Epidemiological and molecular characterization of dengue viruses imported into Guangzhou during 2009–2013

BACKGROUND Dengue virus causes one of the most significant infectious diseases in tropical and subtropical regions, notable number of which is imported into China every year. RESULTS In this study, the molecular epidemiologic and phylogenetic analyses of dengue cases imported into Guangzhou in South China during 2009-2013 were conducted. During that period, 46 imported dengue cases were identified, including four serotypes. Most of the dengue patients were travelling from Southeast Asia, South Asia and Africa. The envelope (E) genes of 20 imported dengue viruses introduced from 13 countries and regions, were sequenced and used for phylogenetic analyses. The results indicated that the DENV-1 genotype I and DENV-2 Asian genotype I were the most predominant DENV strains, which were circulating in Southeast Asia and imported into South China. In addition, the new introduction of DENV-3 genotype III from West Asia was observed. CONCLUSIONS This study provided an overview on the genetic diversity of DENV strains imported into South China, and also gave information about the geographic distribution, dynamic transmission and molecular evolution of epidemic DENV strains.