Background: To establish the incidence of diarrhea and its evolution over time, the causal microorganisms, recurrence and associated mortality in patients with AIDS or severe immunologic alterations (CD4 lymphocytes lower than 0.5 x 10(9)/l).
Methods: A prospective longitudinal study was carried out from 1984 to 1992. The following patients were included in the study: 1) all those patients with diarrhea in whom a pathogenic microorganism was identified in the stools, and 2) patients with fever and positive blood cultures for enteropathogenic bacteria. The patients belonged to a series of 1,456 patients with infection by HIV.
Results: Of the 1,456 controlled patients, 253 (17%) had infection by enteropathogenic microorganisms. The incidence was greater in homosexual patients (26%) than in drug addicts (12%). The most frequent germs were Cryptosporidium, in 104 episodes and Salmonella sp. in 78 episodes (31 as isolated bacteria). The mortality in the 15 days following isolation was 2%, the referred microorganisms being the most frequent responsible for the deaths. The mean of CD4 lymphocytes in the patients with enteropathogens was 0.17 x 10(9)/l). SD 0.14 x 10(9)/l). In patients with infection by Cryptosporidium the CD4 lymphocyte count was lower than that observed in the cases of infection by Isospora belli. Prior to 1988, 21% of the patients had infection by enteropathogenic bacteria and 23% by parasites, those percentages being 3% and 6%, respectively in 1991.
Conclusions: Infections by enteropathogenic microorganisms in patients with infection by the human immunodeficiency virus in an advanced stage are frequent, particularly, in homosexuals. The patients with enteritis by Cryptosporidium have a greater grade of immunosuppression (CD4 lymphocytes lower than 0.1 x 10(9)/l) than patients with infection by other enteropathogenic microorganisms. In the last few years, the incidence of enteropathogenic bacteria, especially Salmonella sp. and protozoa has decreased [corrected].