Fourth person infected in California as bird flu outbreak spreads

A fourth person contracted bird flu in California amid outbreaks in the state’s dairy industry, state officials said Thursday.

As in prior confirmed cases, the person works in the state’s agricultural Central Valley and was in contact with infected dairy cattle, the California Department of Public Health announced in a news release. All people identified with the infection in California have had mild symptoms including eye redness or discharge. None have been hospitalized.

There are no known links between the confirmed cases, which suggests there is widespread transmission among dairy herds and the infected cattle pose risks to people working in or around them.

So far, officials have identified 17 people across the U.S. who were infected with bird flu this year. Nearly all worked with infected dairy or poultry livestock.

Two other people in California's Central Valley are suspected of contracting avian influenza. Lab results that could confirm this are pending from the U.S. Centers for Disease Control and Prevention in Atlanta.

California officials said the risk to the general public remains low, however, people who “interact with infected animals are at higher risk of getting bird flu.”

On Thursday morning, CDC officials said California’s first two cases came from the same strain of virus closely related to those detected in infected dairy cows. There do not appear to be genetic changes to the virus that could cause a greater ability to infect or spread it between people or reduce the efficacy of antiviral medications used to treat it.