January 30, 2006

 

US gears up for new bird flu surveillance plan

 

 

US government agencies, concerned that the migration of wild birds may be key in the spread of the deadly Asian H5N1 strain of bird flu, are preparing to launch a new surveillance and testing programme this spring to see if infected birds are flying into Alaska from Asia.

 

Agencies in the USDA and the US Department of Interior will begin testing thousands of wild birds in Alaska because the state is a temporary home to many birds that have migrated across the Bering Strait.

 

The deadly H5N1 strain--which has not been found in the US--is one of many highly pathogenic forms of bird flu, but there are other forms of the disease, including low-pathogenic types which are not harmful to humans.

 

Ron DeHaven, administrator of the USDA's Animal and Plant Health Inspection Service, or APHIS, said he believes bird flu is traditionally more likely to be spread through commercial poultry, but that wild birds may be the culprit in the recent spread of H5N1 throughout Asia and into Europe.

 

"Wild birds are a natural reservoir of all bird flu viruses and they can sometimes introduce bird flu into our domestic flocks," DeHaven said. "Recent research in China suggests that this particular virus has mutated ... so that it can adapt to certain migratory water fowl."

 

This mutation is of significant concern, he said, because it is likely allowing wild birds to carry the virus without becoming sick themselves.

 

Susan Hasteltine, associate director for biology at the US Geological Service, said she is still uncertain as to whether wild migratory birds present a significant threat for the spread of Asian bird flu to commercial poultry.

 

But the US Geological Service, together with APHIS and the US Fish and Wildlife Service, will be collecting and testing thousands of samples from wild birds killed by hunters, dead or sick birds and apparently healthy birds come spring.

 

Initial testing will be done at 46 stations throughout Alaska, officials said. If any are found positive for H5N1, those samples would be sent to the USDA's National Veterinary Services Laboratory in Ames, Iowa.

 

If the testing finds that the Asian H5N1 virus was carried into the US by a wild bird, that would provide "an early warning" signal, the USDA's DeHaven said.

 

In that scenario, he said, the government would likely be quick to significantly boost testing of wild birds as well as commercial poultry flocks.

 

Most major poultry producers in the US recently agreed to voluntarily increase bird flu testing as a means to calm consumer concerns. That, DeHaven said, means producers will likely test as many as 3 million birds this year.