Escalating Plasmodium falciparum K13 marker prevalence indicative of artemisinin resistance in southern Rwanda.

In 2023, we updated data collected since 2010 on Plasmodium falciparum K13 and MDR1 drug resistance markers in Huye district, southern Rwanda. Artemisinin resistance-associated PfK13 markers occurred in 17.5% of 212 malaria patients (561H, 9.0%; 675V, 5.7%; and 469F, 2.8%), nearly double the frequency from 2019. PfMDR1 N86, linked with lumefantrine tolerance, was close to fixation at 98%. In southern Rwanda, markers signaling resistance to artemisinin and lumefantrine are increasing, albeit at a relatively slow rate.