Transmission dynamics and impact of pandemic influenza A (H1N1) 2009  virus.
D004196:Disease Outbreaks; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000401:mortality / Q000635:transmission*; D012307:Risk Factors