The interrelationship of malnutrition and diarrhea in a periurban area outside Alexandria, Egypt.

BACKGROUND: In the developing world, children are often observed to have both diarrhea and malnutrition. This observation has led many researchers to speculate that diarrhea may produce malnutrition and that malnutrition may predispose to diarrhea. In this study, the interrelationship between diarrhea and malnutrition was investigated among 143 Egyptian children less than 3 years of age.
METHODS: For 22 months, children were followed for diarrhea at twice weekly home visits and measured for nutritional status at approximately 3-month intervals. Nutritional measurements were converted to z-scores based on the National Center for Health Statistics/World Health Organization (NCHS/WHO) reference population.
RESULTS: Three hundred fifty-eight diarrheal episodes were reported with only 1% of episodes lasting 14 days or more. Stunting, wasting, and low weight-for-age were found in 19%, 3%, and 7%, of these children, respectively. When testing whether malnutrition predisposes to diarrhea, a weight-for-age z-score of <-2 standard deviations was associated with increased incidence of diarrhea (RR = 1.7, P < 0.01) but not height-for-age or weight-for-height. Diarrhea itself was associated with a subsequent attack of diarrhea (RR = 2.1, P < 0.001). During short intervals of follow-up (approximately 3 months), an association was detected between diarrhea episodes and growth faltering for height-for-age z-score (-0.16, P < 0.05). This association was reduced, however, when analyzed during 6-month intervals, if no diarrhea was reported in either the first or second half of this interval.
CONCLUSIONS: In a population with moderate malnutrition, both low weight-for-age and diarrhea itself are associated with increased diarrhea risk. Diarrhea alone does not appear to contribute substantially to malnutrition when children have diarrhea-free time for catch-up growth.