Assessing the threat of artemisinin resistance: seasonal and ecological patterns of PfKelch13 mutation distribution in malaria-endemic communities in Ghana.

BACKGROUND

Resistance to Artemisinin-based combination therapies (ACTs) threatens the backbone of Ghana's success in Malaria control. In addition, malaria remains prevalent in the Central Region, raising concerns about the potential emergence of drug resistance. Mutations in the PfKelch13 gene associated with reduced susceptibility have been reported across Africa and in some parts of Ghana, highlighting the need for molecular surveillance in these endemic settings.

METHOD: Dried blood spots were prepared from whole blood, and genomic DNA was amplified using established Plasmodium-specific primers. Selective whole-genome amplification enriched Plasmodium falciparum DNA, and libraries were sequenced using high-throughput Illumina HiSeq 2500 technology.

RESULTS

358 samples were successfully sequenced. PfKelch13 wild-type (WT) allele remained predominant, ranging from 42% to 100%, but the burden and diversity of mutant alleles differed substantially by location. SNPs observed were 127 single mutations, 42 double mutations, 2 Triple mutations, and 1 Quadruple mutation. Neither the ecological zone nor the season was significantly associated with the occurrence of mutant haplotypes; however, the district of origin emerged as statistically significant.

CONCLUSION

The study demonstrates the presence of PfKelch13 mutations in Plasmodium falciparum in the Central Region of Ghana, with substantial genetic diversity but low frequencies of validated resistance markers. The spatial and seasonal heterogeneity observed across transmission settings suggests that factors operating at finer geographical and temporal scales may be important determinants of genetic variation, highlighting limitations of broad ecological classifications. These findings underscore the need for continuous, fine-scale molecular surveillance and therapeutic efficacy studies to detect and mitigate emerging artemisinin resistance proactively.