Artemisinin Partial Resistance in Ethiopian Plasmodium Falciparum: A Multisite Clinical, Molecular and In Vitro Study

Summary

Artemisinin-based combination therapies (ACTs) are the main treatment for falciparum malaria in Africa. Artemisinin partial resistance (ART-R), characterized by delayed parasite clearance after treatment, has been confirmed in four sub-Saharan African countries. In Ethiopia, molecular surveys have detected the Pfkelch13 R622I mutation associated with ART-R at multiple sites, but no study has yet combined clinical, molecular, and in vitro evidence to confirm ART-R per WHO criteria. This multisite study conducted across five sentinel sites in Ethiopia (2024-2025) assessed day-3 parasite positivity after artemether-lumefantrine treatment, Pfkelch13 genotyping, and ring-stage survival assay on culture-adapted field isolates, to determine whether ART-R is confirmed in Ethiopian Plasmodium falciparum populations.

Timeline

Start

2024-05-01

Primary completion

2025-10-30

Completion

2026-04-07

Publications

• Results Uwimana A, Legrand E, Stokes BH, Ndikumana JM, Warsame M, Umulisa N, Ngamije D, Munyaneza T, Mazarati JB, Munguti K, Campagne P, Criscuolo A, Ariey F, Murindahabi M, Ringwald P, Fidock DA, Mbituyumuremyi A, Menard D. Emergence and clonal expansion of in vitro artemisinin-resistant Plasmodium falciparum kelch13 R561H mutant parasites in Rwanda. Nat Med. 2020 Oct;26(10):1602-1608. doi: 10.1038/s41591-020-1005-2. Epub 2020 Aug 3.
• Results Balikagala B, Fukuda N, Ikeda M, Katuro OT, Tachibana SI, Yamauchi M, Opio W, Emoto S, Anywar DA, Kimura E, Palacpac NMQ, Odongo-Aginya EI, Ogwang M, Horii T, Mita T. Evidence of Artemisinin-Resistant Malaria in Africa. N Engl J Med. 2021 Sep 23;385(13):1163-1171. doi: 10.1056/NEJMoa2101746.
• Results Mihreteab S, Platon L, Berhane A, Stokes BH, Warsame M, Campagne P, Criscuolo A, Ma L, Petiot N, Doderer-Lang C, Legrand E, Ward KE, Zehaie Kassahun A, Ringwald P, Fidock DA, Menard D. Increasing Prevalence of Artemisinin-Resistant HRP2-Negative Malaria in Eritrea. N Engl J Med. 2023 Sep 28;389(13):1191-1202. doi: 10.1056/NEJMoa2210956.
• Results Fola AA, Feleke SM, Mohammed H, Brhane BG, Hennelly CM, Assefa A, Crudal RM, Reichert E, Juliano JJ, Cunningham J, Mamo H, Solomon H, Tasew G, Petros B, Parr JB, Bailey JA. Plasmodium falciparum resistant to artemisinin and diagnostics have emerged in Ethiopia. Nat Microbiol. 2023 Oct;8(10):1911-1919. doi: 10.1038/s41564-023-01461-4. Epub 2023 Aug 28.

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Indications