October 2, 2006

Wild ducks in US state Illinois test positive for non-Asian bird flu

The US Department of Agriculture announced Friday (Sep 29) evening that it has once again found bird flu in wild ducks--this time in "migratory Green-winged Teals in Illinois"--and it is not the highly pathogenic "Asian" H5N1 strain of flu that is a threat to humans.

The USDA said that initial tests show the presence of both "H5 and N1 bird flu subtypes," but even further testing proved that some birds are infected with an H5N1 virus which is of a low-pathogenic type.

Birds often carry multiple virus strains, a USDA official said.

"Low pathogenic bird flu commonly occurs in wild birds and can be found in a number of duck populations including the Green-winged Teal," USDA said. "It typically causes only minor sickness or no noticeable symptoms in birds."

The highly pathogenic "Asian" type of H5N1 has spread through Asia, Europe and Africa and killed humans, but it has never been found in the US.

The USDA has previously announced finding the low-pathogenic form of H5N1 bird flu in wild birds. USDA officials have said the low-pathogenic, or "North American" type of bird flu poses no threat to humans.