Prosthetic valve fungal endocarditis due to histoplasmosis

Fungal endocarditis is associated with severe patient morbidity and mortali ty. Unfortunately, fungal endocarditis is difficult to diagnose because fun gal pathogens are uncommonly isolated from routine blood cultures. Histopat hological examination of surgically excised cardiac valves, peripheral embo li and systemic ulcers may be useful in identifying pathogens as etiologica l agents of culture-negative endocarditis. The authors describe a 63-year-o ld man who had culture-negative endocarditis. Multiple echocardiograms show ed progression of the vegetations with valve stenosis despite treatment wit h multiple antimicrobials. He had multiple peripheral emboli before surgery . Disseminated histoplasmosis was diagnosed by bone marrow culture. Yeast o rganisms consistent with histoplasma were shown in the vegetations of his e xcised mitral valve prosthesis. The patient was treated with amphotericin a nd has been doing well in the two years since his surgery. The diagnosis an d management of fungal endocarditis are emphasized.