The California Department of Public Health confirmed last week that two Central Valley residents were confirmed as having H5 bird flu. These are the first human cases of bird flu identified in the state and both individuals had contact with infected dairy cattle.
There is no known link or contact between the two cases, suggesting only animal-to-human spread of the virus in California. In both cases the individuals experienced mild symptoms, including conjunctivitis (eye symptoms), and neither reported respiratory symptoms, nor was hospitalized.
The CDPH, citing patient privacy, were not releasing the hometowns of the individuals.
The risk to the general public remains low, but people who interact with infected animals, like dairy or poultry farm workers, are at higher risk of getting bird flu. CDPH recommends that personal protective equipment, or PPE, such as respirators (N95 masks), eye protection (face shields or safety goggles), and gloves be worn by anyone working with animals or materials that are infected or potentially infected with the bird flu virus. Wearing PPE helps prevent infection.
Pasteurized milk and dairy products continue to be safe to consume, as pasteurization is fully effective at inactivating the bird flu virus. As an added precaution, and according to longstanding state and federal requirements, milk from sick cows is not permitted in the public milk supply.
In late September more than 64,000 birds at a Merced County poultry facility were euthanized after officials found positive results for the highly pathogenic avian flu. The name of the facility was not released by state or federal officials.
CDPH has helped coordinate and support outreach to dairy producers and farm workers on preventive measures that have helped keep human cases low in other states with bird flu outbreaks. CDPH continues to support local health departments in distributing PPE from state and federal stockpiles directly to affected dairy farms, farmworker organizations, poultry farm workers, those who handle raw dairy products, and slaughterhouse workers. To protect California farm workers from bird flu, during the last four months CDPH has distributed more than 340,000 respirators, 1.3 million gloves, 160,000 goggles and face shields, and 168,000 bouffant caps.
In addition, CDPH is working closely with local public health laboratories and local health departments to provide health checks for exposed individuals and ensure testing and treatment are available when needed. As one of the 14 states with infected dairy herds, California also received 5,000 additional doses of seasonal flu vaccine for farm workers from the CDC. CDPH is working to distribute the doses to local health departments with the highest number of dairy farms.
CDPH has been tracking bird flu cases and making preparations for a possible human infection since the state’s first detection in poultry in 2022. CDPH partners closely with the California Department of Food & Agriculture on a broad approach to protect human and animal health. CDPH and the CDC use both human and wastewater surveillance tools to detect and monitor for bird flu, and work closely with local health departments to prepare, prevent, and lessen its impact on human health.
People exposed to infected animals should monitor for the following symptoms for 10 days after their last exposure: eye redness (conjunctivitis), cough, sore throat, runny or stuffy nose, diarrhea, vomiting, muscle or body aches, headaches, fatigue, trouble breathing, and fever. If they start to feel sick, they should immediately isolate, notify their local public health department, and work with public health and health care providers to get timely testing and treatment.
CDPH recommends that all Californians — especially workers at risk for exposure to bird flu — receive a seasonal flu vaccine. Although the seasonal flu vaccine will not protect against bird flu, it can decrease the risk of being infected with both viruses at the same time and reduce the chance of severe illness from seasonal flu.
