USDA and the Department of the Interior announced Saturday the completion of testing on samples collected from wild Northern pintail ducks in Montana, confirming the presence of a low pathogenic H5 avian influenza virus in the samples. Low pathogenic avian flu has been detected in birds in other states and is not a direct risk to human health.

Although initial test results announced Sept. 21 indicated the presence of avian influenza in the Montana samples, further testing was necessary to confirm the subtype and pathogenicity of the virus. These tests ruled out the possibility that the samples carried the dangerous, highly pathogenic H5N1 strain of avian influenza. Highly pathogenic avian influenza strains - including H5N1, which is circulating in parts of Asia, Europe and Africa - can be fatal to chickens and turkeys, harmful to humans, and spread rapidly.

Although the low pathogenic virus poses no direct threat to human health, USDA policy is to attempt to contain the strain in case of a mutation into highly pathogenic avian flu, and because the presence of any strain of avian influenza can affect trade. The U.S. Departments of Agriculture and Interior are working with States and academic institutions to test birds across the country for the highly pathogenic strain of avian influenza.