Dynamic changes of Plasmodium vivax population structure in South Korea

• Genetic diversities of MSP-1 and MSP-3α in 255 Korean Plasmodium vivax isolates were analyzed.
• Both MSP-1 and MSP-3α have dramatically diversified into different subtypes since early 2000s.
• Despite the reduced prevalence in South Korea, the Korean P. vivax population is becoming more genetically diverse.

The vivax malaria epidemic has persisted in South Korea since its reemergence in 1993. Although there has been a significant decrease in the number of malaria cases in recent years, vivax malaria is still a major public health concern. To gain in-depth insight into the genetic makeup of Korean Plasmodium vivax, we analyzed polymorphic patterns of two major antigens, merozoite surface protein-1 (MSP-1) and MSP-3α, in 255 Korean P. vivax isolates collected over an extended period from 1998 to 2013. Combinational genetic analysis of polymorphic patterns of MSP-1 and MSP-3α in the isolates suggests that the P. vivax population in South Korea has been diversifying rapidly, with the appearance of parasites with new genotypes, despite the recent reduction of disease incidence. These results highlight the importance of molecular epidemiological investigations to supervise the genetic variation of the parasite in South Korea.