Humans usually get Q fever by breathing in contaminated droplets released into the air by infected animals. Drinking raw milk has also caused infection in rare cases. People at highest risk for this infection are:
Laboratory workers who work with Coxiella burnetii
Sheep and dairy workers
People at highest risk include those with heart valve problems or weakened immune systems.
It usually takes about 20 days after exposure to the bacteria for symptoms to occur. Most cases are mild, yet some severe cases have been reported.
Common symptoms of early-stage (acute) Q fever may include:
Other symptoms may include:
Yellow skin (jaundice)
Symptoms of long-term (chronic) Q fever may include:
Shortness of breath
Exams and Tests
A health care provider will suspect Q fever in people who have been exposed to the Coxiella burnetii bacteria who develop:
Inflammation of the inside lining of the heart and heart valves
Inflammation of the liver
Q fever is diagnosed with a blood antibody test.
The main treatment for Q fever is antibiotics. For early-stage Q fever, doxycycline is the recommended antibiotic.
If you have the infection for more than 6 months, it is called chronic Q fever. Your health care provider may prescribe both doxycycline and hydroxychloroquine. You may need to take antibiotics for several months or years.
The outlook for people who get treated in the early stages of Q fever is generally good.
Chronic Q fever requires long-term treatment with antibiotics. Your health care provider should check you often to make sure the disease has not returned.
Q fever may lead to these complications:
Inflammation of the heart valves, heart lining, or heart muscle
Inflammation of the thin tissue that surrounds the brain and spinal cord
Tell your health care provider if you have symptoms of Q fever, especially if you believe you have been exposed to Coxiella burnetii. Although many different illnesses can cause similar symptoms, you may need to be evaluated for Q fever.
People at risk (for example, farmers and veterinarians) should always:
Carefully dispose of animal products that may be infected
Disinfect any contaminated areas
Thoroughly wash their hands
Pasteurizing milk can also help prevent Q fever.
Prompt treatment can prevent early Q fever from becoming chronic.
Marrie TJ, Raoult D. Coxiella burnetii (Q fever). In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 8th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2014:chap 190.
Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.