London School of Hygiene & Tropical Medicine

A team of researchers from the London School of Hygiene & Tropical Medicine, working in partnership with colleagues from Senegal, has found that intermittent preventive malaria treatment of children under five has a dramatic impact on malaria frequency.

In a randomised, placebo-controlled trial, 1,136 children aged between two months and five years received either intermittent preventive treatment, consisting of one dose of artesunate plus one dose of sulfadoxine-pyrimethamine, or two placebos. The preventative treatments were carried out on three occasions during the malaria transmission season, in a health-care centre in Niakhar, a rural area of Senegal.

During thirteen weeks of follow up, the intervention led to an 86% reduction in the frequency of clinical episodes of malaria. The incidence of malaria in children with active drugs was 308 episodes per 1,000 person-years at risk, whereas in controls it was 2,250 episodes per 1,000 person-years at risk. The preventative treatment was safe and did not result in children who had received it experiencing more malaria episodes the following year.

According to the World Health Organisation, 90% of deaths from malaria occur in Africa, mostly in children under 5 years of age. In Senegal, the yearly mortality rate from malaria in children has increased substantially since the beginning of the 1990s, due in large part to growing resistance to standard malaria treatments. In addition to developing new malaria drugs there is a need to develop new ways of preventing the disease.

Dr Badara Cisse, a PhD student of the London School of Hygiene & Tropical Medicine (LSHTM) who is now based at the University of Dakar, Senegal, was principal investigator of the trial, and first author of the study, which appears in the February 25 issue of The Lancet. He is a one of 33 research degree students, mostly from malaria-endemic countries, to have been trained under the Capacity Development component of the Gates Malaria Partnership, which aims to strengthen research capability in the field of malaria.

Dr Cisse comments: 'Seasonal intermittent preventive treatment is simple, cheap and dramatic in its impact on malaria in children under five in areas of seasonal malarial transmission. The results of this trial are very encouraging, but we do need to carry out further studies into whether the treatment can be delivered on a bigger scale. If we are to ensure higher rates of coverage, then we need to bring the whole community on board. There is also the question of what the effect might be on drug resistance, which needs to be further explored'.