[The etiological structure of acute respiratory infectious morbidity based on the data from a rapid diagnosis in...

Examination of 60,792 residents of Minsk in different seasons of 1977-1989 by indirect immunofluorescence showed this method to be able of recoding not only mono- but also polyetiological epidemics. The epidemic threshold for influenza A is 15% of positive findings, for influenza B is 7-8%, for polyetiological epidemics (influenza A and B) is 15-16% and 9-10%, respectively. The criterion of the epidemic situation in the city is a twofold increase (or higher) in the level of influenza A and B virus antigen findings in rhinocytological preparations as compared with the previous week.