405 confirmed cases (By April 5). Understanding the transmission dynamics of the infection in each country which affected on a daily basis and evaluating the effectiveness of control policies is critical for our further actions. To date, the statistics of COVID-19 reported cases show more than 80 percent of infected had a mild case of disease, while around 14 percent of infected experienced a severe one and about 5 percent are categorized as critical disease victims. Today's report (2020-04-05; daily updates in the prepared website) shows the confirmed cases of COVID-19 in the US, Spain, Italy, and Germany are 308850, 126168, 124632, and 96092; respectively. Calculating the total Case Fatality Rate (CFR) of Italy (2020-04-04), about 13.3% of confirmed cases passed away. Compared to South Korea's rate of 1.8% (7 times lower than Italy) and China's 4% (69% lower than Italy), the CFR of Italy is too high. There are some effective policies that yield significant changes in the trend of cases. The lockdown policy in China, Italy, and Spain (the effect observed after some days), Shutdown of all non-essential companies in Hubei (the effect observed after 5 days), combined policy in South Korea, and reducing working hours in Iran.

negative: Overview of Serological Techniques for Influenza Vaccine Evaluation: Past, Present and Future Serological techniques commonly used to quantify influenza-specific antibodies include the Haemagglutination Inhibition (HI), Single Radial Haemolysis (SRH) and Virus Neutralization (VN) assays. HI and SRH are established and reproducible techniques, whereas VN is more demanding. Every new influenza vaccine needs to fulfil the strict criteria issued by the European Medicines Agency (EMA) in order to be licensed. These criteria currently apply exclusively to SRH and HI assays and refer to two different target groups—healthy adults and the elderly, but other vaccine recipient age groups have not been considered (i.e., children). The purpose of this timely review is to highlight the current scenario on correlates of protection concerning influenza vaccines and underline the need to revise the criteria and assays currently in use. In addition to SRH and HI assays, the technical advantages provided by other techniques such as the VN assay, pseudotype-based neutralization assay, neuraminidase and cell-mediated immunity assays need to be considered and regulated via EMA criteria, considering the many significant advantages that they could offer for the development of effective vaccines.

negative: Current Trends in Diagnostics of Viral Infections of Unknown Etiology Viruses are evolving at an alarming rate, spreading and inconspicuously adapting to cutting-edge therapies. Therefore, the search for rapid, informative and reliable diagnostic methods is becoming urgent as ever. Conventional clinical tests (PCR, serology, etc.) are being continually optimized, yet provide very limited data. Could high throughput sequencing (HTS) become the future gold standard in molecular diagnostics of viral infections? Compared to conventional clinical tests, HTS is universal and more precise at profiling pathogens. Nevertheless, it has not yet been widely accepted as a diagnostic tool, owing primarily to its high cost and the complexity of sample preparation and data analysis. Those obstacles must be tackled to integrate HTS into daily clinical practice. For this, three objectives are to be achieved: (1) designing and assessing universal protocols for library preparation, (2) assembling purpose-specific pipelines, and (3) building computational infrastructure to suit the needs and financial abilities of modern healthcare centers. Data harvested with HTS could not only augment diagnostics and help to choose the correct therapy, but also facilitate research in epidemiology, genetics and virology. This information, in turn, could significantly aid clinicians in battling viral infections.

negative: Modeling serological testing to inform relaxation of social distancing for COVID-19 control The value of serological testing to inform the public health response to the SARS-CoV-2 pandemic is debated. Using a transmission model, we examined how serology can be implemented to allow seropositive individuals to resume more normal levels of social interaction while offsetting the risks. We simulated the use of widespread serological testing with realistic assay characteristics, in which seropositive individuals partially restore their social contacts and act as immunological ‘shields’. If social distancing is relaxed by 50% at the same time that quarterly serological screening is initiated, approximately 120,000 deaths could be averted and a quarter of the US population could be released from social distancing in the first year of the epidemic, compared to a scenario without serological testing. This strategy has the potential to substantially flatten the COVID-19 epidemic curve while also allowing a substantial number of individuals to safely return to social and economic interactions.

negative: Association between syphilis seroprevalence and age among blood donors in Southern China: an observational study from 2014 to 2017 OBJECTIVE: This study investigated the association between syphilis seroprevalence and age among blood donors, and described the distribution of serological titres among syphilis-infected donors, aiming to confirm the syphilis epidemic characteristics and to promote effective interventions for older adults. METHODS: Data were obtained from the Shenzhen Programme for Syphilis Prevention and Control in 2014–2017. Blood samples were screened using the ELISAs, and confirmed using the Treponema pallidum particle agglutination assay (TPPA) and toluidine red unheated serum test (TRUST). RESULTS: Among 394 792 blood donors, 733 tested TPPA and TRUST positive (active infection), and 728 tested only TPPA positive (historical infection). The overall prevalence of syphilis seropositivity was 370.1 per 100 000 (95% CI 351.1 to 389.0 per 100 000); the prevalence of active infection was 185.7 per 100 000 (95% CI 172.2 to 199.1 per 100 000). People aged ≥45 years displayed a prevalence of 621.8 per 100 000 in syphilis seropositivity and 280.5 per 100 000 in active infection, which were 3.8 times and 2.4 times higher than that for people aged <25 years, respectively. The prevalence of syphilis seropositivity (χ(2) (trend)=311.9, p (trend)<0.001) and active infection (χ(2) (trend)=72.1, p (trend)<0.001) increased significantly with age. After stratification by gender and year of donation, the increasing trend of prevalence with age remained (p (trend)<0.05), except for the prevalence of active infection in males and females in 2014. About 16.3% of donors with active infection and aged ≥45 years had a TRUST titre of ≥1∶8, lower than that of patients aged <25 years (51.3%) and 25–34 years (34.1%). CONCLUSIONS: The findings confirm the high prevalence of syphilis among older adults, and suggest the need to increase awareness among healthcare providers and deliver more targeted prevention interventions for older adults to promote early testing.

negative: Abstract of 29th Regional Congress of the ISBT

negative: Neutralizing antibody responses to SARS-CoV-2 in a COVID-19 recovered patient cohort and their implications Background The COVID-19 pandemic caused by SARS-CoV-2 coronavirus threatens global public health. Currently, neutralizing antibodies (NAbs) versus this virus are expected to correlate with recovery and protection of this disease. However, the characteristics of these antibodies have not been well studied in association with the clinical manifestations in patients. Methods Plasma collected from 175 COVID-19 recovered patients with mild symptoms were screened using a safe and sensitive pseudotyped-lentiviral-vector-based neutralization assay. Spike-binding antibody in plasma were determined by ELISA using RBD, S1, and S2 proteins of SARS-CoV-2. The levels and the time course of SARS-CoV-2-specific NAbs and the spike-binding antibodies were monitored at the same time. Findings SARS-CoV-2 NAbs were unable to cross-reactive with SARS-CoV virus. SARS-CoV-2-specific NAbs were detected in patients from day 10-15 after the onset of the disease and remained thereafter. The titers of NAb among these patients correlated with the spike-binding antibodies targeting S1, RBD, and S2 regions. The titers of NAbs were variable in different patients. Elderly and middle-age patients had significantly higher plasma NAb titers (P<0.0001) and spike-binding antibodies (P=0.0003) than young patients. Notably, among these patients, there were ten patients whose NAb titers were under the detectable level of our assay (ID50: < 40); while in contrast, two patients, showed very high titers of NAb, with ID50 :15989 and 21567 respectively. The NAb titers were positive correlated with plasma CRP levels but negative correlated with the lymphocyte counts of patients at the time of admission, indicating an association between humoral response and cellular immune response. Interpretation The variations of SARS-CoV-2 specific NAbs in recovered COVID-19 patients may raise the concern about the role of NAbs on disease progression. The correlation of NAb titers with age, lymphocyte counts, and blood CRP levels suggested that the interplay between virus and host immune response in coronavirus infections should be further explored for the development of effective vaccine against SARS-CoV-2 virus. Furthermore, titration of NAb is helpful prior to the use of convalescent plasma for prevention or treatment. Funding Ministry of Science and Technology of China, National Natural Science Foundation of China, Shanghai Municipal Health Commission, and Chinese Academy of Medical Sciences

negative: Diseases of the hematologic, immunologic, and lymphatic systems (multisystem diseases) [Image: see text]

negative: RAPID SEROLOGICAL TESTS HAVE A ROLE IN ASYMPTOMATIC HEALTH WORKERS COVID-19 SCREENING Health workers are at high risk for SARS-CoV-2 infection and, if asymptomatic, for transmitting the virus on to fragile cancer patients. We screened 512 health workers of our Cancer Institute with rapid serological test Viva-Diag analyzing, with colorimetric test,IgG/IgM- COVID-19 associated. Five subjects (1%) resulted with Viva-Diag test not-negative for IgM. All of them had rt-PCR SARS-CoV-2 test negative while for 2 out of 5 cases, CLIA analysis confirmed positive IgM expression. In this original study on health workers we demonstrated that Viva-Diag is able to evidence subjects positive for IgM expression. However, discordant results with respect to rt-PCR and CLIA assays clearly refer to further studies to optimize the utilization of the serological test in asymptomatic and in at risk subjects.

negative: Label-free microcantilever-based immunosensors for highly sensitive determination of avian influenza virus H9 We report on label-free immunosensors for the highly sensitive detection of avian influenza virus. The method makes use of the microcantilevers of an atomic force microscope onto which monoclonal antibodies against avian influenza virus were covalently immobilized. The factors influencing the performance of the resulting immunosensors were optimized by measuring the deflections of the cantilever via optical reflection, and this resulted in low detection limits and a wide analytical range. The differential deflection signals revealed specific antigen binding and their intensity is proportional to the logarithm of the concentrations of the virus in solution. Under optimal conditions, the immunosensors exhibit a linear response in the 7.6 ng mL(−1) to 76 μg mL(−1) concentration range of avian influenza virus, and the detection limit is 1.9 ng mL(−1). [Figure: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00604-013-1129-x) contains supplementary material, which is available to authorized users.

negative: Middle East Respiratory Syndrome Coronavirus Transmission in Extended Family, Saudi Arabia, 2014 Risk factors for human-to-human transmission of Middle East respiratory syndrome coronavirus (MERS-CoV) are largely unknown. After MERS-CoV infections occurred in an extended family in Saudi Arabia in 2014, relatives were tested by using real-time reverse transcription PCR (rRT-PCR) and serologic methods. Among 79 relatives, 19 (24%) were MERS-CoV positive; 11 were hospitalized, and 2 died. Eleven (58%) tested positive by rRT-PCR; 8 (42%) tested negative by rRT-PCR but positive by serology. Compared with MERS-CoV–negative adult relatives, MERS-CoV–positive adult relatives were older and more likely to be male and to have chronic medical conditions. Risk factors for household transmission included sleeping in an index patient’s room and touching respiratory secretions from an index patient. Casual contact and simple proximity were not associated with transmission. Serology was more sensitive than standard rRT-PCR for identifying infected relatives, highlighting the value of including serology in future investigations.

negative: Emerging Infections and Pertinent Infections Related to Travel for Patients with Primary Immunodeficiencies In today’s global economy and affordable vacation travel, it is increasingly important that visitors to another country and their physician be familiar with emerging infections, infections unique to a specific geographic region, and risks related to the process of travel. This is never more important than for patients with primary immunodeficiency disorders (PIDD). A recent review addressing common causes of fever in travelers provides important information for the general population Thwaites and Day (N Engl J Med 376:548-560, 2017). This review covers critical infectious and management concerns specifically related to travel for patients with PIDD. This review will discuss the context of the changing landscape of infections, highlight specific infections of concern, and profile distinct infection phenotypes in patients who are immune compromised. The organization of this review will address the environment driving emerging infections and several concerns unique to patients with PIDD. The first section addresses general considerations, the second section profiles specific infections organized according to mechanism of transmission, and the third section focuses on unique phenotypes and unique susceptibilities in patients with PIDDs. This review does not address most parasitic diseases. Reference tables provide easily accessible information on a broader range of infections than is described in the text.

negative: Long-term SARS Coronavirus Excretion from Patient Cohort, China This study investigated the long-term excretion of severe acute respiratory syndrome–associated coronavirus in sputum and stool specimens from 56 infected patients. The median (range) duration of virus excretion in sputa and stools was 21 (14–52) and 27 (16–126) days, respectively. Coexisting illness or conditions were associated with longer viral excretion in stools.

negative: Finding equipoise: CEPI revises its equitable access policy Launched at Davos in January 2017 with funding from sovereign investors and philanthropic institutions, the Coalition for Epidemic Preparedness Innovations (CEPI) is an innovative partnership between public, private, philanthropic, and civil organisations whose mission is to stimulate, finance and co-ordinate vaccine development against diseases with epidemic potential in cases where market incentives fail. As of December 2019, CEPI has committed to investing up to $706 million in vaccine development. This includes 19 vaccine candidates against its priority pathogens (Lassa fever virus, Middle East respiratory syndrome coronavirus, Nipah virus, Chikungunya, Rift Valley fever) and three vaccine platforms to develop vaccines against Disease X, a novel or unanticipated pathogen. As an entity largely supported by public funds, ensuring equitable access to vaccines whose development it supports in low- and middle-income countries is CEPI’s primary focus. CEPI developed an initial equitable access policy shortly after its formation, with key stakeholders expressing strong views about its content and prescriptive nature. The CEPI board instructed that it be revisited after a year. This paper describes the process of revising the policy, and how key issues were resolved. CEPI will continue to take an iterative, rather than prescriptive, approach to its policy—one that reflects the needs of multiple stakeholders and ensures it can meet its equitable access goals.

negative: RAN translation and frameshifting as translational challenges at simple repeats of human neurodegenerative disorders Repeat-associated disorders caused by expansions of short sequences have been classified as coding and noncoding and are thought to be caused by protein gain-of-function and RNA gain-of-function mechanisms, respectively. The boundary between such classifications has recently been blurred by the discovery of repeat-associated non-AUG (RAN) translation reported in spinocerebellar ataxia type 8, myotonic dystrophy type 1, fragile X tremor/ataxia syndrome and C9ORF72 amyotrophic lateral sclerosis and frontotemporal dementia. This noncanonical translation requires no AUG start codon and can initiate in multiple frames of CAG, CGG and GGGGCC repeats of the sense and antisense strands of disease-relevant transcripts. RNA structures formed by the repeats have been suggested as possible triggers; however, the precise mechanism of the translation initiation remains elusive. Templates containing expansions of microsatellites have also been shown to challenge translation elongation, as frameshifting has been recognized across CAG repeats in spinocerebellar ataxia type 3 and Huntington's disease. Determining the critical requirements for RAN translation and frameshifting is essential to decipher the mechanisms that govern these processes. The contribution of unusual translation products to pathogenesis needs to be better understood. In this review, we present current knowledge regarding RAN translation and frameshifting and discuss the proposed mechanisms of translational challenges imposed by simple repeat expansions.

negative: Coronative antibody tires in sera of healthy adults and experimentally infected volunteers. Six coronaviruses isolated in the U.S.A. have been inoculated into volunteers and all produced colds. Between 10 and 20% of infected volunteers developed heterologous antibody responses after these and other experimental infections with coronaviruses. The haemagglutination-inhibition test with the OC43 virus strain was found to detect antibody rises after infection with a variety of strains.Studies on normal adult sera taken between 1965 and 1970 revealed a high frequency of neutralizing antibody to one strain (229 E) and a frequency of HI antibody to strain OC43 which fluctuated from year to year. Complement-fixing antibodies to these two viruses were also found, revealing an apparent increase in the activity of coronaviruses in the general population of the U.K., during the winter of 1968-9.

negative: Anti-severe acute respiratory syndrome coronavirus spike antibodies trigger infection of human immune cells via a pH- and cysteine protease-independent FcγR pathway. Public health measures successfully contained outbreaks of the severe acute respiratory syndrome coronavirus (SARS-CoV) infection. However, the precursor of the SARS-CoV remains in its natural bat reservoir, and reemergence of a human-adapted SARS-like coronavirus remains a plausible public health concern. Vaccination is a major strategy for containing resurgence of SARS in humans, and a number of vaccine candidates have been tested in experimental animal models. We previously reported that antibody elicited by a SARS-CoV vaccine candidate based on recombinant full-length Spike-protein trimers potentiated infection of human B cell lines despite eliciting in vivo a neutralizing and protective immune response in rodents. These observations prompted us to investigate the mechanisms underlying antibody-dependent enhancement (ADE) of SARS-CoV infection in vitro. We demonstrate here that anti-Spike immune serum, while inhibiting viral entry in a permissive cell line, potentiated infection of immune cells by SARS-CoV Spike-pseudotyped lentiviral particles, as well as replication-competent SARS coronavirus. Antibody-mediated infection was dependent on Fcγ receptor II but did not use the endosomal/lysosomal pathway utilized by angiotensin I converting enzyme 2 (ACE2), the accepted receptor for SARS-CoV. This suggests that ADE of SARS-CoV utilizes a novel cell entry mechanism into immune cells. Different SARS vaccine candidates elicit sera that differ in their capacity to induce ADE in immune cells despite their comparable potency to neutralize infection in ACE2-bearing cells. Our results suggest a novel mechanism by which SARS-CoV can enter target cells and illustrate the potential pitfalls associated with immunization against it. These findings should prompt further investigations into SARS pathogenesis.

negative: Isolation of coronaviruses antigenically indistinguishable from bovine coronavirus from wild ruminants with diarrhea. Diarrheal feces from three sambar deer and one waterbuck in a wild animal habitat and one white-tailed deer on a wildlife farm in Ohio contained coronavirus particles which were agglutinated by antiserum to bovine coronavirus (BCV) in immune electron microscopy. Three coronavirus strains were isolated in human rectal tumor cells from the feces of the sambar and white-tailed deer and the waterbuck, respectively. Hemagglutination, receptor-destroying enzyme activity, indirect immunofluorescence, hemagglutination inhibition, virus neutralization, and Western blot (immunoblot) tests showed close biological and antigenic relationships among the isolates and with selected BCV strains. Gnotobiotic and colostrum-deprived calves inoculated with each of these isolates developed diarrhea and shed coronavirus in their feces and from their nasal passages. In a serological survey of coronavirus infections among wild deer, 8.7 and 6.6% of sera from mule deer in Wyoming and from white-tailed deer in Ohio, respectively, were seropositive against both of the isolates and selected BCV isolates by indirect immunofluorescence tests. These results confirm the existence of coronaviruses in wild ruminants and suggest that these species may harbor coronavirus strains transmissible to cattle.

