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

Background: In the developing world, children are often observed to have bo th 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 diarrh ea 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 i ntervals. 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 on ly 1% of episodes lasting 14 days or mon. Stunting, wasting, and low weight -for-age were found in 19%, 3%, and 7%, of these children, respectively. Wh en testing whether malnutrition predisposes to diarrhea, a weight-for-age z -score of <-2 standard deviations was associated with increased incidence o f 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 mont hs), an association was detected between diarrhea episodes and growth falte ring for height-for-age z-score (-0.16, P < 0.05). This association was red uced, however, when analyzed during 6-month intervals, if no diarrhea was r eported in either the first or second half of this interval. Conclusions: In a population with moderate malnutrition, both low weight-fo r-age and diarrhea itself are associated with increased diarrhea risk. Diar rhea alone does not appear to contribute substantially to malnutrition when children have diarrhea-free time for catch-up growth.