Blastocystis hominis gastroenteritis in a hemophiliac with acquired immune deficiency syndrome.

Blastocystis hominis is an enteric protozoan that has occasionally been associated with gastrointestinal illness in man but is not considered an opportunistic pathogen. We describe a 16-year-old hemophiliac with acquired immune deficiency-related complex in whom upper gastrointestinal symptoms in conjunction with high densities of B. hominis in duodenal secretions and stool developed. Furazolidone treatment was associated with eradication of the organism and improvement in clinical symptoms. One month later, the patient had invasive Candida albicans esophagitis and died 2 weeks later of complications of acute pancreatitis. In immunocompetent individuals surveyed in Colorado the frequency of identification of B. hominis in stool concentrates was not different between asymptomatic and symptomatic persons. We suggest that B. hominis may be an opportunistic pathogen in immunocompromised patients and should be sought in duodenal secretions and feces when gastrointestinal symptoms are present.