negative: Emergence of novel coronavirus and progress toward treatment and vaccine In late December 2019, a group of patients was observed with pneumonia-like symptoms that were linked with a wet market in Wuhan, China. The patients were found to have a novel coronavirus genetically related to a bat coronavirus that was termed SARS-CoV-2. The virus gradually spread worldwide and was declared a pandemic by WHO. Scientists have started trials on potential preventive and treatment options. Currently, there is no specific approved treatment for SARS-CoV-2, and various clinical trials are underway to explore better treatments. Some previously approved antiviral and other drugs have shown some in vitro activity. Here we summarize the fight against this novel coronavirus with particular focus on the different treatment options and clinical trials exploring treatment as well as work done toward development of vaccines.

negative: Comparison of immunoglobulin G responses to the spike and nucleocapsid proteins of severe acute respiratory syndrome (SARS) coronavirus in patients with SARS. Both the nucleocapsid (N) and the spike (S) proteins of severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) are able to induce strong humoral responses in humans following an infection. To compare the immunoglobulin G (IgG) responses to the S and N proteins of SARS-CoV in SARS patients during the manifestation/convalescent period with those during the postinfection period, serum samples were collected from hospitalized SARS patients within 6 weeks after the onset of illness (set 1; 57 sequential samples from 19 patients) or 2 to 3 months after their recovery (set 2; 33 postinfection samples from 33 subjects). Serum samples from 100 healthy blood donors (set 3), collected in 2002, were also included. The specific IgG response to whole virus, the fragment from positions 450 to 650 of the S protein (S450-650), and the full-length N protein of SARS-CoV were measured by enzyme-linked immunosorbent assays (ELISAs). Western blot assays were carried out to confirm the ELISA results. Fifty-one of the serum samples in set 1 (89%) bound to the N protein, a proportion similar to that which recognized whole virus (79%) and the S-protein fragment (77%). All 33 serum samples from set 2 were strongly positive for N-protein-specific IgG, while 27 (82%) were positive for anti-S450-650 IgG. Two of the serum samples from set 3 were strongly positive for anti-N-protein IgG but not anti-S450-650 IgG. Similar levels of IgG responses to the S and N proteins were observed in SARS patients during the manifestation and convalescent stages. In the postinfection period, however, a number of patients had much lower serum IgG levels against S450-650 than against the N protein.

negative: Detection of porcine respiratory coronavirus and transmissible gastroenteritis virus by an enzyme-linked immunosorbent assay Abstract An enzyme-linked immunosorbent assay (ELISA) for the detection of transmissible gastroenteritis virus (TGEV) and porcine respiratory coronavirus (PRCV) was developed. A bovine TGEV-specific polyclonal antibody was purified by affinity chromatography with the TRIO Bioprocessing System and was used as the capture antibody, at a concentration of 1.5 μg/well. The F5.39 monoclonal antibody was obtained by the fusion of spleen lymphocytes from TGEV immunized mice with NS-1 myeloma cells. This mAb was used as a second antibody for the ELISA to detect TGEV in field cases, 53 intestinal samples were taken from pigs exhibiting clinical signs of transmissible gastroenteritis. All the positive samples detected by the ELISA were confirmed as positive by immunofluorescence or cell culture immunofluorescence. To study the ability of this ELISA to detect PRCV in nasal swabs and lung samples, 20 seven-day-old piglets were inoculated with a Quebec strain of PRCV. The ELISA was able to detect PRCV in both kinds of samples.

negative: Coronavirus Disease (COVID-19) in Italy: Analysis of Risk Factors and Proposed Remedial Measures

negative: Clinical study of transcutaneous vaccination using a hydrogel patch for tetanus and diphtheria Transcutaneous immunization (TCI) is a non-invasive and easy-to-use vaccination method. We demonstrated the efficacy and safety of a transcutaneous vaccine formulation using a hydrogel patch in animal experiments. In the present study, we performed a clinical study to apply our TCI formulation for vaccination against tetanus and diphtheria in human. The TCI device was a hydrogel patch (antigen-free) applied to the left brachial medial skin of 22 healthy volunteers for 48 h. Next, the hydrogel patch, containing 2 mg tetanus toxoid (TT) and 2 mg diphtheria toxoid (DT) as the TCI formulation, was applied to 27 healthy volunteers for 24 h and some volunteers were vaccinated again by TCI formulation. For safety assessment, the patch application site was observed to assess local adverse events, and systemic adverse events were determined by a blood test. The antigen-free hydrogel patch and TCI formulation containing TT and DT did not induce local or systemic severe adverse events. For vaccine efficacy estimation, toxoid-specific serum antibody titers were determined by ELISA and the toxin-neutralizing activity of the induced antibody was evaluated in a passive-challenge experiment. The anti-TT IgG titer and the anti-DT IgG titer increased, and a significant effect was detected by paired t-test. The antibody titers were maintained at higher level than that before vaccination for at least 1 year. Moreover, toxoid-specific antibodies were produced by the second vaccination in some subjects. Antibodies induced by application of the TCI formulation neutralized the toxin and prevented toxic death in mice. In addition, changes in the skin condition due to application of the TCI formulation were observed under in vivo confocal Raman spectroscopy. The amount of water and patch components in the stratum corneum increased after application of the TCI formulation, suggesting that the change in the skin condition was related to antigen penetration. These data indicate that this easy-to-use TCI system induces an immune response without severe adverse reactions in humans. This easy-to-use and safe TCI formulation enables mass treatment in an outbreak setting and increased vaccination rates in developing countries, and will greatly contribute to worldwide countermeasures against infectious diseases.

negative: Coronavirus Infection in Acute Lower Respiratory Tract Disease of Infants A serologic surveillance of lower respiratory tract disease in 417 hospitalized children under 18 months of age revealed infection with coronaviruses (strains OC43 and/or 229E) in 34 (8.2%). During the same interval, one of 13 control infants was infected. There were two distinct periods lasting six and 14 weeks, respectively, during which the incidence rose to as high as 18.9% of patients with lower respiratory tract disease. The incidence of coronavirus infection in patients with pneumonia and bronchiolitis was higher than the incidences of adenoviruses, influenza, parainfluenza viruses types 1 and 2, and rhinoviruses, and lower only than the incidences of parainfluenza virus type 3 and respiratory syncytial virus. Coronaviruses serologically similar or identical to strain 229E were recovered from frozen nasal washes obtained during the acute phase of pneumonia in two children.

negative: Puces à protéines et perspectives d’applications médicales Résumé Les puces à protéines permettent de détecter les interactions moléculaires avec divers partenaires (protéines, peptides, acides nucléiques, sucres, etc.). Leurs avantages sont cruciaux pour l’analyse à haut débit des protéomes entiers de différents organismes. De plus, les résultats récents prouvent la performance des puces par rapport aux méthodes immunologiques conventionnelles. C’est pourquoi, les puces à antigènes et à anticorps deviennent des outils incontournables dans le domaine médical, en particulier, pour le diagnostic et le pronostic des maladies infectieuses, auto-immunes et allergiques. Les avancées technologiques permettent d’envisager l’introduction de puces miniaturisées dans la pratique médicale pour le monitoring multiparamétrique de pathologies humaines. Abstract Protein microarrays make it possible to detect molecular interactions with various partners (proteins, peptides, nucleic acids, sugars, etc.). Their advantages are crucial for high-throughput analysis of proteomes of different organisms. Moreover, the recent data reveal the performance of microarrays over current immunological methods. Therefore, the antigen and antibody microarrays become indispensable for medical applications, in particular, for diagnosis and prognosis of microbial infections, autoimmune and allergic diseases. The further technological progress might provide the extension of the miniaturized assays for multiparametric monitoring of human pathologies in practical medicine.

negative: Preliminary Results of Seroprevalence of SARS-CoV-2 at Community Clinics in Tokyo Serological evaluation with SARS-CoV-2 specific IgG antibody will be an alternative way to know the pandemic of novel coronavirus disease (COVID-19) if the capacity for diagnostic PCR test is limited. The point-of-care test to detect SARS-CoV-2 specific IgG antibody in peripheral blood (n =202) was performed in two community clinics in Tokyo, Japan. The overall positive rate of SRAS-CoV-2 IgG antibody was 5.9% (95% confidence interval[CI]: 3.1-10.1). Higher rate was observed for healthcare workers (n =55, 9.1 [3.0-20.0]). The limitation on antibody tests includes low sensitivity and potent cross-reactivity with the previous coronavirus. Robust healthcare policy to efficiently monitor COVID-19 spread is warranted in Tokyo.

negative: A Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases: 2013 Recommendations by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM)(a) The critical role of the microbiology laboratory in infectious disease diagnosis calls for a close, positive working relationship between the physician and the microbiologists who provide enormous value to the health care team. This document, developed by both laboratory and clinical experts, provides information on which tests are valuable and in which contexts, and on tests that add little or no value for diagnostic decisions. Sections are divided into anatomic systems, including Bloodstream Infections and Infections of the Cardiovascular System, Central Nervous System Infections, Ocular Infections, Soft Tissue Infections of the Head and Neck, Upper Respiratory Infections, Lower Respiratory Tract infections, Infections of the Gastrointestinal Tract, Intraabdominal Infections, Bone and Joint Infections, Urinary Tract Infections, Genital Infections, and Skin and Soft Tissue Infections; or into etiologic agent groups, including Tickborne Infections, Viral Syndromes, and Blood and Tissue Parasite Infections. Each section contains introductory concepts, a summary of key points, and detailed tables that list suspected agents; the most reliable tests to order; the samples (and volumes) to collect in order of preference; specimen transport devices, procedures, times, and temperatures; and detailed notes on specific issues regarding the test methods, such as when tests are likely to require a specialized laboratory or have prolonged turnaround times. There is redundancy among the tables and sections, as many agents and assay choices overlap. The document is intended to serve as a reference to guide physicians in choosing tests that will aid them to diagnose infectious diseases in their patients.

negative: Evaluation of serological assays available in a biosafety level 2 laboratory and their application for survey of Middle East respiratory syndrome coronavirus among livestock in Ethiopia A serological survey of Middle East respiratory syndrome coronavirus (MERS-CoV) was conducted among dromedary camels and herbivorous animals sharing the same pasturage in Ethiopia. The pseudotyped vesicular stomatitis virus coated with the spike protein of MERS-CoV was used in virus neutralization (VN) tests performed in a biosafety level (BSL)-2 laboratory. The results were similar to those obtained from the VN test using live MERS-CoV and were more sensitive than the ELISA performed using synthetic MERS S1 fragment as the antigen as well as the competitive ELISA performed using a monoclonal antibody against MERS-CoV. According to the comprehensive results of the four types of serodiagnosis methods, positive antibodies were detected only in dromedary camels and the remaining herbivorous animals were not infected with the virus. Moreover, using the present procedure, serological tests for MERS-CoV can be conducted even in BSL 2 laboratory.

negative: Ferret Coronavirus-Associated Diseases A novel coronavirus of ferrets was first described in 1993. This coronavirus caused an enteric disease called epizootic catarrhal enteritis (ECE). Recently, a ferret systemic coronavirus (FRSCV)-associated disease was discovered. This new systemic disease resembles the dry form of feline infectious peritonitis (FIP) and has been reported in the United States and Europe. This article addresses the clinical signs, pathology, pathogenesis, diagnosis, treatment, and prevention of this ferret FIP-like disease.

negative: Clinical evaluation of an immunochromatographic IgM/IgG antibody assay and chest computed tomography for the diagnosis of COVID-19 Background: We evaluated the clinical performance of an immunochromatographic (IC) IgM/IgG antibody assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) and chest computed tomography (CT) for the diagnosis of Coronavirus disease 2019 (COVID-19). Methods: We examined 139 serum specimens collected from 112 patients with COVID-19 and 48 serum specimens collected from 48 non-COVID-19 patients. The presence of IgM/IgG antibody for SARS-CoV2 was determined using the One Step Novel Coronavirus (COVID-19) IgM/IgG Antibody Test. Chest CT was performed in COVID-19 patients on admission. Findings: Of the 139 COVID-19 serum specimens, IgM was detected in 27.8%, 48.0%, and 95.8% of the specimens collected within 1 week, 1-2 weeks, and >2 weeks after symptom onset and IgG was detected in 3.3%, 8.0%, and 62.5%, respectively. Among the 48 non-COVID-19 serum specimens, 1 generated a false-positive result for IgM. Thirty-eight of the 112 COVID-19 patients were asymptomatic, of whom 15 were positive for IgM, and 74 were symptomatic, of whom 22 were positive for IgM and 7 were positive for IgG. The diagnostic sensitivity of CT scan alone and in combination with the IC assay was 57.9 % (22/38) and 68.4% (26/38) for the asymptomatic patients and 74.3% (55/74) and 82.4% (61/74) for the symptomatic patients, respectively. Conclusion: The IC assay had low sensitivity during the early phase of infection, and thus IC assay alone is not recommended for initial diagnostic testing for COVID-19. If RT-qPCR is not available, the combination of chest CT and IC assay may be useful for diagnosing COVID-19.

negative: The performance of RT-PCR compared with a rapid serological assay for acute dengue fever in a diagnostic laboratory Summary The laboratory diagnosis of dengue has largely relied on serological assays, although many different RT-PCR protocols have been reported. Owing to its limited use, the value of RT-PCR in the clinical laboratory has not been fully evaluated. During the outbreak of severe acute respiratory syndrome (SARS) in Singapore in 2003, RT-PCR to detect dengue viral RNA was used as a rapid diagnostic tool to differentiate dengue from SARS among patients who presented to a hospital designated to manage and quarantine SARS cases. A total of 343 results for RT-PCR and 439 results for serology were analysed and compared with the final discharge diagnosis. Our experience indicates that RT-PCR for dengue can be set up rapidly in a clinical laboratory, with very sensitive and specific results for the diagnosis of dengue, particularly in the first 5 days from onset of symptoms.

negative: Rapid diagnostics urgently needed for killer infections

negative: Coronavirus Epidemic and Extracorporeal Therapies in Intensive Care: si vis pacem para bellum

negative: Intensive care admission for Coronavirus OC43 respiratory tract infections Abstract Background Coronavirus OC43 infection causes severe pneumonia in patients presenting with comorbidities, but clinical signs alone do not allow for viral identification. Objectives To analyze acute manifestations of Coronavirus OC43 infections and outcomes of patients admitted to an intensive care unit (ICU). Patients and methods Retrospective and monocentric study performed during a Coronavirus OC43 outbreak. We used multiplex PCR to detect an OC43 outbreak in Reunion Island during the 2016 Southern Hemisphere's winter: seven admissions to the ICU. Results Mean age of patients was 71 [67;76] years, SAPS II was 42 [28;53], pneumonia severity index 159 [139;182] vs 73 [40.5;107] for patients in medical wards, and 43% required mechanical ventilation. Comorbidities were diabetes mellitus (87%), chronic respiratory failure (57%), and chronic renal failure (29%). One patient died from Haemophilus influenzae co-infection. Conclusion As for MERS Co-V infections, underlying comorbidities impacted the clinical outcomes of OC43 infections.

negative: On the stability of sequences inserted into viral genomes Viruses are widely used as vectors for heterologous gene expression in cultured cells or natural hosts, and therefore a large number of viruses with exogenous sequences inserted into their genomes have been engineered. Many of these engineered viruses are viable and express heterologous proteins at high levels, but the inserted sequences often prove to be unstable over time and are rapidly lost, limiting heterologous protein expression. Although virologists are aware that inserted sequences can be unstable, processes leading to insert instability are rarely considered from an evolutionary perspective. Here, we review experimental work on the stability of inserted sequences over a broad range of viruses, and we present some theoretical considerations concerning insert stability. Different virus genome organizations strongly impact insert stability, and factors such as the position of insertion can have a strong effect. In addition, we argue that insert stability not only depends on the characteristics of a particular genome, but that it will also depend on the host environment and the demography of a virus population. The interplay between all factors affecting stability is complex, which makes it challenging to develop a general model to predict the stability of genomic insertions. We highlight key questions and future directions, finding that insert stability is a surprisingly complex problem and that there is need for mechanism-based, predictive models. Combining theoretical models with experimental tests for stability under varying conditions can lead to improved engineering of viral modified genomes, which is a valuable tool for understanding genome evolution as well as for biotechnological applications, such as gene therapy.

negative: Epidemiological and Clinical Aspects of COVID-19; a Narrative Review There are significant misconceptions and many obstacles in the way of illuminating the epidemiological and clinical aspects of COVID-19 as a new emerging epidemic. In addition, usefulness of some evidence published in the context of the recent epidemic for decision making in clinic as well as public health is questionable. However, misinterpreting or ignoring strong evidence in clinical practice and public health probably results in less effective and somehow more harmful decisions for individuals as well as subgroups in general populations of countries in the initial stages of this epidemic. Accordingly, our narrative review appraised epidemiological and clinical aspects of the disease including genetic diversity of coronavirus genus, mode of transmission, incubation period, infectivity, pathogenicity, virulence, immunogenicity, diagnosis, surveillance, clinical case management and also successful measures for preventing its spread in some communities.

negative: Vaccines and Vaccination Livestock vaccines aim to increase livestock product and improve the health and welfare of livestock animals in a cost-efficient manner and prevent disease transmission. Successful livestock vaccines have been generated for pathogens including bacterial, viral, protozoan, and multicellular pathogens. These livestock vaccines have a significant effect on animal health and products and on human health through growing safe food procurement and preventing zoonotic diseases. There are successful production of biotechnological-based animal vaccines licensed for use that include virus-like particle vaccines, gene-deleted marker vaccines, subunit vaccines, DIVA vaccines, and DNA vaccines.

