Neisseria meningitidis native valve endocarditis. A case report.

The so-called nonpathogenic neisseriae are common inhabitants of the upper respiratory tract in humans and are not usually regarded as pathogens. Neisseria meningitidis on the contrary may cause severe disease. These organisms are an uncommon cause of infective endocarditis. The authors report a case of a 64 year-old male, type II diabetic, previously asymptomatic, admitted to hospital because of fever, aphasia and right hemi-paresis. A systolic murmur was heard at the cardiac apex, and three blood cultures were positive for Neisseria meningitidis. The echocardiogram showed a vegetation on the posterior leaflet of the mitral valve, allowing the diagnosis of meningococcal endocarditis. The patient's clinical condition improved on intravenous penicillin therapy, and regression of fever, disappearance of the neurological signs and of the mitral valve vegetation were observed.