Pandemic Influenza A H1N1 in Swine and Other Animals

Influenza A virus infection has been reported in a variety of mammalian and avian species. Wild waterfowl such as ducks and geese are considered the principal reservoir of many influenza A viruses. On May 2, 2009, the first confirmed case of pandemic 2009 H1N1 (pH1N1) in animals was reported in a small swine herd in Canada. A public health investigation concluded that transmission from people to pigs was the likely source of infection. Subsequently the pH1N1 virus has been reported in turkeys, cats, dogs, ferrets, and several wildlife species. Human to animal transmission has been confirmed or suspected in a number of cases. The naming of the virus as "swine flu'' in the international media led to a drop in the demand for pork and subsequently a reduction in the price of pork paid to farmers. Estimates of losses to pork producers in North America run into hundreds of millions of dollars. Increased surveillance of swine populations for influenza viruses has been suggested as a control measure against the development of future pandemic viruses. In order to be successful, future surveillance and reporting policies must include provisions to protect the livelihoods of farmers.