negative: Resilient SARS-CoV-2 diagnostics workflows including viral heat inactivation There is a worldwide shortage of reagents to perform detection of SARS-2. Many clinical diagnostic laboratories rely on commercial platforms that provide integrated end-to-end solutions. While this provides established robust pipelines, there is a clear bottleneck in the supply of reagents given the current situation of extraordinary high demand. Some laboratories resort to implementing kit-free handling procedures, but many other small laboratories will not have the capacity to develop those and/or will perform manual handling of their samples. In order to provide multiple workflows for SARS-CoV-2 nucleic acid detection we compared several commercially available RNA extraction methods: QIAamp Viral RNA Mini Kit (QIAgen), the recently developed RNAdvance Blood (Beckman) and Mag-Bind Viral DNA/RNA 96 Kit (Omega Bio-tek). We also compared different 1-step RT-qPCR Master Mix brands: TaqMan™ Fast Virus 1-Step Master Mix (ThermoFisher Scientific), qPCRBIO Probe 1-Step Go Lo-ROX (PCR Biosystems) and Luna® Universal Probe One-Step RT-qPCR Kit (NEB). We used the Centre for Disease Control (CDC) recommended primers that detect two regions of the viral N gene as well as those that detect the RdRP gene region as per Public Health England (PHE) guidelines (Charite/WHO/PHE). Our data show that the RNA extraction methods provide similar results. Amongst the qPCR reagents tested, TaqMan™ Fast Virus 1-Step Master Mix and Luna® Universal Probe One-Step RT-qPCR Kit proved most sensitive. The N1 and N2 primer-probes provide a more reliable detection than the RdRP-SARSr primer-probe set, particularly in samples with low viral titres. Importantly, we have implemented a protocol using heat inactivation and demonstrate that it has minimal impact on the sensitivity of the qPCR in clinical samples - potentially making SARS-CoV-2 testing portable to settings that do not have CL-3 facilities.

negative: Indirect fluorescent antibody testing of nasopharyngeal swabs for influenza diagnosis in lung transplant recipients Abstract Background: Rapid and reliable diagnosis of respiratory viral infections (RVI) in lung transplant recipients is essential to direct therapy of acute graft dysfunction and identify epidemic trends. Traditional techniques of serology and viral culture are limited by the lack of antibody response and delay in diagnosis. Methods: We examined the clinical utility of indirect fluorescent antibody (IFA) testing in adult lung transplant patients with suspected RVI, compared with serology and culture. Nasopharyngeal and throat swabs (NT) were obtained to sample epithelial cells, followed by application of monoclonal antibody to respiratory syncytial virus, adenovirus, parainfluenza 1–3 and influenza A and B. The Bartels Respiratory Viral Detection kit was used with IFA results available within 24 hours. Results: Nine of 18 patients tested positive for RVI with influenza A (n = 8) and influenza B (n = 1) detected. The sensitivity of IFA (67%) was higher than that of cell culture (45%). With intensive supportive therapy, infection was self-limiting in bronchiolitis obliterans syndrome (BOS) Grade 0–2 patients. However, patients with BOS Grade 3 manifested an acute exacerbation of airflow obstruction, which proved to be irreversible. Conclusions: Lung transplant patients with “flu-like” symptoms should proceed to IFA testing of NT swab specimens for early diagnosis. Samples collected within 7 days of symptom onset have high sensitivity as compared with serology and viral culture techniques.

negative: Middle East respiratory syndrome coronavirus vaccines: current status and novel approaches Middle East respiratory syndrome coronavirus (MERS-CoV) is a cause of severe respiratory infection in humans, specifically the elderly and people with comorbidities. The re-emergence of lethal coronaviruses calls for international collaboration to produce coronavirus vaccines, which are still lacking to date. Ongoing efforts to develop MERS-CoV vaccines should consider the different target populations (dromedary camels and humans) and the correlates of protection. Extending on our current knowledge of MERS, vaccination of dromedary camels to induce mucosal immunity could be a promising approach to diminish MERS-CoV transmission to humans. In addition, it is equally important to develop vaccines for humans that induce broader reactivity against various coronaviruses to be prepared for a potential next CoV outbreak.

negative: More prevalent, less deadly? Bayesian inference of the COVID19 Infection Fatality Ratio from mortality data We use an established semi-mechanistic Bayesian hierarchical model of the COVID-19 pandemic, driven by European mortality data, to estimate the prevalence of immunity. We allow the infection-fatality ratio (IFR) to vary, adapt the model's priors to better reflect emerging information, and re-evaluate the model fitting in the light of current mortality data. The results indicate that the IFR of COVID-19 may be an order of magnitude smaller than the current consensus, with the corollary that the virus is more prevalent than currently believed. These results emerge from a simple model and ought to be treated with caution. They emphasise the value of rapid community-scale antibody testing when this becomes available.

negative: Antigenic Cross-Reactivity between Severe Acute Respiratory Syndrome—Associated Coronavirus and Human Coronaviruses 229E and OC43 Cross-reactivity between antibodies to different human coronaviruses (HCoVs) has not been systematically studied. By use of Western blot analysis, indirect immunofluorescence assay (IFA), and enzyme-linked immunosorbent assay (ELISA), antigenic cross-reactivity between severe acute respiratory syndrome (SARS)—associated coronavirus (SARS-CoV) and 2 HCoVs (229E and OC43) was demonstrated in immunized animals and human serum. In 5 of 11 and 10 of 11 patients with SARS, paired serum samples showed a ⩾4-fold increase in antibody titers against HCoV-229E and HCoV-OC43, respectively, by IFA. Overall, serum samples from convalescent patients who had SARS had a 1-way cross-reactivity with the 2 known HCoVs. Antigens of SARS-CoV and HCoV-OC43 were more cross-reactive than were those of SARS-CoV and HCoV-229E.

negative: 3D printed circuit splitter and flow restriction devices for multiple patient lung ventilation using one anaesthesia workstation or ventilator. The ongoing pandemic of SARS-CoV-2 virus and its associated disease COVID-19 has resulted in widespread ventilator shortages and rationing of care. Massive global supply chain disruption and quarantine measures prevent equipment movement and medical device production.

negative: Immunogenicity and antigenicity of human coronaviruses 229E and OC43. The immunogenicity and antigenicity of human coronaviruses 229E and OC43 were studied by quantitative immunoelectrophoresis. Three distinct antigens were recognized in both coronavirus strains when T-100-solubilized whole virus was tested by two-dimensional immunoelectrophoresis against homologous rabbit antiserum. No antigens cross-reacted between strains, but the electrophoretic patterns against homologous antiserum were highly similar in that both strains had one electrophoretically fast antigen, one of intermediate mobility, and one of slow mobility. Immunization of rabbits with 10(9) plaque-forming units of virus was required for production of antiserum which recognized the three antigens; lesser amounts gave rise to antisera which recognized only one or two components. Precipitin lines excised from two-dimensional immunoelectropherograms were used successfully as immunogens to prepare monospecific antiserum to each of the antigens of OC43 and 229E. Monospecific antiserum to the slow component of 229E neutralized 229E only, and monospecific antiserum to the slow component of OC43 both neutralized and inhibited hemagglutination of OC43 virus. Human convalescent sera which possessed both complement-fixing and neutralizing antibody also recognized the slow-moving component.

negative: Severe Acute Respiratory Syndrome: Pertinent Clinical Characteristics and Therapy Severe acute respiratory syndrome (SARS) is a newly emerged infection that is caused by a previously unrecognized virus–a novel coronavirus designated as SARS-associated coronavirus (SARS-CoV). From November 2002 to July 2003 the cumulative number of worldwide cases was >8000, with a mortality rate of close to 10%. The mortality has been higher in older patients and those with co-morbidities. SARS has been defined using clinical and epidemiological criteria and cases are considered laboratory-confirmed if SARS coronavirus is isolated, if antibody to SARS coronavirus is detected, or a polymerase chain reaction test by appropriate criteria is positive. At the time of writing (24 May 2004), no specific therapy has been recommended. A variety of treatments have been attempted, but there are no controlled data. Most patients have been treated throughout the illness with broad-spectrum antimicrobials, supplemental oxygen, intravenous fluids, and other supportive measures. Transmission of SARS is facilitated by close contact with patients with symptomatic infection. The majority of cases have been reported among healthcare providers and family members of SARS patients. Since SARS-CoV is contagious, measures for prevention center on avoidance of exposure, and infection control strategies for suspected cases and contacts. This includes standard precautions (hand hygiene), contact precautions (gowns, goggles, gloves) and airborne precautions (negative pressure rooms and high efficiency masks). In light of reports of new cases identified during the winter of 2003–4 in China, it seems possible that SARS will be an important cause of pneumonia in the future, and the screening of outpatients at risk for SARS may become part of the pneumonia evaluation.

negative: Immunological Detection and Characterization Immunological methods have been used for viral diagnosis for more than 100 years. Although molecular methods are replacing many older methods of viral diagnosis, there is still a significant role for immunological methods to guide patient care and in the performance of epidemiologic studies. Identification of viral antigens in clinical samples can be accomplished rapidly through the use of point-of-care lateral immunoassays or through the use of more traditional immunofluorescence and enzyme immunoassays in the virology laboratory. Serological assays are also a valuable tool for the clinician and epidemiologist. Many of the available diagnostic assays have enzyme immunoassay formats, but functional assays such as hemagglutination-inhibition and neutralizing antibody tests are also available. In some instances, virus infection can be diagnosed with a single serum sample (e.g., HIV and hepatitis C virus infections) while in other instances paired sera are needed (e.g., those caused by common respiratory viruses). Point-of-care antibody assays are also available for testing blood and saliva samples for some viruses. An understanding of the principles of immunological detection methods is important in the application and interpretation of test results.

negative: T-cell immunity of SARS-CoV: Implications for vaccine development against MERS-CoV Abstract Over 12 years have elapsed since severe acute respiratory syndrome (SARS) triggered the first global alert for coronavirus infections. Virus transmission in humans was quickly halted by public health measures and human infections of SARS coronavirus (SARS-CoV) have not been observed since. However, other coronaviruses still pose a continuous threat to human health, as exemplified by the recent emergence of Middle East respiratory syndrome (MERS) in humans. The work on SARS-CoV widens our knowledge on the epidemiology, pathophysiology and immunology of coronaviruses and may shed light on MERS coronavirus (MERS-CoV). It has been confirmed that T-cell immunity plays an important role in recovery from SARS-CoV infection. Herein, we summarize T-cell immunological studies of SARS-CoV and discuss the potential cross-reactivity of the SARS-CoV-specific immunity against MERS-CoV, which may provide useful recommendations for the development of broad-spectrum vaccines against coronavirus infections.

negative: Lack of serological evidence of Middle East respiratory syndrome coronavirus infection in virus exposed camel abattoir workers in Nigeria, 2016 Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic threat of global public health concern and dromedary camels are the source of zoonotic infection. Although MERS-CoV is enzootic in dromedaries in Africa as well as the Middle East, zoonotic disease has not been reported in Africa. Methods: In an abattoir in Kano, Nigeria, we tested nasal swabs from camels and investigated 261 humans with repeated occupational exposure to camels, many of whom also reported drinking fresh camel milk (n = 138) or urine (n = 94) or using camel urine for medicinal purposes (n = 96). Results: Weekly MERS-CoV RNA detection in January–February 2016 ranged from 0–8.4% of camels sampled. None of the abattoir workers with exposure to camels had evidence of neutralising antibody to MERS-CoV. Conclusion: There is a need for more studies to investigate whether or not zoonotic transmission of MERS-CoV does take place in Africa.

negative: An ELISA for the detection of serum antibodies to both transmissible gastroenteritis virus and porcine respiratory coronavirus Abstract A competition ELISA utilizing a mAb directed towards a peplomer protein epitope common to TGEV, PRCV and related feline and canine coronaviruses is described.

negative: Enhancing immunity in viral infections, with special emphasis on COVID-19: A review Abstract Background and aims Balanced nutrition which can help in maintaining immunity is essential for prevention and management of viral infections. While data regarding nutrition in coronavirus infection (COVID-19) are not available, in this review, we aimed to evaluated evidence from previous clinical trials that evaluated nutrition-based interventions for viral diseases (with special emphasis on respiratory infections), and summaries our observations. Methods A systematic search strategy was employed using keywords to search the literature in 3 key medical databases: PubMed®, Web of Science® and SciVerse Scopus®. Studies were considered eligible if they were controlled trials in humans, measuring immunological parameters, on viral and respiratory infections. Clinical trials on vitamins, minerals, nutraceuticals and probiotics were included. Results total of 640 records were identified initially and 22 studies were included from other sources. After excluding duplicates and articles that did not meet the inclusion criteria, 43 studies were obtained (vitamins: 13; minerals: 8; nutraceuticals: 18 and probiotics: 4). Among vitamins, A and D showed a potential benefit, especially in deficient populations. Among trace elements, selenium and zinc have also shown favourable immune-modulatory effects in viral respiratory infections. Several nutraceuticals and probiotics may have some role in enhancing immune functions. Micronutrients may be beneficial in nutritionally depleted elderly population. Conclusions We summaries possible benefits of some vitamins, trace elements, nutraceuticals and and probiotics. Nutrition principles based on these data could be useful in possible prevention and management of COVID-19

negative: Managing emerging infectious diseases: Is a federal system an impediment to effective laws? In the 1980's and 1990's HIV/AIDS was the emerging infectious disease. In 2003–2004 we saw the emergence of SARS, Avian influenza and Anthrax in a man made form used for bioterrorism. Emergency powers legislation in Australia is a patchwork of Commonwealth quarantine laws and State and Territory based emergency powers in public health legislation. It is time for a review of such legislation and time for consideration of the efficacy of such legislation from a country wide perspective in an age when we have to consider the possibility of mass outbreaks of communicable diseases which ignore jurisdictional boundaries.

negative: Do we need an ethical framework for hospital infection control? Summary Strategies for the control of the spread of infection in hospitals may lead to constraints on individual autonomy, freedom of movement, or contact with others. Codes of (ethical) practice for healthcare professionals tend to emphasise responsibilities to individual patients. Ethical frameworks for public health focus on groups of individuals (populations), the majority of whom are relatively healthy and empowered. Hospital infection control professionals must take account of both of these perspectives, sensitive to the care of infected and potentially infectious individuals, while protecting the vulnerable and relatively dependent population of hospital patients from further compromise to their health. A number of frameworks for an ethics of public health have been proposed over the last few years but there are sufficient differences in ethical considerations between collective interventions that aim to protect and promote the health of the public and interventions taken in the context of hospital infection control to justify a distinctive ethics of hospital infection control. Professional bodies may be best placed to lead the development of such a framework.

negative: Serological and molecular rapid diagnostic tests for Toxoplasma infection in humans and animals Infection by Toxoplasma gondii is prevalent worldwide. The parasite can infect a broad spectrum of vertebrate hosts, but infection of fetuses and immunocompromised patients is of particular concern. Easy-to-perform, robust, and highly sensitive and specific methods to detect Toxoplasma infection are important for the treatment and management of patients. Rapid diagnostic methods that do not sacrifice the accuracy of the assay and give reproducible results in a short time are highly desirable. In this context, rapid diagnostic tests (RDTs), especially with point-of-care (POC) features, are promising diagnostic methods in clinical microbiology laboratories, especially in areas with minimal laboratory facilities. More advanced methods using microfluidics and sensor technology will be the future trend. In this review, we discuss serological and molecular-based rapid diagnostic tests for detecting Toxoplasma infection in humans as well as animals.

negative: Feline Infectious Peritonitis (Feline Coronavirus)

negative: New Diagnostic Tools for Infectious Disease

negative: COVID-19 Vaccine Candidates: Prediction and Validation of 174 SARS-CoV-2 Epitopes The recent outbreak of SARS-CoV-2 (2019-nCoV) virus has highlighted the need for fast and efficacious vaccine development. Stimulation of a proper immune response that leads to protection is highly dependent on presentation of epitopes to circulating T-cells via the HLA complex. SARS-CoV-2 is a large RNA virus and testing of all overlapping peptides in vitro to deconvolute an immune response is not feasible. Therefore HLA-binding prediction tools are often used to narrow down the number of peptides to test. We tested 19 epitope-HLA-binding prediction tools, and using an in vitro peptide MHC stability assay, we assessed 777 peptides that were predicted to be good binders across 11 MHC allotypes. In this investigation of potential SARS-CoV-2 epitopes we found that current prediction tools vary in performance when assessing binding stability, and they are highly dependent on the MHC allotype in question. Designing a COVID-19 vaccine where only a few epitope targets are included is therefore a very challenging task. Here, we present 174 SARS-CoV-2 epitopes with high prediction binding scores, validated to bind stably to 11 HLA allotypes. Our findings may contribute to the design of an efficacious vaccine against COVID-19.

negative: Presence of Middle East respiratory syndrome coronavirus antibodies in Saudi Arabia: a nationwide, cross-sectional, serological study BACKGROUND: Scientific evidence suggests that dromedary camels are the intermediary host for the Middle East respiratory syndrome coronavirus (MERS-CoV). However, the actual number of infections in people who have had contact with camels is unknown and most index patients cannot recall any such contact. We aimed to do a nationwide serosurvey in Saudi Arabia to establish the prevalence of MERS-CoV antibodies, both in the general population and in populations of individuals who have maximum exposure to camels. METHODS: In the cross-sectional serosurvey, we tested human serum samples obtained from healthy individuals older than 15 years who attended primary health-care centres or participated in a national burden-of-disease study in all 13 provinces of Saudi Arabia. Additionally, we tested serum samples from shepherds and abattoir workers with occupational exposure to camels. Samples were screened by recombinant ELISA and MERS-CoV seropositivity was confirmed by recombinant immunofluorescence and plaque reduction neutralisation tests. We used two-tailed Mann Whitney U exact tests, χ(2), and Fisher's exact tests to analyse the data. FINDINGS: Between Dec 1, 2012, and Dec 1, 2013, we obtained individual serum samples from 10 009 individuals. Anti-MERS-CoV antibodies were confirmed in 15 (0·15%; 95% CI 0·09–0·24) of 10 009 people in six of the 13 provinces. The mean age of seropositive individuals was significantly younger than that of patients with reported, laboratory-confirmed, primary Middle Eastern respiratory syndrome (43·5 years [SD 17·3] vs 53·8 years [17·5]; p=0·008). Men had a higher antibody prevalence than did women (11 [0·25%] of 4341 vs two [0·05%] of 4378; p=0·028) and antibody prevalence was significantly higher in central versus coastal provinces (14 [0·26%] of 5479 vs one [0·02%] of 4529; p=0·003). Compared with the general population, seroprevalence of MERS-CoV antibodies was significantly increased by 15 times in shepherds (two [2·3%] of 87, p=0·0004) and by 23 times in slaughterhouse workers (five [3·6%] of 140; p<0·0001). INTERPRETATION: Seroprevalence of MERS-CoV antibodies was significantly higher in camel-exposed individuals than in the general population. By simple multiplication, a projected 44 951 (95% CI 26 971–71 922) individuals older than 15 years might be seropositive for MERS-CoV in Saudi Arabia. These individuals might be the source of infection for patients with confirmed MERS who had no previous exposure to camels. FUNDING: European Union, German Centre for Infection Research, Federal Ministry of Education and Research, German Research Council, and Ministry of Health of Saudi Arabia.

