Washington state health officials said four agricultural workers tested presumptively positive for avian influenza, marking the first presumed human cases in the state.

Four people have reportedly developed symptoms of avian influenza after working with infected poultry in Franklin County.

Like the two previously reported cases, the individual was a dairy worker who had occupational exposure to infected dairy cows.

The CDC’s Timothy M. Uyeki, M.D, however, cautioned that if the virus changes, and especially if it begins to infect pigs, that would be a game changer, allowing the virus to mutate to one that is more of a threat to people.

Four agricultural workers in southeast Washington have preliminarily tested positive for bird flu after working with an infected poultry flock at a commercial egg farm. The cases, if confirmed, would be the first time people in Washington have contracted the virus since officials began tracking its rise across the U.

Bird flu has infected a commercial flock of about 800,000 fowl at an egg farm in southeast Washington, the state’s Department of Agriculture said. It’s the first detection in

The California Department of Public Health (CDPH) reported Friday that 13 total human cases of bird flu have been confirmed in the state. The CDPH said the cases have been identified from Central Valley residents who had direct contact with infected dairy cattle.