The 2017 Dengue virus 1 outbreak in northern Vietnam was caused by a locally circulating virus group

Abstract

Background Dengue virus (DENV) is a member of insect vector-borne viruses, and it causes dengue fever. Southeast Asia is the epi-center of dengue fever in the world. The characterization of the virus is essential to identify the transmission and evolution of DENV. Objectives In 2017, there was an outbreak of Dengue virus type 1 (DENV1) in northern Vietnam and the neighboring countries. To identify the genetic character of the outbreak virus in the area, we conducted whole-genome sequencing analysis on the samples positive for the DENV1 along with real-time PCR. Study design In total, 1026 blood samples were collected from patients with suspected dengue fever in Ha Nam and Hai Duong province, nearby areas of the capital of Vietnam. After screening by real-time PCR, 40 of DENV1 positive samples were subjected to whole-genome sequencing, and 28 complete coding sequences were obtained. Results All 28 sequences were genotype I of DENV1, which is dominant in the southeast and East Asian countries. The phylogenetic analysis of the E region showed that they fell into a single cluster with the reported sequences from Vietnam between 2009 and 2016, in which the isolates from other countries are very rare. Our results suggested that the 2017 outbreak in the area was caused by locally circulating viruses.

An outbreak of a novel lineage of dengue virus 2 in Vietnam in 2022

“…To determine whether the current epidemic strains were similar to the strains that were prevalent at T A B L E 1 Relation between primary/secondary dengue infection and DENV genome positivity using real-time PCR in Vung Tau, 2022. and 2017. 8,12,13 In 2019, a large DENV-2 outbreak with closely related strains isolated earlier in Southeast Asian countries was reported in Vietnam. 14 Because the newly identified DENV-2 lineage in this report has not been previously identified in Vietnam, it is worth exploring its origin.…”

“…We collected 1889 serum samples from patients with suspected dengue and collected information on disease manifestations. Viral RNA was extracted from the specimens using a Qiagen Viral RNA Mini Kit (Qiagen), and real‐time polymerase chain reaction (PCR) was used for DENV testing 8 …”

“…We used enzyme‐linked immunosorbent assays (ELISAs; Dengue ELISA IgM CAPTURE and Dengue ELISA IgG; VIRCELL). Because DENV infection was confirmed by real‐time PCR, primary infection was defined as IgG‐negative and IgM‐positive or IgG and IgM‐negative, and secondary infection was defined as IgG/IgM >1.2 8,10 …”

Epidemiology of dengue, chikungunya and Zika virus infections in travellers: A 16-year retrospective descriptive study at a tertiary care centre in Prague, Czech Republic

“…These travellers are more likely to visit distant areas and rural regions. Interestingly, the only serotype isolated from travellers returning from Vietnam was DENV-1, which was the predominant serotype during the 2017 outbreak [ 27 ]. DENV-1 was also found in patients returning from the Maldives.…”

Anti‐Dengue Screening on Several Vietnamese Medicinal Plants: Experimental Evidences and Computational Analyses

“…[7] Recently, Takemura et al reported that the dengue outbreak in northern Vietnam in 2017 was caused by a locally circulative viral group. [8] In Thailand, a survey on dengue fever between 2011-2016 revealed that people from 10-14 years old were most vulnerable to the infection, followed by 15-19 years old. Different serotypes had been identified, i. e., DENV-2 in 2012, DENV-3 in 2014, DENV-4, and DENV-3 in 2015.…”