negative: Donor-derived infection—the challenge for transplant safety Organ transplantation, including of the heart, lung, kidney, liver, pancreas, and small bowel, is considered the therapy of choice for end-stage organ failure. Each year, over 70,000 organs are implanted worldwide. One donor may provide multiple organs, as well as corneas and other tissues, for multiple recipients. The degree of risk for transmission of infection carried with grafts, notably of viruses, is largely unknown and, for a specific organ, difficult to assess. The approach to microbiological screening of organ donors varies with national and regional regulations and with the availability and performance of microbiological assays used for potential donors. Transmission of both expected or common, and unexpected infections has been observed in organ transplants, generally recognized after development of clusters of infections among recipients of organs from a common donor. Other than for unusual or catastrophic events, few data exist that define the incidence and manifestations of donor-derived infections or the ideal assays to use in screening to prevent such transmissions. Absolute prevention of the transmission of donor-derived infections in organ transplantation is not possible. However, improvements in screening technologies will enhance the safety of transplantation in the future. SUPPLEMENTARY INFORMATION: The online version of this article (doi:10.1038/nrneph.2014.159) contains supplementary material, which is available to authorized users.

negative: Rapid detection of anti-H5 avian influenza virus antibody by fluorescence polarization immunoassay using a portable fluorescence polarization analyzer Abstract A rapid, facile and selective detection of anti-H5 subtype avian influenza virus (AIV) antibody in serum by fluorescence polarization immunoassay (FPIA) was achieved. A fragment of recombinant H5 subtype AIVhemagglutinin was produced and labeled with fluorescein to use it as a labeled antigen in FPIA. This labeled antigen was mixed with anti-AIV sera (H1–H16 subtypes) and FP of the mixture was measured using a portable FP analyzer on a microdevice. It was found that FP increased in proportion to the concentration of anti-H5 AIV antibody (serum) and was significantly higher than FP obtained with the other sera. The selective detection of anti-H5 subtype AIV antibody was confirmed. The required volume of original sample was 2 μL and analysis time was within 20 min. This detection system realizes an efficient on-site diagnosis and surveillance of AIV.

negative: Eosinophil Responses During COVID-19 Infections and Coronavirus Vaccination Abstract Eosinophils are circulating and tissue-resident leukocytes that have potent pro-inflammatory effects in a number of diseases. Recently, eosinophils have been shown to have a variety of other functions, including immunoregulation and antiviral activity. Eosinophil levels vary dramatically in a number of clinical settings, especially following eosinophil-targeted therapy, which is now available to selectively deplete these cells. There are key COVID-19–related questions concerning eosinophils whose answers affect recommended prevention and care. First, do patients with eosinophilia-associated diseases have an altered course of COVID-19? Second, do patients with eosinopenia (now intentionally induced by biological drugs) have unique COVID-19 susceptibility and/or disease course? This is a particularly relevant question as eosinopenia is associated with acute respiratory deterioration during infection with the Severe Acute Respiratory Syndrome (SARS)-Corona Virus (CoV)-2, the causative agent of COVID-19. Third, do eosinophils contribute to the lung pathology induced during COVID-19 and will they contribute to immunopotentiation potentially associated with emerging COVID-19 vaccines? Herein, we address these timely questions and project considerations during the emerging COVID-19 pandemic.

negative: Testing for SARS‐CoV‐2: the day the world turned its attention to the clinical laboratory In the last few months, an unprecedented number of laboratory tests for COVID‐19 have been developed at a remarkable speed. With the rapid adoption of these tests into clinical practice, combined with the widespread publicity they received, questions arose related to the different types of tests, their utility, performance, and regulatory approval status. The aim of this publication is to provide a general landscape of laboratory testing for COVID‐19 and offer a historical and regulatory perspective associated with them. Specifically, we aim to elaborate on the regulatory complexities of diagnostic testing in the U.S. and its implications to the present outbreak, as well as provide a synopsis of laboratory tests that have been developed for COVID‐19. We will first address the detection of Sars‐Cov‐2 directly by either nucleic acid amplification tests (NAAT) or by the detection of the viral protein for active infections. Subsequently, we will provide an overview of serological tests that can aid not only in diagnosis but additionally help to identify prior infections and potential immunity.

negative: Reliability and usefulness of a rapid IgM‐IgG antibody test for the diagnosis of SARS-CoV-2 infection: a preliminary report.

negative: Measures for diagnosing and treating infections by a novel coronavirus responsible for a pneumonia outbreak originating in Wuhan, China Abstract On 10 January 2020, a new coronavirus causing a pneumonia outbreak in Wuhan City in central China was denoted as 2019-nCoV by the World Health Organization (WHO). As of 24 January 2020, there were 887 confirmed cases of 2019-nCoV infection, including 26 deaths, reported in China and other countries. Therefore, combating this new virus and stopping the epidemic is a matter of urgency. Here, we focus on advances in research and development of fast diagnosis methods, as well as potential prophylactics and therapeutics to prevent or treat 2019-nCoV infection.

negative: Seroprevalence of MERS-CoV in healthy adults in western Saudi Arabia, 2011–2016 Abstract Background The Middle East respiratory syndrome coronavirus (MERS-CoV) is a newly recognized zoonotic coronavirus. Current evidence confirms the role of dromedaries in primary human infections but does not explain the sporadic community cases. However, asymptomatic or subclinical cases could represent a possible source of infection in the community. Methods Archived human sera (7461) collected between 2011 and 2016 from healthy adult blood donors from 50 different nationalities in the western part of Saudi Arabia were obtained for MERS-CoV seroprevalence investigation. Samples were tested for MERS-CoV S1-specific antibodies (Abs) by ELISA and confirmed by testing for neutralizing Abs (nAbs) using both pseudotyped and live virus neutralization assays. Results Out of 7461 samples, 174 sera from individuals with 18 different nationalities were ELISA positive (2.3%, 95% CI 2.0–2.7). Presence of nAbs was confirmed in 17 samples (0.23%, 95% CI 0.1–0.4) of which one sample exhibited positivity in both neutralization assays. Confirmed seropositivity was identified in young (15–44 years) men and women from Saudi Arabia, Egypt, Yemen, Pakistan, Palestine, Sudan, and India without significant preference. Conclusions An increasing trend of MERS-CoV seroprevalence was observed in the general population in western Saudi Arabia, suggesting that asymptomatic or mild infections might exist and act as an unrecognized source of infection. Seropositivity of individuals from different nationalities underscores the potential MERS exportation outside of the Arabian Peninsula. Thus, enhanced and continuous surveillance is highly warranted.

negative: Prevalence and implications of feline coronavirus infections of captive and free-ranging cheetahs (Acinonyx jubatus). The extent and progression of exposure to feline infectious peritonitis (FIP) virus in the cheetah, Acinonyx jubatus, was monitored by a world-wide serological survey with indirect fluorescent antibody titers to coronavirus. The indirect fluorescent antibody assay was validated by Western blots, which showed that all indirect fluorescent antibody-positive cheetah sera detected both domestic cat and cheetah coronavirus structural proteins. There was a poor correlation between indirect fluorescent antibody results and the presence of coronaviruslike particles in cheetah feces, suggesting that electron microscopic detection of shed particles may not be an easily interpreted diagnostic parameter for FIP disease. Low, but verifiable (by Western blots [immunoblots]) antibody titers against coronavirus were detected in eight free-ranging cheetahs from east Africa as well as from captive cheetahs throughout the world. Of 20 North American cheetah facilities screened, 9 had cheetahs with measurable antibodies to feline coronavirus. Five facilities showed patterns of an ongoing epizootic. Retrospective FIP virus titers of an FIP outbreak in a cheetah-breeding facility in Oregon were monitored over a 5-year period and are interpreted here in terms of clinical disease progression. During that outbreak the morbidity was over 90% and the mortality was 60%, far greater than any previously reported epizootic of FIP in any cat species. Age of infection was a significant risk factor in this epizootic, with infants (less than 3 months old) displaying significantly higher risk for mortality than subadults or adults. Based upon these observations, empirical generalizations are drawn which address epidemiologic concerns for cheetahs in the context of this lethal infectious agent.

negative: Enzyme Immunoassays for Infectious Diseases

negative: Hospital-Associated Outbreak of Middle East Respiratory Syndrome Coronavirus: A Serologic, Epidemiologic, and Clinical Description BACKGROUND: In April 2012, the Jordan Ministry of Health investigated an outbreak of lower respiratory illnesses at a hospital in Jordan; 2 fatal cases were retrospectively confirmed by real-time reverse transcription polymerase chain reaction (rRT-PCR) to be the first detected cases of Middle East respiratory syndrome (MERS-CoV). METHODS: Epidemiologic and clinical characteristics of selected potential cases were assessed through serum blood specimens, medical record reviews, and interviews with surviving outbreak members, household contacts, and healthcare personnel. Cases of MERS-CoV infection were identified using 3 US Centers for Disease Control and Prevention serologic tests for detection of anti–MERS-CoV antibodies. RESULTS: Specimens and interviews were obtained from 124 subjects. Seven previously unconfirmed individuals tested positive for anti–MERS-CoV antibodies by at least 2 of 3 serologic tests, in addition to 2 fatal cases identified by rRT-PCR. The case-fatality rate among the 9 total cases was 22%. Six subjects were healthcare workers at the outbreak hospital, yielding an attack rate of 10% among potentially exposed outbreak hospital personnel. There was no evidence of MERS-CoV transmission at 2 transfer hospitals having acceptable infection control practices. CONCLUSIONS: Novel serologic tests allowed for the detection of otherwise unrecognized cases of MERS-CoV infection among contacts in a Jordanian hospital-associated respiratory illness outbreak in April 2012, resulting in a total of 9 test-positive cases. Serologic results suggest that further spread of this outbreak to transfer hospitals did not occur. Most subjects had no major, underlying medical conditions; none were on hemodialysis. Our observed case-fatality rate was lower than has been reported from outbreaks elsewhere.

negative: Molecular and serological investigation of 2019-nCoV infected patients: implication of multiple shedding routes In December 2019, a novel coronavirus (2019-nCoV) caused an outbreak in Wuhan, China, and soon spread to other parts of the world. It was believed that 2019-nCoV was transmitted through respiratory tract and then induced pneumonia, thus molecular diagnosis based on oral swabs was used for confirmation of this disease. Likewise, patient will be released upon two times of negative detection from oral swabs. However, many coronaviruses can also be transmitted through oral-fecal route by infecting intestines. Whether 2019-nCoV infected patients also carry virus in other organs like intestine need to be tested. We conducted investigation on patients in a local hospital who were infected with this virus. We found the presence of 2019-nCoV in anal swabs and blood as well, and more anal swab positives than oral swab positives in a later stage of infection, suggesting shedding and thereby transmitted through oral-fecal route. We also showed serology test can improve detection positive rate thus should be used in future epidemiology. Our report provides a cautionary warning that 2019-nCoV may be shed through multiple routes.

negative: Comparison of enzyme-linked immunosorbent assay and RT-PCR for the detection of porcine epidemic diarrhoea virus Abstract Porcine epidemic diarrhoea (PED) is a contagious enteric disease of pigs caused by a coronavirus. A double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) based on the use of monoclonal antibodies was developed for the detection of porcine epidemic diarrhoea virus (PEDV). The DAS-ELISA was compared with RT-PCR in the examination of 506 specimens collected during 2006–2007 from pigs originating from different farms located in the Po valley. Both faecal samples obtained directly from the rectum of live animals showing clinical signs and intestinal samples collected from the caecum of deceased pigs were included in the study. The correlation between the two methods was higher when testing faecal samples (K =0.97, 95% CI: 0.94–1.00) than testing intestinal samples (K =0.62, 95% CI: 0.35–0.89). The use of ELISA technology provided an efficient and effective mean of evaluating the presence of coronavirus PED antigen in field samples and indicates that this procedure is a very useful tool in epidemiological studies.

negative: Middle East respiratory syndrome coronavirus-encoded ORF8b strongly antagonizes IFN-β promoter activation: its implication for vaccine design Middle East respiratory syndrome coronavirus (MERS-CoV) is a causative agent of severe-to-fatal pneumonia especially in patients with pre-existing conditions, such as smoking and chronic obstructive pulmonary disease (COPD). MERS-CoV transmission continues to be reported in the Saudi Arabian Peninsula since its discovery in 2012. However, it has rarely been epidemic outside the area except one large outbreak in South Korea in May 2015. The genome of the epidemic MERS-CoV isolated from a Korean patient revealed its homology to previously reported strains. MERS-CoV encodes 5 accessory proteins and generally, they do not participate in the genome transcription and replication but rather are involved in viral evasion of the host innate immune responses. Here we report that ORF8b, an accessory protein of MERS-CoV, strongly inhibits both MDA5- and RIG-I-mediated activation of interferon beta promoter activity while downstream signaling molecules were left largely unaffected. Of note, MDA5 protein levels were significantly down-regulated by ORF8b and co-expression of ORF4a and ORF4b. These novel findings will facilitate elucidation of mechanisms of virus-encoded evasion strategies, thus helping design rationale antiviral countermeasures against deadly MERS-CoV infection.

negative: Induction of robust immunity response in mice by dual-expression-system-based recombinant baculovirus expressing the capsid protein of porcine circovirus type 2 BACKGROUND: Porcine circovirus type 2 (PCV2) is associated with post-weaning multisystemic wasting syndrome (PMWS), an emerging swine disease that causes progressive weight loss, dyspnea, tachypnea, anemia, jaundice, and diarrhea in piglets. Although baculovirus is an enveloped virus that infects insects in nature, it has emerged as a vaccine vector, and we used it to develop a novel candidate vaccine for a preventive or therapeutic strategy to control PCV2 infections. METHODS: Immunoblotting analysis of recombinant baculovirus and immunofluorescent staining of baculovirus-infected cells were followed using anti-ORF2 monoclonal antibodies. The BALB/c mice were immunized intramuscularly with this baculovirus. The titers of antibodies were mensurated with a Cap-protein-specific enzyme-linked immunosorbent assay (ELISA) and a serum neutralization assay. The IFN-γ response in splenocytes harvested from immunized mice was measured by ELISA. Student's t-test was used to compare immune responses of different groups. RESULTS: In this study, we successfully constructed a dual-expression-system-based recombinant baculovirus BV-GD-ORF2, which can display the PCV2 capsid (Cap) protein and VSV-G protein on the viral envelope and also expressing Cap protein on transduced mammalian cells, thereby functioning as both a subunit and a DNA vaccine. After infection, the Cap protein was expressed and displayed on the viral surface, as demonstrated with an indirect fluorescence assay and immunoblotting. The vaccination of mice with recombinant baculovirus BV-GD-ORF2 successfully induced robust Cap-protein-specific humoral and cellular immune responses. CONCLUSIONS: Our findings collectively demonstrate that the recombinant baculovirus BV-GD-ORF2 is a potential vaccine against PCV2 infections.

negative: Rapid discovery and optimization of therapeutic antibodies against emerging infectious diseases Using a comprehensive set of discovery and optimization tools, antibodies were produced with the ability to neutralize SARS coronavirus (SARS-CoV) infection in Vero E6 cells and in animal models. These anti-SARS antibodies were discovered using a novel DNA display method, which can identify new antibodies within days. Once neutralizing antibodies were identified, a comprehensive and effective means of converting the mouse sequences to human frameworks was accomplished using HuFR™ (human framework reassembly) technology. The best variant (61G4) from this screen showed a 3.5–4-fold improvement in neutralization of SARS-CoV infection in vitro. Finally, using a complete site-saturation mutagenesis methodology focused on the CDR (complementarity determining regions), a single point mutation (51E7) was identified that improved the 80% plaque reduction neutralization of the virus by greater than 8-fold. These discovery and evolution strategies can be applied to any emerging pathogen or toxin where a causative agent is known.

negative: 6th International Conference on Emerging Zoonoses The 6th International Conference on Emerging Zoonoses, held at Cancun, Mexico, 24–27 February 2011, offered 84 participants from 18 countries, a snapshot of current research in numerous zoonoses caused by viruses, bacteria or prions. Co‐chaired by Professors Heinz Feldmann and Jürgen Richt, the conference explored 10 topics: (i) The ecology of emerging zoonotic diseases; (ii) The role of wildlife in emerging zoonoses; (iii) Cross‐species transmission of zoonotic pathogens; (iv) Emerging and neglected influenza viruses; (v) Haemorrhagic fever viruses; (vi) Emerging bacterial diseases; (vii) Outbreak responses to zoonotic diseases; (viii) Food‐borne zoonotic diseases; (ix) Prion diseases; and (x) Modelling and prediction of emergence of zoonoses. Human medicine, veterinary medicine and environmental challenges are viewed as a unity, which must be considered under the umbrella of ‘One Health’. Several presentations attempted to integrate the insights gained from field data with mathematical models in the search for effective control measures of specific zoonoses. The overriding objective of the research presentations was to create, improve and use the tools essential to address the risk of contagions in a globalized society. In seeking to fulfil this objective, a three‐step approach has often been applied: (i) use cultured cells, model and natural animal hosts and human clinical models to study infection; (ii) combine traditional histopathological and biochemical approaches with functional genomics, proteomics and computational biology; and (iii) obtain signatures of virulence and insights into mechanisms of host defense response, immune evasion and pathogenesis. This meeting review summarizes 39 of the conference presentations and mentions briefly the 16 articles in this Special Supplement, most of which were presented at the conference in earlier versions. The full affiliations of all presenters and many colleagues have been included to facilitate further inquiries from readers.

negative: Status, quality and specific needs of Zika virus (ZIKV) diagnostic capacity and capability in National Reference Laboratories for arboviruses in 30 EU/EEA countries, May 2016 With international travel, Zika virus (ZIKV) is introduced to Europe regularly. A country's ability to robustly detect ZIKV introduction and local transmission is important to minimise the risk for a ZIKV outbreak. Therefore, sufficient expertise and diagnostic capacity and capability are required in European laboratories. To assess the capacity, quality, operational specifics (guidelines and algorithms), technical and interpretation issues and other possible difficulties that were related to ZIKV diagnostics in European countries, a questionnaire was conducted among national reference laboratories in 30 countries in the European Union/European Economic Area (EU/EEA) in May 2016. While the coverage and capacity of ZIKV diagnostics in the EU/EEA national reference laboratories were found to be adequate, the assessment of the quality and needs indicated several crucial points of improvement that will need support at national and EU/EEA level to improve ZIKV preparedness, response and EU/EEA ZIKV surveillance activities.

