Q Fever

Last Reviewed: October 2011

What is Q fever?

Q fever is a rickettsial infection caused by Coxiella burnetii.

How common is Q fever and who can get it?

Veterinarians, meat processing plant workers, sheep and dairy workers, livestock farmers and others who work with pregnant cattle, sheep and goats are most at risk for exposure to Coxiella burnetii. Although it is hard to determine how many cases of Q fever occur every year, it is believed that the disease is underreported.

How is Q fever spread?

Sheep, goats and cattle are the main source of Q fever. It is spread from contact with excretions such as milk, urine, feces and the afterbirth of infected animals. Often the bacterium can exist for extended periods of time in soil and dust. Therefore, most human infections are thought to be caused by the inhalation of contaminated barnyard dust.

What are the symptoms of Q fever?

Most acute cases of Q fever begin with sudden onset of one or more of the following: high fevers (up to 104-105° F), severe headache, general malaise, myalgia, confusion, sore throat, chills, sweats, non-productive cough, nausea, vomiting, diarrhea, abdominal pain, and chest pain. Fever usually lasts for one to two weeks. Weight loss can occur and persist for some time. Thirty to 50 percent of patients with symptomatic infections will develop pneumonia. Only about half of those who are infected with the bacteria show clinical signs of the disease. Chronic illness such as endocarditis (heart disease) can occur after acute illness or in cases where infection does not cause an acute illness.

How soon after exposure do symptoms develop?

Most patients become ill two to three weeks following exposure. Chronic disease can develop up to two years after initial infection.

Can Q fever be spread person to person?

Direct, person-to-person infection occurs rarely, if ever.

How is it diagnosed?

Laboratory diagnosis is accomplished through the identification of specific antibodies to Coxiella burnetii.

What is the treatment for illness caused by Q fever?

Doxycycline is the treatment of choice for Q fever and should be administered for 15-21 days. Treatment of chronic infections like endocarditis require longer courses of antibiotic therapy.

Is there a way to prevent infection?

Exposure to Coxiella burnetii can be reduced on farms by avoiding direct contact with placenta and birth products of sheep, goats and cattle. Gloves, arm sleeves and protective eyewear should be routinely worn when assisting with animal births, especially in cases involving aborted fetuses. While vaccines exist for Q fever, none are readily available in the United States. Laboratory workers who routinely work with the organism are at highest risk of infection and should get vaccinated. In addition, only pasteurized milk and milk products should be consumed.