Analysis Of Life-Saving Potential In Seasonal Prevention Of Malaria In African Children
A team of scientists analysed the potential impact of a new strategy tocontrol malaria in Africa which takes a similar approach to that used toprotect travellers going to malaria endemic areas and found that evenwith moderate levels of coverage it could lead to significant publichealth improvements.Malaria experts see this new approach, called seasonal malariachemoprevention (SMC), as an exciting new tool in the fight againstmalaria. The study highlights the areas of Africa where this approachcould be used most effectively and will assist deployment of this newcontrol measure where it is needed urgently. The study, published in Nature Communications, was led by the LondonSchool of Hygiene & Tropical Medicine and involved a collaboration ofresearchers in the UK and Africa.
In some parts of Africa, malaria is only a major problem for a fewmonths of the year during and immediately after the rainy season. Inthese areas, providing monthly courses of a cheap antimalarial drugcombination (sulphadoxine-pyrimethamine and amodiaquine) to youngchildren during the malaria transmission season when they are at highestrisk has been shown to prevent approximately 80% of severe anduncomplicated malaria cases. It has been found that large-scale administration of antimalarialmedicines once-per-month on repeated occasions can be carried outsuccessfully, that it is very safe and that it provides protection evenif children are sleeping under insecticide treated bed-nets.
Currently,the main approaches to malaria control are use of insecticide treatedbed-nets and spraying of homes with insecticide, combined with promptdiagnostic testing and effective treatment of malaria patients withartemisinin-based combination therapies. Combining satellite maps of rainfall with information on the malariaburden in different areas of Africa, the researchers identified theregions where seasonal malaria chemoprevention would be useful andcost-effective. The largest impact would be in countries of the Saheland sub-Sahel, a wide-belt of Africa ranging from The Gambia and Senegalin the West to parts of Sudan in the East. Key countries are Nigeria,Niger, Burkina Faso and Mali, where approximately 14 million childrenunder five are at risk in areas suitable for this approach. Following a review of the evidence including these findings by itsMalaria Policy Advisory Committee, the World Health Organization (WHO)recently formally recommended seasonal malaria chemoprevention as policyfor malaria control in the Sahel and sub-Sahel.
Some of the countries inWest Africa identified in this study may wish to introduce SMC intotheir national malaria control programmes. The team also estimated the number of children at risk of malaria inthese areas, and the number of malaria cases and deaths that could beprevented if seasonal malaria chemoprevention is widely used. There areapproximately 40 million children under five living in parts of Africasuitable for SMC who could benefit from this intervention and around150,000 childhood deaths from malaria each year. Making realistic ratherthan optimistic assumptions about how many children could be reached andhow effective this approach would be, the researchers estimate thataround 11 million cases of malaria and approximately 50,000 deaths frommalaria could be prevented per year if SMC was fully implemented.
Lead author Dr Matt Cairns, of the London School of Hygiene andTropical Medicine, said: "Providing insecticide-treated nets is animportant way of protecting children from malaria, but in some areas itisn't enough - children need additional methods of protection. We haveidentified two large areas of Africa where monthly seasonalchemoprevention could be an effective addition to existing approachesthat reduce exposure to mosquitoes. If this control measure could bedeployed widely it could prevent many millions of cases of malaria andtens of thousands of deaths every year."
Professor Sir Brian Greenwood, one of the senior authors of the studyand a leading expert on malaria control, said: "Excitingly, this issomething that is available to put into action immediately, so childrenwill start to benefit from this approach now rather than in three orfive years' time. The key is to ensure that the promise becomes areality." Dr Robert Newman, Director of the WHO Global Malaria Programme,remarked: "This intervention has great potential to contribute towardsthe achievement of the health-related Millennium Development Goals inthe Sahel sub-Region of Africa; the opportunity for policy adoption andimplementation should be seized quickly."