Effect of zinc supplementation on malaria and other causes of morbidity in west African children: randomised double blind placebo controlled

Abstract

Objective: To study the effects of zinc supplementation on malaria and other causes of morbidity in young children living in an area holoendemic for malaria in west Africa. Design: Randomised, double blind, placebo controlled efficacy trial. Setting: 18 villages in rural northwestern Burkina Faso. Participants: 709 children were enrolled; 685 completed the trial. Intervention: Supplementation with zinc (12.5 mg zinc sulphate) or placebo daily for six days a week for six months. Main outcome measures: The primary outcome was the incidence of symptomatic falciparum malaria. Secondary outcomes were the severity of malaria episodes, prevalence of malaria parasite, mean parasite densities, mean packed cell volume, prevalence of other morbidity, and all cause mortality. Results: The mean number of malaria episodes per child (defined as a temperature ≥37.5°C with ≥5000 parasites/μl) was 1.7, 99.7% due to infection with Plasmodium falciparum. No difference was found between the zinc and placebo groups in the incidence of falciparum malaria (relative risk 0.98, 95% confidence interval 0.86 to 1.11), mean temperature, and mean parasite densities during malaria episodes, nor in malaria parasite rates, mean parasite densities, and mean packed cell volume during cross sectional surveys. Zinc supplementation was significantly associated with a reduced prevalence of diarrhoea (0.87, 0.79 to 0.95). All cause mortality was non-significantly lower in children given zinc compared with those given placebo (5 v 12, P=0.1). Conclusions: Zinc supplementation has no effect on morbidity from falciparum malaria in children in rural west Africa, but it does reduce morbidity associated with diarrhoea. What is already known on this topic Zinc deficiency is common in infants in developing countries Zinc supplementation has been shown to reduce morbidity from infectious disease in such populations, particularly through reductions in morbidity from diarrhoea and respiratory infections Limited evidence exists for zinc supplementation being effective in reducing morbidity from malaria What this study adds Zinc supplementation has no effect on falciparum malaria in children in rural west Africa It is effective in reducing morbidity from diarrhoea and may help to reduce mortality from all causes