Temporal Changes in the Genetic Diversity of Plasmodium vivax Merozoite Surface Protein-1 in Myanmar.

Haung Naw,Jinyoung Lee,Jung-Mi Kang,Yi Yi Mya,Byoung-Kuk Na,Zaw Than Htun,Moe Kyaw Myint,Ho-Joon Shin,Tuấn Cường Võ,Hương Giang Lê,Tong-Soo Kim,Mya Moe

doi:10.3390/pathogens10080916

Abstract

Despite a significant decline in the incidence of malaria in Myanmar recently, malaria is still an important public health concern in the country. Although Plasmodium falciparum is associated with the highest incidence of malaria in Myanmar, the proportion of P. vivax cases has shown a gradual increase in recent years. The genetic diversity of P. vivax merozoite surface protein-1 block 5-6 (pvmsp-1 ICB 5-6) in the P. vivax population of Myanmar was analyzed to obtain a comprehensive insight into its genetic heterogeneity and evolutionary history. High levels of genetic diversity of pvmsp-1 ICB 5-6 were identified in the P. vivax isolates collected from Myanmar between 2013 and 2015. Thirty-nine distinct haplotypes of pvmsp-1 ICB 5-6 (13 for Sal I type, 20 for recombinant type, and 6 for Belem type) were found at the amino acid level. Comparative analyses of the genetic diversity of pvmsp-1 ICB 5-6 sequences in the recent (2013–2015) and the past (2004) P. vivax populations in Myanmar revealed genetic expansion of the pvmsp-1 ICB 5-6 in recent years, albeit with a declined incidence. The recent increase in the genetic heterogeneity of Myanmar pvmsp-1 ICB 5-6 is attributed to a combination of factors, including accumulated mutations and recombination. These results suggest that the size of the P. vivax population in Myanmar is sufficient to enable the generation and maintenance of genetic diversity, warranting continuous molecular surveillance of genetic variation in Myanmar P. vivax.

Highlights

Malaria is an important public health disease that is caused by Plasmodium species, which is transmitted by female Anopheles mosquito vectors
A total of 83 pvmsp-1 ICB 5-6 sequences were successfully amplified in Myanmar P. vivax isolates collected between 2013 and 2015
Despite remarkable reductions in the incidence of malaria in the Mandalay area of Myanmar in the last decade, the P. vivax population in the area is increasing in genetic diversity, suggesting that the size of Myanmar P. vivax population is still sufficient to facilitate the generation and maintenance of genetic diversity

Summary

Introduction

Malaria is an important public health disease that is caused by Plasmodium species, which is transmitted by female Anopheles mosquito vectors. The global cases of malaria have declined substantially in recent decades, malaria is still a public health concern in many endemic countries. Myanmar is a country with malaria prevalence accounting for 31% of the reported cases in the Greater Mekong Subregion (GMS) [1]. Four major species of Plasmodium infecting humans have been reported to be circulating in Myanmar [4]. The incidence of Plasmodium falciparum was the highest in the country in the last few decades, but the proportion of P. vivax infections has been gradually increasing in recent years [1,5,6]

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Conclusion