03-04-2025
First bird flu confirmed in San Bernardino County dairy farms since California outbreak
The bird flu virus has been detected in four dairy farms in San Bernardino County.
In the last 30 days, an investigation by the California Department of Food & Agriculture and the California Animal Health and Food Safety Laboratory System (CAHFS) has confirmed the presence of H5N1 bird flu in San Bernardino County dairy farms.
California has experienced a significant outbreak of the Highly Pathogenic Avian Influenza (HPAI), commonly known as the bird flu, since March 2024.
What started as an infection at a duck farm in Merced County has since infected 755 dairies throughout the state. Of the infected, 422 dairies have fully recovered and are released from quarantine, San Bernardino County officials said in a statement.
The risk of infection to people from H5N1 remains relatively low and no person-to-person spread of bird flu has been detected in California thus far.
'While the risk of bird flu to the general public remains low, the detection of this virus in animals across multiple farms serves as a reminder to practice caution when handling animals or animal products,' San Bernardino County Health Officer Sharon Wang said. 'It's crucial to avoid raw milk consumption and follow proper food safety practices to reduce any potential risk of exposure.'
On Dec. 18, Gov. Gavin Newsom proclaimed a State of Emergency to streamline and expedite the state's response to Avian Influenza A (H5N1). At the time of the governor's declaration, the virus spread in 16 states among dairy cattle, following its first confirmed detection in Texas and Kansas in March 2024.
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Avian Influenza, commonly called bird flu, is broken down by the CDFA as a disease found in some populations of wild waterfowl that can infect chickens, turkeys, pheasants, quail, ducks, geese, and guinea fowl, as well as a wide variety of other domesticated and wild birds.
Once the disease is introduced into domestic bird populations, subsequent spread is typically caused by domestic bird-to-bird contact or through contact with contaminated people, feed, or equipment.
Each year there is a flu season for birds (just as there is for humans) and, as with people, some forms of the flu are worse than others, according to public health officials.
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According to the CDFA, a dairy will be placed under a 60-day quarantine to reduce the risk of viral spread when tested positive for H5N1 bird flu.
After that timeframe, the CDFA will begin testing infected dairies through creamery samples. Clinical signs include fever, dehydration, lethargy, abnormal tacky or loose feces, sudden drop in milk production, and respiratory signs like clear nasal discharge.
An infected dairy will need three consecutive negative creamery samples with seven days between tests.
Once the dairy has three negative test results, the CDFA will complete a quarantine release form. Dairies released from quarantine will be placed on the surveillance list for weekly testing through creameries.
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Milk from clinically affected or known positive dairy cattle must be discarded for a minimum 30-day quarantine.
According to the California Department of Public Health, only pasteurized milk and dairy products are safe to consume as pasteurization inactivates the bird flu virus.
Symptoms typically appear within two to eight days of exposure, but can be up to 10 days, and may include:
Eye redness or discharge
Cough or sore throat
Runny or stuffy nose
Diarrhea or vomiting
Muscle or body aches
Headaches
Fatigue
Difficulty breathing
Fever
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The San Bernardino Department of Public Health recommends avoiding the consumption of unpasteurized 'raw' milk and undercooked meat.
Raw milk can contain harmful germs that may cause serious illness, particularly in children under 5 years old, pregnant individuals, and people with weakened immune systems. Choose pasteurized milk and dairy products, as the pasteurization process eliminates the bird flu virus.
Try to avoid interacting with infected dairy cows, poultry, or wildlife to decrease the risk of infection. Wearing protective clothing when working with birds, wildlife, livestock, or their environments, and washing hands frequently after handling animals or being in their environment may also help prevent the spread of bird flu.
For more details on bird flu, please visit the California Department of Public Health's Current Bird Flu Situation webpage.
McKenna is a reporter for the Daily Press. She can be reached at mmobley@
This article originally appeared on Victorville Daily Press: Bird flu confirmed in San Bernardino County dairies
