Molecular epidemiology of dengue viruses in southern China from 1978 to 2006

Abstract

To investigate molecular epidemiology of dengue viruses (DENV) in southern China, a total of 14 dengue isolates were collected in southern China during each epidemic year between 1978 and 2006 and their full-length genome sequences were obtained by using RT-PCR method. The E gene sequences from additional 6 dengue fever patients in Guangzhou in 2006 were also obtained by using RT-PCR method. Combined with DENVs sequences published in GenBank, phylogenetic analysis and recombination analysis were performed. One hundred and twenty-five E gene sequences and 60 complete genome sequences published in the GenBank were also involved. Phylogenetic analysis showed that there was a wide genetic diversity of DENVs isolated in southern China. DENV-1 strains exist in almost all of the clades of genotype I and IV except the Asia 1 clade of genotype I; DENV-2 stains are grouped into four of the five genotypes except American genotype. DENV-4 strains are grouped into 2 genotypes (I and II). Phylogenetic analysis also showed that all DENV-4 isolates and two DENV-2 isolates were closely related to the prior isolates from neighboring Southeast Asia countries. The DENV-1 strain isolated during the 2006 epidemic is highly homologous to the strains isolated during the 2001 epidemic.Recombination analysis showed no inter-serotype recombination, but 22 intra-serotype recombination events were found across the 32 complete genomes of all Chinese isolates. The study suggested that dengue fever epidemic in Southern China over the past 30 years presented two important modes, 1) imported-cases-induced endemic prevalence; 2) endogenous epidemic outbreak with natural epidemic focus. Recombination may play an important role in dengue virus evolution and adaptation.

An Epidemic of Dengue-1 in a Remote Village in Rural Laos

“…Some putative recombinant strains from China (numbers 1, 4–9, 11,12, and 14 in Table S4) were identified, as described by Wu et al . [33]. The other recombination events (numbers 2, 3, 10, and 13) were further investigated by phylogenetic analysis presented in Supporting Material Figure S4.…”

Isolation and characterization of dengue virus serotype 2 from the large dengue outbreak in Guangdong, China in 2014

“…In this study, we for the first time identified the pathogen as DENV-2 from patient serum inoculation using HTS, and obtained 97% sequences of complete genome, without any prior information about the pathogen and without amplification using specific primers. DENV-1 was predominant and responsible for the epidemics of dengue fever in Guangdong for decades [25]. However, the other three serotypes, DENV-2, DENV-3, and DENV-4, were all occasionally isolated in the past decade [2630].…”

Inhibition of dengue virus replication by diisopropyl chrysin-7-yl phosphate

“…Thus co-circulation of multiple DENV serotypes could finally increase the risk of secondary infection and the percentage of severe dengue cases. In mainland China, DENV1 had been thought to be predominant and responsible for the epidemics of dengue fever in southern China for decades (Wu et al, 2011). However, the other three types of DENV had also been frequently detected (Jiang et al, 2012;Zhao et al, 2012aZhao et al, , 2012bZhao et al, , 2014.…”