True about measles is all except
Measles (Rubeola): Incubation period: 10-14 days. Causative agent: RNA Paramyxovirus (so for only one serotype known) Source of infection: Cases (Carriers are not known to occur) Period of communicability: 4 days before and 5 days after the appearance of the rash. (Rash is retroauricular in origin) Measles has no second attacks (life long immunity is seen) Secondary attack rate of measle is 80% Measles shows a cyclical trend: Increases every 2-3 years. Blood cell type predominantly infected in Measles: Monocyte. Pathognomic clinical feature: Koplik spots (on buccal mucosa opposite Lower 2nd molar) Pathognomic microscopic feature: Wahin Finkedly cells (Multinucleated giant cells) MC complication of measles in young children: Otitis media. SSPE: Subacute sclerosing pan Encephalitis. Is a rare complication of measles: 1 per 10000-100000 cases of Measles (7-10 years after initial infection) Epidemic of measles occur: If propoion of susceptible children is > 40% If measles is introduced in a virgin community it infects >90% of children. Eradication of measles: Requires a vaccination coverage >96% Baby measles (Exanthem subitum-roseola infantum): Sixth disease (3 day fever) Ref: Park 25th edition Pgno: 159