Association of malnutrition and diarrhea in children aged under five years. A prospective follow-up study in a rural Sudanese community.

Results are reported from a one-year follow-up study conducted in 1983 and 1984 of 445 Sudanese children aged under five years that was designed to address the hypothesis that malnutrition increases the incidence of diarrheal disease. Children were weighed and measured at two-month intervals ("child intervals") and diarrhea incidence was ascertained during biweekly house visits. During child intervals that followed a prior episode of diarrhea, underweight (weight-for-age less than 90% of expected) was associated with a higher incidence of diarrhea after adjusting for the potential confounding effects of age and socioeconomic factors (odds ratio (OR) = 1.7, 95% confidence interval (CI) = 1.1-2.8). During child intervals with no history of diarrhea in the preceding interval, the association with underweight was less (OR = 1.2, 95% CI = 0.9-1.6); among these children, stunting (height-for-age less than 95% of expected) was significantly associated with diarrhea (OR = 1.4, 95% CI = 1.0-1.8). Moderate malnutrition (weight-for-age less than 75% of expected) was associated with a twofold increased risk of multiple episodes of diarrhea during a follow-up interval whether or not diarrhea had occurred in the preceding interval (OR = 2.0, 95% CI = 1.2-3.5) after adjusting for age, socioeconomic factors, and diarrhea in preceding interval. Age, rainy season, and history of diarrhea in preceding interval were found to be strongly associated with incidence of diarrhea. These data are consistent with the hypothesis that malnutrition increases the risk of childhood diarrhea.