Common parasites that cause diarrhea in AIDS
Among the protozoa, C. parvum is the most common parasite causing diarrhea in AIDS and has been identified in up to 11% of symptomatic patients. Although a cause of acute diarrhea, cryptosporidiosis is found most commonly in HIV-infected patients with chronic diarrhea. In some studies of HIV-infected patients with chronic diarrhea, microsporidia ( E. bieneusi and E. intestinalis ) are the most commonly identified pathogens. Giardia is also a consideration in patients with diarrhea, especially when chronic and associated with the upper GI symptoms of nausea and bloating. Isospora belli is a rare GI pathogen in HIV-infected patients in North America, whereas it is endemic in many developing countries, such as Haiti.