Key points
- People with Q fever typically have mild symptoms, including fever and chills. Some people may have more severe symptoms.
- A small percentage of people who are infected develop a more serious form of the disease called chronic Q fever.
Signs and symptoms
About half of people who are infected with Coxiella burnetii, the bacteria that causes Q fever, will get sick. Illness typically develops 2-3 weeks after being exposed to the bacteria. Signs and symptoms of Q fever may include:
- Fever
- Chills or sweats
- Fatigue (tiredness)
- Headache
- Muscle aches
- Nausea, vomiting, or diarrhea
- Chest pain
- Weight loss
- Cough
Symptoms can be mild or severe. People who develop severe disease may experience infection of the lungs (pneumonia) or liver (hepatitis).
People who are infected during pregnancy may be at risk for miscarriage, stillbirth, pre-term delivery, or low infant birth weight.
Chronic Q fever
A small percentage of people (fewer than 5 out of 100) who become infected with Coxiella burnetii bacteria develop a more serious infection called chronic Q fever. Chronic Q fever develops months or years following initial Q fever infection. People with chronic Q fever can develop an infection of heart valves (called endocarditis). People with endocarditis may experience night sweats, fatigue, shortness of breath, weight loss, or swelling of their limbs. A healthcare provider will need to perform a series of tests to diagnose endocarditis.
Chronic Q fever is serious and can be deadly if not treated correctly. Chronic Q fever infection requires months or years of antibiotic treatment. Chronic Q fever is more likely to occur in people with heart valve disease, blood vessel abnormalities, or in people with weakened immune systems. People infected during pregnancy may also be at risk for developing chronic Q fever.