[Polymicrobial endocarditis: a clinical and evolutive study of 12 cases diagnosed during a 10-year period].

Polymicrobial endocarditis (PE) is uncommon, whether in series of cases of polymicrobial bacteriemia or of endocarditis. Among the 201 cases of infective endocarditis seen between 1986 and 1995 by an infectious diseases service, 12 patients had PE (6%). Nine were males, mean age was 28 years and ten were active intravenous drug users. All of them were HIV (+) and 50% had AIDS. Eleven subjects had infection of the tricuspid valve and 58% developed septic pulmonary emboli. The most common organism encountered was Staphylococcus aureus in 8 patients followed by Streptococcus viridans and S. pneumoniae in three. The most common combinations of organisms were S. aureus and S. pneumoniae in 3 cases and S. aureus and Pseudomonas aeruginosa in two. Two patients died, one with Xantomona maltophilia and another with Candida albicans. The symptoms of PE were usually indistinguishable from endocarditis caused by a single organism and the prognosis depended on the species rather than the number of organisms isolated.