Distinct genetic clades of enterovirus D68 detected in 2010, 2013, and 2015 in Osaka City, Japan

PLoS One. 2017 Sep 13;12(9):e0184335. doi: 10.1371/journal.pone.0184335. eCollection 2017.

Abstract

The first upsurge of enterovirus D68 (EV-D68), a causative agent of acute respiratory infections (ARIs), in Japan was reported in Osaka City in 2010. In this study, which began in 2010, we surveyed EV-D68 in children with ARIs and analyzed sequences of EV-D68 strains detected. Real-time PCR of 19 respiratory viruses or subtypes of viruses, including enterovirus, was performed on 2,215 specimens from ARI patients (<10 years of age) collected between November 2010 and December 2015 in Osaka City, Japan. EV-D68 was identified in 18 enterovirus-positive specimens (n = 4 in 2013, n = 1 in 2014, and n = 13 in 2015) by analysis of viral protein 1 (VP1) or VP4 sequences, followed by a BLAST search for similar sequences. All EV-D68 strains were detected between June and October (summer to autumn), except for one strain detected in 2014. A phylogenetic analysis of available VP1 sequences revealed that the Osaka strains detected in 2010, 2013, and 2015 belonged to distinct clusters (Clades C, A, and B [Subclade B3], respectively). Comparison of the 5' untranslated regions of these viruses showed that Osaka strains in Clades A, B (Subclade B3), and C commonly had deletions at nucleotide positions 681-703 corresponding to the prototype Fermon strain. Clades B and C had deletions from nucleotide positions 713-724. Since the EV-D68 epidemic in 2010, EV-D68 re-emerged in Osaka City, Japan, in 2013 and 2015. Results of this study indicate that distinct clades of EV-D68 contributed to re-emergences of this virus in 2010, 2013, and 2015 in this limited region.

MeSH terms

  • Child
  • Child, Preschool
  • Communicable Diseases, Emerging / virology
  • Disease Outbreaks / statistics & numerical data
  • Enterovirus D, Human / classification*
  • Enterovirus D, Human / genetics*
  • Enterovirus Infections / epidemiology*
  • Enterovirus Infections / virology*
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Japan / epidemiology
  • Male
  • Phylogeny
  • Respiratory Tract Infections / virology
  • Sequence Analysis, DNA
  • Urbanization
  • Viral Structural Proteins / genetics

Substances

  • Viral Structural Proteins

Grants and funding

This study was partially supported by JSPS KAKENHI Grant Number 26460819 to AK and the Japan Agency for Medical Research and Development to TK.