Preliminary analysis of the conserved Plasmodium falciparum k13 gene in Arbaminch and Mirab Abaya, Ethiopia.

BACKGROUND: Reports from East and Horn of Africa showed artemisinin resistance is threatening control efforts. The Pfkelch13 (k13) gene mutation in Plasmodium falciparum is essential for tracking artemisinin resistance, which significantly jeopardizes malaria treatment effectiveness. The objective of this study was to assess the occurrence and prevalence of k13 gene polymorphisms at selected public health facilities of Arbaminch and Mirab Abaya, Ethiopia. METHODS: A cross-sectional study was conducted in Arbaminch and Mirab Abaya from May to December 2023. A total of 52 P. falciparum mono-infection samples confirmed by PCR were analysed. Sanger sequencing was used to obtain the sequences of k13 gene propeller domain, and phylogenetic analysis was performed using Molecular Evolutionary Genetic Analysis software version 11. Gene flow and differentiation were analysed with DnaSP6, while sequences from six other African countries were included from global database for haplotype network analysis using PopART 1.7. RESULTS: Among the 52 participants, 28 (52.8%) were male and 24 (47.2%) were female. The median age was 19 years old with an interquartile range of 15 to 32 years. There was no polymorphism identified in the studied samples indicating high genetic conservation (pairwise similarity index = 0.982). Isolates from Mirab Abaya exhibited strong genetic homogeneity, while Arbaminch samples showed slight divergence and yet remained largely conserved. Ethiopian haplotypes contributed significantly to a dominant African haplotype, with no k13 mutations detected. Although mild genetic diversity was observed in some African countries, haplotype and nucleotide diversity were not statistically significant. A negative Fu and Li's D statistic was observed, suggesting that low-frequency mutations could be due to selective sweep in the parasite population. CONCLUSION: This study found no evidence of P. falciparum k13 gene mutations in isolates from Arbaminch and Mirab Abaya, indicating a high level of genetic conservation. Although minor genetic divergence was observed, particularly among Arbaminch isolates, the overall population remained genetically homogeneous. These findings highlight the continued effectiveness of artemisinin-based combination therapy in the region and emphasize the need for ongoing molecular surveillance to monitor potential resistance emergence.