Published in:
Open Access 01-12-2015 | Research article
Phylogenetic analysis of dengue virus reveals the high relatedness between imported and local strains during the 2013 dengue outbreak in Yunnan, China: a retrospective analysis
Published in: BMC Infectious Diseases | Issue 1/2015
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Background
An outbreak of dengue virus (DENV) occurred in Yunnan province. More than 2,000 individuals were infected from August to November 2013. In this study, we aimed to characterize the origin and prevalence of DENV in Dehong prefecture of Yunnan province using phylogenetic and evolutionary analyses of DENV strains collected from local patients and foreign travelers.
Methods
A total of 41 DENV-positive serum samples were randomly collected from travelers who entered China at Ruili port or local patients with dengue fever in Dehong prefecture of Yunnan province, China. The envelope (E) gene of DENV was amplified and sequenced. The distributions and evolutionary characteristics of different genotypes were elucidated by phylogenetic and Bayesian analyses.
Results
Phylogenetically, all of the 41 DENV-positive samples could be classified into genotype I (43.9%) of serotype DENV-1 and the Asian I genotype (56.1%) of serotype DENV-2. DENV strains derived from local patients and foreign travelers were scattered equally within these two clusters. Furthermore, the DENV strains from the two populations exhibited high relatedness based on evolutionary characteristics.
Conclusions
These results suggested that imported and local DENV strains occurring during the dengue outbreak in 2013 were highly related. Additionally, these data may suggest that this dengue outbreak was caused by a newly imported infection from the neighboring country of Myanmar.