The U.S. Department of Agriculture announced final test results, which confirm that an H5N1 avian influenza virus detected in samples collected earlier this month from two
The USDA National Veterinary Services Laboratories confirmed the presence of the "North American strain" of low pathogenic H5N1 avian influenza in one of twenty samples collected from the two wild mute swans. Preliminary test results announced on August 14 indicated that an H5N1 strain could be present in two of the collected samples. Only one of the samples contained high enough levels of the virus to conduct confirmatory testing. As previously announced, genetic testing ruled out the possibility that either of the samples carried the highly pathogenic strain of H5N1 avian influenza that is circulating overseas.
Low pathogenic strains of avian influenza commonly occur in wild birds and typically cause only minor sickness or no noticeable signs of disease in birds. Low pathogenic H5N1 is very different from the more severe highly pathogenic H5N1 circulating in parts of
The Departments of Agriculture and Interior are working collaboratively with States to sample wild birds throughout the