In some parts of Africa, more than 60% of malaria cases occur in just 4 months of the year, during the rainy season.1 Around 39 million African children under 5 years of age live in these regions and an estimated 152,000 die from malaria each year.2
In March 2012, WHO-recommended seasonal malaria chemoprevention (SMC)3 with sulfadoxinepyrimethamine and amodiaquine (SP+AQ) for children aged between 3 and 59 months in areas of high seasonal malaria transmission across the Sahel sub-region, where SP and AQ remain effective.1 In east and southern Africa, there are high levels of resistance to SP.
As part of the West Africa Roll Back Malaria (RBM) SMC working group, MMV is working to support the implementation of SMC in the Sahel sub-region; and with Guilin to develop child-friendly formulations.
From 2011 to 2012, Cheikh Anta Diop University of Dakar, Senegal, conducted a pilot study, combining SMC with home management of malaria. Prof Jean Louis Ndiaye explains the challenges and the potential impact of SMC.
1. What impact do you believe SMC can have for the children of Senegal and the wider Sahel region?
Based on our pilot study we know that SMC can protect around 83% of children from malaria. This means that, free from malaria, children are able to attend school and parents are able to go to work. It also means the workload of health workers is reduced during the transmission season. We are starting to see empty hospital beds in districts where SMC is implemented. In addition, during SMC rounds, when a volunteer comes across a sick child, he/she will then be referred to a health centre; so SMC is acting as a screening programme and improving overall health care in rural villages. At the national level, I believe it can help us reach the pre-elimination stage of malaria control.
2. Based on your experience in Senegal, what key hurdles must be overcome to ensure widespread implementation of SMC across the Sahel?
The key is to ensure countries secure sufficient quantities of the medicines in a timely fashion. This is particularly important for SMC – if you miss the season, you have missed the opportunity to use and benefit from this preventive strategy. To avoid this, it’s important to communicate the importance of SMC and to mobilize adequate funding.
Today, there is only one manufacturer producing SP+AQ that is approved for purchase by the Global Fund. We need to ensure that this company has the capacity to manufacture sufficient quantities.
We also need to work on ensuring people (mostly mothers, caregivers and community health workers) are sensitized to the use and importance of SMC, to ensure drug compliance. At the moment, we have two drugs that are coblistered, which means we cannot be sure that children are always receiving both the medicines at the same time.
Also, there is no infant formulation. When you are treating young children and giving them tablets it is not really easy, especially as AQ is very bitter. You sometimes see children running out of the house when the time comes to take their medicine. If they don’t take the complete course there can be problems with under dosing, which can then lead to drug resistance.
3. What do you think is the likelihood that drug resistance to the current SMC drug regimen will emerge? How will this be managed?
We might see resistance emerging. During the implementation pilot, we saw that there was an increase in molecular markers for drug resistance in the SMC districts. It wasn’t at a level where we need to be concerned at the moment, but it is something we must monitor at least every 2 years. There are some places in east and southern Africa where you probably would not be able to use SP+AQ because of the levels of resistance. In Senegal, we should have 3–5 years of effective SMC, combined with artemisinin-based combination therapy for treatment; with this, I think we can move to pre-elimination.
1. WHO Policy Recommendation: “Seasonal Malaria Chemoprevention (SMC) for Plasmodium falciparum malaria control in highly seasonal transmission areas of the Sahel sub-region in Africa”. March 2012.
2. Cairns M et al. “Estimating the potential public health impact of seasonal malaria chemoprevention in African children.” Nat Commun. 3:881 (2012).
3. Seasonal Malaria Chemoprevention: previously termed intermittent preventive treatment in children, is the intermittent administration of full treatment courses of an effective antimalarial medicine during the malaria season to prevent malarial illness.