Hajj and 2009 pandemic influenza A H1N1.
D003140:Communicable Disease Control / Q000458:organization & administration*; D004196:Disease Outbreaks / Q000517:prevention & control*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission; D007514:Islam; D012529:Saudi Arabia; D014195:Travel