imposed economic burden of common disease was completely definite , but with wide range which differed based on the diseases and therapeutic methods ( 1 , 2 ) . despite the hygiene improvement in the medical centers in the recent century , healthcare associated infections ( hais ) are considered as growing public health worldwide ( 3 ) . the national nosocomial infection surveillance program was established in iran since 2007 based on national nosocomial infection surveillance ( nnis ) system definitions which classified for four major groups including pulmonary , urinary tract , blood stream , and surgical site infections ( 4 ) . annually the hais was announced 10 to 15 % by health system in iran in recent years ( 5 ) . hais had the highest occurrence at icu ward which was related to the most use of invasive therapeutic devices(6 ) . hais may be assumed as leading causes of death especially at intensive care unit ( icu ) ward in patients with terminal medical conditions , such as advanced malignancy or end stage kidney or liver disease ( 7 , 8) . hais caused the increased hospitalization stay , staff time , cost of laboratory tests on the pathogens and antimicrobial treatment ( 9 , 10 ) . the antimicrobial treatment related financial cost is a main part of the health economic burden , but data about this subject are rarely found in iran . understanding differences in economic burden of hais and antimicrobial treatment compared to other patients in health system informs patients , physician and government in order to promote quality of patients health besides reducing morbidity , mortality , and prevention of wasting time and money . this study focused on economic burden estimation and daily cost evaluation created by hais and limited for hospitalized patients at icu of university hospital ; because these patients are potentially susceptible to infections ( 11 ) . this study highlighted the necessity for efficient policy making which aimed to increase the survival rate of critical icu s patients at university hospitals . one of the most significant current assay was attempting to summarize and highlight the major findings of the epidemiology of hais and evaluate economic burden of antimicrobial treatment and hais for icu s patients . this study conducted the cross - sectional prospective surveillance study for adult patients ( 15 < years of age ) admitted at medical - surgical icu ( ms - icu ) ward of taleghani hospital between 2012 - 2013 . taleghani hospital is a public hospital with 620 beds located in tehran , iran . from 474 patients hospitalized at icu icu s patients who previously acquired infections with non origin of hospital and non origin of icu ward , neonatal patients ( < 15years ) , patients hospitalized for less than 2 days were excluded from this study . also cases for superinfection were excluded . . common surveillance of hais was performed by infection control nurses and infectious diseases specialist physicians . 198 studied hospitalized patients in icu who do not infect with any hais were assumed as control group and also , patients with hais with origin of icu ward were assumed as case group . measurement of hais associated economic burden 
  prescription of antimicrobial agents was recommended by an infectious disease consultant . all of charts , prescriptions and therapeutic indications were registered in medical record of patients . therapeutic methods and agents cost were calculated and examined in us dollars based on 2012 prices of antimicrobial agents and were mentioned in text and tables . according to the reports released by iranian central bank and world bank organization from 2012 to 2013 ; for example , one ppp$ ( purchasing power parity $ ) was estimated around 24 , 850 rails in 2013 . therefore , 24,8850 rails were used as the reference value to convert costs from iranian rails to ppp$ ( 12 , 13 ) . the patients with hais were assumed as the case group and patients without any hais as the control group . the descriptive statistics and frequency distribution such as mean , standard deviation and percentage were used . odds ratios ( or ) and the confidence intervals ( 95 % ci ) of the ors were calculated by logistic regression analysis . the mean age of infected patients was 63.6  3.24 and 52.74  1.32 at uninfected patients ( p= 0.047 , table 1 ) . the results showed that mortality for infected patients was more than un - infected ( adj . or : 2.5 ; 95 % ci : 1.3 - 4.90 , p - value=0.005 ) . in addition , the unit of blood for infected patients was 10.38 25 and for un - infected was 5.36  0.64 ( p=0.023 ) . also , there is an association between hospitalization days and risk of infection ( adj . or : 1.14 ; 95 % ci : 1.07 - 1.21 , p - value<0.001 ) . the most common type of hais was ventilator associated with pneumonia ( vap ) ( 9.39 % ) followed by the urinary tract infection ( uti ) ( 5.71 % ) and blood stream infection ( bsi ) ( 3.26 % ) . however , the cost of antibiotic per day increased in the infected patients but the total economic burden of hospitalization for two groups was approximately equal . albeit , the highest antibiotic associated economic burden was observed for patients with bsi ; the highest total economic burden of hospitalization was allocated for patients bsi which was followed by uti and vap ( table 2 ) . although , there are abundant epidemiological researches about hais around the world ( 8 , - ) , so far , there have been little researches about hais in iran especially for icu hospitalized patients , related economic burden and antibiotic associated cost . in this study , we aimed at obtaining an estimate of the cost of antibiotic and hais for the first time in iran . 