Prosthetic valve endocarditis due to Coxiella burnetii: six cases]

PURPOSE: Prosthetic valve endocarditis is a dangerous complication of valvular surgery (3-6%). Among involved pathogens, Coxiella burnetii is an occasional agent, though isolated with increasing frequency. We report our experience with this peculiar endocarditis and lay stress on specific diagnostic and therapeutic difficulties. METHODS: Between 1990 and 1995, six patients retrospectively met the diagnosis criteria for definite endocarditis due to Coxiella burnetii. RESULTS: Five Algerian men and one French woman presented with prosthetic valve endocarditis with negative blood cultures (on bioprosthesis: four cases, on mechanical valve: two cases). The main clinical and biological feature was febrile congestive heart failure with hepatomegaly, splenomegaly, hepatic and renal abnormalities, inflammatory syndrome, hypergammaglobulinemia, anemia and lymphopenia. Serological testing for Coxiella burnetii provided diagnosis in all cases. Echocardiography displayed vegetations in all cases. Valvular replacement was performed in four patients. With antibiotic therapy including doxycycline or/and hydroxychloroquine, quinolones or rifampicine, all patients experienced complete clinical, biological and echographic remission. CONCLUSION: Q fever prosthetic valve endocarditis presents as a systemic disorder occurring in patients with valvular heart disease. From now on, early diagnosis and efficient medical treatment may provide permanent prosthetic sterilization.