title: Did the 2009 pandemic influenza virus originate in humans?
authors.forename: Hana M
authors.initials: HM
authors.lastname: Weingartl
mesh_terms: D000818:Animals; D004196:Disease Outbreaks; D019143:Evolution, Molecular; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D015047:Zoonoses / Q000453:epidemiology / Q000635:transmission* / Q000821:virology*