Undernutrition in relation to childhood infections: a prospective study in the Sudan.

OBJECTIVE: The aim of the study was to examine the relationships between nutritional status and diarrhoea and respiratory infections. DESIGN: Prospective cohort study within the framework of a randomized double-blind placebo-controlled intervention trial. SETTING: In rural communities in the Khartoum and Gezira regions, in Northern Sudan. SUBJECTS: 28,753 Sudanese pre-school children between 6 months and 6 y old. METHODS: Relative risks of subsequent diarrhoea and respiratory infections in relation to nutritional status measured by anthropometry (Z-scores of height-for-age (H/A), weight-for-height (W/H), and weight-for-age (W/A), which reflect stunting, wasting and underweight, respectively) were estimated using odds ratios from logistic regression adjusting for various covariates. RESULTS: H/A, W/H and W/A were significantly and inversely associated with subsequent diarrhoea and febrile diarrhoea (P for trend <0.001) with risks being 2.00 times higher (95% confidence interval, CI (1.64, 2.43)) among children with W/A Z-scores below -4 Z, and 1.75 times higher (95% CI (1.56, 1.96)) among those with a W/A Z-score between -4 and -3 Z compared with children having a W/A Z-score > or =1. Age, gender, region of residence and seasonality modified these associations. Also, febrile cough was inversely associated with W/A and W/H (P<0.03), with risks ranging from 1.41 times higher (95% CI (1.02, 1.97)) to 1.21 times higher (95% CI (1.04, 1.41)) in the group of underweight children with W/A Z-scores below -4 and between -2 and -1 Z, all compared with normally nourished children (> or =-1 Z). CONCLUSIONS: The reduction of severe but also mild and moderate undernutrition is necessary through nutrition, health and socio-economic improvement in order to prevent morbidity.