[Etiological characteristics of influenzal diseases in children's collectives under long-term observation].

As the result of epidemiological and virological observations, the factors which determined the duration of carriership at the period of mixed influenza A and B epidemic were established. Most children released influenza virus A for 7-9 days and influenza B virus for 10-12 days. The duration of carriership in children depended on their age, the level of humoral antibodies in their sera taken before the disease and the manifestation of their immune reaction to influenza virus infection.