Molecular evolution of enterovirus 68 detected in the Philippines

PLoS One. 2013 Sep 20;8(9):e74221. doi: 10.1371/journal.pone.0074221. eCollection 2013.

Abstract

Background: Detection of Enterovirus 68 (EV68) has recently been increased. However, underlying evolutionary mechanism of this increasing trend is not fully understood.

Methods: Nasopharyngeal swabs were collected from 5,240 patients with acute respiratory infections in the Philippines from June 2009 to December 2011. EV68 was detected by polymerase chain reaction (PCR) targeting for 5' untranslated region (5'UTR), viral protein 1 (VP1), and VP4/VP2. Phylogenetic trees were generated using the obtained sequences.

Results: Of the 5,240 tested samples, 12 EV68 positive cases were detected between August and December in 2011 (detection rate, 0.23%). The detection rate was higher among inpatients than outpatients (p<0.0001). Among VP1 sequences detected from 7 patients in 2011, 5 in lineage 2 were diverged from those detected in the Philippines in 2008, however, 2 in lineage 3 were not diverged from strains detected in the Philippines in 2008 but closely associated with strains detected in the United States. Combined with our previous report, EV68 occurrences were observed twice in the Philippines within the last four years.

Conclusions: EV68 detections might be occurring in cyclic patterns, and viruses might have been maintained in the community while some strains might have been newly introduced.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5' Untranslated Regions
  • Adolescent
  • Adult
  • Aged
  • Bayes Theorem
  • Capsid Proteins / genetics*
  • Child
  • Child, Preschool
  • DNA, Viral / genetics*
  • DNA, Viral / isolation & purification
  • Enterovirus / classification
  • Enterovirus / genetics*
  • Enterovirus / isolation & purification
  • Enterovirus Infections / diagnosis*
  • Enterovirus Infections / genetics
  • Enterovirus Infections / virology
  • Evolution, Molecular*
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Philippines
  • Phylogeny
  • Prospective Studies
  • Young Adult

Substances

  • 5' Untranslated Regions
  • Capsid Proteins
  • DNA, Viral

Associated data

  • GENBANK/AF081348

Grants and funding

This work was supported by a grant-in-aid from the Japan Initiative for Global research Network on Infectious Diseases (J-GRID) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, Science and Technology Research Partnership for Sustainable Development (SATREPS) from Japan Science and Technology Agency (JST) and Japan International Cooperation Agency (JICA), and Research Fellowships for Young Scientists from Japan Society for the Promotion of Science (JSPS), Japan. The funding agencies had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.