Declining CD4+ T-lymphocyte counts are associated with increased risk of enteric parasitosis and chronic diarrhea:: Results of a 3-year longitudinal study

From January 1991 through September 1994, we observed people who were infected with HIV to assess the impact of enteric parasite-associated diarrhea. Respondents answered comprehensive questionnaires covering clinical and epidemiologic information and provided stool specimens monthly, which were examined unstained as well as stained with trichrome, chromotrope 2R, and with Kinyoun carbol-fuchsin, and with indirect immunofluorescence for Cryptosporidium. In all, 602 participants, who were interviewed, provided stool specimens at 3254 monthly visits. Parasites were associated with 50 of 354 (14.1%) acute diarrheal episodes (lasting less than or equal to 28 days) and with 97 of 279 (34.8%) chronic episodes (lasting >228 days). A parasite was associated with 31 of 222 (14.0%) episodes that occurred when CD4(+) counts were greater than or equal to 200 cell/mu l and with 150 of 566 (26.5%) episodes that occurred when CD4(+) counts were <200 cells/mu l. The most commonly identified parasite was C parvum, which was associated with Is of 354 (5.1%) acute episodes and 36 (12.9%) of the 279 chronic episodes of diarrhea. In this patient population, enteric protozoan parasites were commonly associated with imunosuppression worsened, and were more likely to be associated with chronic rather than acute diarrhea.