Molecular epidemiology of human respiratory syncytial virus over three consecutive seasons in Latvia

Reinis Balmaks, Irina Ribakova, Dace Gardovska, Andris Kazaks

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


Lower respiratory tract infections caused by the human respiratory syncytial virus (HRSV) represent an immense burden of the disease, especially in young children. This study aimed to investigate the evolutionary history of HRSV strains isolated in the Children's Clinical University Hospital (Riga, Latvia) over three consecutive HRSV seasons. Of 207 samples from children hospitalized with lower respiratory tract infections, 88 (42.5%) tested positive for HRSV by RT-PCR. The seasonal activity started and peaked later than the average for the Northern hemisphere. Patients with HRSV lower respiratory tract infection were significantly younger than patients not infected with HRSV. HRSV-A viruses predominated for two consecutive seasons and were followed by an HRSV-B dominant season. Phylogenetic analysis based on glycoprotein G gene partial sequences revealed that viruses of both groups belonged to the worldwide dominant genotypes NA1 (HRSVA) and BA-IV (HRSV-B). High diversity of this gene was driven only partially by selection pressure, as only two positively selected sites were identified in each group. Two of the HRSV-A isolates in this study contained a 72-nt duplication in the C-terminal end of the G gene (genotype ON1) that was first described in Canada in the 2010-2011 season. Initial spatial and temporal dynamics of this novel genotype were reconstructed by discrete phylogeographic analysis. Fifteen years after acquiring comparable 60-nt duplication in the G gene, genotype BA lineages have replaced all other HRSV-B strains. However, the population size of genotype ON1 plateaued soon and even decreased slightly before the beginning of the 2012-2013 season.

Original languageEnglish
Pages (from-to)1971-1982
Number of pages12
JournalJournal of Medical Virology
Issue number11
Publication statusPublished - Nov 2014


  • Glycoprotein G
  • HRSV genotypes
  • Phylogenetic analysis
  • Phylogeographic analysis

Field of Science*

  • 1.6 Biological sciences
  • 3.3 Health sciences

Publication Type*

  • 1.1. Scientific article indexed in Web of Science and/or Scopus database


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