Objectives: The reported prevalence of enteric pathogens, especially microsporidiosis, in HIV infection varies greatly. In this study, the prevalence rates for microsporidiosis and other enteric pathogens in HIV-infected individuals referred for gastrointestinal symptoms were compared.
Methods: This prospective study included 250 HIV-infected individuals (179 with AIDS) who were referred for GI evaluation (diarrhea in 194). The prevalence rates of symptomatic intestinal disease due to microsporidiosis and other intestinal pathogens were determined by clinical evaluation, and their epidemiological, clinical, and immunological characteristics were compared.
Results: Enteric pathogens were identified in 83% of 141 AIDS patients with diarrhea, 2% of 53 AIDS patients without diarrhea, and 3% of 56 non-AIDS patients. Microsporidia was the most common pathogen found (39% of AIDS patients with diarrhea). Two or more coexisting infections were found in 28% of AIDS patients with diarrhea. The prevalence rates for coexisting infections were similar to those predicted from the individual prevalence rates, with the exception of cryptosporidiosis and microsporidiosis, which were lower than predicted. Patients with microsporidiosis had severely depressed CD4 lymphocyte counts in peripheral blood. All patients with microsporidiosis, except one, had diarrhea, and D xylose malabsorption was universal in patients with microsporidiosis.
Conclusion: Microsporidiosis is a common cause of chronic diarrhea, malabsorption, and weight loss in AIDS patients.