Diarrhoea, CD4 counts and enteric infections in a community-based cohort of HIV-infected adults in Uganda

Objectives: To examine relationships between diarrhoea, CD4 cell counts and stool pathogens in a community-based cohort of HIV-infected adults in Uganda. Patients and methods: Stool specimens, obtained between October 1995 and December 1997, were linked to patients' symptoms and laboratory results. The relationship between CD4 counts and symptoms was tested using the Wilcoxon rank-sum test and those between organisms and diarrhoea using first a univariate Mantel-Haenszel analysis and then a logistic regression model adjusted for CD4 count and multiple organisms. Results: 1213 HIV-infected individuals (70% women, median CD4 cell count at enrollment 215 cells/mul) were followed for 1224 person years of observation (pyo). 484 stool samples were examined, 35 7 from patients with diarrhoea. The rate of diarrhoea was 661 episodes per 1000 pyo. CD4 counts were significantly lower in individuals with diarrhoea than those without (P < 0.001, Wilcoxon rank-sum test). Forty-nine percent of diarrhoeal stools and 39% of stools from asymptomatic patients contained enteric pathogens. The most frequent isolates were helminths (29.5% of all stools), followed by bacteria (19.2%) and then protozoa (8.9%). Rates of isolation of diarrhoea-associated pathogens were 29%, from diarrhoeal stools and 17% from asymptomatic stools (P = 0.01, χ(2) test). The association between diarrhoea and infection with bacteria or protozoa was weak and there was no association with helminths. Cryptosporidium parvum infection alone was associated with low CD4 counts. Conclusions: Diarrhoea was common and most strongly associated with low CD4 counts. Bacteria were frequently found, even in stools from asymptomatic individuals. Over two-thirds of diarrhoeal episodes were undiagnosed, suggesting that unidentified agents or primary HIV enteropathy are important causes of diarrhoea in this population.