Additional Confirmed Cases of Q fever (Coxiella burnetii) in Colorado

June 11, 2018:

Coxiella burnetii has been detected on four farms in 2018 in four Colorado counties.  

  • Rio Grande County (February):  Raw milk herd-share dairy with several goat abortions.  Further testing revealed C burnetii in additional goats, cows, and yaks on the farm.
  • Pueblo County (April):  Small hobby farm with recent goat abortion and sick neonatal lambs.  One person associated with the farm was diagnosed with Q Fever.
  • Yuma County (May):  Meat goat herd with 80% abortion rate.
  • Larimer County (June):  Breeding/show goat herd with several abortions.  

CDA has not determined any epidemiologic links between these four farms and is continuing to trace high risk movements, such as pregnant animals.  Individual farms are implementing best management practices to protect public health and animal health.

C burnetii is a reportable disease in Colorado (to the State Veterinarian’s Office and Colorado Department of Public Health and Environment).  It is also on the OIE list of reportable diseases and is a CDC Category B bioterrorism agent.  

Coxiella burnetii:

C burnetii is a zoonotic bacterial infection associated primarily with parturient ruminants although domestic animals, such as cats and a variety of wild animals, have been identified as sources of infection.  In ruminants, the infection is usually subclinical but can cause anorexia and late term abortions. Reports have implicated C burnetii as a cause of infertility and sporadic abortion with necrotizing placentitis in ruminants.  

In known infected herds, the periparturient period represents a significant risk for transmission due to large amounts of environmental contamination associated with abortion.  Standard abortion control measures, 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 the placenta is ideal; if unavailable, a vaginal swab would be the next best sample.

Zoonotic Risk:

The zoonotic infection in people associated with C burnetii is widely known as 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).  

Workers should use adequate personal protective equipment to protect against exposure.  Individuals who have artificial heart valves are at particular risk, as well as anyone who is significantly immunocompromised.  Pregnant women should take precautions to prevent exposure.

Symptoms of Q fever in people include: fever, chills or night sweats, headache or pain behind the eyes, muscle pain, vomiting, diarrhea, or abdominal pain, fatigue, and cough or chest pain.  Symptoms can be mild or severe. People with severe disease may develop pneumonia or hepatitis. Chronic infection (months to years) can cause vegetative endocarditis, which may be fatal if untreated.  

Women who are infected during pregnancy may be at risk for miscarriage, stillbirth, pre-term delivery, or low infant birth weight.  


If you have questions regarding animal health, please contact the State Veterinarian’s Office at (303)869-9130.

If you have questions regarding human health, please contact the Colorado Department of Public Health and Environment at (303)692-2700.