INVESTIGATION OF CHRONIC DIARRHEA IN ACQUIRED-IMMUNODEFICIENCY-SYNDROME - A PROSPECTIVE-STUDY OF 155 PATIENTS

Background and Aims-The optimum diagnostic investigation for patients with acquired immunodeficiency syndrome (AIDS) and diarrhoea is not kn own. Often no pathogen is detected and it is unclear whether this is b ecause pathogens are absent in some patients or the investigations use d fail to detect them. The hypothesis that AIDS related diarrhoea is u sually due to an infection, which can be identified by a simple diagno stic strategy based on the results of intensive investigation of a coh ort of such patients,was investigated. Methods-155 patients with AIDS and chronic diarrhoea underwent contemporaneous examination of stools, duodenal, jejunal, and rectal biopsy specimens and duodenal aspirate for bacterial, protozoal, and viral pathogens. A decision tree analysi s was used to determine the best sequential diagnostic strategy for cl inicians. Results-128 of 155 patients investigated (83%) had at least one potential pathogen. The presenting clinical features could not pre dict the presence or site of the pathogens. Stool analysis identified the most pathogens (93 of 199, 47%). Rectal biopsy was essential for t he diagnosis of cytomegalovirus and adenovirus. Duodenal biopsy. was a s helpful as jejunal biopsy and detected some treatable pathogens miss ed by other methods. Electron microscopy, impression smears, and duode nal aspirate yielded little extra information. If gut biopsy was reser ved for patients without a stool pathogen, some treatable pathogens wo uld have been missed. Conclusion-Most patients with AIDS and chronic d iarrhoea have at least one gut pathogen, which can be identified by st ool analysis and light microscopic examination of duodenal and rectal biopsies. Some pathogens will be missed unless all these investigation s are done on all such patients.