Genetic diversity of Plasmodium vivax population in Anhui province of China

Bo Huang,Fangli Lu,Yucheng Xu,Xuchu Hu,Hong Guo,Fei Xu,Yaming Yang,Xin-Zhuan Su,Shiguang Huang,Shanqing Wang

doi:10.1186/1475-2875-13-13

Abstract

BackgroundAlthough the numbers of malaria cases in China have been declining in recent years, outbreaks of Plasmodium vivax malaria were still being reported in rural areas south of the Yellow River. To better understand the transmission dynamics of P. vivax parasites in China, the extent of genetic diversity of P. vivax populations circulating in Bozhou of Anhui province of China were investigated using three polymorphic genetic markers: merozoite surface proteins 1 and 3α (pvmsp-1 and pvmsp-3α) and circumsporozoite protein (pvcsp).MethodsForty-five P. vivax clinical isolates from Bouzhou of Anhui province were collected from 2009 to 2010 and were analysed using PCR/RFLP or DNA sequencing.ResultsSeven and six distinct allelic variants were identified using PCR/RFLP analysis of pvmsp-3α with HhaI and AluI, respectively. DNA sequence analysis of pvmsp-1 (variable block 5) revealed that there were Sal-I and recombinant types but not Belem type, and seven distinct allelic variants in pvmsp-1 were detected, with recombinant subtype 2 (R2) being predominant (66.7%). All the isolates carried pvcsp with VK210 type but not VK247 or P. vivax-like types in the samples. Sequence analysis of pvcsp gene revealed 12 distinct allelic variants, with VK210-1 being predominant (41.5%).ConclusionsThe present data indicate that there is some degree of genetic diversity among P. vivax populations in Anhui province of China. The genetic data obtained may assist in the surveillance of P. vivax infection in endemic areas or in tracking potential future disease outbreak.

Highlights

The numbers of malaria cases in China have been declining in recent years, outbreaks of Plasmodium vivax malaria were still being reported in rural areas south of the Yellow River
DNA sequence polymorphism and clustering of pvmsp-1 All 45 isolates from Bozhou were successfully amplified for pvmsp-1 gene
Some of the P. vivax isolates examined in this study showed 100% identity with strains from other regions of China or even from different Asian countries, including Anhui province [AY465398 with S3 (Sal-I type)], Liaoning province [JQ606831 with S3, and JQ606834 with recombinant subtype 2 (R2)], Fujian province [AY538672 with R2], Hainan province [AY465377 with S2], Yunnan province [AY465391 with R2], South Korea [HQ171940 with S3, and HQ171937 with R2], North Korea [AF15 3032 with R2], India [AY229866 with S1], and Iran [AY502161 with R1]

Summary

Introduction

The numbers of malaria cases in China have been declining in recent years, outbreaks of Plasmodium vivax malaria were still being reported in rural areas south of the Yellow River. China in 2010, with the goal to eliminate malaria by 2015 in a majority of the regions with the exception of the border region in Yunnan province, and to completely eliminate malaria from China by 2020 To achieve this ambitious goal, studying population structure, genetic diversity, and transmission of Plasmodium parasites in endemic areas will provide important information for disease control and management, including baseline data essential for monitoring drug resistance and for predicting the origin and spread of parasite variants within and between populations, and the performance of malaria vaccines under development [6,7]. The population diversity of clinical P. vivax isolates from Anhui province of central China was evaluated using the above three polymorphic markers, and the molecular diversity data may provide important information for vivax malaria surveillance and for tracking parasites in future outbreaks in this area

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Results

Conclusion