Genetic Diversity of Field Isolates from the Thai-Myanmar Border during the Period of 2006-2016.

High levels of genetic variants of have previously been reported in Thailand. Circumsporozoite surface protein (CSP), merozoite surface protein (MSP), and microsatellite markers were used to determine the genetic polymorphisms of . This study aimed to investigate the molecular epidemiology of populations at the Thai-Myanmar border by genotyping the , , and genes. Four hundred and forty clinical isolates were collected from the Mae Sot and Sai Yok districts from 2006-2007 and 2014-2016. Polymerase chain reaction with restriction fragment length polymorphism (RFLP) was used to investigate the genetic polymorphisms of the target genes. Based on PCR band size variations, 14 different alleles were identified: eight for VK210 and six for VK247. The VK210 genotype was the dominant variant during both sample collection periods. Based on PCR genotyping, three distinct types (A, B, and C) for both and were observed. Following RFLP, 28 and 14 allelic variants of and 36 and 20 allelic variants of with varying frequencies were identified during the first and second periods, respectively. High genetic variants of and were found in the study area. exhibited a higher level of genetic diversity and multiple-genotype infection versus .