negative: A new and rapid approach for detecting COVID-19 based on S1 protein fragments. The pandemic of novel coronavirus disease 2019 (COVID-19) seriously threatened the public health all over the world. A colloidal gold immunochromatography assay for IgM/IgG antibodies against the receptor-binding domain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) S1 protein was established to assess its rapid diagnostic value. We first designed and manufactured all contents of the test cassette of SARS-CoV-2 rapid test kit: the colloidal gold-labeled mouse-antihuman lgM/lgG antibody, the recombinant SARS-CoV-2 antigen, the nitrocellulose membrane control line, and specimen diluents. Furthermore, reverse transcription-polymerase chain reaction (RT-PCR) assay, colloidal gold immunochromatography assay, serological validation of cross reaction with other common viruses, and clinical validation were performed. The kit was finally evaluated by 75 serum/plasma samples of SARS-CoV-2 infection cases and 139 healthy samples as control, with the result of that the sensitivity, specificity, and accuracy for IgM were 90.67%, 97.84%, and 95.33%, whereas for IgG were 69.33%, 99.28%, and 88.79%, respectively; the combination of IgM and IgG could improve the value: 92.00%, 97.12%, and 95.33%, respectively. Therefore, the rapid detection kit has high sensitivity and specificity, especially for IgM&IgG, showing a critical value in clinical application and epidemic control of COVID-19.

negative: Development of monoclonal antibodies and serological assays including indirect ELISA and fluorescent microsphere immunoassays for diagnosis of porcine deltacoronavirus BACKGROUND: A novel porcine deltacoronavirus (PDCoV), also known as porcine coronavirus HKU15, was reported in China in 2012 and identified in the U.S. in early 2014. Since then, PDCoV has been identified in a number of U.S. states and linked with clinical disease including acute diarrhea and vomiting in the absence of other identifiable pathogens. Since PDCoV was just recently linked with clinical disease, few specific antibody-based reagents were available to assist in diagnosis of PDCoV and limited serological capabilities were available to detect an antibody response to this virus. Therefore, the overall objective of this project was to develop and validate selected diagnostic reagents and assays for PDCoV antigen and antibody detection. RESULTS: The nucleoprotein of PDCoV was expressed as a recombinant protein and purified for use as an antigen to immunize mice for polyclonal, hyperimmune sera and monoclonal antibody (mAb) production. The resulting mAbs were evaluated for use in fluorescent antibody staining methods to detect PDCoV infected cells following virus isolation attempts and for immunohistochemistry staining of intestinal tissues of infected pigs. The same antigen was used to develop serological tests to detect the antibody response to PDCoV in pigs following infection. Serum samples from swine herds with recent documentation of PDCoV infection and samples from expected naïve herds were used for initial assay optimization. The tests were optimized in a checkerboard fashion to reduce signal to noise ratios using samples of known status. Statistical analysis was performed to establish assay cutoff values and assess diagnostic sensitivities and specificities. At least 629 known negative serum samples and 311 known positive samples were evaluated for each assay. The enzyme linked immunosorbent assay (ELISA) showed diagnostic sensitivity (DSe) of 96.1 % and diagnostic specificity (DSp) of 96.2 %. The fluorescent microsphere immunoassay (FMIA) showed a DSe of 95.8 % and DSp of 98.1 %. Both ELISA and FMIA detected seroconversion of challenged pigs between 8–14 days post-infection (DPI). An indirect fluorescent antibody (IFA) test was also developed using cell culture adapted PDCoV for comparative purposes. CONCLUSION: These new, specific reagents and serological assays will allow for improved diagnosis of PDCoV. Since many aspects of PDCoV infection and transmission are still not fully understood, the reagents and assays developed in this project should provide valuable tools to help understand this disease and to aid in the control and surveillance of porcine deltacoronavirus outbreaks.

negative: Failed detection of the full-length genome of SARS-CoV-2 by ultra-deep sequencing from the recovered and discharged patients retested viral PCR positive Over 10 percent of recovered and discharged patients retested positive for SARS-CoV-2, raising a public health concern whether they could be potential origins of infection. In this study, we found that detectable viral genome in discharged patients might only mean the presence of viral fragments, and could hardly form an infection origin for its extremely low concentration.

negative: Coronavirus-positive Nasopharyngeal Aspirate as Predictor for Severe Acute Respiratory Syndrome Mortality Severe acute respiratory syndrome (SARS) has caused a major epidemic worldwide. A novel coronavirus is deemed to be the causative agent. Early diagnosis can be made with reverse transcriptase-polymerase chain reaction (RT-PCR) of nasopharyngeal aspirate samples. We compared symptoms of 156 SARS-positive and 62 SARS-negative patients in Hong Kong; SARS was confirmed by RT-PCR. The RT-PCR–positive patients had significantly more shortness of breath, a lower lymphocyte count, and a lower lactate dehydrogenase level; they were also more likely to have bilateral and multifocal chest radiograph involvement, to be admitted to intensive care, to need mechanical ventilation, and to have higher mortality rates. By multivariate analysis, positive RT-PCR on nasopharyngeal aspirate samples was an independent predictor of death within 30 days.

negative: Transmission Electron Microscopy Improves the Diagnostic Sensitivity in Nonbacterial Etiology of Severe Pneumonia: A Retrospective Study BACKGROUND: Severe pneumonia is responsible for great mortality and morbidity worldwide, and early-applied effective anti-infective therapy can improve the prognosis of patients. However, identification of infectious agents in severe pneumonia remains a major challenge so far. In this study, the potential utility of transmission electron microscopy (TEM) in detecting nonbacterial pathogens in patients with severe pneumonia was retrospectively evaluated. MATERIALS AND METHODS: A total of 106 patients diagnosed with severe pneumonia at our hospital from September 2015 to December 2017 were included, and their baseline clinical characteristics were collected. Nonbacterial infectious agents detected by TEM in bronchoalveolar lavage fluid (BALF) and serological tests were summarized. The detection rates were further compared between TEM and serological tests. RESULTS: BALF examination under the transmission electron microscope revealed 24 viruses, 16 mycoplasmas, 18 chlamydia, 2 fungi and 74 bacteria in 99 samples, among which 61 samples were mixed infections. The combined use of serological tests and TEM significantly improved the detection rate of nonbacterial infectious agents in patients with severe pneumonia. CONCLUSIONS: Our data support that implementation of TEM could improve the sensitivity for detecting viruses, atypical pathogens and mixed infections in BALF from patient of severe pneumonia. Therefore, TEM may be used as an auxiliary diagnostic method of other microbiological tests in severe pneumonia.

negative: From SARS-CoV to SARS-CoV-2: safety and broad-spectrum are important for coronavirus vaccine development The global pandemic of COVID-19 caused by SARS-CoV-2 (also known as 2019-nCoV and HCoV-19) has posed serious threats to public health and economic stability worldwide, thus calling for development of vaccines against SARS-CoV-2 and other emerging and reemerging coronaviruses. Since SARS-CoV-2 and SARS-CoV have high similarity of their genomic sequences and share the same cellular receptor (ACE2), it is essential to learn the lessons and experiences from the development of SARS-CoV vaccines for the development of SARS-CoV-2 vaccines. In this review, we summarized the current knowledge on the advantages and disadvantages of the SARS-CoV vaccine candidates and prospected the strategies for the development of safe, effective and broad-spectrum coronavirus vaccines for prevention of infection by currently circulating SARS-CoV-2 and other emerging and reemerging coronaviruses that may cause future epidemics or pandemics.

negative: Evaluation of an enzyme-linked immunosorbent assay for the detection of transmissible gastroenteritis virus antibodies An enzyme-linked immunosorbent assay (ELISA) using a detergent-solubilized antigen of purified virus was developed for detection of antibody against porcine transmissible gastroenteritis (TGE) virus in swine serum. The ELISA demonstrated antibody responses in pigs immunized intramuscularly with the attenuated TO-163 strain of TGE virus and in pigs orally infected with the virulent Shizuoka strain of the virus. The results of the ELISA were well correlated with those of the neutralization test. These results indicate the usefulness of the ELISA as a serological tool for TGE virus antibody.

negative: Detection of viruses by counting single fluorescent genetically biotinylated reporter immunophage using a lateral flow assay. We demonstrated a lateral flow immunoassay (LFA) for detection of viruses using fluorescently labeled M13 bacteriophage as reporters and single-reporter counting as the readout. AviTag-biotinylated M13 phage were functionalized with antibodies using avidin-biotin conjugation and fluorescently labeled with AlexaFluor 555. Individual phage bound to target viruses (here MS2 as a model) captured on an LFA membrane strip were imaged using epi-fluorescence microscopy. Using automated image processing, we counted the number of bound phage in micrographs as a function of target concentration. The resultant assay was more sensitive than enzyme-linked immunosorbent assays and traditional colloidal-gold nanoparticle LFAs for direct detection of viruses.

negative: Characterization of novel monoclonal antibodies against the MERS-coronavirus spike protein and their application in species-independent antibody detection by competitive ELISA Abstract Since discovering the Middle East respiratory syndrome coronavirus (MERS-CoV) as a causative agent of severe respiratory illness in the Middle East in 2012, serological testing has been conducted to assess antibody responses in patients and to investigate the zoonotic reservoir of the virus. Although the virus neutralization test is the gold standard assay for MERS diagnosis and for investigating the zoonotic reservoir, it uses live virus and so must be performed in high containment laboratories. Competitive ELISA (cELISA), in which a labeled monoclonal antibody (MAb) competes with test serum antibodies for target epitopes, may be a suitable alternative because it detects antibodies in a species-independent manner. In this study, novel MAbs against the spike protein of MERS-CoV were produced and characterized. One of these MAbs was used to develop a cELISA. The cELISA detected MERS-CoV-specific antibodies in sera from MERS-CoV-infected rats and rabbits immunized with the spike protein of MERS-CoV. The MAb-based cELISA was validated using sera from Ethiopian dromedary camels. Relative to the neutralization test, the cELISA detected MERS-CoV-specific antibodies in 66 Ethiopian dromedary camels with a sensitivity and specificity of 98% and 100%, respectively. The cELISA and neutralization test results correlated well (Pearson’s correlation coefficients=0.71–0.76, depending on the cELISA serum dilution). This cELISA may be useful for MERS epidemiological investigations on MERS-CoV infection.

negative: Case Report: Diagnosis of Novel Coronavirus Disease (COVID-19) versus Tropical Diseases in Pakistan A 25-year-old medical student presented in Multan, Pakistan with a high fever, cough, myalgia, and diarrhea consistent with the typical signs and symptoms of novel coronavirus disease (COVID-19). The patient had traveled to high COVID-19–risk areas within Pakistan and had no significant medical and surgical history. Based on nasopharyngeal and oropharyngeal swab testing, the patient was found to be negative for COVID-19. He subsequently developed a diffuse rash and had serology consistent with dengue and measles. The patient was treated symptomatically, and his condition gradually improved over 7 days. This case highlights the high prevalence of many tropical diseases in low-income countries and the need for clinicians to consider alternate diagnoses in addition to testing for COVID-19 during the pandemic.

negative: Diagnosis of human coronavirus infection by immunofluorescence: Method and application to respiratory disease in hospitalized children Rabbit antisera were prepared against coronavirus strains 229E and OC43 and used successfully to detect viral antigen in epithelial cells shed from the nasopharynx of symptomatic volunteers who had received coronavirus inocula three to four days before. The same serologic reagents were applied to nasopharyngeal secretion cells obtained from 106 infants and children hospitalized with respiratory tract disease and apparently not infected with conventional respiratory viruses. No coronavirus infections were detected by this method. It appears that coronavirus OC43 or 229E infections were not common in children in Tyneside hospitals during the period of study. However, fluorescence is a useful method for detection of coronavirus infections in symptomatic human subjects.

negative: The use of masks and respirators to prevent transmission of influenza: a systematic review of the scientific evidence Please cite this paper as: bin‐Reza et al. (2012) The use of masks and respirators to prevent transmission of influenza: a systematic review of the scientific evidence. Influenza and Other Respiratory Viruses 6(4), 257–267. There are limited data on the use of masks and respirators to reduce transmission of influenza. A systematic review was undertaken to help inform pandemic influenza guidance in the United Kingdom. The initial review was performed in November 2009 and updated in June 2010 and January 2011. Inclusion criteria included randomised controlled trials and quasi‐experimental and observational studies of humans published in English with an outcome of laboratory‐confirmed or clinically‐diagnosed influenza and other viral respiratory infections. There were 17 eligible studies. Six of eight randomised controlled trials found no significant differences between control and intervention groups (masks with or without hand hygiene; N95/P2 respirators). One household trial found that mask wearing coupled with hand sanitiser use reduced secondary transmission of upper respiratory infection/influenza‐like illness/laboratory‐confirmed influenza compared with education; hand sanitiser alone resulted in no reduction. One hospital‐based trial found a lower rate of clinical respiratory illness associated with non‐fit‐tested N95 respirator use compared with medical masks. Eight of nine retrospective observational studies found that mask and/or respirator use was independently associated with a reduced risk of severe acute respiratory syndrome (SARS). Findings, however, may not be applicable to influenza and many studies were suboptimal. None of the studies established a conclusive relationship between mask/respirator use and protection against influenza infection. Some evidence suggests that mask use is best undertaken as part of a package of personal protection especially hand hygiene. The effectiveness of masks and respirators is likely linked to early, consistent and correct usage.

negative: SARS: Epidemiology, Clinical Presentation, Management, and Infection Control Measures Severe acute respiratory syndrome (SARS) is a recently recognized febrile respiratory illness that first appeared in southern China in November 2002, has since spread to several countries, and has resulted in more than 8000 cases and more than 750 deaths. The disease has been etiologically linked to a novel coronavirus that has been named the SARS-associated coronavirus. It appears to be spread primarily by large droplet transmission. There is no specific therapy, and management consists of supportive care. This article summarizes currently available information regarding the epidemiology, clinical features, etiologic agent, and modes of transmission of the disease, as well as infection control measures appropriate to contain SARS.

negative: COVID-19, Modern Pandemic: A Systematic Review From Front-Line Health Care Providers’ Perspective Coronavirus disease 2019 (COVID-19) caused infection in 168,000 cases worldwide in about 148 countries and killed more than 6,610 people around the world as of March 16, 2020, as per the World Health Organization (WHO). Compared to severe acute respiratory syndrome and Middle East respiratory syndrome, there is the rapid transmission, long incubation period, and disease containment is becoming extremely difficult. The main aim of this systematic review is to provide a comprehensive clinical summary of all the available data from high-quality research articles relevant to the epidemiology, demographics, trends in hospitalization and outcomes, clinical signs and symptoms, diagnostic methods and treatment methods of COVID-19, thus increasing awareness in health care providers. We also discussed various preventive measures to combat COVID-19 effectively. A systematic and protocol-driven approach is needed to contain this disease, which was declared as a global pandemic on March 11, 2020, by the WHO.

negative: Oral Research Communications of the 22(nd) ECVIM‐CA Congress

negative: Extended SIR prediction of the epidemics trend of COVID-19 in Italy and compared with Hunan, China Background: Coronavirus Disease 2019 (COVID19) is currently a global public health threat. Outside of China, Italy is one of the most suffering countries with the COVID19 epidemic. It is important to predict the epidemics trend of COVID19 epidemic in Italy to help develop public health strategies. Methods: We used time series data of COVID 19 from Jan 22,2020 to Mar 16,2020. An infectious disease dynamic extended susceptible infected removed (eSIR) model, which covers the effects of different intervention measures in dissimilar periods, was applied to estimate the epidemic trend in Italy. The basic reproductive number was estimated using Markov Chain Monte Carlo methods and presented using the resulting posterior mean and 95% credible interval (CI). Hunan, with similar total number of populations in Italy, was used as a comparative item. Results: In the eSIR model, we estimated that the basic reproductive number for COVID 19 was respectively 4.10 (95% CI: 2.15 to 6.77) in Italy and 3.15(95% CI: 1.71 to 5.21) in Hunan. There would be totally 30 086 infected cases (95%CI:7920-81 869) under the current country blockade and the endpoint would be Apr 25 (95%CI: Mar 30 to Aug 07) in Italy. If the country blockade is imposed 5 day later, the total number of infected cases would expand the infection scale 1.50 times. Conclusion: Italy's current strict measures can efficaciously prevent the further spread of COVID19 and should be maintained. Necessary strict public health measures be implemented as soon as possible in other European countries with a high number of COVID19 cases. The most effective strategy needs to be confirmed in further studies.

negative: Pandemic Flu: Clinical management of patients with an influenza-like illness during an influenza pandemic

negative: Report from the American Society for Microbiology COVID-19 International Summit, 23 March 2020: Value of Diagnostic Testing for SARS–CoV-2/COVID-19

negative: Determination of coronavirus 229E antibody by an immune‐adherence hemagglutination method An immune‐adherence hemagglutination (IAHA) method for coronavirus 229E antibody determination has been developed both for diagnosis of recent infections and for detection of long‐past infections. Results have been compared with those obtained by complement fixation (CF), neutralization (Nt), and indirect hemagglutination (IHA) tests. The IAHA method has been shown to be as sensitive as the CF, Nt, and IHA tests in detecting cases of acute 229E infection. However, in a seroepidemiological survey of 343 healthy people of all ages, IAHA detected 229E antibody in 254 individuals (74.0%), Nt in 166 (48.3%), IHA in 89 (25.9%), and CF in 30 (8.7%). A study of the prevalence of coronavirus 229E IAHA antibody in the different age groups has shown that during the second decade of life nearly 100% of the population acquire this type of antibody, whereas only 50% are positive at the end of the first decade. In the older age groups, the high frequency of CF antibody (“marker” of recent infection) indirectly confirms the high rate of 229E reinfections and the nonprotective nature of IAHA antibody. CF titer ⩾ 1:8 in 90% of cases corresponded to IAHA titers ⩾ 1:64. However, sera with IAHA titers of ⩾ 1:128 were often CF‐negative. Recent 229E infections (or reinfections), as determined by the presence of CF antibody, were more frequent in April‐May than in October‐November. Three cases of acute infection showing 229E seroconversion (two adults and one child) were observed during the winter‐spring season. IAHA appears to be the test of choice for seroepidemiological surveys.

