Emergency quarantine zone. Click image for larger view.

OLYMPIA, Wash. – The Washington State Department of Agriculture (WSDA) implemented a quarantine zone for avian influenza that covers roughly 20 miles around two locations where a highly pathogenic strain of bird flu was identified in backyard poultry flocks.

The zone includes parts of Benton and Franklin counties, according to the agency. The quarantine restricts the movement of poultry eggs, live poultry and poultry products out of the zone. However, exemptions will be made for operations that obtain special permits and meet specific criteria, WSDA said. Highly pathogenic H5 avian influenza was confirmed in a backyard poultry flock of 150 birds near Benton City. In December, WSDA confirmed the presence of H5N2 in northern pintail ducks and H5N8 in captive Gyrfalcons.

The US Department of Agriculture plans to increase testing of poultry and other domestic birds within an area 10 km around the two affected flocks, WSDA said.

No additional cases of avian influenza have been identified, WSDA added, and the virus has not been found in commercial poultry flocks anywhere in the state or in the United States. However, the presence of the H5N2 and H5N8 strains in migratory birds continues to be the biggest risk, the agency said.