Signs and Symptoms

About 5 out of 10 people infected with Coxiella burnetii 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
  • Stomach pain
  • Weight loss
  • Non-productive cough

Symptoms can be mild or severe.  People who develop severe disease may experience infection of the lungs (pneumonia) or liver (hepatitis).

Women who are infected during pregnancy may be at risk for miscarriage, stillbirth, pre-term delivery, or low infant birth weight.

Chronic Q fever

A very small percentage of people (less than 5 out of 100) who become infected with C. 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 often develop an infection of one or more 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 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.  Women infected during pregnancy may also be at risk for developing chronic Q fever.