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Bird flu detected in dairy cows in 12 states

Health officials are trying to get ahead of the H5N1 bird flu spreading through dairy cows nationwide.
Chickens stand in their cages at a farm
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Summer is almost synonymous with state and county fairs — a time to enjoy the best food and agriculture your state has to offer — and interacting with cows, chickens, goats and other animals is a big part of the festivities.

But this year, you may see more protective measures in place as bird flu infections continue to spread among cow herds across the country.

Health officials are trying to get ahead of the H5N1 bird fluspreading through dairy cows nationwide, weeks before fair season gets underway.

The CDC says over 100 dairy cattle herds in around a dozen states have reported cases of the highly infectious disease since March.

Bird flu spreads from animal to animal, but has jumped to four humans in the U.S. since 2022, all of whom interacted with infected cows or poultry.

Federal health officials say the current risk to humans is very low.

Related story: Person in Mexico died of a bird flu strain that hadn't been confirmed before in a human, WHO says

But experts say because of patchwork testing across the country, there could be a higher risk of disease spreading even further among different species at state fairs through farming equipment and visitors.

"Humans actually can transmit H5N1 to other animals by walking on soil and then going to another farm," said Dr. Peter Chin-Hong, professor of medicine and infectious disease specialist at UCSF.

Some counties aren't showing cows at fairs, while some states are requiring animal and milk tests and vet inspections for anyone bringing lactating dairy cows to fairs and exhibitions.

"I would caution people against any unpasteurized cheese or raw milk that you might also find at these state farms," he said.

He also recommends washing your hands, and says it's unlikely humans will get infected unless they have prolonged exposure to a sick animal.