negative: What Have We Learned About Middle East Respiratory Syndrome Coronavirus Emergence in Humans? A Systematic Literature Review Background: Middle East respiratory syndrome coronavirus (MERS-CoV) was first identified in humans in 2012. A systematic literature review was conducted to synthesize current knowledge and identify critical knowledge gaps. Materials and Methods: We conducted a systematic review on MERS-CoV using PRISMA guidelines. We identified 407 relevant, peer-reviewed publications and selected 208 of these based on their contributions to four key areas: virology; clinical characteristics, outcomes, therapeutic and preventive options; epidemiology and transmission; and animal interface and the search for natural hosts of MERS-CoV. Results: Dipeptidyl peptidase 4 (DPP4/CD26) was identified as the human receptor for MERS-CoV, and a variety of molecular and serological assays developed. Dromedary camels remain the only documented zoonotic source of human infection, but MERS-like CoVs have been detected in bat species globally, as well as in dromedary camels throughout the Middle East and Africa. However, despite evidence of camel-to-human MERS-CoV transmission and cases apparently related to camel contact, the source of many primary cases remains unknown. There have been sustained health care-associated human outbreaks in Saudi Arabia and South Korea, the latter originating from one traveler returning from the Middle East. Transmission mechanisms are poorly understood; for health care, this may include environmental contamination. Various potential therapeutics have been identified, but not yet evaluated in human clinical trials. At least one candidate vaccine has progressed to Phase I trials. Conclusions: There has been substantial MERS-CoV research since 2012, but significant knowledge gaps persist, especially in epidemiology and natural history of the infection. There have been few rigorous studies of baseline prevalence, transmission, and spectrum of disease. Terms such as “camel exposure” and the epidemiological relationships of cases should be clearly defined and standardized. We strongly recommend a shared and accessible registry or database. Coronaviruses will likely continue to emerge, arguing for a unified “One Health” approach.

negative: Microneedle array delivered recombinant coronavirus vaccines: Immunogenicity and rapid translational development Abstract Background Coronaviruses pose a serious threat to global health as evidenced by Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and COVID-19. SARS Coronavirus (SARS-CoV), MERS Coronavirus (MERS-CoV), and the novel coronavirus, previously dubbed 2019-nCoV, and now officially named SARS-CoV-2, are the causative agents of the SARS, MERS, and COVID-19 disease outbreaks, respectively. Safe vaccines that rapidly induce potent and long-lasting virus-specific immune responses against these infectious agents are urgently needed. The coronavirus spike (S) protein, a characteristic structural component of the viral envelope, is considered a key target for vaccines for the prevention of coronavirus infection. Methods We first generated codon optimized MERS-S1 subunit vaccines fused with a foldon trimerization domain to mimic the native viral structure. In variant constructs, we engineered immune stimulants (RS09 or flagellin, as TLR4 or TLR5 agonists, respectively) into this trimeric design. We comprehensively tested the pre-clinical immunogenicity of MERS-CoV vaccines in mice when delivered subcutaneously by traditional needle injection, or intracutaneously by dissolving microneedle arrays (MNAs) by evaluating virus specific IgG antibodies in the serum of vaccinated mice by ELISA and using virus neutralization assays. Driven by the urgent need for COVID-19 vaccines, we utilized this strategy to rapidly develop MNA SARS-CoV-2 subunit vaccines and tested their pre-clinical immunogenicity in vivo by exploiting our substantial experience with MNA MERS-CoV vaccines. Findings Here we describe the development of MNA delivered MERS-CoV vaccines and their pre-clinical immunogenicity. Specifically, MNA delivered MERS-S1 subunit vaccines elicited strong and long-lasting antigen-specific antibody responses. Building on our ongoing efforts to develop MERS-CoV vaccines, promising immunogenicity of MNA-delivered MERS-CoV vaccines, and our experience with MNA fabrication and delivery, including clinical trials, we rapidly designed and produced clinically-translatable MNA SARS-CoV-2 subunit vaccines within 4 weeks of the identification of the SARS-CoV-2 S1 sequence. Most importantly, these MNA delivered SARS-CoV-2 S1 subunit vaccines elicited potent antigen-specific antibody responses that were evident beginning 2 weeks after immunization. Interpretation MNA delivery of coronaviruses-S1 subunit vaccines is a promising immunization strategy against coronavirus infection. Progressive scientific and technological efforts enable quicker responses to emerging pandemics. Our ongoing efforts to develop MNA-MERS-S1 subunit vaccines enabled us to rapidly design and produce MNA SARS-CoV-2 subunit vaccines capable of inducing potent virus-specific antibody responses. Collectively, our results support the clinical development of MNA delivered recombinant protein subunit vaccines against SARS, MERS, COVID-19, and other emerging infectious diseases.

negative: Comparison of different samples for 2019 novel coronavirus detection by nucleic acid amplification tests Abstract A severe respiratory ongoing outbreak of pneumonia associated with 2019 novel coronavirus was recently emerged in China. Here, we reported the epidemiological, clinical, laboratory and radiological characteristics of 19 suspect cases. We compared the positive ratio of 2019-nCoV nucleic acid amplification test from different samples including oropharyngeal swab, blood, urine and stool with 3different Fluorescent RT-PCR kits. Nine out of the 19 patients were detected 2019-nCoV infection using oropharyngeal swab samples, and the virus nucleic acid was also detected in eight of these nine patients using stool samples. None of positive results was identified in the blood and urine samples. Thses three different kits got the same result for each sample and the positive ratio of nucleic acid detection for 2019-nCoV was only 47.4% in the suspect patients. Therefore, it is possible that the really infected patients have been missed by using nucleic acid detection only. It might be better to make a diagnosis combining the Computed Tomography scans and the nucleic acid detection together.

negative: Feline Infectious Peritonitis Feline infectious peritonitis (FIP) occurs most frequently in young animals from multicat households. Ocular manifestations of FIP are extremely common with the noneffusive form of the disease. All cats suspected of having FIP should undergo a thorough ophthalmic examination. Uveitis (inflarrunation of the iris, ciliary body, and choroid) is the primary clinical sign of ocular FIP. Treatment with anti-inflammatory medications is only supportive and aimed at disease palliation.

negative: Prevalence of antibodies to four human coronaviruses is lower in nasal secretions than in serum. Little is known about the prevalence of mucosal antibodies induced by infection with human coronaviruses (HCoV), including HCoV-229E and -OC43 and recently described strains (HCoV-NL63 and -HKU1). By enzyme-linked immunosorbent assay, we measured anti-HCoV IgG antibodies in serum and IgA antibodies in nasal wash specimens collected at seven U.S. sites from 105 adults aged 50 years and older (mean age, 67 ± 9 years) with chronic obstructive pulmonary disease. Most patients (95 [90%]) had at least one more chronic disease. More patients had serum antibody to each HCoV strain (104 [99%] had antibody to HCoV-229E, 105 [100%] had antibody to HCoV-OC43, 103 [98%] had antibody to HCoV-NL63, and 96 [91%] had antibody to HCoV-HKU1) than had antibody to each HCoV strain in nasal wash specimens (12 [11%] had antibody to HCoV-229E, 22 [22%] had antibody to HCoV-OC43, 8 [8%] had antibody to HCoV-NL63, and 31 [31%] had antibody to HCoV-HKU1), respectively (P < 0.0001). The proportions of subjects with IgA antibodies in nasal wash specimens and the geometric mean IgA antibody titers were statistically higher for HCoV-OC43 and -HKU1 than for HCoV-229E and -NL63. A higher proportion of patients with heart disease than not had IgA antibodies to HCoV-NL63 (6 [16%] versus 2 [3%]; P = 0.014). Correlations were highest for serum antibody titers between group I strains (HCoV-229E and -NL63 [r = 0.443; P < 0.0001]) and between group II strains (HCoV-OC43 and -HKU1 [r = 0.603; P < 0.0001]) and not statistically significant between HCoV-NL63 and -OC43 and between HCoV-NL63 and -HKU1. Patients likely had experienced infections with more than one HCoV strain, and IgG antibodies to these HCoV strains in serum were more likely to be detected than IgA antibodies to these HCoV strains in nasal wash specimens.

negative: Effects of temperature on COVID-19 transmission Coronavirus disease 2019 (COVID19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARSCoV2), it was first identified in 2019 in Wuhan, China and has resulted in the 2019-20 coronavirus pandemic. As of March 1, 2020, 79,968 patients in China and 7169 outside of China had tested positive for COVID19 and a mortality rate of 3.6% has been observed amongst Chinese patients. Its primary mode of transmission is via respiratory droplets from coughs and sneezes. The virus can remain viable for up to three days on plastic and stainless steel or in aerosols for upto 3 hours and is relatively more stable than the known human coronaviruses. It is stable in faeces at room temperature for at least 1-2 days and can be stable in infected patients for up to 4 days. Heat at 56 degree Celsius kills the SARS coronavirus at around 10000 units per 15 minutes. Thus, temperature is an important factor in survival of COVID19 virus and this article focuses on understanding the relationship between temperature and COVID19 transmission from the data available between January-March 2020.

negative: Serodiagnosis of sporotrichosis infection in cats by enzyme-linked immunosorbent assay using a specific antigen, SsCBF, and crude exoantigens Abstract The main objective of this study is to standardize an ELISA for the diagnosis of feline sporotrichosis. Sporothrix schenckii is the etiological agent of human and animal sporotrichosis. Cats may act as reservoirs for S. schenckii and can transmit the infection to humans by a bite or scratch. There are few methods for the serological diagnosis of fungal diseases in animals. In this paper, an ELISA test for the diagnosis of cat sporotrichosis is proposed, which detects S. schenckii-specific antibodies in feline sera. Two different kinds of antigens were used: “SsCBF”, a specific molecule from S. schenckii that consists of a Con A-binding fraction derived from a peptido-rhamnomannan component of the cell wall, and a S. schenckii crude exoantigen preparation. The ELISA was developed, optimized, and evaluated using sera from 30 cats with proven sporotrichosis (by culture isolation); 22 sera from healthy feral cats from a zoonosis center were used as negative controls. SsCBF showed 90% sensitivity and 96% specificity in ELISA; while crude exoantigens demonstrated 96% sensitivity and 98% specificity. The ELISA assay described here would be a valuable screening tool for the detection of specific S. schenckii antibodies in cats with sporotrichosis. The assay is inexpensive, quick to perform, easy to interpret, and permits the diagnosis of feline sporotrichosis.

negative: Immune surveillance in the skin: mechanisms and clinical consequences The skin, as the primary interface between the body and the environment, provides the first line of defence against a broad array of microbial pathogens and trauma. In addition to its properties as a physical barrier, the skin has many active defence mechanisms. In this review, we discuss the interaction between the innate and adaptive immune systems in the skin as a model for immune function at epithelial-cell interfaces with the environment. How these mechanisms account for the robust nature of cutaneous immune surveillance and how their dysregulation drives the pathogenesis of inflammatory skin disorders and skin-based tumours are the subjects of this review.

negative: Teicoplanin: an alternative drug for the treatment of coronavirus COVID-19? In December 2019, a new coronavirus, named SARS-CoV-2, has emerged from China causing pneumonia outbreaks first in the Wuhan region and have now spread worldwide because of its probable high transmission efficiency. Due to the lack of efficient and specific treatments and the need to contain the epidemic, drug repurposing appears to be the best tool to find therapeutic solution. Chloroquine, remdesivir, lopinavir, ribavirin or ritonavir have shown efficacy to inhibit coronavirus in vitro. Teicoplanin, an antibiotic used to treat staphylococci infection, previously showed efficacy to inhibit the first stage of MERS-coronarivus viral cycle in human cells. This activity is conserved on the SARS-Cov-2, thus placing teicoplanin as a potential treatment for patients with this virus.

negative: Evaluation of the Serologic Cross-Reactivity between Transmissible Gastroenteritis Coronavirus and Porcine Respiratory Coronavirus Using Commercial Blocking Enzyme-Linked Immunosorbent Assay Kits This study compared the performances of three commercial transmissible gastroenteritis virus/porcine respiratory coronavirus (TGEV/PRCV) blocking enzyme-linked immunosorbent assays (ELISAs) using serum samples (n = 528) collected over a 49-day observation period from pigs inoculated with TGEV strain Purdue (n = 12), TGEV strain Miller (n = 12), PRCV (n = 12), or with virus-free culture medium (n = 12). ELISA results were evaluated both with “suspect” results interpreted as positive and then as negative. All commercial kits showed excellent diagnostic specificity (99 to 100%) when testing samples from pigs inoculated with virus-free culture medium. However, analyses revealed differences between the kits in diagnostic sensitivity (percent TGEV- or PRCV-seropositive pigs), and all kits showed significant (P < 0.05) cross-reactivity between TGEV and PRCV serum antibodies, particularly during early stages of the infections. Serologic cross-reactivity between TGEV and PRCV seemed to be TGEV strain dependent, with a higher percentage of PRCV-false-positive results for pigs inoculated with TGEV Purdue than for TGEV Miller. Moreover, the overall proportion of false positives was higher when suspect results were interpreted as positive, regardless of the ELISA kit evaluated. IMPORTANCE Current measures to prevent TGEV from entering a naive herd include quarantine and testing for TGEV-seronegative animals. However, TGEV serology is complicated due to the cross-reactivity with PRCV, which circulates subclinically in most swine herds worldwide. Conventional serological tests cannot distinguish between TGEV and PRCV antibodies; however, blocking ELISAs using antigen containing a large deletion in the amino terminus of the PRCV S protein permit differentiation of PRCV and TGEV antibodies. Several commercial TGEV/PRCV blocking ELISAs are available, but performance comparisons have not been reported in recent research. This study demonstrates that the serologic cross-reactivity between TGEV and PRCV affects the accuracy of commercial blocking ELISAs. Individual test results must be interpreted with caution, particularly in the event of suspect results. Therefore, commercial TGEV/PRCV blocking ELISAs should only be applied on a herd basis.

negative: The behaviour of recent isolates of human respiratory coronavirus in vitro and in volunteers: Evidence of heterogeneity among 229E‐related strains Strains of human coronavirus (HCV) isolated between 1974 and 1976 have been studied in vitro and in volunteers. All strains caused colds in volunteers, and those cultivable in tissue culture (TC) produced significantly more coryza and less sore throat than strains growing only in organ culture (OC). The TC strains were serologically related to 229E, but these isolates produced colds with a frequency and severity that contrasted with the effects of 229E itself. Tests on volunteers' preinfection sera showed that the prevalence of antibody to 229E had increased during the period 1961–1979 and that during 1977–1979 only 11% of subjects had no neutralising antibody against 229E. Susceptibility to the 229E‐related isolates PR and TO was associated with low preinfection serum neutralising antibody against the homologous virus, and paired sera frequently showed fourfold or greater antibody rises, most commonly against the homologous strain. Volunteers infected with TO were immune when reinoculated with the same strain approximately 1 year later, but other similar volunteers were at least partly susceptible to infection with a heterologous 229E‐related virus after similar time intervals. Although the strains of HCV that were grown in tissue culture were all related to the prototype 229E, they appeared not to be identical with it, and this heterogeneity is probably a significant factor in the epidemiology of HCV infections.

negative: Trends in the Development and Approval of Monoclonal Antibodies for Viral Infections Monoclonal antibodies (mAbs) developed for either the prevention or treatment of viral diseases represent a small, but valuable, class of products. Since 1985, commercial firms have initiated clinical studies involving a total of 28 mAbs. To date, one product (palivizumab) has been approved and eight candidates are currently in clinical study. Most commercial mAbs studied as antiviral agents in the clinic have either directly or indirectly targeted human immunodeficiency virus, respiratory syncytial virus, or hepatitis C virus infections. However, the ability of mAbs to bind to specific targets and utilize various anti-infective modes of action would seem to make them well suited for the prevention and/or treatment of a wider variety of viral diseases. A number of factors, including the continuing need for innovative medicines for viral infections, the global spread of viral infections, and increased government funding for the study of pathogen countermeasures, have prompted companies to reconsider mAbs as antiviral agents. Public sector research into the use of mAbs against emerging pathogens, such as severe acute respiratory syndrome coronavirus, may have already provided candidates for further development.

negative: MERS coronavirus: Data gaps for laboratory preparedness Abstract Since the emergence of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) in 2012, many questions remain on modes of transmission and sources of virus. In outbreak situations, especially with emerging organisms causing severe human disease, it is important to understand the full spectrum of disease, and shedding kinetics in relation to infectivity and the ability to transmit the microorganism. Laboratory response capacity during the early stages of an outbreak focuses on development of virological and immunological methods for patient diagnosis, for contact tracing, and for epidemiological studies into sources, modes of transmission, identification of risk groups, and animal reservoirs. However, optimal use of this core public health laboratory capacity requires a fundamental understanding of kinetics of viral shedding and antibody response, of assay validation and of interpretation of test outcomes. We reviewed available data from MERS-CoV case reports, and compared this with data on kinetics of shedding and immune response from published literature on other human coronaviruses (hCoVs). We identify and discuss important data gaps, and biases that limit the laboratory preparedness to this novel disease. Public health management will benefit from standardised reporting of methods used, details of test outcomes by sample type, sampling date, in relation to symptoms and risk factors, along with the currently reported demographic, clinical and epidemiological findings.

negative: Cyclodextrins: Emerging Medicines of the New Millennium Cyclodextrins, since their discovery in the late 19th century, were mainly regarded as excipients. Nevertheless, developments in cyclodextrin research have shown that some of these hosts can capture and include biomolecules, highlighting fatty acids and cholesterol, which implies that they are not inert and that their action may be used in specific medicinal purposes. The present review, centered on literature reports from the year 2000 until the present day, presents a comprehensive description of the known biological activities of cyclodextrins and their implications for medicinal applications. The paper is divided into two main sections, one devoted to the properties and applications of cyclodextrins as active pharmaceutical ingredients in a variety of pathologies, from infectious ailments to cardiovascular dysfunctions and metabolic diseases. The second section is dedicated to the use of cyclodextrins in a range of biomedical technologies.

negative: Could BCG be used to protect against COVID-19? Nearly 100 years since it was first used in humans as a vaccine for tuberculosis, Bacillus Calmette–Guérin (BCG) has been suggested as a possible agent to prevent coronavirus disease 2019 (COVID-19). A number of studies are underway to investigate this possibility but — even if they prove effective — many questions will remain.

