Avian influenza has been found in a backyard poultry flock in southeast Washington after previously showing up in wild birds in the northwest part of the state, but state officials say there is no immediate public health concern.

State Agriculture Department officials said Friday the virus has not been found in commercial poultry in Washington or elsewhere in the United States. They say the virus poses no apparent threat to humans but highly pathogenic strains can be deadly to domestic poultry and sometimes to wild birds.

Officials say the owner of the flock of about 150 birds near Benton City contacted the Agriculture Department after losing nearly 50 birds in the past week.

The virus confirmed in the flock is similar to the virus found in a Washington captive gyrfalcon last month, although additional testing is being conducted to identify the strain.

British Columbia officials say an avian influenza outbreak there has spread to more than a half dozen poultry farms and affected about 245,000 birds.