Spatio-temporal trends of artemisinin-based combination therapy efficacy from 2010 to 2024 in sub-Saharan Africa: a systematic review and meta-analysis

Abstract Background Artemisinin-based Combination Therapy (ACT) has contributed to the reduction of malaria burden in sub-Saharan Africa. However, the number of global cases has risen since 2015. Resistances to artemisinin reported from Southeast Asia and recently emerged in sub-Saharan Africa might threaten ACT efficacy. We conducted a systematic review and meta-analysis on ACT efficacy trends in sub-Saharan Africa from January 2010 to December 2024. Methods We systematically searched PubMed/Medline and Scopus for studies published between 2010 and 2024 that met the World Health Organisation (WHO) criteria for therapeutic efficacy studies. Two reviewers have independently assessed the eligibility criteria and extracted data. ACT efficacy was measured using the PCR-corrected Adequate Clinical and Parasitological Response (ACPR) at day 28 or 42. Meta-analysis was conducted using R. Results The meta-analysis included 116 studies with a total of 17,341 participants for artemether-lumefantrine (AL), 8,855 for artesunate-amodiaquine (AS-AQ), 5,544 for dihydroartemisinin-piperaquine (DHA-PPQ), and 346 for artesunate-pyronaridine (AS-PY). Over the period under review, from 2010 to 2024, the PCR-corrected ACPR for AS-AQ, DHA-PPQ, and AS-PY remained above 90% across sub-Saharan Africa. For AL, the PCR-corrected ACPR remained high between 2010 and 2014, consistently exceeding 90% (range: 91–100%). However, from 2015 to 2024, the efficacy showed greater variability, with PCR-corrected ACPR values ranging from 74% to 100%. Notably, this efficacy dropped below the 90% threshold in several countries, including Kenya (2017), Burkina Faso (2018), Uganda (2019), and Nigeria (2020). Conclusions While AS-AQ, DHA-PPQ, and AS-PY have maintained high efficacy over time in sub-Saharan Africa, there is a concern about the declining efficacy of AL in some West and East African countries. Our findings suggest that AS-PY could be a promising candidate for inclusion in first-line malaria treatments to address the declining efficacy of AL. Continuous monitoring of ACT efficacy, innovative and efficient control strategies are crucial to prevent the spread of antimalarial drug resistance. Registration PROSPERO number CRD42023432718