Therapeutic efficacy of dihydroartemisinin-piperaquine and artesunate-pyronaridine combinations in the treatment of uncomplicated Plasmodium falciparum malaria in Ghana, 2023

Benjamin Abuaku^1*Paul Boateng²Nana Yaw Peprah²Alexander Asamoah²Nancy Odurowah Duah-Quashie¹Sena Matrevi¹Eunice Obeng Amoako¹Neils Quashie^1,3Felicia Owusu-Antwi⁴Kwadwo Ansah Koram¹Keziah Laurencia Malm²

• ¹Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
• ²Ghana Health Service, Accra, Ghana
• ³University of Ghana Medical School, Accra, Ghana
• ⁴World Health Organization, Country Office, Accra, Ghana

Malaria case management in Ghana is a key intervention within the national malaria elimination agenda. Currently, artesunate-amodiaquine (AS-AQ), artemether-lumefantrine (AL), and artesunate-pyronaridine (AP) are the first-line medicines for treating whilst dihydroartemisinin-piperaquine (DHAP) is the second-line medicine. As part of a surveillance system established to monitor the therapeutic efficacy of Ghana's first-line and second-line antimalarial medicines, the efficacy of DHAP and AP were studied among children (6 months to 9 years) with uncomplicated malaria in five (5) DHAP sentinel sites and four (4) AP sentinel sites between August and December, 2023. The DHAP study was a follow-up to the baseline conducted in 2020/2021, and the AP study was to provide baseline data after its introduction in 2022. The 3/3 PCR-genotyping approach distinguished between reinfection and recrudescence using merozoite surface protein 1 (msp1)-specific primers: RO33, MAD20, K1; merozoite protein 2 (msp2)-specific primers: IC 3D7 and FC; and glutamate-rich protein (glurp). PCR-uncorrected cure rates on day-42 ranged between 98.8% (95% CI: 93.2-100) and 100% for DHAP with an overall PCR-uncorrected cure rate of 99.2% (95% CI: 97.6-99.8); and between 85.0% (95% CI: 70.2-94.3) and 100% for AP with an overall PCR-uncorrected cure rate AP and DHAP Efficacy in Ghana of 96.2% (95% CI: 92.9-98.0). PCR-corrected cure rates on day-42 was 100% in all DHAP sites; and ranged between 91.9% (95% CI: 78.1-98.3) and 100% for AP with an overall PCR-corrected cure rate of 97.3% (95% CI: 94.3-98.8). Day-3 parasitemia was prevalent in only one (1) DHAP site (1/60 – 1.7%) and one (1) AP site (1/65 – 1.5%) with an overall prevalence of 0.3% for DHAP and 0.4% for AP. Neither treatment with DHAP nor AP resulted in an early treatment failure (ETF). We conclude that the therapeutic efficacy level of DHAP has remained high (> 90%) since the baseline study in 2020/2021. Also, the baseline efficacy level of AP is high (> 90%) warranting the use of both DHAP and AP in the treatment of uncomplicated malaria in the country.