Avian flu linked to cold-front movements

PRINCETON, N.J., April 15 (UPI) -- U.S. and Dutch scientists say they've linked avian influenza (H5N1) outbreaks in Europe during the winter of 2005-2006 to the movement of cold weather fronts.

Researchers from Princeton University in the United States and the Erasmus Medical Center in the Netherlands showed the outbreaks occurred at the edge of cold fronts, driven by aggregated movements of wild waterbirds flying away from areas of frozen water.

The researchers said they found most H5N1 outbreaks occurred at the edge of cold fronts, where bodies of freshwater remained unfrozen. Many wild waterbirds need unfrozen bodies of freshwater in winter to feed, the scientists said, and the resulting congregation of different species likely created ideal conditions for the transmission of the H5N1 virus within and between wild bird species.

The study was detailed in the April 8 issue of the journal PLoS Pathogens.