From the Centers for Disease Control and Prevention. Update: influenza activity--worldwide, 1994.
D000349:Africa / Q000453:epidemiology; D001208:Asia / Q000453:epidemiology; D002489:Central America / Q000453:epidemiology; D005060:Europe / Q000453:epidemiology; D014943:Global Health; D006801:Humans; D009980:Influenza A virus / Q000302:isolation & purification; D009981:Influenza B virus / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology*; D009656:North America / Q000453:epidemiology; D010139:Pacific Islands / Q000453:epidemiology; D013020:South America / Q000453:epidemiology