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

Abstract

Dengue has been well recognized as a global public health threat, but only sporadic epidemics and imported cases were reported in recent decades in China. Since July 2014, an unexpected large dengue outbreak has occurred in Guangdong province, China, resulting in more than 40000 patients including six deaths. To clarify and characterize the causative agent of this outbreak, the acute phase serum from a patient diagnosed with severe dengue was subjected to virus isolation and high-throughput sequencing (HTS). Traditional real-time RT-PCR and HTS with Ion Torrent PGM detected the presence of dengue virus serotype 2 (DENV-2). A clinical DENV-2 isolate GZ05/2014 was obtained by culturing the patient serum in mosquito C6/36 cells. The complete genome of GZ05/2014 was determined and deposited in GenBank under the access number KP012546. Phylogenetic analysis based on the complete envelope gene showed that the newly DENV-2 isolate belonged to Cosmopolitan genotype and clustered closely with other Guangdong strains isolated in the past decade. No amino acid mutations that are obviously known to increase virulence or replication were identified throughout the genome of GZ05/2014. The high homology of Guangdong DENV-2 strains indicated the possibility of establishment of local DENV-2 circulation in Guangdong, China. These results help clarify the origin of this epidemic and predict the future status of dengue in China. dengue virus serotype 2, virus isolation, phylogenetic analysis, envelope gene Citation:

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

“…Phylogenetic analyses revealed that DENV2/SZ/2015 isolate was closely related to former China isolates. This finding was consistent with previous report that DENV2 strains circulating in Guangdong have been stable since their introduction (Zhao et al, 2014), indicating that dengue fever cannot be simply treated as an imported epidemic disease anymore. A DENV1 strain was also determined.…”

“…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. In the present study, we characterized a DENV2 strain from Shenzhen, Guangdong.…”

Dengue in China: not a passing problem

“…The co-circulation of multiple serotypes of DENV increases the risk of severity of disease. Genomic sequence analysis of the newly isolated DENV-2 in Guangzhou during this outbreak demonstrated high homology to the ones isolated in the past decade in Guangdong [3]. Individuals that have been exposed to DENV-2 this year are prone to development of severe disease when infected with a secondary heterotypic DENV infection, due to the phenomena of antibody-dependent enhancement of infection.…”

Zika virus: a new threat from mosquitoes

“…First, it is critical to study the ecologic, entomologic, viral, and host determinants that account for its rapid transmission and disease association. Viral genome analysis combined with reverse genetic studies will help identify potential viral determinants (Zhao et al, 2014). Second, flavivirus infection has never before been linked to birth defect.…”