Highly Pathogenic Avian Influenza (HPAI) has been identified in dairy cattle, a disease that is highly contagious and often fatal in poultry. The virus, which includes A (H5) and A (H7) strains, is frequently transmitted to domestic poultry by wild birds.
Public health risk assessment
While the risk to the general public remains low, mild illnesses have been reported among livestock workers exposed to the virus in other states.
Symptoms in dairy cattle
Dairy cattle experiencing HPAI may show symptoms such as decreased milk production, fever, dehydration, and a decrease in feed consumption. Milk from affected animals may appear thick, discolored, or clumpy. Unlike poultry, dairy cattle typically do not die from the virus but most recover within a few weeks.
History of virus spread
In early 2024, an unknown milk drop syndrome was identified in adult dairy cattle in the Texas panhandle, later affecting dairies in Kansas and New Mexico. On March 25, 2024, cattle on a Texas dairy were confirmed to have HPAI. Since that time, numerous dairies across many states have tested positive.
Transmission methods and routes
The spread of cases in dairy cattle appears to have moved from an initial infected farm through routes including milk, animal movement, equipment, and people.
New USDA testing regulations
As of April 24, 2024, the USDA issued a federal order requiring that milk from lactating dairy cattle must test negative for HPAI before crossing state lines. To assist with compliance, the Utah Department of Agriculture and Food developed a Bovine HPAI Certified Tester Training Program to allow producers to collect milk samples themselves.
Food safety recommendations
For food safety, officials recommended the pasteurization of dairy products and cooking poultry and eggs to an internal temperature of 165 degrees Fahrenheit.
Individuals with prolonged, regular exposure to poultry or dairy cattle who exhibit symptoms such as fever, cough, sore throat, difficulty breathing, or body aches should contact their local health department. For more information on avian influenza in humans, the Utah Department of Health and Human Services provides resources at https://epi.utah.gov/bird-flu-in-humans/.
