Abstract:

Artemisinin partial resistance (ART-R) represents a growing concern for malaria control in Sub-Saharan Africa. This narrative review synthesizes current evidence on the epidemiology, molecular markers, therapeutic efficacy, transmission dynamics, and surveillance of ART-R. Structured searches of peer-reviewed literature and grey sources published between 2020 and 2025 were conducted, focusing on clinical studies of artemisinin-based combination therapy (ACT) efficacy, PfKelch13 (PfK13) mutations, and surveillance reports. Data were extracted descriptively and synthesized thematically across four domains: emergence patterns, molecular markers and phenotypic expression, treatment efficacy and partner drug susceptibility, and transmission and surveillance capacity. Validated PfK13 mutations associated with ART-R, including R561H, C469Y, A675V, and R622I, have emerged independently across Sub-Saharan African countries. While delayed parasite clearance is observed with these mutations, first-line ACTs continue to show high cure rates in many settings, reflecting the combined activity of artemisinin derivatives and partner drugs. Candidate PfK13 mutations and markers of altered partner drug susceptibility have also been reported, highlighting potential emerging vulnerabilities in the ACT framework. Prolonged parasite clearance may increase the window of transmission, particularly in low to moderate transmission settings. Surveillance capacity is expanding but remains uneven, with gaps in genomic monitoring, timely reporting, and integration into policy processes. Overall, ART-R in Sub-Saharan Africa remains focal and of low prevalence, with limited evidence of widespread clinical impact. Strengthening integrated molecular and therapeutic surveillance, improving data-to-policy translation, and implementing targeted interventions in high-risk areas are critical to prevent wider dissemination and sustain ACT effectiveness, thereby supporting malaria control gains across the region.

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