title: Genetic diversity of Plasmodium vivax population before elimination of malaria in Hainan Province, China.
abstract: BACKGROUND
  Hainan Province is one of the most severe endemic regions with high transmission of Plasmodium falciparum and Plasmodium vivax in China. However, the incidence of P. falciparum and P. vivax has dropped dramatically since 2007 and a national elimination malaria programme (NEMP) was launched after 2010. To better understand the genetic information on P. vivax population before elimination of malaria in Hainan Province, the extent of genetic diversity of P. vivax isolates in Hainan Province was investigated using four polymorphic genetic markers, including P. vivax merozoite surface proteins 1, 3α, and 3β (pvmsp-1, pvmsp-3α, and pvmsp-3β) and circumsporozoite protein (pvcsp).
  
  
  METHODS
  Isolates of P. vivax (n = 27) from Hainan Province were collected from 2009 to 2010 and pvmsp-1 and pvcsp were analysed by DNA sequencing, respectively. Using polymerase chain reaction-restriction fragment length polymorphism were analysed in pvmsp-3α, and pvmsp-3β.
  
  
  RESULTS
  The DNA sequencing analysis on pvmsp1 revealed that there were three allele types: Salvador-1 (Sal-1), Belem and recombinant (R) types. Among them, Sal-1 type was a dominant strain with eight variant subtypes (88.9%), whereas R- (3.7%) and Belem-type strains (7.4%) had one variant subtypes, respectively. All the isolates carried pvcsp with VK210 type accounting for 85.2% (23/27 isolates) and VK247 type accounting for 14.8% (4/27). Only type A and type B alleles were successfully amplified in pvmsp-3α gene, and a high level of polymorphism was observed in pvmsp-3α. Considering pvmsp-3β gene, type A was the predominant type in 17 isolates (63%), whereas type B was dominant in only ten isolates (37%).
  
  
  CONCLUSIONS
  The present data indicate that there was high degree of genetic diversity among P. vivax population in Hainan Province of China during the pre-elimination stage of malaria, with 26 unique haplotypes observed among 27 samples.
authors.affiliation: Hainan Provincial Centre for Disease Control and Prevention, Haikou, 570203, China. yuchunlee@126.com.
authors.forename: Yu-Chun
authors.initials: YC
authors.lastname: Li
authors.affiliation: Hainan Provincial Centre for Disease Control and Prevention, Haikou, 570203, China. wangguangze63@126.com.
authors.forename: Guang-Ze
authors.initials: GZ
authors.lastname: Wang
authors.affiliation: Hainan Provincial Centre for Disease Control and Prevention, Haikou, 570203, China. mengfeng1@126.com.
authors.forename: Feng
authors.initials: F
authors.lastname: Meng
authors.affiliation: Hainan Provincial Centre for Disease Control and Prevention, Haikou, 570203, China. zengwen72@126.com.
authors.forename: Wen
authors.initials: W
authors.lastname: Zeng
authors.affiliation: Hainan Provincial Centre for Disease Control and Prevention, Haikou, 570203, China. hechanghua2006@126.com.
authors.forename: Chang-hua
authors.initials: CH
authors.lastname: He
authors.affiliation: Hainan Provincial Centre for Disease Control and Prevention, Haikou, 570203, China. huximin372@sohu.com.
authors.forename: Xi-Min
authors.initials: XM
authors.lastname: Hu
authors.affiliation: Hainan Provincial Centre for Disease Control and Prevention, Haikou, 570203, China. wangsqkevin@163.com.
authors.forename: Shan-Qing
authors.initials: SQ
authors.lastname: Wang
mesh_terms: D000953:Antigens, Protozoan / Q000235:genetics; D002681:China; D060740:Disease Eradication; D014644:Genetic Variation; D006801:Humans; D016780:Malaria, Vivax / Q000469:parasitology* / Q000517:prevention & control; D020066:Merozoite Surface Protein 1 / Q000235:genetics; D010966:Plasmodium vivax / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D015800:Protozoan Proteins / Q000235:genetics
chemical_list: D000953:Antigens, Protozoan; D020066:Merozoite Surface Protein 1; D015800:Protozoan Proteins; C041595:circumsporozoite protein, Protozoan; C089133:merozoite surface protein 3, Plasmodium