Molecular Surveillance of Plasmodium vivax and Plasmodium falciparum Drug Resistance Genes in the Republic of Korea: 2022–2025

In the Republic of Korea (ROK), chloroquine is the first-line treatment for Plasmodium vivax (P. vivax), and primaquine is also prescribed to prevent relapse. For Plasmodium falciparum (P. falciparum), atovaquone-proguanil, pyronaridine-artesunate, and mefloquine are recommended. This study monitored drug resistance genes in blood samples collected from patients with P. vivax (soldiers, relapsed, and imported) and P. falciparum (soldiers and civilians) between 2022 and 2025. In P. vivax, several Pvmdr-1 mutations showed high prevalence, with S515R, G698S, L845F, M908L, T958M, and F1076L observed in nearly all isolates, while T529 and E1233 mutation showed moderate prevalence. S513R, Y541C, A829V, and S1358 mutation were occasionally identified, all of which were imported or soldiers receiving prophylactic chemotherapy. Significant differences in mutation prevalence were identified among groups (p < 0.05). However, no significant temporal trends were observed. In P. falciparum, the Y184F mutation in Pfmdr-1 was highly prevalent, and A675V mutation in PfK13 was detected only in soldiers. Group comparisons revealed significant differences (p < 0.05), whereas temporal trends were not observed. Because drug resistance gene mutations can be closely linked to treatment, surveillance of drug resistance genes is expected to contribute to malaria eradication in the ROK through providing basic information related to treatment.