Holding the line against artemisinin partial resistance in Africa: the case for preemptive treatment policy

Two decades of progress against falciparum malaria have been bought with a single class of medicines, and that class is now being undermined on the continent that can least absorb the loss. Partial resistance to artemisinin, encoded by mutations in the Plasmodium falciparum kelch13 gene, has emerged independently across East Africa and the Horn of Africa, and the World Health Organization now records confirmed or suspected resistance in at least eight African countries. Southeast Asia has already shown where this road ends: in Cambodia, as resistance markers rose, the efficacy of dihydroartemisinin-piperaquine fell from 98% to 63%, and multi-country efficacy reached 50% within roughly a decade. Africa is not a milder version of that setting. Higher transmission, partial acquired immunity that masks treatment failure, and greater parasite diversity all lengthen the gap between resistance arriving and a reactive system noticing it. This Perspective argues that the prevailing reactive model, which changes first-line therapy only after measured failure breaches 10%, is the wrong design for such a region, and reframes that threshold as a structural liability during the establishment phase of resistance. It sets out a preemptive agenda built largely from tools that already exist: multiple first-line therapies, prepared triple combinations, a stocked non-artemisinin pipeline, interventions that lower drug pressure, and molecular surveillance funded as core infrastructure. It then answers the main objections to acting early. The window to act ahead of failure is open, narrow, and closing.