Enterovirus D68 in Viet Nam (2009-2015)
Nguyen Thi Han Ny1,2, Nguyen To Anh1, Vu Thi Ty Hang1
1Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.
Wellcome Open Research
|August 31, 2017
Summary
Enterovirus D68 (EV-D68) has been circulating in Vietnam since 2008, causing moderate respiratory infections in young children. Vietnamese EV-D68 strains are genetically similar to other Asian viruses.
Area of Science:
- Virology
- Infectious Diseases
- Public Health
Background:
- Enterovirus D68 (EV-D68) outbreaks have increased globally, particularly in the USA and Europe between 2010-2014.
- EV-D68 has been linked to respiratory infections since 1962.
Purpose of the Study:
- To detect, characterize, and analyze the genetic diversity of EV-D68 in Vietnam.
- To understand the molecular epidemiology of EV-D68 in central and southern Vietnam between 2009 and 2015.
Main Methods:
- EV-D68 specific PCR was used on enterovirus/rhinovirus PCR positive respiratory and CSF samples from Vietnamese patients.
- Whole-genome sequencing was performed using a MiSeq approach.
- Phylogenetic analysis, evolutionary rate estimation, and recombination detection were conducted using BEAST and RDP.
Main Results:
- EV-D68 was detected in 3.4% of respiratory samples, with all positive cases occurring in young children (11.8-24.5 months) with moderate respiratory infections.
- Phylogenetic analysis revealed Vietnamese EV-D68 sequences clustered with Asian strains, specifically in B1 and A2 clades.
- One intra-sub-clade recombination event was identified, and the estimated evolutionary rate was 5.12E-3 substitutions/site/year, suggesting introduction into Vietnam around 2008.
Conclusions:
- This study provides the first evidence of EV-D68 circulation in Vietnam since 2008.
- Vietnamese EV-D68 strains are closely related to Asian variants and distinct from those in the US and Europe.
- The findings highlight the importance of ongoing surveillance for EV-D68 in Vietnam.
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