A newly identified strain of highly pathogenic avian influenza (HPAI) has been detected in U.S. dairy cattle, raising concerns about potential transmission risks and its impact on livestock and public health. The U.S. Department of Agriculture (USDA) confirmed that genotype D1.1 of the H5N1 virus was found in dairy cows in Nevada following routine milk testing.
This discovery marks the first time this specific genotype has been identified in cattle. Previously, a different strain, B3.13, had been detected in dairy herds. USDA officials stated that genotype D1.1 has circulated among wild birds, mammals and domestic poultry across North America in recent months, particularly during the fall and winter.
In response, the Nevada Department of Agriculture, in collaboration with the USDA, has initiated farm investigations and expanded testing efforts to assess risks and implement containment strategies. The agencies are also working to trace the source of the infection to prevent further spread.
“While this detection is concerning, our established testing strategy has allowed us to identify and address potential risks quickly,” Dr. Rosemary Sifford, USDA’s Chief Veterinary Officer said. “We continue to monitor the situation closely and reinforce biosecurity measures.”
The USDA has repeatedly stated that its bird flu eradication strategy remains unchanged despite the emergence of the new genotype. Officials emphasize that the National Milk Testing Strategy has proven effective in identifying and managing outbreaks, ensuring that the virus is monitored and contained.
Public health officials are also evaluating potential risks to humans. According to the Centers for Disease Control and Prevention no human cases of this genotype have been reported, and the risk to the general public remains low. However, experts caution that continued surveillance is essential. “There is currently no evidence that commercial milk or dairy products pose a risk to consumers, as pasteurization effectively neutralizes the virus,” the FDA reported in its latest investigation.
Concerns about economic effects, particularly food prices, have been raised. “The price of eggs may rise, and the virus could grow, though it’s unlikely,” Nurse Anna Fitzpatrick of Staples High School said. “Our food is imported and regulated by Compass Group U.S.A and Chartwells Schools, with daily monitoring ensuring safety. So far, no concerns.” Cook Jill Brooks of the Staples Cafeteria said
“Viruses evolve, and we must remain vigilant,” said Dr. David Swayne, a former director of the USDA’s Southeast Poultry Research Laboratory. “Understanding the genetic changes in this strain will help inform mitigation efforts and protect both animal and human health.”
Officials encourage dairy farmers to remain proactive by following biosecurity protocols and reporting any unusual illness in cattle. For now, authorities stress that the U.S. food supply remains safe. Pasteurization effectively eliminates the virus in milk, and there is no evidence suggesting that properly handled dairy products pose a threat to consumers. However, the FDA urges ongoing monitoring and vigilance to prevent further spread within livestock populations.
