Nevada Dairy Worker Infected With Different Bird Flu Strain

A bird flu strain spreading among dairy cows in Nevada has infected a dairy worker, the Central Nevada Health District confirmed. The farm worker, who had been near infected cows, experienced conjunctivitis with no other reported symptoms and is recovering. The case marks the first for the state of Nevada.

The patient was found to have a strain of bird flu called D1.1, which is prevalent in wild birds. D1.1 is a different strain of the virus that’s caused the majority of human infections in the U.S., called B3.13, NBC News reported. The D1.1 strain has a mutation that could make the virus spread more easily in mammals and marks the second strain that has circulated from birds to dairy cows, the news agency reported.

The one person who died from bird flu in the U.S. had been hospitalized in Louisiana with the D1.1 genotype as well. The U.S. Centers for Disease Control and Prevention (CDC) estimates D1.1 is responsible for 15 of the 68 human cases of bird flu confirmed last year.

The case brings the U.S. outbreak of the virus to nearly 70 people since April 2024, Reuters reported. The U.S. Centers for Disease Control and Prevention (CDC) still considers the bird flu risk to the public health low.

The U.S. Department of Agriculture reported for the first time last week that a second strain of bird flu was found in dairy cattle in Nevada, a discovery that concerned experts.

Last month, the CDC also said the U.S. should increase testing for bird flu in hospitalized patients, ideally within 24 hours of admission.