the virus in samples from different cases has been analysed by an international collaboration who found that the virus jumped to humans in 2008, probably after June, and not later than the end of November. The research also indicated the virus had been latent in pigs for several months prior to the outbreak, suggesting a need to increase agricultural surveillance to prevent future outbreaks. See also 2009 flu pandemic 2009 flu pandemic in Mexico COVID-19 pandemic Public health Swine influenza References External links Gene sequence information from Influenza Research Database Graphical Image of the viral makeup of the 2009 pandemic h1n1 virus – NEJM Health-EU portal EU response to influenza European Commission – Public Health EU coordination on Pandemic (H1N1) 2009 Microscopic image of the H1N1 virus Microscopic image of the H1N1 virus 2009 swine flu pandemic Influenza A virus subtype H1N1 Infraspecific virus taxa