(Reuters) - The state of Washington said Tuesday it has established a third poultry quarantine zone after state officials discovered that a flock of about 100 birds in Okanogan County was infected with the avian influenza virus.
The Washington State Department of Agriculture adopted an emergency rule on Sunday to establish the new quarantine area, which encompasses a six-mile area in Oroville, Wash., state officials said.
State officials are conducting additional tests to identify the specific flue strain that infected the flock. About half of the 100 birds have died, according to agriculture officials.
The quarantine generally restricts the movement of all eggs, poultry or poultry products from leaving that area.
The state had set up the first emergency quarantine in the area on Jan. 29, after a flock of nearly 5,000 birds tested positive for the H5N2 influenza strain. Another quarantine zone was also set up in Clallam County, in response to a separate infected flock.
The U.S. Department of Agriculture said at the time the virus did not pose a health risk to the public, and birds and other poultry products from such infected flocks would not enter the food system.
Regardless, China last month banned all imports of U.S. poultry products and eggs following the discovery of avian influenza in the U.S. Pacific Northwest, the USDA said. All poultry shipped to China after Jan. 8 was to be returned or destroyed, the agency said. [ID:nL1N0UR2FQ]
The virus is extremely contagious among poultry and can spread rapidly through a flock, killing birds in as little as 48 hours. The H5N2 strain has also been found in backyard chicken flocks in Idaho.
A different strain, H5N8, forced a temporary quarantine of a Foster Farms turkey ranch in California last month, with the birds destroyed to prevent the spread of the disease to migratory and commercial flocks.
Reporting By P.J. Huffstutter in Chicago; Editing by Grant McCool