Bird Flu Detected in Yolo County
Jan 28, 2025 02:35PM ● By Yolo County News Release
Bird flu has been detected in 100 commercial flocks and 37 backyard flocks in California, affecting over 23 million birds. Photo by Ralph from Pixabay
WOODLAND, CA (MPG) - Avian influenza, also known as bird flu and influenza A (H5N1), has been detected in a backyard poultry flock in Yolo County, according to the Yolo County Health and Human Services Agency and the Yolo County Agricultural Commissioner.
While bird flu has been detected in wild birds in Yolo County since 2022, this is the first detection of bird flu in poultry in the county. Since 2022, bird flu has been detected in 100 commercial flocks and 37 backyard flocks in California, affecting over 23 million birds.
All birds in the affected backyard flock have died or been euthanized, so there is no ongoing risk to other animals or humans. New birds were introduced into the flock from a source in another county days before the birds began exhibiting symptoms, making it likely that the infection was acquired elsewhere and imported into Yolo County. Yolo County Public Health is monitoring two people exposed to the affected birds; both remain asymptomatic.
“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,” said Dr. Aimee Sisson, Yolo County’s public health officer. “The risk to the general public from bird flu remains low, although people who work with dairy cows, poultry, or wildlife are at increased risk and should wear personal protective equipment when working with these animals. To protect themselves from bird flu, Yolo County residents should not touch wild birds, sick or dead wildlife and should avoid consumption of raw milk or raw dairy products.”
In addition to previous detections of bird flu in wild birds in Yolo County, influenza A (H5N1) has also been detected sporadically and at low levels in wastewater in the cities of Davis and Woodland since late November 2024, likely related to dairy products.
The current bird flu outbreak in the United States and California involves transmission of bird flu from wild birds to poultry and cows, and then from cows and poultry to humans. While 38 human cases of bird flu have occurred in California since August 2024, no person-to-person spread of bird flu has been detected in California and all cases have been associated with mild illness. All but two of California’s human cases have occurred in dairy workers.
Bird flu is caused by a virus that can spread from infected animals to people by breathing in dust or droplets with the virus; splashing raw milk into the eyes, nose, or mouth; touching the eyes, nose, or mouth with unwashed hands after handling raw milk, cow or bird feces, sick or dead animals, or other contaminated surfaces; and potentially through consumption of raw dairy products. Symptoms of bird flu are similar to those of other respiratory diseases, including fever, cough, sore throat, runny or stuffy nose, body aches, and eye redness or discharge.
The risk to the general public from bird flu is currently low. To protect against infection, members of the public should avoid contact with sick or dead animals and avoid contact with wild birds, which may appear healthy despite being infected. People should also avoid raw milk and dairy products because they may contain live bird flu virus. Pasteurized milk products are safe to drink, and cooked beef and poultry products remain safe to eat. Pasteurization and cooking destroy the bird flu virus.
People who come into contact with cows, poultry, wild birds, or other wildlife are at increased risk of bird flu exposure and infection. These individuals should wear personal protective equipment when coming into contact with animals, including an N95 respirator, eye protection, gloves, coveralls, and boots (and/or change their clothes and shoes). Individuals should also wash their hands before eating, drinking, or touching their face.
Bird flu infections in Californians have been mild to date, but public health experts warn that the bird flu virus could evolve into something capable of causing more severe disease and/or able to spread from person-to-person. U.S., state, and local public health departments continue to monitor the bird flu situation closely. In the meantime, they recommend that residents receive a seasonal flu vaccine, which will reduce the likelihood of an individual becoming infected with both bird flu and seasonal flu at the same time. Such a co-infection can create an opportunity for the bird flu virus to progress.
For more information about bird flu in California, visit the California Department of Public Health’s Bird Flu website and the California Department of Food and Agriculture’s (CDFA) on poultry and dairy infections. The California Department of Food and Agriculture is the lead agency working with poultry and livestock producers across the state to address the current outbreak. Recently, the California Department of Food and Agriculture placed a ban on poultry and dairy cattle exhibitions at fairs and shows in order to protect the remaining unaffected herds and flocks across California.
Yolo County residents with backyard flocks can obtain more information on how to protect their birds by visiting www.CDFA.CA.gov/ahfss/Animal_Health/BioSpecies/BioPoultry. The wastewater levels of influenza A (H5) in Yolo County are available at Data.WasteWaterScan.org. Organizations that work with dairy, poultry or wildlife can request personal protective equipment by contacting [email protected].