title: Influenza.
mesh_terms: D005060:Europe / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007251:Influenza, Human / Q000453:epidemiology*; D007723:Korea / Q000453:epidemiology; D014586:USSR / Q000453:epidemiology; D014481:United States / Q000453:epidemiology