Four workers at a commercial egg farm near Pasco in Eastern Washington have tested positive for avian influenza, according to preliminary test results.
They work at a commercial poultry operation that reported many chickens suddenly dying on Oct. 11, with tests confirming an avian influenza outbreak on Tuesday. About 800,000 chickens are being euthanized.
The worker are the first presumed human cases of the H5 bird flu virus under investigation in Washington state, the Washington state Department of Health said Sunday.
The workers have had mild symptoms and have been offered antiviral medication by the Benton Franklin Health District.
The chicken are believed to have been infected by migrating waterfowl, with the infection spreading from the chickens to the workers.
Other workers at the farm are being tested and the number of human cases being investigated could increase, according to the Department of Health.
Although the Department of Health has not identified the farm with the avian influenza outbreak other than to say it is in Franklin County, the outbreak follows one in December 2022 at the large Oakdale Farms poultry operation north of Pasco.
The Benton Franklin Health District is confirming preliminary results of worker testing done at the Washington state Public Health Laboratory by sending samples to the Centers for Disease Control and Prevention.
The state Department of Health and the Benton Franklin Health District have provided personal protective equipment to workers on the farm and are providing testing, vaccines and treatment for workers with symptoms. It also is monitoring other workers for symptoms of avian influenza.
Workers at other poultry farms in the greater Tri-Cities area with symptoms such as red eyes or respiratory infections since Oct. 7 should contact the Benton Franklin Health District at 509-460-4550.
The CDC considers the risk to the general public low, said Dr. Umair Shaw, Washington state Secretary of Health, in a news media call Sunday.
However, people who are exposed to infected birds, cattle or other animals are at higher risk of infection and should take precautions, such as wearing persona protection equipment, according to the Department of Health.
It also warns people not to handle dead birds and to keep their pets away from them.