Study Finds H5N1 Cases in Vets with No Known Contact
A recent study by the U.S. Centers for Disease Control and Prevention (CDC) found that three veterinarians unknowingly contracted avian influenza A (H5N1). These veterinarians, who work with cattle, had no knowledge of exposure to infected animals. The findings suggest that the virus may be present in areas where cases have not yet been identified.
Blood samples from 150 veterinarians across 46 states in the U.S. and Canada were tested for H5N1 antibodies. Three U.S. veterinarians tested positive, despite showing no symptoms. Two of them reported no exposure to infected animals, and one worked in Georgia and South Carolina—states with no confirmed cases in cattle.
"These findings suggest there could be U.S. states with A(H5)-positive people and animals that have not yet been identified," the CDC report stated. The study emphasized that while the risk to the public remains low, improved testing and monitoring are necessary.
Although the infected veterinarians wore gloves and protective clothing, none used respiratory or eye protection—important safeguards when working in regions with confirmed cases. Experts warn that H5N1 can be present in high concentrations in infected cattle’s milk, posing exposure risks.
The H5N1 outbreak in dairy cattle was first identified in March 2024, with the first human cases appearing in April. The CDC urges increased herd and bulk milk testing to detect infections early.
Regular testing and protective measures are crucial to reducing infection risks. “Increased testing of herds and bulk milking tanks can help monitor for additional A(H5) positive herds and help better protect bovine veterinary practitioners and other animal workers,” the report stated.