H5N1 Spreads in Nigeria
Recombinomics Commentary
January 12, 2007
Veterinary officials in white protective suits and masks culled thousands of chickens at a farm in the far northwestern Nigerian state of Sokoto after bird flu was detected there for the first time.
The above comments confirm H5N1 in a new region in Nigeria. H5N1 has been recently confirmed or suspect in several additional Nigerian states. Last year, the first OIE report cases were on February 6. The earlier reporting this year may be related to increased awareness, since last year's confirmation was accompanied by media reports describing early deaths.
The sequences of H5N1 isolates from last season's outbreaks were all of the Qinghai strain (Clade 2 sub-clade 2), but the sequence analysis supported multiple independent entries, point toward wild birds. These polymorphisims could be traced to wild isolates in Europe as well as Egypt, consistent with transportation and transmission by long range migratory birds. In addition, the isolates had regional differences, demonstrating acquisition of additional polymorphism from local sequences.
Initial results from patients infected in Egypt this season identify new polymorphisms that are expected to be present in the sequences in Nigeria and neighboring countries, as was seen last season.
Information on the H5N1 Qinghai sequences in the current outbreaks in Nigeria would be useful.
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