Q-fever results from infection by Coxiella burnetti. This is an unusual spore-like organism that is highly resistant to environmental conditions. It is found worldwide, except in New Zealand, and transmitted to humans and other animals by aerosol, direct contact with reproductive discharges,or infected milk. Ticks can spread infection among ruminants and people.
Since the organism is so resistant in the environment it can become airborne and travel one-half mile or more. It can survive up to 30 days in dried saliva and 120 days in dust.
The most common farm animal reservoirs for Q-fever are goats, sheep and cattle. Ticks and wild birds can also harbor this organism. It is also transmitted to humans. Reproductive failure is sometimes the only symptom in animals.
Symptoms: Abortion in late pregnancy, stillbirths, retained placenta, endometritis (inflammation of the lining of the uterus), infertility and small or weak offspring in ruminants.
- Animals may appear asymptomatic.
- Goats will have decreased appetite and may be depressed one or two days before an abortion.
Clincial Signs: With the aid of a veterinarian or extension agent, submit milk, feces, fetal tissue, placenta, vaginal discharge and blood for polymerase chain reaction assay (PCR).
Treatment: Isolate infected animals. Antibiotics may decrease the risk of abortion and suppress infection but not eliminate infection.
Vaccination is not available in the United States. It will not eliminate shedding of organism.
This disease is communicable to humans. Use extreme care when handling these animals.
- Wear protective clothing, disposable gloves and a face mask to prevent inhalation of organism when handling suspect or known infected animals and fluids.
- Correctly dispose of placenta, birth products, fetal membranes and aborted fetuses at farms housing sheep and goats.
- Use only pasteurized milk and milk products.
- Large numbers of organisms are present in placenta, fetal fluids, aborted fetuses, milk, urine and feces. Serologically negative animals may shed the organisms.
- Diagnosis in humans is done by blood test within the second week of illness. Most cases occur in people exposed to farm animals or their products.
- Q-fever is a self-limiting illness, most cases resolve on their own within two days to two weeks.
- Clinical signs in humans include fever, chills, severe headache, fatigue and non-productive cough.