Seroepidemiologic and Occupational Risk Survey for Coxiella burnetii Antibodies among US Veterinarians

Background. Little is known about the occurrence of Q fever among veterinarians in the United States. In this study, we sought to estimate the prevalence of Coxiella burnetii antibodies among veterinarians and to identify risk factors for exposure. Methods. We tested serum samples from 508 veterinarians who attended the 143rd American Veterinary Medical Association Annual Convention in 2006. Samples were screened using a Q fever IgG enzyme-linked immunosorbent assay (ELISA). Samples with positive or equivocal results of ELISA were confirmed using phase I and phase II IgG immunofluorescence antibody assays, and end point IgG titers were determined for samples with positive results. Results. Antibodies against C. burnetii were detected in 113 (22.2%) of 508 veterinarians. Risk factors associated with seropositivity included age >= 46 years, routine contact with ponds, and treatment of cattle, swine, or wildlife. Conclusions. Veterinarians have a high level of exposure to C. burnetii, the causative organism of Q fever, especially those veterinarians who treat livestock. In this study, risk of C. burnetii seropositivity was also independently associated with contact with ponds. The role of exposure to standing bodies of water in infection is not usually considered and should be investigated in future studies. Additionally, the evidence of past infection with C. burnetii in 120% of veterinarians also highlights the need for use of appropriate personal protective equipment when treating animals that are potentially infected with C. burnetii. Physicians should consider the risk of infection with C. burnetii when treating ill veterinarians and others with potential occupational exposures.