Q fever is an infection caused by the bacterium Coxiella burnetii. Q fever is usually a mild disease with flu-like symptoms. Many people have no symptoms at all. In a small percentage of people, the infection can resurface years later. This more deadly form of Q fever can damage your heart, liver, brain and lungs.

Q fever is transmitted to humans by animals, most commonly sheep, goats and cattle. When you inhale barnyard dust particles contaminated by infected animals, you may become infected. High-risk occupations include farming, veterinary medicine and animal research.

Mild cases of Q fever clear up quickly with antibiotic treatment. But if Q fever recurs, you may need to take antibiotics for at least 18 months.