Cows at three California dairy farms have been placed under quarantine after testing positive for avian influenza, commonly known as bird flu, according to the state’s department of food and agriculture (CDFA).
Currently, there are no threats to California’s milk or food supply. As the leading dairy-producing state in the U.S., California is prioritizing containment measures to prevent further spread of the virus.
Despite the positive tests in livestock, no human cases of the bird flu virus have been reported in connection with the latest outbreak. The California Department of Public Health (CDPH) is working with the CDFA to monitor potential human exposure and said it plans to make sure proper public health measures are in place.
“We have been preparing for this possibility since earlier this year when HPA1 detections were confirmed at dairy farms in other states,” said Karen Ross, the CDFA’s secretary, in a statement. Ross emphasized that the department is leveraging its extensive experience HPA1, particularly from previous poultry outbreaks, to manage the situation effectively.
“This is a tough time for our dairy farmers given the economic challenges they’re facing in a dynamic market, so I want to assure them that we are approaching this incident with the utmost urgency,” Ross said.
The virus was detected after herds at Central Valley farms began showing symptoms on August 25, 2024. Preliminary tests conducted by the California Animal Health and Food Safety (CAHFS) laboratory network were confirmed by the National Veterinary Services Laboratory (NVSL).
Although the bird flu virus is “not considered a significant public health threat,” and the risk for humans is low, the department said there are still concerns for dairy workers that come in close contact with the infected cows. In July, four farm workers in Colorado were said to have been infected with the bird flu virus, according to the state’s health department.
To minimize the risk of infection, the CDPH recommends that personal protective equipment (PPE), such as masks, gloves, caps, face shields, and safety goggles, be used by farm workers and emergency responders handling infected animals or materials.