The US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) today confirmed 12 more H5N1 avian flu detections in dairy cattle, all from California, as more outbreaks were confirmed in poultry across four states.
The newly confirmed detections in California’s dairy cattle, where outbreaks have been under way since late August, push the state’s total to 697 and the national total to 912 across 16 states.
Most of California’s outbreaks in dairy cattle have affected herds in the Central Valley, but detections were recently confirmed in the southern part of the state, which led to the state’s governor declaring a state of emergency on December 18 to free up more resources for battling the virus in dairy cows, poultry, and people exposed to sick animals or contaminated products.
Poultry outbreaks include large Ohio layer farm
Of the newly confirmed outbreaks in poultry, three of the four states had more detections on commercial farms, including a layer farm in Ohio’s Darke County that has about 1 million birds. The event marks the state’s second H5N1 detection this month.
Elsewhere, the virus struck a broiler farm in California’s Sacramento County that houses nearly 154,000 birds. In Michigan, the virus was found on another turkey farm in Ottawa County, the second in a week. The facility has 75,500 birds.
The virus continues to strike backyard birds, with the latest event involving a location in Missouri’s Pemiscot County with a flock of 70 birds.
USDA fine-tunes poultry indemnity conditions
In related developments, APHIS today announced updates to its conditions for poultry facilities to receive indemnity and compensation after flocks test positive for highly pathogenic avian influenza.
Recognizing the importance of strong biosecurity measures as a tool for battling the virus in poultry, the group said it now requires farmers to undergo a biosecurity audit before restocking poultry and receiving future indemnity payouts.
Despite federal, state, local, and industry outreach, APHIS said some farms continue to face biosecurity challenges, with some experiencing multiple outbreaks on their farms.
Since 2022, when the H5N1 outbreak began in US poultry, APHIS has made payments to more than 1,200 producers. Of those, 67 have had at least two outbreaks, and 18 premises have been infected three or more times. APHIS said those with reinfections have received more than $365 million of the nearly $1.1 billion in compensation distributed so far.
Maricopa County reports wastewater detections
Arizona’s Maricopa County, an area that includes Phoenix, today said its wastewater monitoring has turned up avian flu, though no human cases have been detected. The H5 subtype was detected by all three cities in Maricopa County that conduct wastewater monitoring: Phoenix, Surprise, and Tempe. However, it added that it’s not possible to confirm a precise source location.
Earlier this month, the virus was detected at a poultry farm in Pinal County, as well as in a backyard flock and a zoo in Maricopa County. Genetic analysis of the virus found in both Arizona counties suggests the virus is related to the genotype circulating in wild birds, which is different than the one circulating in dairy cattle, which has never been detected in Arizona.
Nick Staab, MD, MSPH, assistant medical director at the Maricopa Department of Public Health, said, “Given that no human cases have been identified in Maricopa County through our other disease detection methods and there is no recent documented spread of H5N1 influenza from human to human, the overall risk of avian flu to people remains low.”
