Veterinarians who work with birds are at an increased risk for avian influenza infection and should be among those with priority access to pandemic influenza vaccines and antivirals, according to a study conducted by researchers at the University of Iowa College of Public Health.
The study, "Infection due to 3 avian influenza subtypes in United States veterinarians," is published in the July 1 issue of the journal Clinical Infectious Diseases.
The researchers, led by Kendall Myers, a doctoral student in occupational and environmental health, and Gregory Gray, MD, a professor of epidemiology, examined blood samples from a group of U.S. veterinarians for evidence of previous avian influenza virus infection. The veterinarians all had occupational exposure to live chickens, ducks, turkeys, geese, or quail.
The study showed that, compared with the control group, the veterinarians who worked with birds had substantially higher concentrations of antibodies in their blood against the H5, H6, and H7 avian virus strains, indicating previous infections with these viruses. The infections were likely a result of the mild forms of avian influenza virus that have occasionally circulated among wild and domestic birds in the United States, according to the researchers. The greatest risk factor for infection reported by veterinarians was examining birds known to be sick with influenza.
"Veterinarians and others with frequent and close contact to infected birds may be among the first to be infected with a pandemic strain of influenza," Myers said in a prepared statement. "They have the potential to spread the illness to their families and communities. Because of this, we suggest that veterinarians should be considered for inclusion on priority access lists for pandemic influenza vaccines and antivirals."
The authors reported in their study that a better understanding of interspecies transmission of avian influenza is a crucial component in efforts to minimize the effects of a pandemic.
"While these avian influenza virus infections in veterinarians were likely mild or subclinical, the story might be very different should aggressive avian influenza strains enter the United States like the H5N1 strains infecting domestic birds in Asia," Dr. Gray said.
"As federal officials continue to plan for a pandemic event, it is increasingly important to identify the best ways to protect veterinarians and other agricultural workers most at risk for zoonotic diseases."