H1N1 swine flu virus passed from human back to pigs in Canada
May 3, 2009
Health authorities have confirmed the presence of H1N1 in Alberta pigs, and say the virus may have jumped from a farm worker to the animals, in what could be the first case of human-to-animal transmission of the virus.
Dr. Brian Evans, of the Canadian Food Inspection Agency, said a Canadian returned from Mexico on April 12, and began work at an Alberta swine farm on April 14.
“This person was exhibiting flu-like symptoms following the return, and may have exposed swine on the farm to an influenza virus,” said Evans. “I can tell you that the traveler has recovered.”
It was later confirmed that the pigs were, in fact, infected with the same H1N1 virus spreading around the world.
“We have determined that the virus H1N1, found in these pigs, is the virus which is being tracked in the human population,” said Evans.
Evans said it is not uncommon for influenza to jump from humans to pigs. He also said there is no evidence humans can get H1N1 from eating pork, and urged against any bans of Canadian products.
Approximately 10 percent of the 2,200 pigs on the farm have been infected, Evans said.
Canada’s chief public health officer Dr. David Butler-Jones said the spread of a human virus to a pig is not common but does happen “from time to time.”
Butler-Jones said the current strain is “very adaptive,” and warned it could mutate by recombining with any other bird, pig or human material. But he echoed assurances that the latest development is no cause for food safety alarm.