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Q fever endocarditis

Didier Raoult, MD, PhD
Section Editor
Stephen B Calderwood, MD
Deputy Editor
Jennifer Mitty, MD, MPH


Q fever results from infection with Coxiella burnetii, a Proteobacteria that is mostly spread through aerosol transmission from infected animals and is found in most countries throughout the world. Q fever can present as an acute or more chronic disease.

Persistent localized infections (eg, endocarditis, infection of aneurysms or vascular grafts, bone and joint infections) can develop in a patient after symptomatic acute Q fever or following asymptomatic infection. Endocarditis, which is the most common manifestation among those with persistent infection, can be severe and even fatal. However, diagnosing Q fever endocarditis is difficult and primarily relies upon nonspecific cardiac findings, the presence of peripheral manifestations (eg, liver, kidney, and splenic involvement), the results of serologic or molecular tests, and/or the findings on imaging studies.

This topic reviews the diagnosis and treatment of patients with endocarditis associated with persistent Q fever infection. Discussions of the clinical manifestations, diagnosis, and treatment of acute Q fever (including endocarditis associated with acute infection), as well as an overview of culture-negative endocarditis, are found elsewhere. (See "Clinical manifestations and diagnosis of Q fever" and "Treatment and prevention of Q fever" and "Epidemiology, microbiology, and diagnosis of culture-negative endocarditis".)


Most cases of subacute or chronic endocarditis secondary to C. burnetii develop between two months and two years following acute Q fever. However, only 20 to 40 percent of patients who develop endocarditis have symptoms of acute infection. (See "Clinical manifestations and diagnosis of Q fever", section on 'Acute infection'.)

Q fever endocarditis occurs primarily in men over the age of 40, and in those who are immunocompromised, pregnant, and/or have underlying valvular damage [1-6]. This was illustrated in a retrospective study of 302 patients diagnosed with acute Q fever, which noted the following [2]:

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Literature review current through: Oct 2017. | This topic last updated: Apr 29, 2016.
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