Commentary
Fujian Clade 2.3 H5N1 In Whooper Swans in Japan
Recombinomics Commentary 21:27
May 14, 2008
The Agriculture, Forestry and Fisheries Ministry announced Tuesday that the deadly H5N1 bird influenza virus detected in six dead swans in Akita Prefecture and Hokkaido were all of the same type.
it differs from the virus which in the past is verified in the country, presently has become popular in Indonesia and Vietnam
The above comment and translation indicates that the H5N1 found in whooper swans at three distinct locations in Japan (see satellite map) are closely related to each other, but are distinct from the Uvs Lake clade 2.2.3 H5N1 detected in 2006/2007 in South Korea and Japan and instead is more closely related to H5N1 in Indonesia (clade 2.1) or Vietnam (clade 2.3 – Fujian strain).
The detection of clade 2.1 or 2.3 in long range migratory birds in Japan and Korea has not been reported previously. The presence of either clade in whooper swans migrating to the north creates additional opportunities for co-infections and rapid evolution via recombination.
In the past H5N1 outbreaks in South Korea were quickly followed by detection of H5N1 in Japan. In 2003/2004 the H5N1 was a precursor of the Qinghai strain (clade 2.2). In 2006/2007, the H5N1 in both countries was the Uvs Lake strain of clade 2.2.3, which was derived from the Qinghai strain.
Recent reports from South Korea indicate the H5N1 was closely related to H5N1 from Vietnam. Thus, it appears that clade 2.3 (Fujian strain) which has recently migrated into Vietnam and has been linked to recent human cases, is now in long range migratory birds in northern Japan which normally migrate to the north in the summer. This migration sets the stage for the movement of clade 2.3 into Mongolia, Siberia, and North America.
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