From the Centers for Disease Control. Influenza activity--United States, 1991-1992.
D000328:Adult; D000368:Aged; D002648:Child; D004196:Disease Outbreaks; D006801:Humans; D009980:Influenza A virus; D007251:Influenza, Human / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology