Sunday, May 3, 2009

May 3 WHO Briefing on H1N1

The WHO briefing opened with a discussion by Peter Ben Embarek, a scientist with the food safety program, about the current report from Canada that swine have been infected with the H1N1 virus.

Embarek noted that Canada announced H1N1 in a swine herd; these swine were not carriers of the virus, but were infected by a farm worker who recently traveled to Mexico. The herd was infected between 12-14 April, and it took nearly 10 days before the swine began showing symptoms, which were mild.

Embarek clarified that swine are not a reservoir for the currently circulating H1N1 disease, which is a mutated form of swine flu, and that these swine contracted the disease from a human. He also reiterated that you cannot get H1N1 from eating cooked pork. The focus now in Canada is monitoring swine near the infected farm and preventing spread of the virus in additon to preventing humans who are in regular contact with these infected swine (who were previously infected by a farm worker) from getting the new H1N1 virus.

WHO still does not recommend an embargo on meat, because the virus isn't present in swine herds en masse and the virus is sensitive to heat - so cooking the meat would render any potentially infected meat safe.

Questions:
Q: When was WHO notified that H1N1 was found in Canadian pigs? Given that the virus went from human to pig then back to human, does this show anything?
A: WHO was informed just before Canadian authorties made a formal announcement about the situation late last night. 10% of herd was affected and it was not very serious. He also clarified that there is no information at this time that other people have been infected by the pigs. Following good, general biosecurity guidelines, the farm is under quarantine and no animals have left the premises.

Q: Does the mixing back and forth (between swine and humans of H1N1) cause risk of a more severe disease?
A: There is no sign that this is happening; however, that could happen. As influenza viruses change, they could become stronger, milder, or stay the same.

Q: Given the current mixing, is there a risk of H5N1 and H1N1 mixing into a cocktail?
A: That is a concern, but we have no way of knowing if that could happen. That's why WHO is encouraging national authorities to actively monitor animals and keep the viruses from spreading geographically.

Q: When are we likely to go to Phase 6?
A: This is of course not easy to predict, because transmission of influenza virus doesn’t always move at the same speed. Since we have not seen sustained human-to-human transmission outside the Americas, it wouldn't "be prudent to predict" or set a timeline.

WHO Virtual Press Briefing Center: http://www.who.int/mediacentre/multimedia/swineflupressbriefings/en/index.html

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