Illinois wild bird samples undergo additional testing for bird flu

Oct 3 2006

The U.S. Department of Agriculture (USDA) and Department of the Interior (DOI) have announced a detection of the H5 and N1 avian influenza subtypes in samples from wild, migratory Green-winged Teals in Illinois.

Initial tests confirm that these wild duck samples do not contain the highly pathogenic H5N1 strain that has spread through birds in Asia, Europe and Africa.

These samples were collected from apparently healthy birds and initial test results indicate the presence of low pathogenic avian influenza (LPAI) virus, which poses no threat to human health.

The bird samples were collected on Sept. 24 in the Rice Lake Conservation Area of Fulton County, Illinois, through a partnership between USDA and the Illinois Department of Natural Resources as part of an expanded wild bird monitoring program. USDA and DOI are working collaboratively with states to sample wild birds throughout the U.S. for the presence of highly pathogenic avian influenza (HPAI). As a result of this expanded testing program, USDA and DOI expect to identify additional cases of common strains of avian influenza in birds, which is not cause for concern.

The ducks were showing no sign of sickness, which also suggests this is LPAI. Eleven samples were collected directly from the ducks. Of those samples, a pool of five samples tested positive for H5 and were sent to USDA's National Veterinary Services Laboratories (NVSL) in Ames, Iowa, for confirmatory testing. One of the five samples screened by NVSL tested positive for both H5 and N1. However, this does not mean these ducks are infected with an H5N1 strain. It is possible that there could be two separate avian influenza viruses, one containing H5 and the other containing N1. Confirmatory testing underway at NVSL will clarify whether one or more strains of the virus are present, the specific subtype, as well as confirm the pathogenicity. These results are expected within two to three weeks and will be made public when completed.

Low pathogenic avian influenza commonly occurs in wild birds and can be found in a number of duck populations including the Green-winged Teal. It typically causes only minor sickness or no noticeable symptoms in birds. These strains of the virus include LPAI H5N1, commonly referred to as "North American" H5N1, which is very different from the more severe HPAI H5N1 circulating overseas.

Duck populations, including Green-winged Teal, are commonly hunted. There is no known health risk to hunters or hunting dogs from contact with low pathogenic forms of avian influenza virus. Nevertheless, hunters are always encouraged to use common sense sanitation practices, such as hand washing and thorough cooking, when handling or preparing wildlife of any kind. DOI has issued guidelines for safe handling and preparation of wild game.