Bird flu found in Yolo County backyard poultry flock, health officials say

At least one bird in a Yolo County poultry flock tested positive this week for avian influenza, an illness that has spread through the country and prompted Gov. Gavin Newsom to declare a state of emergency last month.

Avian influenza, H5N1, had been detected in wild birds in Yolo County since 2022 but never before in a backyard poultry flock, according to a Thursday news release from county officials. Two people were exposed to the birds, but exhibited no symptoms.

There is no ongoing risk to animals or humans from this flock because all the infected birds have died or were euthanized, the news release said. It’s likely the infection came from another county because the illness struck when poultry from outside Yolo County mingled with the local flock, county health officials said.

The chance for people to become infected is low, the release said. There were 38 human cases in California through Jan. 15, most of whom got the virus after being exposed to infected cattle, according to the latest update from the California Department of Public Health.

“The detection of bird flu in a backyard poultry flock in Yolo County is not unexpected given the widespread nature of bird flu in California poultry and dairy cows,” Yolo County Public Health Officer Dr. Aimee Sisson said in a prepared statement.

It is safe to consume pasteurized milk products and cooked beef and poultry products. But people should avoid raw milk and raw dairy products because they may contain live bird flu virus.

Yolo County officials were told Tuesday of the bird flu’s detection.

Avian influenza has also been found “sporadically and at low levels in wastewater in the cities of Davis and Woodland since late November 2024, likely related to dairy products,” the release said.

The virus can spread when people get raw milk into their eyes, nose or mouth; by touching cow or bird feces; and “potentially through consumption of raw dairy products.” the release said.

Symptoms for avian influenza include fever, coughing, sore throat, runny or stuffy nose, body aches and eye redness or discharge.