Wednesday, December 17, 2008

Recombinomics: Is Novel H5N1 Migrating Through China Clade 0 or 7?

Commentary

Is Novel H5N1 Migrating Through China Clade 0 or 7?
Recombinomics Commentary 03:12
December 17, 2008

For the problems of the Jiangsu Provincial Department of Agriculture and Forestry animal husbandry and veterinary department of the Ministry of Agriculture immediately sent to sample the professional sector detection testing, the results of a surprise: The emergence of the virus in the past and the south of different avian influenza virus.

When a reporter asked led to the emergence of this new virus causes, Chunxi said that the movement of migratory birds suspected to be caused by the source of the virus - the year before in such a situation occurred in Shanxi Province.

The above translation offers a few additional clues on the novel H5N1 in Jiangsu province. This translation and other reports suggest the sequence is from the past and the above mentions an outbreak in Shanxi.

The Shanxi reference likely refers to a 2005 outbreak, which involved a novel H5N1 that was vaccine resistant. OIE reports indicated three different vaccines were used to try to control the massive spread. Media reports of an outbreak in Vietnam suggest it was clade 7, which would have been related to the H5N1 isolated from the 2005 outbreak in Shanxi. The HA sequence also had many changes near the receptor binding domain.

Alternatively, the reference to the past may be linked to the clade 0 H5N1 isolate at Qinghai Lake in June of this year. The isolate was closely related to 2003 Hubei/Shandong sequences, which were related to 1997 sequences from Hubei, which were close to the clade 0 Guangdong goose, the first H5N1 isolated in China in 1996.

Thus, the above translation suggests the H5N1 in Jiangsu is either clade 0 or clade 7. Both clades have cause human infections in the past. Clade 0 caused the 1997 outbreak in Hong Kong and clade 7 killed the first confirmed H5N1 fatality in China (Beijing 2003).

Thus, both possibilities represent the re-emergence of older H5N1 isolates that would be poorly unrecognized by current vaccines.

The OIE report may define the clade, but both are cause for concern. The possibility that the same clade is in India and Bangladesh also remains open.

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