negative: COVID-19 and intracerebral haemorrhage: causative or coincidental? Pneumonia appears to be the most common manifestation of coronavirus disease 2019 (COVID-19), but some extrapulmonary involvement, such as gastrointestinal, cardiac and renal, has been reported. The limited clinical data about the virus's behavior to date, especially extrapulmonary symptoms, suggest that we should be aware of the possibility of initial cerebrovascular manifestations of COVID-19.

negative: Experimental screening studies on rabies virus transmission and oral rabies vaccination of the Greater Kudu (Tragelaphus strepsiceros) Rabies in the Greater Kudu (Tragelaphus strepsiceros) in Namibia is unique and found in such magnitude as has not been reported elsewhere in southern Africa. Reasons as to why Kudus appear to be exceptionally susceptible to rabies still remain speculative at best. Because the current severe rabies endemic in Kudus continues to have an enormous negative impact on the Namibian agricultural sector, we set out to question existing dogmas regarding the epidemiology of the disease in a unique experimental setting. In addition, we explored effective measures to protect these antelopes. Although we were able to confirm high susceptibly of kudus for rabies and sporadic horizontal rabies virus transmission to contact animals, we contend that these observations cannot plausibly explain the rapid spread of the disease in Kudus over large territories. Since parenteral vaccination of free-roaming Kudus is virtually impossible, oral rabies vaccination using modified life virus vaccines with a high safety profile would be the ultimate solution to the problem. In a proof-of-concept study using a 3rd generation oral rabies virus vaccine construct (SPBN GASGAS) we found evidence that Kudus can be vaccinated by the oral route and protected against a subsequent rabies infection. In a second phase, more targeted studies need to be initiated by focusing on optimizing oral vaccine uptake and delivery.

negative: Development, characterization, and application of monoclonal antibodies against severe acute respiratory syndrome coronavirus nucleocapsid protein. Five monoclonal antibodies (MAbs) against recombinant nucleocapsid protein (NP) of severe acute respiratory syndrome (SARS)-causing coronavirus (CoV) were developed by hybridoma technology. Epitope mapping by Western blotting showed that these anti-SARS-CoV NP MAbs bind to distinct domains of NP. These anti-SARS-CoV NP MAbs, with their high specificity, are potentially ideal candidates for developing early and sensitive diagnostic assays for SARS-CoV.

negative: Severe acute respiratory syndrome and dentistry A retrospective view ABSTRACT Background Severe acute respiratory syndrome, or SARS, which has created panic in Asia and in some parts of North America, is the first epidemic of the new century. Although it has been well-contained, sporadic cases continue to emerge. Objectives The authors trace the emergence of the SARS outbreak from southern China and its spread worldwide, discuss the viral etiology of the infection and its clinical features, and review the infection control guidelines issued during the outbreak by the health authorities in Hong Kong, the Centers for Disease Control and Prevention, the World Health Organization and the American Dental Association. They also review the prospects for a new outbreak and preventive measures. Overview The disease, which is caused by a novel coronavirus termed the “SARS coronavirus,” or SARS-CoV, essentially spreads through droplet infection and affects people of any age. It has a mortality rate ranging from 10 to 15 percent. A major hallmark of this disease has been the rate at which it has affected health care workers through nosocomial transmission; in some countries, up to one-fourth to one-third of those infected were in this category. However, no dental health care worker has been affected by SARS in a nosocomial or dental setting. Conclusions and Clinical Implications Researchers believe that a combination of factors, including the universal infection control measures that the dental community has implemented and/or the low degree of viral shedding in the prodromal phase of SARS, may have obviated the spread of the disease in dental settings. The dental community should reflect on this outbreak to reinforce the currently applied infection control measures.

negative: Clinical characteristics of 51 patients discharged from hospital with COVID-19 in Chongqing，China Abstract Background：Since December 2019, Severe acute respiratory syndrome coronavirus 2（SARS-CoV-2）-infected disease (Coronavirus Disease 2019，COVID-19) emerged in Wuhan , China，and rapidly spread throughout China，even throughout the world. We try to describe the epidemiological and clinical characteristics of COVID-19 in non-Wuhan area，and explore its effective treatment. Methods：Retrospective, single-center case series of the 51 hospitalized patients with confirmed COVID-19 at Chongqing University Three Gorges Hospital in Chongqing, China, from January 20 to February 3, 2020；The discharge time was from January 29 to February 11, 2020. The main results and indicators of epidemiology, demography, clinical manifestation, laboratory examination, imaging data and treatment data of 51 patients with covid-19 were collected and analyzed. The changes of blood routine and biochemical indexes at discharge and admission were compared. Compare the clinical characteristics of severe patients (including severe and critical patients) and non- severe patients (general patients). Results： Of 51 hospitalized patients with COVID-19, the median age was 45 years (interquartile range, 34-51; range, 16-68 years) and 32 (62.7%) were men.43（84.3%）patients had been to Wuhan or Other Hubei areas outside Wuhan，and 4（7.7%） patients had a clear contact history of COVID-19 patients before the onset of the disease, and 4（7.7%） patients had no clear epidemiological history of COVID-19.Common symptoms included fever (43 [84.3%]), cough (38 [74.5%]) and fatigue (22 [43.1%]). Lymphopenia was observed in 26 patients (51.0%), and elevated C-reactive protein level in 32 patients (62.7%). Ground-glass opacity was the typical radiological finding on chest computed tomography (41 [80.4%])，Local consolidation of pneumonia in some patients(17 [33.3%]).Most of the patients were treated with traditional Chinese medicine decoction (28 [54.9%])，all of them received aerosol inhalation of recombinant human interferon a-1b for injection and oral antiviral therapy with Lopinavir and Ritonavir tablets (51 [100%]); Most of the patients were given Bacillus licheniformis capsules regulated intestinal flora treatment (44 [86.3%]). 10 patients (19.6%) received short-term (3-5 days) glucocorticoid treatment. Compared with non-severe patients (n = 44), severe patients (n = 7) were older (median age, 52 years vs 44 years), had a higher proportion of diabetes mellitus (4 [57.1%] vs 0 [0.0%]), most of them needed antibiotic treatment (7 [100%] vs 4 [9.1%], most of them needed nutritional diet (6 [85.7%) vs 0 [0.0%], and were more likely to have dyspnea (6 [85.7%] vs 5 [11.4%])，most of them needed noninvasive mechanical ventilation (6 [85.7%] vs 0 [0.0%]). Except one patient died, the remaining 50 patients were discharged according to the discharge standard, the common clinical symptoms disappeared basically, the lymphocyte increased significantly (P=0.008), CRP decreased significantly (P <0.001). The median length of stay was 12 days (IQR, 9-13). Conclusion：In 51 single center cases confirmed as COVID-19 and discharged from the hospital, 13.7% of the patients were severe. The main clinical symptoms of patients with COVID-19 were fever, cough and asthenia，Some patients had obvious dyspnea. They had clinical laboratory and radiologic characteristics. There is no specific drug treatment for the disease. For the treatment of COVID-19, in addition to oxygen inhalation and antiviral treatment, attention should be paid to the dialectical treatment of traditional Chinese medicine, regulation of intestinal flora, nutritional support treatment and other comprehensive treatment.

negative: Chapter 11 Medical Management and Diagnostic Approaches Abstract This chapter reviews the basic principles of medical management of rat colonies and diagnostic approaches to detect infectious diseases of rats. As is the case with all other species, rats are susceptible to a variety of injuries and diseases that can cause distress, morbidity, or mortality. Any facility that houses rats must develop monitoring programs designed to rapidly identify health-related problems so they can be communicated to appropriate veterinary or animal care personnel to be resolved. These programs generally consist of multiple components, some of which are directed toward individual animals and others that assess the health status of rat populations as a whole. Topics include individual animal monitoring and care, signs of illness and distress, colony health management, components of microbiological monitoring programs, including agents commonly targeted and sentinel programs, quarantine, biological material screening, diagnostic testing methodologies, including culture, serology, molecular diagnostic and histopathology, test profiles and interpretation, management of disease outbreaks, and treatment and prevention strategies for infectious agents.

negative: Chapter 3 Biology and Diseases of Mice Today’s laboratory mouse, Mus musculus, has its origins as the ‘house mouse’ of North America and Europe. Beginning with mice bred by mouse fanciers, laboratory stocks (outbred) derived from M. musculus musculus from eastern Europe and M. m. domesticus from western Europe were developed into inbred strains. Since the mid-1980s, additional strains have been developed from Asian mice (M. m. castaneus from Thailand and M. m. molossinus from Japan) and from M. spretus which originated from the western Mediterranean region.

negative: Feasibility of Using Convalescent Plasma Immunotherapy for MERS-CoV Infection, Saudi Arabia We explored the feasibility of collecting convalescent plasma for passive immunotherapy of Middle East respiratory syndrome coronavirus (MERS-CoV) infection by using ELISA to screen serum samples from 443 potential plasma donors: 196 patients with suspected or laboratory-confirmed MERS-CoV infection, 230 healthcare workers, and 17 household contacts exposed to MERS-CoV. ELISA-reactive samples were further tested by indirect fluorescent antibody and microneutralization assays. Of the 443 tested samples, 12 (2.7%) had a reactive ELISA result, and 9 of the 12 had reactive indirect fluorescent antibody and microneutralization assay titers. Undertaking clinical trials of convalescent plasma for passive immunotherapy of MERS-CoV infection may be feasible, but such trials would be challenging because of the small pool of potential donors with sufficiently high antibody titers. Alternative strategies to identify convalescent plasma donors with adequate antibody titers should be explored, including the sampling of serum from patients with more severe disease and sampling at earlier points during illness.

negative: Special Anniversary Review: Twenty-five years of human immunodeficiency virus research: successes and challenges During 25 years of research since HIV-1 was first identified in Paris, there have been great advances in our understanding of the virus and of the immune system. Practical advances include the early development of diagnostic tests of infection that made blood donation safe, and since 1996, combination anti-retroviral therapy that has great reduced incidence of AIDS in HIV-infected people who have access to the drugs. HIV prevention through behavioural change has been successful, and we do not yet have any safe and efficacious microbicides or vaccines.

negative: FebriDx(®): A Rapid Diagnostic Test for Differentiating Bacterial and Viral Aetiologies in Acute Respiratory Infections FebriDx(®) is a rapid, point-of-care diagnostic test that is designed to aid in the differentiation of bacterial and viral acute respiratory infections (ARIs), thus helping to guide decisions regarding the prescription of antibiotics in the outpatient setting. FebriDx carries a CE mark for use in the EU and is also approved in several other countries, including Canada, Saudi Arabia and Singapore. It is indicated for use in patients > 2 years old with symptoms consistent with a community-acquired ARI. The test involves the use of an immunoassay on a fingerstick blood sample to provide simultaneous, qualitative measurement of elevated levels of C-reactive protein (CRP) and myxovirus resistance protein A (MxA). In two prospective, multicentre studies in patients with acute upper respiratory tract infections, FebriDx was shown to be both sensitive and specific in identifying patients with a clinically significant infection and in differentiating between infections of bacterial and viral aetiology. The test is simple, requires no additional equipment and produces actionable results in ~ 10 min. As was demonstrated in a small, retrospective analysis, FebriDx results can help guide (improve) antibiotic prescribing decisions. Reducing the unnecessary or inappropriate prescription of antibiotics for ARIs of probable viral aetiology is important for antibiotic stewardship and can also reduce the unnecessary exposure of patients to the risk of antibiotic-related adverse events. FebriDx thus represents a useful diagnostic tool in the outpatient setting.

negative: Differential diagnosis of pandemic (H1N1) 2009 infection by detection of haemagglutinin with an enzyme-linked immunoassay A sensitive and convenient immunoassay that can directly differentiate pandemic (H1N1) 2009 (pH1N1) virus from seasonal influenza virus can play an important role in the clinic. In the presented study, a double-sandwich ELISA (pH1N1 ELISA), based on two monoclonal antibodies against haemagglutinin (HA) of the pH1N1 virus, was developed. After laboratory determination of the sensitivity and specificity characteristics, the performance of this assay was evaluated in a cohort of 904 patients with influenza-like illness. All seven strains of pH1N1 virus tested were positive by pH1N1 ELISA, with an average lower detection limit of 10(3.0 ± 0.4) tissue culture infective dose (TCID)(50)/mL (or 0.009 ± 0.005 HA titre). Cross-reaction of the assay with seasonal influenza virus and other common respiratory pathogens was rare. In pH1N1-infected patients, the sensitivity of the pH1N1 ELISA was 92.3% (84/91, 95% CI 84.8–96.9%), which is significantly higher than that of the BD Directigen EZ Flu A + B test (70.3%, p <0.01). The specificity of pH1N1 ELISA in seasonal influenza A patients was 100.0% (171/171, 95% CI 97.9–100.0%), similar to that in non-influenza A patients (640/642, 99.7%, 95% CI 98.9–100.0%). The positive predictive value for pH1N1 ELISA was 97.7% and the negative predictive value was 99.1% in this study population with a pH1N1 prevalence of 10.1%. In conclusion, detection of HA of pH1N1 virus by immunoassay appears to be a convenient and reliable method for the differential diagnosis of pH1N1 from other respiratory pathogens, including seasonal influenza virus.

negative: SEROLOGIC TESTS FOR DETECTION OF ANTIBODY TO RODENT VIRUSES

negative: Estimating Infection Attack Rates and Severity in Real Time during an Influenza Pandemic: Analysis of Serial Cross-Sectional Serologic Surveillance Data BACKGROUND: In an emerging influenza pandemic, estimating severity (the probability of a severe outcome, such as hospitalization, if infected) is a public health priority. As many influenza infections are subclinical, sero-surveillance is needed to allow reliable real-time estimates of infection attack rate (IAR) and severity. METHODS AND FINDINGS: We tested 14,766 sera collected during the first wave of the 2009 pandemic in Hong Kong using viral microneutralization. We estimated IAR and infection-hospitalization probability (IHP) from the serial cross-sectional serologic data and hospitalization data. Had our serologic data been available weekly in real time, we would have obtained reliable IHP estimates 1 wk after, 1–2 wk before, and 3 wk after epidemic peak for individuals aged 5–14 y, 15–29 y, and 30–59 y. The ratio of IAR to pre-existing seroprevalence, which decreased with age, was a major determinant for the timeliness of reliable estimates. If we began sero-surveillance 3 wk after community transmission was confirmed, with 150, 350, and 500 specimens per week for individuals aged 5–14 y, 15–19 y, and 20–29 y, respectively, we would have obtained reliable IHP estimates for these age groups 4 wk before the peak. For 30–59 y olds, even 800 specimens per week would not have generated reliable estimates until the peak because the ratio of IAR to pre-existing seroprevalence for this age group was low. The performance of serial cross-sectional sero-surveillance substantially deteriorates if test specificity is not near 100% or pre-existing seroprevalence is not near zero. These potential limitations could be mitigated by choosing a higher titer cutoff for seropositivity. If the epidemic doubling time is longer than 6 d, then serial cross-sectional sero-surveillance with 300 specimens per week would yield reliable estimates when IAR reaches around 6%–10%. CONCLUSIONS: Serial cross-sectional serologic data together with clinical surveillance data can allow reliable real-time estimates of IAR and severity in an emerging pandemic. Sero-surveillance for pandemics should be considered. Please see later in the article for the Editors' Summary

negative: A systematic review of antibody mediated immunity to coronaviruses: antibody kinetics, correlates of protection, and association of antibody responses with severity of disease The duration and nature of immunity generated in response to SARS-CoV-2 infection is unknown. Many public health responses and modeled scenarios for COVID-19 outbreaks caused by SARSCoV-2 assume that infection results in an immune response that protects individuals from future infections or illness for some amount of time. The timescale of protection is a critical determinant of the future impact of the pathogen. The presence or absence of protective immunity due to infection or vaccination (when available) will affect future transmission and illness severity. The dynamics of immunity and nature of protection are relevant to discussions surrounding therapeutic use of convalescent sera as well as efforts to identify individuals with protective immunity. Here, we review the scientific literature on antibody immunity to coronaviruses, including SARS-CoV-2 as well as the related SARS-CoV-1, MERS-CoV and human endemic coronaviruses (HCoVs). We reviewed 1281 abstracts and identified 322 manuscripts relevant to 5 areas of focus: 1) antibody kinetics, 2) correlates of protection, 3) immunopathogenesis, 4) antigenic diversity and cross-reactivity, and 5) population seroprevalence. While studies of SARS-CoV-2 are necessary to determine immune responses to it, evidence from other coronaviruses can provide clues and guide future research.

negative: Diagnosis of Viral Infections Accurate diagnosis of viral infections enhances the ability of the clinician to make decisions on appropriate treatment of patients, evaluate disease progression and prevent misuse of antibiotics. Knowledge of the pathogen involved also allow implementation of infection control and monitoring of success of antiviral treatments that may affect the prognosis of patients. Epidemiological data collected through accurate diagnostics play an important role in public health through identification and control of outbreaks, implementation of appropriate diagnostic tests, vaccination programs and treatment but also to recognize common and emerging pathogens in a community. It is key that the clinician have an understanding of appropriate specimens to send to the laboratory and the value of specific nucleic acid and serological testing for different viral pathogens. Molecular techniques have revolutionized viral diagnoses over the past decade and enhanced both the sensitivity and specificity of tests and the speed by which a diagnosis can be made and new tests be developed. The continued use of serology for viruses with a short viremia, or for chronic infections should however complement these tests. This chapter aims to provide an overview of the available tests, the principles of testing and appropriate tests to select for different viruses and syndromes. Also provided is a glimpse of new developments in diagnostics that may further enhance the capacity to make a conclusive diagnosis in the near future.

negative: Positive rate of RT-PCR detection of SARS-CoV-2 infection in 4880 cases from one hospital in Wuhan, China, from Jan to Feb 2020 Abstract Background There’s an outbreak of a novel coronavirus (SARS-CoV-2) infection since December 2019, first in China, and currently with more than 80 thousand confirmed infection globally in 29 countries till March 2, 2020. Identification, isolation and caring for patients early are essential to limit human-to-human transmission including reducing secondary infections among close contacts and health care workers, preventing transmission amplification events. The RT-PCR detection of viral nucleic acid test (NAT) was one of the most quickly established laboratory diagnosis method in a novel viral pandemic, just as in this COVID-19 outbreak. Methods 4880 cases that had respiratory infection symptoms or close contact with COVID-19 patients in hospital in Wuhan, China, were tested for SARS-CoV-2 infection by use of quantitative RT-PCR (qRT-PCR) on samples from the respiratory tract. Positive rates were calculated in groups divided by genders or ages. Results The positive rate was about 38% for the total 4880 specimens. Male and older population had a significant higher positive rates. However, 57% was positive among the specimens from the Fever Clinics. Binary logistic regression analysis showed that age, not gender, was the risk factor for SARS-CoV-2 infection in fever clinics. Conclusions Therefore, we concluded that viral NAT played an important role in identifying SARS-CoV-2 infection.

