Malaria Consortium trustee, Professor Sir Brian Greenwood, talks to meta-charity, GiveWell, on the potential resistance of antimalarial drugs currently used for seasonal malaria chemoprevention
The discussion highlights the uncertainty over when a malaria parasite will develop resistance to a drug. Experts estimate that resistance develops over 10 to 15 years, but can take as long as 50 years. Because SP and AQ work through different mechanisms, resistance would require mutations to both SP and AQ. Professor Greenwood says that, SP/AQ is likely to be effective for up to 10 years.
If resistance happens, the discussion points to potential alternatives – such as replacing SP/AQ with an artemisinin-based drug for prevention. However, there are risks involved, as artemisinin resistant parasites already exist in Cambodia and its broad use can encourage resistance in Africa.
Monitoring potential resistance through ACCESS-SMC, a Malaria Consortium-led SMC project in the Sahel, could be a means of tracking mutations, says Professor Greenwood. A detection of resistance could occur if areas show signs of loss of effectiveness in SMC and treatment failures. ACCESS-SMC treated 6.4 million children in 2016, and is continuing to expand SMC in the Sahel, with the aim of reaching all 25 million eligible children.
Professor Sir Brian Greenwood is a Professor of Clinical Tropical Medicine at London School of Hygiene & Tropical Medicine, and a Trustee of Malaria Consortium.