Co-circulation of two genotypes of dengue virus serotype 3 in Guangzhou, China, 2009

Tao Jiang,Wei-Ze Zhou,Yong-Qiang Deng,Shun-Ya Zhu,Xue-Dong Yu,Wen-Xin Hong,Fu-Chun Zhang,E-De Qin,Man Yu,Jian Wang,Cheng-Feng Qin

doi:10.1186/1743-422x-9-125

Abstract

Dengue is emerging as the most important mosquito borne viral disease in the world. In mainland China, sporadic and large outbreaks of dengue illness caused by the four serotypes of dengue virus (DENV-1 to DENV-4) have been well documented. Guangdong province is the major affected area in China, and DENV-1 has dominantly circulated in Guangdong for a long time. In this study, a family cluster of DENV-3 infection in Guangzhou was described. Three cases were diagnosed as dengue fever based on clinical manifestation, serological and RT-PCR assays. Two DENV-3 strains were isolated in C6/36 cells and the complete genome sequences were determined. Phylogenetic analysis revealed that the new DENV-3 isolates from the family cluster were grouped within genotype III. Considering the fact that several DENV-3 strains within genotype V were also identified in Guangzhou in 2009, at least two genotypes of DENV-3 co-circulated in Guangzhou. Careful investigation and virological analysis should be warranted in the future.

Highlights

Dengue is increasing in both frequency and magnitude worldwide, posing a heavy public health and economic burden especially in tropical and subtropical countries
Dengue virus (DENV) contains four serotypes, and each of them can cause a wide spectrum of clinical manifestations, including mild dengue fever (DF), severe dengue haemorrhagic fever (DHF) and deadly dengue shock syndrome (DSS)
Two of the three cases were positive for DENV-specific RT-PCR

Summary

Introduction

Dengue is increasing in both frequency and magnitude worldwide, posing a heavy public health and economic burden especially in tropical and subtropical countries. Dengue ranks as the most important mosquitoborne viral disease in the world. Population growth, urbanization, international travel, and global warming continuously enhance vector transmission and disease outbreaks [2]. Dengue virus (DENV) contains four serotypes, and each of them can cause a wide spectrum of clinical manifestations, including mild dengue fever (DF), severe dengue haemorrhagic fever (DHF) and deadly dengue shock syndrome (DSS). The pathogenesis of DHF and DSS remains poorly understood. Secondary infection with another DENV serotypes clearly increased the risk of severe diseases via the mechanism of antibody dependent enhancement (ADE) [3,4,5]. Epidemiological and in vivo data indicated that antiDENV antibodies mediated pathogenesis of a second heterotypic DENV infection [6,7,8]

Methods

Results

Conclusion