Role of different methods for the detection of diarrhoeal pathogens in HIV-infected patients in Brazil.

To evaluate the ability of different diagnostic methods for the detection of AIDS-related diarrhoeal pathogens in developing countries, we studied 40 HIV-infected patients with diarrhoea. All patients were subjected to stool examinations for parasites, stool culture and peroral jejunal biopsy. Jejunal specimens were processed for histological examination with several stains and for transmission electron microscopy (TEM). Jejunal juice and mucosa were cultured. An aetiologic agent was found in twenty patients. Eleven stool specimens were positive for parasites and stool culture was positive in three patients. The enteropathogens detected by these two methods included every microorganism amenable to treatment. Histological examination revealed four agents not previously identified. TEM added to diagnosis in only two patients. All cultures of jejunal mucosa and jejunal juice were negative, even when stool culture was positive. We conclude that a minimal investigation consisting of stool examination for parasites and stool culture is a cost-effective strategy in the management of AIDS-related diarrhoea in developing countries.