Geographical origin of Plasmodium vivax in the Republic of Korea: Haplotype network analysis based on the parasite's mitochondrial genome

Background. The Republic of Korea (South Korea) is one of the countries where vivax malaria had been successfully eradicated by the late 1970s. However, re-emergence of vivax malaria in South Korea was reported in 1993. Several epidemiological studies and some genetic studies using antigenic molecules of Plasmodium vivax in the country have been reported, but the evolutionary history of P. vivax has not been fully understood. In this study, the origin of the South Korean P. vivax population was estimated by molecular phylogeographic analysis. Methods. A haplotype network analysis based on P. vivax mitochondrial (mt) DNA sequences was conducted on 11 P. vivax isolates from South Korea and another 282 P. vivax isolates collected worldwide. Results. The network analysis of P. vivax mtDNA sequences showed that the coexistence of two different groups (A and B) in South Korea. Groups A and B were identical or close to two different populations in southern China. Conclusions. Although the direct introduction of the two P. vivax populations in South Korea were thought to have been from North Korea, the results of this analysis suggest the genealogical origin to be the two different populations in southern China.