Coxiella burnetii is a zoonotic bacterial infection associated with parturient ruminants. In ruminants, the infection is usually subclinical but can cause anorexia and late term abortions.
In infected herds, the periparturient period represents a significant risk for transmission due to large amounts of environmental contamination associated with abortion. Standard abortion control measure, including prompt removal of aborted materials (using personal protective equipment), segregation of animals by pregnancy status, and diagnostic evaluations of abortions, are all warranted.
C burnetii is common in livestock and animal testing does have limitations, as shedding can be intermittent. ELISA and PCR tests are available at Colorado State University, Veterinary Diagnostic Laboratory. Culling of animals based on serologic testing is not recommended. For abortions, PCR testing of the placenta is ideal; if unavailable, a vaginal swab is the next best sample.
The zoonotic infection in people associated with C burnetii is widely known an Q fever. The greatest risk of transmission occurs at parturition by inhalation, ingestion, or direct contact with birth fluids or placenta. The organism is also shed in milk, urine, and feces.
C burnetii is highly infectious and a single organism can reportedly cause infection via the aerosol route in people. Transmission may also occur by consumption of unpasteurized milk. Q fever occurs more frequently in persons who have occupational contact with high-risk species (including farmers and veterinarians).