County of Marin Health and Human Services

H5N1 (Bird Flu)

Marin County Public Health is closely monitoring the national H5N1 bird flu outbreak that has impacted birds, livestock, and, rarely, humans. H5N1 has been detected in both wild birds and poultry in Marin County. There are no reported cases of H5N1 bird flu in cows or humans in California. While the current risk to the general public from H5N1 bird flu is low, the situation is evolving, and Marin County Public Health will continue to provide updates to our community.

For more information, visit the CDC’s H5N1 Bird Flu: Current Situation Summary web page.

What is H5N1 Bird Flu?

H5N1 bird flu is a specific strain or type of influenza virus. H5N1 bird flu is also called highly pathogenic avian influenza (HPAI). H5N1 bird flu can infect wild birds, poultry, and mammals such as cows. Human infections with H5N1 bird flu are rare, but spread of the virus may lead to changes that make it more likely to infect humans.

What is Marin County Public Health Doing?

Marin County Public Health is taking an approach to H5N1 that acknowledges the interconnectedness of health between humans, animals, and ecosystems. We are actively collaborating with local, state, and federal partners to address animal and public health concerns, and protect the health of the community. 

MCPH is working with local farmers to identify sick animals early and protect workers from infection. This proactive approach is part of the Department’s ongoing work to ensure community safety by preparing in advance for various diseases, even before there are cases here.

As of May 20, 2024, MCPH is testing wastewater for H5N1 bird flu levels in order to determine if and when the virus may be circulating locally. No H5N1 bird flu has been detected in wastewater in Marin County. The presence of H5N1 in wastewater may not indicate human infections have occurred and will be interpreted in the context of other data regarding animal and human health. 

What can you do to stay safe?

CDC has indicated that the current risk to the general public from H5N1 bird flu is low. People should:

  • Wash your hands regularly, especially before eating and after interacting with animals.
  • Avoid unprotected exposures to sick or dead animals including wild birds, poultry, and other domesticated birds. Handling sick or dead animals safely requires personal protective equipment and training.
  • Do not drink or eat unpasteurized (raw) milk or raw cheese. Raw milk and cheese have not gone through a process called pasteurization that kills disease-causing germs. The milk of cows infected with H5N1 carries live virus. For more information about how raw milk can make you sick, visit the  CDC’s Raw Milk web page.

Recommendations for Agricultural Workers

People who have job-related or recreational exposure to infected animals, including wild birds, poultry, and dairy cows, are at greater risk of being exposed to H5N1 bird flu. These people may include farmers or workers on poultry and dairy farms, slaughterhouse workers, backyard bird flock owners, veterinarians and veterinary staff, animal rescue workers, and emergency responders. In addition to the recommendations above, these people should also:

  • Follow all CDC recommendations for worker protection to reduce the risk of infection
  • Call your doctor if you feel sick. Symptoms of H5N1 bird flu can include red or watery eyes, cough, sore throat, and fever.

The California Department of Public Health has also created an educational flyer for agricultural workers about H5N1 bird flu. Please access the PDF here: English / Spanish

Learn More

For more information on H5N1 bird flu, refer to the CDC’s H5N1 Bird Flu: Current Situation Summary web page.

Additional Resources