[Coxiella burnetii endocarditis on a bioprosthetic valve: review of the literature apropos of a case].

A 51-year-old woman, originating from Algeria, developed Q fever endocarditis on porcine bioprosthetic mitral valve. She had chronic course with nonspecific symptoms, such as dyspnea and fever, hepatosplenomegaly, and developed progressive cardiac failure. Worsening of hemodynamic state led to prosthetic valve replacement. Hemocultures were all negative, and the diagnosis of Q fever was unexpectedly performed by systematic screening for specific serum antibody to Coxiella burnetti. High phase I and II specific IgG and IgA antibody titers against C burnetii were found. The patient was treated by doxycycline and ofloxacin, and improved rapidly. Prosthetic valve constitutes likely predisposing factor for the development of chronic Q fever endocarditis. This observation emphasizes the need to search for Q fever in prosthetic valve dysfunction, in particular when hemocultures are negative.