The new H1N1 influenza virus has been found in pigs in Alberta, Canada. This marks the first time this virus has been found in pigs, or any other non-human species. It’s not surprising – genetically speaking, the virus is most closely related to other swine influenza viruses (which is why it was originally referred to as "swine flu"), so it should be able to infect pigs. However, this is still a disappointing development because if the virus becomes established in the pig population, the pigs could become a potential reservoir for human infection.
In this case, the source of the pig infections is presumed to be a person – a farmhand that contracted the infection in Mexico. He became ill upon returning to Canada, and the pigs started showing flu-like signs about ten days after he returned to work. Various swine industry and health organizations sent out reminders to pig producers that sick people and/or people returning from Mexico should avoid contact with pigs, however the farmhand in question here returned from Mexico before much of this information became available.
I assume that much more information about this situation will soon become available. A close review of biosecurity practices on this farm is needed to determine if transmission occurred because of defiicient infection control protocols, or whether transmission occurred despite the use of standard practices. The farm is under quarantine and the pigs are being closely monitored to determine what effects this virus will have on them and how long is will stay in the herd. Undoubtedly, close monitoring of other pigs farms (both in Canada and many parts of the world) will continue, with particular emphasis on farms where individuals potentially exposed to the H1N1 virus may have had contact with pigs.