RESUMEN
Microsporidia are intracellular protozoa that mainly affect AIDS patients and chronic diarrhea, caused by the strains Enterocytozoon bieneusi and septata intestinalis, is the most common clinical manifestation. The diagnosis is made in intestinal biopsies, however the recently developed trichomic stain with chromotrope 2R, is able to detect microsporidia in stools and has a good correlation with the biopsy. Using this technique, we studied 43 asymptomatic HIV infected subjects, 89 AIDS patients with chronic diarrhea and 186 patients with acute diarrhea as controls. Thirty three percent of patients with AIDS, 16.3 percent of HIV infected subjects and none of the individuals with acute diarrhea had microsporidia in their stools (p<0.05). In 15 patients with AIDS we detected intermitted stool microsporidia shedding; this finding should encourage repetitive examinations in negative cases. The trichomic stain for microsporidia is proposed as a routine test in AIDS patients with diarrhea