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

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.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.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.Malaria is distributed not only in tropical and subtropical areas but also in some temperate areas of the world. Plasmodium falciparum, which is distributed in tropical and subtropical areas, accounts for 90% of malaria cases. Like P. falciparum, Plasmodium vivax is distributed in tropical and subtropical areas, but its range extends to some temperate areas. In Asian and South American countries, the proportion of P. falciparum cases is gradually decreasing due to global malaria controls programmes, such as The Roll Back Malaria Partnership and The Global Fund. On the other hand, the proportion of P. vivax cases is gradually increasing [1]. Therefore, P. vivax should be given greater attention than it has received.The Republic of Korea (South Korea) is one of the countries where vivax malaria had been successfully eradicated by the late 1970s. This was due to an effective national eradication programme conducted by the National Malaria Eradication Service under the operation of the South Korean government with the support of the WHO [2-4]. However, in 1993, the first case of indigenous vivax malaria after the eradication program was reported from the border area between North and South Korea in the western Demilitarized Zone (DMZ) [5]. The number of cases steadily increased until 2000 (4,142 cases), at which point they began to gradually