[Acute and chronic Q fever; epidemiology, symptoms, diagnosis and therapy of infection caused by Coxiella burnetii].

Q fever is a zoonosis caused by Coxiella burnetii, an obligate intracellular bacterium. Domestic ungulates and parturient cats are the primary reservoirs of infection. The animals excrete the bacterium in urine, faeces, milk and amniotic fluid. After desiccation the micro-organism spreads via aerosols. After inhalation or ingestion and an incubation period of 2-6 weeks acute Q fever may develop with atypical pneumonia and hepatitis as major clinical symptoms. The infection also may present as a flu-like illness or remain asymptomatic. Generally, the prognosis is favourable. However, endocarditis or another chronic form of Q fever occasionally develops with possibly fatal outcome. Diagnosis relies upon serologic testing with an indirect immunofluorescence method. Doxycycline is the antibiotic of choice in the treatment of Q fever. Endocarditis needs therapy for years with the addition of rifampin or hydroxychloroquine. Q fever is poorly recognised due to the variety of clinical presentations.