Monday, October 3, 2011

Robert Webster: 'We ignore bird flu at our peril'

With the UN issuing renewed warnings and a Hollywood disaster movie stoking our fears, bird flu is back in the news. We meet the man who first warned of a pandemic 50 years ago – and who is worried again now.
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Scientists are still uncertain what prompted the reassortment and why Mexico was the centre – H1N1 was what scientists call a "triple reassortant", containing genes from a human flu, and genes from both north American and Eurasian strains of swine flu.

Despite having invested millions in disease surveillance since the 1990s, Webster says the virus caught flu-watchers with their "pants down". "In 2009, we were focused on H5N1. We just did not imagine that a variant of H1N1 would suddenly appear because the virus had been stable for years. It was in its monogamous phase. The view was that it couldn't mate with other viruses."

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However, the agency said its biggest concern was the appearance of the new 2.3.2. group of viruses in China and Vietnam, and the associated risk that migratory waterfowl could carry the virus further afield, leading to a resurgence of "backyard" poultry infections across the Middle East and Europe, as had occurred in 2005-6.

Webster believes the focus on 2.3.2. is premature. He is more worried about the related 2.2.1 strain that is endemic in Egypt's poultry industry (there have already been 32 human infections and 12 deaths this year, the highest of any country in the world). Concern is mounting in Bangladesh over the prevalence of another virus – H9N2 – that is endemic to live bird markets.

Webster argues that we need to know more about the duck's role in perpetuating viruses in the wild. "These viruses could be coming out of chickens and the ducks are just picking it up in the water or it could be that the duck is transferring the virus to its young when it breeds. We just don't have a good answer to that."

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