The regions in Africa that are most susceptible to seasonal malaria and may therefore benefit most from preventative drug programmes are mapped in a paper in Nature Communications this week. Because large numbers of children are estimated to reside in this area, the authors suggest that deploying this method could avert a large number of malaria episodes and many thousands of deaths in several countries where malaria is currently not adequately controlled.
Seasonal malaria chemoprevention (SMC) in children is a promising tool for the control of malaria in areas where transmission of malaria is highly seasonal, however this drug-based method for malaria prevention is not currently employed widely. Matthew Cairns and colleagues looked at 56 sites over Africa where monthly malaria incidence was measured over 12 consecutive months. From this they highlight two large areas of Africa that are likely to have both sufficient seasonality, based on rainfall levels, and sufficient malaria incidence for SMC to be both effective and cost-effective. They estimate that a large population of children under 5 is at risk of malaria in these areas.
The authors mapped the potential impact of SMC administration over 4 months, however they note that some regions they identify as being optimal for treatment have two peaks during the year where climate relates to malarial incidence. They caution that their approach to SMC administration over 4 months of the year does not account for this scenario and further tweaking will be needed in these instances. Despite this, they conclude that a simple algorithm based on their findings could be developed to help policy makers decide whether the malaria incidence in their country, or certain regions within their country, is sufficiently seasonal for the deployment of SMC. They suggest that the algorithm could also indicate the potential impact of the implementation of SMC with different levels of efficacy and coverage.