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H5N1 in Qingahi and Xinjiang Evolving Via Recombination
Recombinomics Commentary
June 12, 2005
>> The regional director for the World Health Organization, Dr. Shigeru Omi, told reporters in Beijing yesterday that the two recent outbreaks in remote areas in which hundreds of birds died were worrisome because they involved migratory waterfowl and domestic geese, birds that until now had been fairly resistant to the disease. <<
These changes in the pathogenicity of H5N1 are due to recombination. Although the sequences have not been released by the Harbin lab in China, which used the sequence of the HA cleavage site to classify H5N1 isoalted from both outbreaks as HPAI (Highly Pathogenic Avian Influenza), H5N1 has been evolving and expanding its host range via recombination, ever since it was initially isolated in Asia from a 1996 infection of a goose in Guangdong.
Each season new versions are generated via recombination, and the version in the latest two outbreaks in China may have sequences from India as parental sequences since the first reported bird deaths in Qinghai Lake were bar headed geese found on May 4 and bar headed geese begin migrating from the northern plains of India to Qinghai Lake in May and June.
The current H5N1 version was involved in the death of 519 water fowl (5 species) listed in the May 21 OIE report and additional comments at subsequent press conferences raised the total to over 1000, while third parties reported over 8000 deaths (12 bird species). These Abundant News reports also detail deaths in other mammals, including humans.
The Tacheng, Xinjiang outbreak involved domestic geese and it both outbreaks, the H5N1 isolates rapidly killed test chickens, a property also used in designating the H5N1 HPAI.
This latest version of H5N1 will probably be significantly different than the H5N1 versions in southern Vietnam/Cambodia or northern Vietnam/Thailand and all may be relatively unaffected by antibodies generated against the bird flu pandemic human vaccine which uses 2004 human isolates from Vietnam.
The latest results from China increases the urgency for releasing the sequence data on the new H5N1 as well as on the ground inspections in China and India. Without knowledge of the location and sequences of these newer versions of H5N1 containment and vaccination efforts are destined to fail miserably.
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