Avian Influenza, Moving but Not Migrating

December 29, 2005 — 

It appears that the H5N1 strain of avian influenza is not moving around the globe with migratory waterfowl as had once been feared.

A number of researchers tracking the movements of migratory waterfowl and the influenza virus have determined that the movement of the virus is not following the typical waterfowl migratory patterns. Despite reports in the summer and early fall that would appear to indicate that the virus was moving with migratory birds, viral distribution patterns have not continued to follow the expected migratory pathways.

The virus has not been detected in either Western Europe or the Nile delta where it would have been expected to appear at over-wintering sites. Also, no infected migrating waterfowl have been detected in the Philippines which serves as a major stopover for migratory birds from China, Japan and Korea. The Philippine Department of Agriculture has been actively sampling migrating waterfowl since October.

The H5N1 virus, as yet undetected in North America, is capable of infecting numerous avian species but has not mutated sufficiently to readily move from human to human. Recent evaluation the current worldwide pattern of viral distribution strongly implicates domestic poultry as the preferred reservoir for this viral strain, making transmission much more likely as a result of contact with domestic poultry rather than wild birds. This strain of the virus is known to infect nearly 60 avian species and has resulted in 71 human fatalities, most resulting from direct contact with domestic poultry.

Sources:

CBS News, December 28, 2005

http://www.cbsnews.com/stories/2005/12/28/ap/health/mainD8EP4V886.shtml

Asian Journal, December 26, 2005

http://www.asianjournal.com/?c=131&a=9349&sid=52f607a9b5da8b433d201e933bb7ce56

U.S. Geological Survey's National Wildlife Health Center

http://www.nwhc.usgs.gov/