The Epidemiology of Influenza

摘要: If the diagnosis of influenza in individual patient is at times ambiguous, identification epidemics not. In north temperate zone, abrupt appearance febrile respiratory disease affecting adults as well children early winter can be assumed to pending virologic con-firmation. Characteristically, sporadic cases are seen late November and December; then, following Christmas holidays, becomes epidemic. School industrial absenteeism clinic visits increase, somewhat later excess mortality related pneumonia occurs.