Influenza in the world.
D000349:Africa / Q000453:epidemiology; D004196:Disease Outbreaks; D005060:Europe / Q000453:epidemiology; D014943:Global Health; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology*; D009656:North America / Q000453:epidemiology; D013020:South America / Q000453:epidemiology