Zhaoqing YangJun MiaoYaming HuangXinyi LiChaturong PutaporntipSomchai JongwutiwesQi GaoRachanee UdomsangpetchJetsumon SattabongkotLiwang CuiKunming Medical CollegeMalaria DepartmentChulalongkorn UniversityJiangsu Institute of Parasitic DiseasesMahidol UniversityArmed Forces Research Institute of Medical Sciences, ThailandPennsylvania State University2018-08-202018-08-202006-12-01Acta Tropica. Vol.100, No.3 (2006), 205-2120001706X2-s2.0-33846581910https://repository.li.mahidol.ac.th/handle/123456789/23282The recent resurgence of Plasmodium vivax malaria requires close epidemiological surveillance and monitoring of the circulating parasite populations. In this study, we developed a combination of polymerase chain reaction and restriction fragment length polymorphism (PCR/RFLP) method to investigate the genetic diversity of the P. vivax merozoite surface protein 3β (PvMSP3β) gene among four Asian parasite populations representing both tropical and temperate strains with dramatic divergent relapse patterns (N = 143). Using P. vivax field isolates from symptomatic patients, we have validated the feasibility of this protocol in distinguishing parasite genotypes. We have shown that PCR alone could detect three major size polymorphisms of the PvMSP3β gene, and restriction analysis detected a total of 12 alleles within these Asian samples. Samples from different geographical areas differed dramatically in their PvMSP3β allele composition and frequency, indicating that complex, yet different parasite genotypes were circulating in different endemic areas. This protocol allowed easy detections of multiple infections, which reached 20.5% in the samples from Thailand. It is interesting to note that samples from one temperate site in China collected during a recent outbreak of the disease also showed a high level of genetic diversity with multiple infections accounting for 5.6% of the samples. When combined with the PvMSP3α locus, this method provides better capability in distinguishing P. vivax genotypes and detecting mixed genotype infections. © 2006 Elsevier B.V. All rights reserved.Mahidol UniversityImmunology and MicrobiologyMedicineArticleSCOPUS10.1016/j.actatropica.2006.10.011