May 5, 2008

US research shows swine, avian flu genes contain similar virus

New research from the USDA Agricultural Research Service shows that virus found from two Midwestern swine production facilities in 2006 has evolved into a new strain of H2 influenza virus and the pathogen is similar to the trait that caused the 1957 flu pandemic.

The discovery was startling as the virus-- first identified by a veterinary diagnostician from the University of Minnesota--contains both swine and bird flu viruses.

Molecular studies indicate that the mystery pig pathogen is actually an H2N3 influenza virus closely related to an H2N3 strain found in mallard ducks--being seen for the first time in mammals.

Both swine facilities used pond water frequented by migrating waterfowl.

In the newly isolated swine H2N3, the avian H2 and N3 gene segments mixed with gene segments from common swine influenza viruses, giving it the ability to infect swine--as well as mice and ferrets

This suggests the need for continued monitoring of both swine and livestock workers for H2-subtype viruses and other influenza strains.