Q fever: epidemiology, diagnosis, and treatment.

Q fever, a zoonosis caused by Coxiella burnetii, is seen throughout the world. Recent reports suggest that its incidence in the United States is increasing, with more than 30 cases reported in the US military. The disease has many acute and chronic manifestations. Endocarditis is the most common form of chronic disease, and recent studies have led to substantial changes in the approach to its diagnosis and treatment. Military and civilian health care professionals need to consider Q fever when evaluating patients with appropriate geographic exposures and clinical presentations to prevent delays in diagnosis and treatment.