Microgeographically diverse Plasmodium vivax populations at the Thai-Myanmar border

• Published in: Infection, genetics and evolution Vol. 45; pp. 341 - 346
• Main Authors: Gupta, Bhavna, Parker, Daniel M., Fan, Qi, Reddy, B.P. Niranjan, Yan, Guiyun, Sattabongkot, Jetsumon, Cui, Liwang
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-11-2016
• Subjects: Adolescent; Adult; Antigens, Protozoan - genetics; Asymptomatic Infections - epidemiology; Child; Child, Preschool; Cross-Sectional Studies; DNA, Protozoan - genetics; Female; Genetic diversity; Genetic Variation; Haplotypes; Humans; Infant; Malaria, Vivax - epidemiology; Malaria, Vivax - parasitology; Male; Microgeographic; Middle Aged; Molecular Epidemiology; Myanmar - epidemiology; Phylogeny; Plasmodium vivax; Plasmodium vivax - classification; Plasmodium vivax - genetics; Polymerase Chain Reaction; Pvmsp3α; Pvmsp3β; Thai-Myanmar; Thailand - epidemiology; Young Adult; Microgeographic; Plasmodium vivax; Genetic diversity; Thai-Myanmar; Pvmsp3α; Pvmsp3β
• ISSN: 1567-1348; 1567-7257
• DOI: 10.1016/j.meegid.2016.09.021

Malaria transmission along international borders of the Greater Mekong Subregion is a big challenge for regional malaria elimination. At the Thai-Myanmar border, Plasmodium falciparum cases have dropped dramatically; however, increasing P. vivax prevalence and the emerging reports on hidden malaria burden due to asymptomatic infections demand attention. We conducted cross-sectional surveys to detect asymptomatic malaria infections in a small village located at Thai-Myanmar border and genotyped P. vivax infections in order to understand the level of genetic diversity on such a microgeographic scale. PCR/RFLP and DNA sequencing identified high levels of genetic polymorphisms at both Pvmsp3α and Pvmsp3β loci among P. vivax infections. Combining the PCR/RFLP patterns of Pvmsp3α and Pvmsp3β, a total of 10 genotypes were observed among 17 samples, while concatenated DNA sequences of Pvmsp3α and 3β generated 14 haplotypes with haplotype diversity of 0.97. These markedly diverse parasites on a microgeographic scale suggest the circulation of a considerably large parasite population at the international border.
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•Genetic diversity among P. vivax isolates was evaluated at a microgeographic scale.•Cross sectional surveys identified large number of asymptomatic P. vivax infections.•PCR/RFLP and DNA sequence polymorphisms in Pvmsp3α and Pvmsp3β gene were evaluated.•High level of genetic polymorphism was observed at both loci.