Abdominal aortic aneurysm and Coxiella burnetii infection: report of three cases and review of the literature.

Coxiella burnetii, the etiologic agent of Q fever, is mainly responsible for endocarditis with negative blood culture results, but only a few cases of C. burnetii infections of aortic aneurysms have been published. We report three cases of abdominal aortic aneurysms treated in patients with Q fever infection with simultaneous endocarditis (n = 1) and previous history of cardiac valve replacement for endocarditis (n = 1). A coeliac aortic aneurysm was diagnosed in one patient treated for acute Q fever with persistent serologic results showing chronic infection despite adequate antibiotic therapy and without endocarditis. Resection of the aneurysm cured the chronic infection, and C. burnetii was identified by culture of the aneurysmal wall. In the two other cases, chronic infection of C. burnetii was diagnosed by serologic examination after surgery for an abdominal aortic aneurysm. One patient with negative blood culture results had amaurosis fugax due to endocarditis and required aortic valve replacement; recurrent fever without evidence of valve dysfunction or infection developed in one patient who had had prosthetic cardiac valve replacement 6 months earlier for endocarditis. Aortic aneurysms were treated with in situ prosthetic grafts and long-term antibiotic therapy. At a mean follow-up of 12 years, no septic aortic complications occurred, and serologic test results have remained negative. The presence of an aortic aneurysm and cardiac valve disease seems to be a predisposing factor for chronic C. burnetii infection. Diagnosis particularly relies on the physician's awareness of this condition and is confirmed by serologic examination. Aortic aneurysm resection is mandatory to cure the chronic infection and must be associated with long-term antibiotic therapy.