[Study on the polymorphism in circumsporozoite protein of Plasmodium vivax before the completion on elimination program of malaria, in Hainan province].

Objective: To explore the polymorphism in circumsporozoite protein of Plasmodium vivax before malaria was eliminated in Hainan island.

Methods: PCR amplification, sequencing, and alignment methodologies were conducted and phylogenetic tree constructed.

Results: From all the cases, 19 of them belonged to two types, with 18 as VK210 type and 1 as VK247 type. VK210 type could be divided into seven kinds of subtypes but VK247 had only one type. Ratio of tropical strain with temperate stain in VK210 type was explored between the two stages:control or elimination. Phylogenetic tree was constructed by amino acid sequencing which clearly manifested that VK210 type and VK247 type belonged to different clusters.

Conclusion: Compared the proportion of two types in the control stage, there was no significant difference seen in the stage of elimination.