A new study revealed that avian influenza has silently passed from animals to some veterinarians. The research, published by the Centers for Disease Control and Prevention (CDC), supports earlier findings of infections among agricultural workers that were initially undiagnosed. While affected workers recalled symptoms of H5N1 avian influenza, veterinarians did not report experiencing such symptoms.
The study suggests that the official count of 68 confirmed human infections in the last year in the United States is likely significantly lower than reality, according to Dr. Gregory Gray, an infectious disease specialist at the University of Texas in Galveston. Although many infected individuals may not show symptoms and therefore do not seek medical attention, even a small proportion could represent hundreds or thousands of infected people in the country.
Researcher Jacqueline Nolting from Ohio State University, a collaborator with the CDC on the study, mentioned that infected individuals often generate antibody responses that can provide natural immunity, which is encouraging. However, she warned that if the virus mutates to severely affect people or spreads easily among them, the situation would change drastically.
Authorities urge caution when coming into contact with birds as H5N1 avian influenza has spread among birds, livestock, and other animals. Although the veterinarians studied did not display typical symptoms of the disease, three of them showed evidence of antibodies against H5N1 infection. The use of respiratory, eye protection, and gloves is recommended when handling poultry to prevent transmission.
While the risk to the general public is currently considered low, experts like Keith Poulsen from the Wisconsin Veterinary Diagnostic Laboratory emphasize the need for veterinarians and workers in contact with animals to adequately protect themselves with safety equipment. Previous studies have revealed undiagnosed infections in agricultural workers, suggesting that the actual number of avian influenza cases could be considerably higher than officially reported.