<prompt> Measles is caused by aSingle stranded RNA enveloped virusSingle stranded RNA non-enveloped virusDouble stranded RNA enveloped virusDouble stranded RNA non-enveloped virus  <response>: Answer: a Single stranded RNA enveloped virus PANIKER 9th EDITION P-305DNA virusesFully double strandedPartially double strandedSingle strandedNaked DNAHerpesvirusPoxvirusAdenovirusPapovavirusHBVParvovirusCircovirusParvovirusAdenovirusPapovavirus RNA virusesDouble stranded RNA virus: Reovirus, PicobirnavirusSingle stranded RNASS - Enveloped RNASS- Nonenveloped RNAPositive sense Picorna Toga Calci Flavi CoronaNegative sense Rhabdo Orthomyxo Paramyxo Arena Bunya Arena Retro Filo Bunya Orthomyxo Paramyxo Toga Rhabdo Corona Picorna Calci ReoMEASLES RUBEOLA Measles virus Paramyovirus - hemagglutinin present; neuraminidase absent Measles is a winter disease Children 1-5 years are mostly affected Source of infection is a case of measles No carrier state No animal reservoir IP: 9-lldays; 7 days following vaccine Secondary attack rate 80 Communicability 4 days before and 5 days after the appearance of rash Pathognomic feature - Kopliks spots in the buccal mucosa appears 2 days before rash, opposite to lower first and second molars, fade with the onset of rash; sometimes seen on the conjunctiva and intestinal mucosa The red maculopapular rash first appears on the forehead and spreads downwards In malnourished children it can cause hemorrhagic rashes - black measles Most common complication - otitis media Most common life-threatening complication - bacterial pneumonia Streptococcus pneumoniae and H influenzae type b - common causes of bacterial pneumonia Giant cell pneumonia - serious complication in those with deficiencies in cell-mediated immunity Protracted diarrhea may occur in children Spontaneous abortion and premature delivery can occur in pregnant women No congenital anomalies reported Children may develop acute vitamin A and treated with vitamin A which reduces morbidity and mortality Multinucleated giant cells called Warthin-Finkedly cells are pathognomic of measles Acute encephalitis occurs 1 in 1000 cases Subacute sclerosing panencephalitis SSPE or Dawson inclusion body encephalitis is a rare complication Develops 5-15 years after initial measles infection Frequency 1 in 10000 to 1 in 100000 cases. Progressive mental deterioration, involuntary movements, muscular rigidity, coma. Usually fatal within 1-3 years after onset Defective measles virus in brain cells seen Demonstration of high titre measles antibody in CSF and serum is diagnostic Most often develops in persons infected with measles virus at 2 years of ageCell surface receptors for Measles virus CD46 complement regulatory protein that inactivates C3 convertases SLAM Signaling lymphocytic activation molecule Nectin 4 adherens junction proteinMeasles vaccine Live attenuated vaccine Edmonston Zagreb strain One dose of vaccine gives 95 protection; Vaccine efficacy is 85 No spread of virus from vaccinees to contacts Susceptible contacts over 9 months can be given the vaccine within 3 days of exposure, as IP of measles induced by vaccine is 7 days compared to 10 days for the naturally acquired virus Toxic shock syndrome occurs when the vaccine is contaminated or the same vial is used for more than one session on the same day. The vaccine should not be used 4 hrs after opening the vial Eradication of measles requires immunization coverage of 96 Atypical measles - measles infection due to formalin inactivated vaccine; rash begin in palms and soles Modified measles - in individuals who have received serum Ig after exposure to measles virus. 