Highly pathogenic H5 avian influenza viruses have been found in captive birds and wild ducks in Washington state.
The strains are not considered to be human health risks.
In January, U.S. Department of Agriculture authorities reported that an H5N8 influenza virus had been found in guinea fowl and chickens in a mixed-bird flock exposed to migratory waterfowl in southern Washington.
The same strain had been found in captive gyrfalcons in December 2014 in Whatcom County, which borders British Columbia. The department also had identified in December an H5N2 influenza strain in pintail ducks that were in Whatcom County.
USDA information indicates the influenza strains have been found in other countries without any known connection with disease in humans.
An announcement from the Washington State Department of Agriculture indicates the poultry flock owner had contacted the agency after 50 birds from the 150-bird flock had died within a week. The remaining birds were depopulated Dec. 21, according to a USDA report to the World Organisation for Animal Health (OIE).
The Canadian Food Inspection Agency also announced in December that an H5N2 influenza virus had been found on chicken and turkey farms in the Fraser Valley, which is in southern British Columbia. U.S. authorities have been conducting increased surveillance for avian influenza because of those outbreaks in British Columbia, USDA information states.