A randomized controlled trial of the effect of antihelminthic treatment and micronutrient fortification on health status and school performance of rural primary school children

Single interventions for helminthic infections and micronutrient deficienci es are effective, but it is not clear whether combined interventions will p rovide equal, additive or synergistic effects to improve children's health. The study objective was to determine the impact of single and combined int erventions on nutritional status and scholastic and cognitive performance o f school children. A double-blind, randomized, placebo-controlled trial in 11 rural South African primary schools randomly allocated 579 children aged between 8 and 10 years into six study groups, half of whom received antihe lminthic treatment at baseline. The de-wormed and non-de-wormed arms were f urther divided into three groups and given biscuits, either unfortified or fortified with vitamin A and iron or with vitamin A only, given daily for 1 6 weeks. The outcome measures were anthropometric, micronutrient and parasi te status, and scholastic and cognitive test scores. There was a significan t treatment effect of vitamin A on serum retinol (p<0.01), and the suggesti on of an additive effect between vitamin A fortification and de-worming. Fo rtified biscuits improved micronutrient status in rural primary school chil dren; vitamin A with de-worming had a greater impact on micronutrient statu s than vitamin A fortification alone and antihelminthic treatment significa ntly reduced the overall prevalence of parasite infection. The burden of mi cronutrient deficiency (anaemia, iron and vitamin A) and stunting in this s tudy population was low and, coupled with the restricted duration of the in tervention (16 weeks), might have limited the impact of the interventions.