H5N1 in Sweden Matches Denmark and Northern Germany
Recombinomics Commentary
December 17, 2007
Sequences from the NS gene from 23 wild bird isolates from Sweden have been released (see list below). 21 of the 23 sequences match previous sequences from northern Germany and Denmark also collected in early 2006 (see list). Two of the sequence match isolates with a broader distribution, which extend from Europe to the Middle East, to western Africa (see list). This series once again shows the value of regional markers in tracing the movement of H5N1 in general, and the Qinghai strain (clade 2.2) in countries west of China.
These data once again raise serious doubt about the explanation of the detection failures of H5N1 in western Europe in the fall of 2005 and early 2006. The explanation maintains that H5N1 was not introduced into western Europe in the fall of 2005, when no EU country reported H5N1, but was introduced by a westward migration of birds in eastern Europe in the dead of winter, while seeking open waters.
Although many of the sequences from isolates in 2005.2006 still have not been released, and this series from Sweden only includes the NS gene, it is clear that the vast majority of isolates in northern Germany, Denmark, and Sweden, represented a sub-clade that was not found in eastern Europe, or any other location. Similarly, a sub-clade in southern Germany matched isolates from Switzerland, that were also not found in eastern Europe, or any other location. These regional isolates were also collected in the dead of winter in 2006, which provide additional evidence against on eastern Europe origin.
Similarly, the sequence of HA and NA from H5N1 from a healthy teal in Egypt collected in December, 2005 provides additional evidence. At that time, all EU countries as well as all African countries were denying introductions of H5N1. Yet the sequence in the Nile Delta in 2005 was closely related to a 2006 isolate from Austria.
These examples, as well as other isolates with regional markers, indicate H5N1 was introduced into EU countries in the fall of 2005, and were missed because of a surveillance system that was fatally flawed for the detection of H5N1 in live healthy birds. These failures persist to this day, as more countries report H5N1 in domestic poultry in regions that fail to find H5N1 in live or dead wild birds.
These continues failures again point to a need for a major revision in surveillance programs worldwide, including countries with sophisticated and advanced technical expertise.
A/goosander/Sweden/V539/06
A/tufted_duck/Sweden/V685/06
A/tufted_duck/Sweden/V428/06
A/mallard/Sweden/2724/06
A/Eurasian_eagel_owl/Sweden/V1218/06
A/tufted_duck/Sweden/V526/06
A/greater_scaup/Sweden/V791/06
A/tufted_duck/Sweden/V998/06
A/mute_swan/Sweden/V827/06
A/Canada_goose/Sweden/V828/06
A/Canada_goose/Sweden/V978/06
A/Eurasian_eagel_owl/Sweden/V618/06
A/greater_scaup/Sweden/V543/06
A/tufted_duck/Sweden/V789/06
A/greater_scaup/Sweden/V1061/06
A/tufted_duck/Sweden/V1027/06
A/tufted_duck/Sweden/V919/06
A/smew/Sweden/V820/06
A/buzzard/Sweden/V651/06
A/tufted_duck/Sweden/V686/06
A/mink/Sweden/V907/06
A/tufted_duck/Sweden/V599/06
A/herring_gull/Sweden/V1116/06
Media Links
Recombinomics Presentations
Recombinomics Publications
Recombinomics Paper at Nature Precedings