negative: Rapid radiological improvement of COVID-19 pneumonia after treatment with tocilizumab

negative: Global and regional effects of potentially modifiable risk factors associated with acute stroke in 32 countries (INTERSTROKE): a case-control study. BACKGROUND Stroke is a leading cause of death and disability, especially in low-income and middle-income countries. We sought to quantify the importance of potentially modifiable risk factors for stroke in different regions of the world, and in key populations and primary pathological subtypes of stroke. METHODS We completed a standardised international case-control study in 32 countries in Asia, America, Europe, Australia, the Middle East, and Africa. Cases were patients with acute first stroke (within 5 days of symptom onset and 72 h of hospital admission). Controls were hospital-based or community-based individuals with no history of stroke, and were matched with cases, recruited in a 1:1 ratio, for age and sex. All participants completed a clinical assessment and were requested to provide blood and urine samples. Odds ratios (OR) and their population attributable risks (PARs) were calculated, with 99% confidence intervals. FINDINGS Between Jan 11, 2007, and Aug 8, 2015, 26 919 participants were recruited from 32 countries (13 447 cases [10 388 with ischaemic stroke and 3059 intracerebral haemorrhage] and 13 472 controls). Previous history of hypertension or blood pressure of 140/90 mm Hg or higher (OR 2·98, 99% CI 2·72-3·28; PAR 47·9%, 99% CI 45·1-50·6), regular physical activity (0·60, 0·52-0·70; 35·8%, 27·7-44·7), apolipoprotein (Apo)B/ApoA1 ratio (1·84, 1·65-2·06 for highest vs lowest tertile; 26·8%, 22·2-31·9 for top two tertiles vs lowest tertile), diet (0·60, 0·53-0·67 for highest vs lowest tertile of modified Alternative Healthy Eating Index [mAHEI]; 23·2%, 18·2-28·9 for lowest two tertiles vs highest tertile of mAHEI), waist-to-hip ratio (1·44, 1·27-1·64 for highest vs lowest tertile; 18·6%, 13·3-25·3 for top two tertiles vs lowest), psychosocial factors (2·20, 1·78-2·72; 17·4%, 13·1-22·6), current smoking (1·67, 1·49-1·87; 12·4%, 10·2-14·9), cardiac causes (3·17, 2·68-3·75; 9·1%, 8·0-10·2), alcohol consumption (2·09, 1·64-2·67 for high or heavy episodic intake vs never or former drinker; 5·8%, 3·4-9·7 for current alcohol drinker vs never or former drinker), and diabetes mellitus (1·16, 1·05-1·30; 3·9%, 1·9-7·6) were associated with all stroke. Collectively, these risk factors accounted for 90·7% of the PAR for all stroke worldwide (91·5% for ischaemic stroke, 87·1% for intracerebral haemorrhage), and were consistent across regions (ranging from 82·7% in Africa to 97·4% in southeast Asia), sex (90·6% in men and in women), and age groups (92·2% in patients aged ≤55 years, 90·0% in patients aged >55 years). We observed regional variations in the importance of individual risk factors, which were related to variations in the magnitude of ORs (rather than direction, which we observed for diet) and differences in prevalence of risk factors among regions. Hypertension was more associated with intracerebral haemorrhage than with ischaemic stroke, whereas current smoking, diabetes, apolipoproteins, and cardiac causes were more associated with ischaemic stroke (p<0·0001). INTERPRETATION Ten potentially modifiable risk factors are collectively associated with about 90% of the PAR of stroke in each major region of the world, among ethnic groups, in men and women, and in all ages. However, we found important regional variations in the relative importance of most individual risk factors for stroke, which could contribute to worldwide variations in frequency and case-mix of stroke. Our findings support developing both global and region-specific programmes to prevent stroke. FUNDING Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Canadian Stroke Network, Health Research Board Ireland, Swedish Research Council, Swedish Heart and Lung Foundation, The Health & Medical Care Committee of the Regional Executive Board, Region Västra Götaland (Sweden), AstraZeneca, Boehringer Ingelheim (Canada), Pfizer (Canada), MSD, Chest, Heart and Stroke Scotland, and The Stroke Association, with support from The UK Stroke Research Network.

negative: Preparedness for molecular testing of Middle East respiratory syndrome coronavirus among laboratories in the Western Pacific Region.

negative: Moving past serology: Diagnostic options without serum Abstract Detecting antibodies formed in serum in response to infection is the traditional function of serology. Diagnostic modalities have included complement fixation tests, agar gel immune-diffusion, radioimmunoassay, ELISA and immunofluorescence. More recent technology now allows for the direct detection of pathogens by PCR. This review details the options for diagnostic testing using specimen types other than serum, identifying the advantages and disadvantages of these options and providing evidence for more widespread use of these techniques and specimen types.

negative: Diagnostic evaluation of assays for detection of antibodies against porcine epidemic diarrhea virus (PEDV) in pigs exposed to different PEDV strains Abstract Porcine epidemic diarrhea virus (PEDV) has caused economic losses in the Americas, Asia and Europe in recent years. Reliable serological assays are essential for epidemiological studies and vaccine evaluation. The objective of this study was to compare the ability of five enzyme-linked immunosorbent assays (ELISAs) to detect antibodies against different PEDV strains in pig serum. A total of 732 serum samples from North American or European pigs were tested. Samples included experimental samples from pigs infected with classical (G1a PEDV) or variant genogroup 1 PEDV (G1b PEDV), pandemic genogroup 2 PEDV (G2b PEDV) or non-infected controls. Field samples from herds with confirmed or unknown PEDV exposure were also used. Three indirect ELISAs based on G2b antigens (ELISAs 1, 2 and 3), a competitive ELISA based on the G2b antigen (ELISA 4) and a competitive ELISA based on the G1a antigen (ELISA 5) were compared. Overall, the tests had a moderate agreement (κ=0.61). G1a PEDV infected pigs were earliest detected by ELISA 3, G1b PEDV infected pigs were earliest detected by ELISAs 4 and 5 and the performance of all tests was similar for the G2b PEDV group. ELISA 1 showed the overall lowest detection on experimentally and field derived samples. Diagnostic sensitivity and specificity with a 95% probability interval were estimated to be 68.2% (62.1–74.4%) and 97.5% (95.2–99.0%) for ELISA 1, 73.7% (71.5–79.6%) and 98.4% (96.6–99.5%) for ELISA 2, 86.2% (81.1–90.6%) and 91.6% (87.7–94.8%) for ELISA 3, 78.3% (72.8–83.5%) and 99.7% (98.2–100%) for ELISA 4, and 93.5% (90.3–96.0%) and 91.2% (83.8–97.9%) for ELISA 5. Differences in detection among assays seem to be more related to intrinsic factors of an assay than to the PEDV antigen used.

negative: Causes of endogenous uveitis in cats presented to referral clinics in North Carolina OBJECTIVE: To investigate the causes of endogenous uveitis in cats presenting to referral ophthalmology clinics in North Carolina. PROCEDURE: Medical records of cats diagnosed with endogenous uveitis at North Carolina State University's College of Veterinary Medicine (NCSU‐CVM) or Animal Eye Care Associates of Cary, NC between 2003 and 2015 were reviewed. Inclusion criteria were cats that had complete diagnostic workups, including clinical, clinicopathological, serological, and histopathological data, as well as imaging modalities. Serology was consistently completed for feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), feline coronavirus (FCoV), Toxoplasma gondii, and Bartonella spp. RESULTS: One hundred and twenty cats met the inclusion criteria. Seroprevalence of FeLV (2.7%), FIV (7.3%), FCoV (34.7%), T. gondii (23.7%), and Bartonella spp. (43.2%) was observed, with a combined seroprevalence of 59.2%. Nineteen cats (15.8%) were diagnosed with feline infectious peritonitis (FIP) based on clinical, hematological, serological, histopathological, and necropsy findings. The average age of all cases was 7.62 years, while the average age of cats diagnosed with FIP was 1.82 years. Neoplasia was diagnosed in six cats (5.0%). No underlying etiology was found in 49 cats (40.8%). CONCLUSIONS: Both idiopathic and neoplastic causes of uveitis were less prevalent than previously reported in studies, while seropositivity was higher than previously reported for the study area. This may be due to improved diagnostic capabilities or that cats with infectious disease were more likely to be referred. Because of the high prevalence of FIP, young cats with uveitis should be evaluated for hyperglobulinemia and FCoV serology should be performed as minimal diagnostics.

negative: Sequential informed pooling approach to detect SARS-CoV2 infection The alarming spread of the pandemic coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 virus is requiring several measures to reduce the risk of contagion. Every successful strategy in controlling SARS-CoV2 infection depends on the timely viral diagnosis which should include asymptomatic carriers. Consequently, strategies to increase the throughput for clinical laboratories to conduct large-scale diagnostic testing are urgently needed. Here we support the hypothesis that standard diagnostic protocol for SARS-CoV-2 virus could be conveniently applied to pooled samples obtained from different subjects. We suggest that a two-step sequential pooling procedure could identify positive subjects, ensuring at the same time significant benefits of costs and time. Simulation data are used to assess the efficiency, in terms of number of required tests, both for random assignment of the subjects to the pools and for situations when epidemiological and clinical data are used to create an "informed" version of the pooling. Different scenarios are examined in the simulations to measure the effect of different pool sizes and different values for the virus frequency. Our results allow to customize the pooling strategy according to the specific characteristics of the cohort to be tested.

negative: Bayesian Network Analysis of Covid-19 data reveals higher Infection Prevalence Rates and lower Fatality Rates than widely reported Widely reported statistics on Covid-19 across the globe fail to take account of both the uncertainty of the data and possible explanations for this uncertainty. In this paper we use a Bayesian Network (BN) model to estimate the Covid-19 infection prevalence rate (IPR) and infection fatality rate (IFR) for different countries and regions, where relevant data are available. This combines multiple sources of data in a single model. The results show that Chelsea Mass. USA and Gangelt Germany have relatively higher infection prevalence rates (IPR) than Santa Clara USA, Kobe, Japan and England and Wales. In all cases the infection prevalence is significantly higher than what has been widely reported, with much higher community infection rates in all locations. For Santa Clara and Chelsea, both in the USA, the most likely IFR values are 0.3-0.4%. Kobe, Japan is very unusual in comparison with the others with values an order of magnitude less than the others at, 0.001%. The IFR for Spain is centred around 1%. England and Wales lie between Spain and the USA/German values with an IFR around 0.8%. There remains some uncertainty around these estimates but an IFR greater than 1% looks remote for all regions/countries. We use a Bayesian technique called "virtual evidence" to test the sensitivity of the IFR to two significant sources of uncertainty: survey quality and uncertainty about Covid-19 death counts. In response the adjusted estimates for IFR are most likely to be in the range 0.3%-0.5%.

negative: Optimization of Microbiological Laboratory Detection Strategy for Patients in A Designated Hospital Treating Novel Coronavirus Pneumonia in Anhui Province Novel coronavirus pneumonia (NCP) is an emerging, highly contagious community acquired pneumonia (CAP) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Highly efficient and accurate microbiological laboratory assay is essential to confirm the SARS-CoV-2 infection, rule out other pathogens that can cause CAP, and monitor secondary infections. Here, we enrolled and provide microbiological analysis for 129 suspected and 52 transferred confirmed NCP patients hospitalized in the First Affiliated Hospital of University of Science and Technology of China (USTC) from Jan 21 to Feb 29, 2020. By analyzing the dual swab samples (sputum and pharyngeal) from 129 suspected patients with realtime RT-PCR, we confirmed 33 SARS-CoV-2 infections, with two co-infection cases with adenovirus or rhinovirus. We also used multiplex PCR to detect 13 common respiratory tract pathogens in 96 non-NCP patients, and found that 30 patients (31.25%) were infected with at least one respiratory tract pathogen that may cause CAP. Further, we performed bacterial and fungal cultures as well as fungal serologic tests and found that there is no secondary bacterial/fungal infections in confirmed NCP patients. Our studies suggest that, during the epidemic of NCP in Anhui province, there was a certain proportion of infection and co-infection of other common pathogens of CAP, and the secondary bacterial and fungal infection is not detectable in NCP patients. In comparison with SARS-CoV-2 detection alone, this optimized strategy combining multiple pathogen detection for identification of NCP and other CAP patients as well as cultures and serologic tests for confirmed patients increases the diagnosis efficiency and facilitates the personalized medication.

negative: Potent neutralizing antibodies in the sera of convalescent COVID-19 patients are directed against conserved linear epitopes on the SARS-CoV-2 spike protein The ongoing SARS-CoV-2 pandemic demands rapid identification of immunogenic targets for the design of efficient vaccines and serological detection tools. In this report, using pools of overlapping linear peptides and functional assays, we present two immunodominant regions on the spike glycoprotein that were highly recognized by neutralizing antibodies in the sera of COVID-19 convalescent patients. One is highly specific to SARS-CoV-2, and the other is a potential pan-coronavirus target.

negative: Rapid establishment of laboratory diagnostics for the novel coronavirus SARS-CoV-2 in Bavaria, Germany, February 2020 The need for timely establishment of diagnostic assays arose when Germany was confronted with the first travel-associated outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Europe. We describe our laboratory experiences during a large contact tracing investigation, comparing previously published real-time RT-PCR assays in different PCR systems and a commercial kit. We found that assay performance using the same primers and probes with different PCR systems varied and the commercial kit performed well.

negative: Serological prevalence of canine respiratory coronavirus Abstract Canine respiratory coronavirus (CRCoV) has recently been detected in dogs; it is a group 2 coronavirus showing similarity to bovine coronavirus (BCoV) but is distinct from canine enteric coronavirus (CECoV). CRCoV may play an important role in canine infectious respiratory disease (CIRD) either by predisposing to further and potentially more serious viral and bacterial infections or possibly as a primary pathogen. The prevalence of serum antibodies to CRCoV, in a population of dogs in the south east of England, has been shown previously to be 30.1% on the first day of entry to a rehoming kennel [Erles, K., Toomey, C., Brooks, H.W., Brownlie, J., 2003. Detection of a group 2 coronavirus in dogs with canine infectious respiratory disease. Virology 310, 216–223]. The purpose of this study was to establish the prevalence of CRCoV in the general canine population within as well as outside the UK. An ELISA, used to test for the presence of antibodies to CRCoV in canine serum samples, identified seropositive dogs in UK, USA, Canada, Republic of Ireland and Greece. The development of an ELISA based on CRCoV antigen and immunofluorescence assay are described here. 54.7% (547/1000) of North American and 36.0% (297/824) of United Kingdom dogs were seropositive for CRCoV. The age and geographical distribution of seropositive dogs was also assessed. The cross-reactivity demonstrated between CRCoV antibodies from different countries and a UK viral isolate suggests immunological similarity. The overall prevalence of this virus in both North America and the UK suggests that CRCoV has international significance and that further epidemiological studies are required.

negative: COVID-19 Testing: The Threat of False-Negative Results

negative: Establishment of a reference panel for the detection of anti-SARS-CoV antibodies Abstract The immunological assays for detection of antibodies against SARS-CoV were developed in-house and some of them are available commercially. However, the antigens used in these assays differed. In order to validate the reliability of these assays, the standard panel should be established. In this study, we have expressed and purified severe acute respiratory syndrome (SARS) structural proteins and their fragments and developed indirect enzyme-linked immunosorbent assays (ELISAs) that detect antibodies against the SARS N, N1, N2, S1, SC, S2, and M proteins as well as the human coronavirus OC43 and 229E N proteins. These assays were used to screen 58 samples from SARS convalescent patients, 40 serial serum specimens from patients at different phases of SARS infection, and 88 plasma specimens from normal blood donors. The samples from normal blood donors were also tested for antibodies against other respiratory virus. The representative samples were chosen to comprise a reference panel of SARS antibodies that may be used for the detection of SARS. The panel is composed of 25 positive samples, 25 negative samples, 7 diluted samples for anti-N antibody, 6 diluted samples for anti-S antibody, and one sample for validating precision. Comparison of detection results with different SARS antibody assays indicated that our panel should differentiate the specificity and sensitivity of different assays.

negative: What Lies Ahead?: Scientists Look into Their Crystal Balls Viral pathogenesis is a field in rapid evolution, reflecting the dynamic development of systems biology and the continuing introduction of new or improved methodologies. Therefore, this final chapter is dedicated to “futurism,” a look at what lies ahead for this field. We have recruited a number of scientists to write short pieces where they are free to speculate on future developments in their respective areas of expertise.

negative: Managing Cancer Care during the COVID-19 Pandemic and Beyond Abstract COVID-19 pandemic has posed insurmountable challenges to health care systems globally. Cancer therapy is complex, and outcomes are centered on timing. Many oncology societies and health ministries have issued guidelines for cancer care to enable oncologists and patients navigate the crisis. Lessons learned should inform care models for future pandemics.

negative: Treatment guidance for lung cancer patients during the COVID-19 pandemic Abstract The global COVID-19 pandemic continues to escalate at a rapid pace inundating medical facilities and creating significant challenges globally. The risk of SARS-CoV-2 infection in cancer patients appears to be higher especially as they are more likely to present with an immunocompromised condition, either from the cancer itself or from the treatments they receive. A major consideration in the delivery of cancer care during the pandemic is to balance the risk of patient exposure and infection with the need to provide effective cancer treatment. Many aspects of the SARS-CoV-2 infection remain poorly characterized currently and even less is known about the course of infection in the context of a patient with cancer. As SARS-CoV-2 is highly contagious, the risk of infection directly affects the cancer patient being treated, other cancer patients in close proximity, and health care providers. Infection at any level for patients or providers can cause significant disruption to even the most effective treatment plans. Lung cancer patients, especially those with reduced lung function and cardiopulmonary co-morbidities are more likely to have increased risk and mortality from COVID-19 as one of its common manifestation is as an acute respiratory illness. The purpose of this manuscript is to present a practical multidisciplinary and international overview to assist in treatment for lung cancer patients during this pandemic, with the caveat that evidence is lacking in many areas. It is expected that firmer recommendations can be developed as more evidence becomes available.