Avian Flu

Avian Influenza

November 19, 2024

H5N1 Avian Influenza or "bird flu” is a type of influenza virus that primarily affects birds. H5N1 is also called highly pathogenic avian influenza (HPAI), based on the disease severity in poultry. H5N1 has been detected in wild and farmed birds in the US since 2022, including in Alameda County. H5N1 bird flu can also infect mammals such as cats, raccoons and skunks. Human infections are rare but can occur, especially in people with prolonged contact with infected animals.

The Alameda County Public Health Department has been monitoring a multi-state outbreak of H5N1 bird flu in dairy cows in the United States, including at over 275 dairies in the Central Valley of California. There are no commercial dairy cattle herds in Alameda County. Since April 2024, multiple cases of H5N1 bird flu have been reported in the U.S., including in dairy farm workers in California. So far, the California farm worker cases are reported to have experienced mild symptoms, including eye redness or discharge (conjunctivitis), and none were hospitalized. According to the CDC, the immediate risk to the general public from H5 bird flu remains low.

The Food and Drug Administration (FDA) and United States Department of Agriculture (USDA) have indicated that the commercial milk supply is safe, based on recent laboratory testing. The pasteurization process kills disease-causing germs in milk and milk products. However, the FDA does not know at this time if H5N1 can be transmitted through consumption of unpasteurized (raw) milk and products (such as cheese) made from raw milk from infected cows. For more information about how raw milk can make you sick, visit the CDC’s Raw Milk webpage. The USDA is confident that the meat supply is safe.

Please visit the CDC website for information about worker protection and personal protective equipment (PPE) for poultry or livestock farmers and other workers who could be exposed to H5N1. CDPH also has flyers about using PPE in English and Spanish. ACPHD has offered PPE to employers whose workers have contact with poultry and other wildlife. Backyard flock owners (and other Alameda County residents who may come into contact with sick, dead or infected animals, animal feces, litter, raw milk, and other materials the animal has come in contact with) can follow these instructions to order PPE.