Influenza in the world. 1 October 2002-30 September 2003.
D014943:Global Health; D006801:Humans; D009980:Influenza A virus / Q000302:isolation & purification*; D009981:Influenza B virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology; D011159:Population Surveillance; D013997:Time Factors