Independent H5N1 Wild Bird Introductions in Europe
Recombinomics Commentary
June 29, 2007
It would be helpful if the investigating laboratory could make public the
information on the similarity of current isolates from German swans and
Czech turkeys (as well as the Czech swan, recently reportedly suspected?!)
to Kuwaiti isolates. The Kuwaiti isolates were derived from poultry and
from "captive hunting" falcons. Allegedly, falcons were imported to Kuwait from central Asia. Falconry is practised in Europe as well; relevant data would be welcomed. - Mod.AS
The above Promed commentary is useful, but release of the actual sequences would be more helpful. Many general statements are made on relatedness of sequences, but the generation of phylogenetic trees is a trivial task, and the relationships between sequences can be determined independently by the scientific community, which would aid in the rapid characterization of the isolates. Media reports have already indicated that the Kuwait and Czech turkey isolates are 99.5% identical. Moreover, additional reports from the investigating laboratory in Germany indicate that the relationship between the Czech turkeys and Nuremberg birds is 99.2%. Both of these numbers highlight a wild bird relationship, but neither indicates that the outbreaks were closely linked. Closely linked sequences, like those in Hungary and the UK were 99.96% identical. The identity numbers between Germany, the Czech Republic, and Kuwait are typical for sub-clades.
The Czech swan has been confirmed by sequencing and an OIE report has been filed, although the report does not give identity numbers for comparisons with the Czech turkeys or Kuwait isolates. Similarly, the Saxony bird isolates have been said to be similar to the Nuremberg isolates, but the per cent identity has not been given. Moreover, media reports now indicate a 10th wild bird in Germany has tested positive, providing additional evidence of a large wild bird reservoir that has gone undetected in Germany and the Czech Republic, as well as neighboring countries.
The presence of H5N1 in wild birds in Hungary, as well as poultry in Krasnodar, Moscow, Kuwait, Turkey, and Egypt strongly suggest H5N1 is widespread in western Europe and endemic, leading to outbreaks in June, in wild birds that are not migratory.
Attempts to link falcons really has no basis, and is another attempt to revive the "wild birds as victims" explanation, which was thoroughly discounted by the appearance of clade 2.2 in all H5N1 outbreaks west of China, include those in February, 2006 in wild birds that were not migratory but were H5N1 positive in areas that had been deemed H5N1 negative in the fall of 2005, when the H5N1 infected wild birds migrated into the region.
Media sources
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