Update: influenza activity--worldwide, 1988-89.
D000328:Adult; D001208:Asia / Q000453:epidemiology; D002170:Canada / Q000453:epidemiology; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D013020:South America / Q000453:epidemiology; D014481:United States / Q000453:epidemiology