Prevalence of molecular markers related to artemisinin partial resistance and ACT partner drug resistance in the Plasmodium falciparum population in Kongo Central, DRC

BACKGROUND: Artemisinin-based combination therapies (ACTs) are the cornerstone of Plasmodium falciparum malaria treatment. Recent reports have documented P. falciparum with mutations associated with artemisinin partial resistance in eastern DRC, raising concerns about reduced drug susceptibility. This study examines the prevalence of mutations linked to reduced ACT efficacy in P. falciparum isolates collected December 2024-February 2025 in the Kongo Central Province, western DRC. METHOD: Dried blood spots were obtained from children under two years of age attending targeted health facilities and testing positive for malaria with rapid diagnostic tests. Diagnosis was confirmed with qPCR and Illumina-targeted amplicon sequencing was used to analyse mutations in the pfk13, pfubp-1, pfcoronin, pfmdr-1 and pfcrt genes. RESULTS: Pfk13 Q613E classified by WHO as potential marker of artemisinin partial resistance was found in a single sample, while pfubp-1 mutations D1525E and E1528D, also suspected of being linked to artemisinin partial resistance were found in 20% and 22% of the sequencing positive samples, respectively. N-Y-S-N-D and N-F-S-N-D were the dominating pfmdr1 haplotypes while the pfcrt wildtype C-V-M-N-K haplotype was highly dominant as well (90%). CONCLUSION: Our results suggest no immediate concern of maintaining artemisinin and ACTs as first-in-line treatment for malaria in Kongo Central, DRC. However, the findings are of concern and continued molecular surveillance is needed to monitor emerging resistance patterns and allow for a timely response.