19.2 % hais rate that we found was somewhat higher than rate report by iranian national health system ( 5 ) . comparison of frequency of criteria in infected and uninfected patients the incidence of hais by site of infection and its impact on the length and cost of hospital stay / day it can potentially cause higher rate of hais in icu ward rather than other wards of hospitals consistent with other studies ( 19 ) . the predominant site of infection differs by the studied population , ward of hospitalization , type of performed surveillance , sampling and season in which the search is concluded ( 1 , 20 ) . however , the longest hospitalization , mechanical ventilation and the oldest age were observed for vap ( table 3 ) . in addition , the presence of invasive devices , type of prescribed antibiotics , length of hospitalization and severity of underlying disease can be assumed as the main risk factors of hais at icu s patients . similar to rosenthal meta analysis study , klebsiella pneumonia , escherichia coli and staphylococcus were mostly found in the common site of infections in this study ( 19 ) . the economic burden of hais seems to be moderately high in iran and it imposes a relatively heavy financial burden on the iranian national health system because of its high prevalence at icu and its impact on survival rate , waste of time , and money . however , this high economic burden may have been due to hais , they may have also been related to our research strategy focused on hais . the financial burden of hais related to total antibiotic was doubled for the other patients ( adj . or : 1.5 ; 95%ci : 1.25 - 1.80 , p - value<0.001 ) . hais imposed the excess economic burden related to antibiotic which is on average 2.09 ppp$ per day for each infected patients in this study . although , there is nt significant relation between total economic burdens of hospitalization / day between infected and un - infected patients ; maybe , the time of study and number of samples were the reasons of that . if the results of the study are emerged with other hospitals , the different results will be likely obtained . the financial burden of hais related to excess total hospitalization per day increased to 3.4 ppp$ than the un - infected patients . it may be due to prescription of infrequent and normally more expensive antibiotics which imposed high financial burden . although it was observed that bsi and uti had the most total economic burden of hospitalization . in accordance with iranian national health system report , in which 3000 beds are belonging to icu ( 21 ) and 19.2 % hai rate and 7.29 days as the mean of hospitalization days in this study , it was estimated that 576 patients involved in hais at icu ward in iran per week . it was approximated weekly and annually that hais associated economic burden of antibiotic was 8,426.882 ppp$ and 433,382.40 ppp$ respectively in iran .   the mean age , mean transfused blood and incidence of mortality by site of infection the criteria for hais financial burden hais is more prevalent in icu s patients and remains as an important patient safety problem and the financial and social costs are staggering . the economic burden of hais and antibiotic seems to be moderately high in iran and it imposes a relatively heavy economic burden on the iranian national health system because of its high prevalence at icu and its impact on survival rate , hospitalization length , implementation of more expensive therapies , more prescription and infrequent antibiotics with heavier costs . however , possible mistreatment of patients certainly effects on the financial burden , but one of the limitations of the study is the disability to examine possible mistreatment . the nnis has established in recent decade in iran which has weak point as a neoteric program ( 5 ) . this research highlights the importance of hais in our country and establishes scientific policies to prevent the loss of patients , waste of time , and money . in conclusion , length of stay and antibiotic prescription were the main cost of icu s patients that could be minimized by enhancement of the quality of insurance industry in our country and deletion of possible mistreatments .
so far , too little attention has been paid to total burden of healthcare associated infections ( hais ) in iran . in the present study 
 , we aimed to assess the rate of hais , as well as economic burden of hospitalization and antibiotic related cost associated with hais in icu at training taleghani hospital in iran and to compare our results with national nosocomial infections surveillance ( nnis ) system . 
 this research to date for the first time has tended to focus on the economic burden of hais rather than epidemiology of hais evaluation . 
 the total of 474 patients was followed up in this study . 
 overall , the rate of hais was 19.2 % in which ventilator associated pneumonia ( vap ) was dominant hais and followed by urinary tract infection ( uti ) . 
 importantly , mortality rate increased significantly in infected patients . 
 the highest total hospitalization economic burden and antibiotic related cost were observed for patients having blood stream infection ( bsi ) . 
 the results demonstrated significant differences between antibiotic related cost in patients and uninfected patients . 
 antibiotic related absolute extra cost for hais was 2.09 ppp$ per day . 
 estimation of direct annually hais associated economic burden of antibiotic and total hospitalization was 433,382.4 ppp$ and 705,024 ppp$ respectively in iran at intensive care unit ( icu ) . 
 the most obvious findings were a strong relationship between relatively heavy antibiotic related financial burden , higher mortality rate , longer hospitalization time , and hais emergence on the iranian national health system . 
 it also reflects , more fundamentally a shift toward the need for comprehensive thinking about hais at icu ward from iran s hospitals . on the question of 
 the research found that : with the implementation of policies and strategies to reduce hospital infections , which will benefit ; patient , society , and/or national health system ? !