[Endocarditis due to Corynebacterium diphtheriae cause by contact with intravenous drugs: report of 5 cases].

The clinical features of 5 patients with invasive disease due to nontoxigenic Corynebacterium diphtheriae are presented. 4 patients had proven left sided endocarditis, and one had probable endocarditis of the mitral valve. 4 patients were intravenous drug abusers, and one had a girl friend who was also an iv-drug abuser. Only one patient had antibodies against human immunodeficiency virus. 2 patients with endocarditis of the mitral or the aortic valve, and one patient with endocarditis of a prosthetic aortic valve, died of septic complications. All patients or their partners frequented the same community of drug abusers. Since the blood culture isolates shared common features for biotyping, resistance patterns and also for ribotyping in three tested patients, we assume that all patients were infected by the same clone of C. diphtheriae. Drug abusers may become a new reservoir for C. diphtheriae infection. Along with our patients, we present an overview of the 49 published cases of C. diphtheriae endocarditis.