Efficacy of Artemether-Lumefantrine for the Treatment of Plasmodium falciparum Malaria in Bohicon and Kandi, Republic of Benin, 2018-2019.

In 2005, artemether-lumefantrine (AL), an artemisinin-based combination therapy, was introduced as the first-line treatment of uncomplicated Plasmodium falciparum malaria in Benin. Per World Health Organization recommendations to monitor the efficacy of antimalarial treatment, we conducted a therapeutic efficacy study with AL for uncomplicated P. falciparum malaria in Bohicon and Kandi, Benin, from 2018 to 2019. Febrile patients aged 6 to 59 months with confirmed P. falciparum monoinfection received supervised doses of AL for 3 days. We monitored patients clinically and parasitologically on days 1, 2, 3, 7, 14, 21, and 28. A molecular analysis to detect mutations in the P. falciparum Kelch propeller gene (Pfk13) gene was carried out on day 0 samples. A total of 205 patients were included in the study. In Bohicon, the uncorrected adequate clinical and parasitological response (ACPR) proportion was 91.3% (95% confidence interval [CI]: 84.6-95.8%), whereas in Kandi this proportion was 96.7% (95% CI: 90.6-99.3%). Genotype-corrected ACPR proportions were 96.3% (95% CI: 90.9-99.0%) and 96.7% (95% CI: 90.6-99.3%) in Bohicon and Kandi, respectively. On day 3, 100% of patients in Bohicon and 98.9% of patients in Kandi had undetectable parasitemia. The C580Y mutation in the Pfk13 gene was not observed. AL remains effective for P. falciparum malaria in these two sites in Benin. Monitoring antimalarial efficacy and prevalence of molecular-resistance markers in Benin should be continued to allow for early detection of antimalarial resistance and to guide treatment policies.