Emergence And Circulation of Dengue Virus Serotype 2 In Guangzhou Over A Period of 20 Years

Objectives The dengue epidemic in Guangzhou has imposed a rising burden on society and health infrastructure. Here we present the genotype data for dengue virus serotype 2 (DENV-2) to improve the understanding of dengue epidemic. Methods We sequenced the envelope gene of DENV-2 obtained from patient serum sample, and subsequently performed the maximum-likelihood phylogenetic analysis using PhyMLv3.1, the maximum clade credibility analysis using BEAST v.1.10.4 and selection pressure analysis using Datamonkey 2.0 . Results The DENV-2 prevalent in Guangzhou region related to the strains of Southeast Asian countries.Our results suggest that the Malaysia/Indian subcontinent genotype is prevalent in Guangzhou and no genotype shift has occurred during the last 20 years. Episodic positive selection was detected at one site. Conclusions Prevention and monitoring imported cases are important for local control. The shift between the lineages of the Malaysia/Indian subcontinent genotype, which originated at different time points, may be the underlying cause of rising DENV-2 cases in Guangzhou.The low rate of dengue haemorrhagic fever in Guangzhou may be explained by the dominance of the less virulent Malaysia/Indian subcontinent genotype.