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

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 degrees C with >/=5000 parasites/microliter) 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.