Uvs Lake Saudi Arabia H5N1 Has G743A
Recombinomics Commentary 23:09
March 3, 2008
The NA sequence from the wild bird isolate, A/houbara bustard/Saudi Arabia/6732-1/2007 has been released at Genbank. The HA sequence was released earlier and it was closely related to the clade 2.2.3 sequences from Kuwait. Therefore, the presence of G743A in the Saudi sequence was not a surprise.
However, the recently released sequence provides a more complete picture of G743A acquisitions in clade 2.2.3. The sequences in circulation in Europe and the Middle East trace back to the Uvs Lake outbreak in the summer of 2006. That outbreak was on a par with the Qinghai Lake wild bird outbreak a year earlier. Therefore, the spread of the Uvs Lake sequences was expected/
The Uvs Lake sequences were detected in environment samples from wild birds, as well as dead poultry in south Korea at the end of 2006. Like Uvs Lake however, these sequences did not have H743A.
In February however, there were H5N1 outbreaks in Moscow and Kuwait. The Moscow sequences were clade 2.2.3, but they did not trace back to Uvs Lake. Instead they were closely related to Azerbaijan sequences. However, the Kuwait sequences did trace back to Uvs Lake and both sets of sequences acquired G743A, even though they represented distinct clade 2.2.3 lineages.
At the same G743A was acquired by multiple clade 2.2.1 sequences in Egypt. Prior to February, 2007 there were not reported sequences from Egypt with G743A. However, in February, 2007 G743A appeared on distinct lineages in Egypt, and this was followed by the acquisition of additional lineages in Egypt, as well as distinct lineages in Ghana and Nigeria. In all cases, earlier closely related sequences had been reported that did not have G743A.
Since February, 2007, all published Uvs Lake NA sequences have had G743A.
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