Agricultural Commissioner / Sealer of Weights & Measure


August 11, 2022

New Detections of Highly Pathogenic Avian Influenza (HPAI)

This is to notify you that the Eurasian strain H5N1 Highly Pathogenic Avian Influenza (HPAI) has been confirmed by the National Veterinary Services Laboratory in a backyard flock in Sacramento County, California.  The chickens that were still alive after receiving a presumptive positive test from the California Animal Health and Food Safety Laboratory (CAHFS) were immediately euthanized and disposed in order to prevent further spread.    CAHFS is also reporting cases in wild Canada geese and a Muscovy duck in Stanislaus county, a Wood duck in Mendocino county, and a wild Canada goose in Santa Clara county.  The virus was previously detected in other wild birds in Butte, Colusa, Glenn, Placer, Plumas, Sacramento, Siskiyou, Solano, and Sonoma Counties.

According to the U.S. Centers for Disease Control and Prevention (CDC), the public health risk associated with these avian influenza detections in birds remains low. As a reminder, the proper handling and cooking of all poultry and eggs to an internal temperature of 165 ˚F is recommended as a general food safety precaution.

Note that when USDA announces what some consider a backyard flock of poultry that is confirmed positive for HPAI, it will be called “non-poultry.”  This is a trade term that is important to use because there is an agreed upon understanding of the meaning.  When they use “poultry” it means the products enter commerce and there is increased risk of cross contamination between commercial flocks.  “Non-poultry” are treated more like wild bird detections.

As part of existing avian influenza response plans, CDFA is conducting additional surveillance and testing in areas around the affected flocks. The United States has the strongest AI surveillance program in the world, and CDFA, the California Department of Fish and Wildlife and the California Animal Health and Food Safety Laboratory System as well as cooperating poultry owners and managers continually test for the disease in commercial poultry operations, live bird markets and in migratory wild bird populations.  To date, there have been no detection of this strain of avian influenza in commercial poultry in California.

Anyone involved with poultry production from the small backyard to the large commercial producer should review their biosecurity activities to assure the health of their birds. California poultry owners are encouraged to visit the CDFA Avian Health Program website for biosecurity tools and support at:  CDFA - AHFSS - AHB - Avian Health (

Additional background
Avian influenza (AI) is caused by an influenza type A virus which can infect poultry (such as chickens, turkeys, pheasants, quail, domestic ducks, geese, and guinea fowl) and is carried by free flying waterfowl such as ducks, geese and shorebirds. AI viruses are classified by a combination of two groups of proteins: hemagglutinin or “H” proteins, of which there are 16 (H1–H16), and neuraminidase or “N” proteins, of which there are 9 (N1–N9). Many different combinations of “H” and “N” proteins are possible. Each combination is considered a different subtype and can be further broken down into different strains which circulate within flyways/geographic regions. AI viruses are further classified by their pathogenicity (low or high)—the ability of a particular virus strain to produce disease in domestic poultry.


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