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Human vs. Animal Outbreaks of the 2009 Swine-Origin H1N1 Influenza A epidemic


The majority of emerging infectious diseases are zoonotic in origin, including recently emerging influenza viruses such as the 2009 swine-origin H1N1 influenza A epidemic. The epidemic that year affected both human and animal populations as it spread globally. In fact, before the end of 2009, 14 different countries reported H1N1 infected swine. In order to better understand the zoonotic nature of the epidemic and the relationship between human and animal disease surveillance data streams, we compared 2009 reports of H1N1 infection to define the temporal relationship between reported cases in animals and humans. Generally, human cases preceded animal cases at a country-level, supporting the potential of H1N1 infection to be a “reverse zoonosis”, and the value of integrating human and animal disease report data.

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This research is supported in part by the National Library of Medicine (NLM) grants R00 LM009825 to Matthew Scotch and G08 LM009776-01A2 to John S. Brownstein. The project is also supported in part by a research grant from to John S. Brownstein.

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Correspondence to Matthew Scotch.

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Scotch, M., Brownstein, J.S., Vegso, S. et al. Human vs. Animal Outbreaks of the 2009 Swine-Origin H1N1 Influenza A epidemic. EcoHealth 8, 376–380 (2011).

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  • Influenza A virus
  • H1N1 subtype
  • population surveillance
  • zoonoses
  • disease outbreaks