title: Influenza types and patient population.
authors.forename: J C
authors.initials: JC
authors.lastname: de Jong
authors.forename: E C
authors.initials: EC
authors.lastname: Claas
authors.forename: A D
authors.initials: AD
authors.lastname: Osterhaus
mesh_terms: D004739:England / Q000453:epidemiology; D006801:Humans; D009980:Influenza A virus / Q000302:isolation & purification*; D009981:Influenza B virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology; D009426:Netherlands / Q000453:epidemiology; D014852:Wales / Q000453:epidemiology