Intestinal Microspora infections in a patient with acquired immunodeficiency syndrome

A 24 year old man with AIDS diagnosed in 1989 and a history of several episodes of pulmonary pneumocystosis developed chronic diarrhea and severe epigastric pain. Endoscopy revealed a granular intestinal mucosa. There was atrophy of villi and Giemsa, Ziehl-Nielsen and Gram staining identified 1.5 to 2 u spores in the cytoplasm of intestinal cells. Transmission electron microscopy of the spores revealed a thick wall, a sporoplasm with a nucleus, ribosomes, a posterior vacuole and a polar filament with multiple coils; no mitochondria were seen. Thus, the patient had intestinal microsporidiosis caused by Enterocytozoon bieneusi. This is a rare pathogen recently identified in man.