Molecular Epidemiology of Dengue Viruses Isolated in Shantou city, China, during 2015-2017

Abstract

Dengue affects tropical and subtropical regions, including Guangdong province of China. Dengue cases have been reported almost every year in Shantou city in Guangdong province. To understand the molecular characteristics of dengue viruses (DENVs) isolated in Shantou, we performed a molecular epidemiological study based on envelope protein (E) gene of the DENVs isolated from the cases. Totally, 174 serum samples were collected from 174 dengue-suspected patients during 2015-2017. 33.9% (59/174) were diagnosed with dengue. Serotypes of DENVs were identified in 27 samples, 37% (10/27), 55.6% (15/27), 3.7% (1/27), 3.7% (1/27) were DENV-1, DENV-2 DENV-3 and DENV-4, respectively. Genotype Ⅰ and Ⅳ were detected in DENV-1 while only Cosmopolitan genotype was detected in DENV-2. The replacement of predominant serotype (genotype)，which took place every year，implied that the dengue endemic in Shantou might be caused by imported infection rather than local circulation. Our results suggested that DENVs in Shantou were closely related to the strains circulating in Southeast Asian countries, which were possibly transmitted to Shantou through some relay point cities.