Emergence of a novel subclade of influenza A(H3N2) virus in London, December 2016 to January 2017

Euro Surveill. 2017 Feb 23;22(8):30466. doi: 10.2807/1560-7917.ES.2017.22.8.30466.

Abstract

We report the molecular investigations of a large influenza A(H3N2) outbreak, in a season characterised by sharp increase in influenza admissions since December 2016. Analysis of haemagglutinin (HA) sequences demonstrated co-circulation of multiple clades (3C.3a, 3C.2a and 3C.2a1). Most variants fell into a novel subclade (proposed as 3C.2a2); they possessed four unique amino acid substitutions in the HA protein and loss of a potential glycosylation site. These changes potentially modify the H3N2 strain antigenicity.

Keywords: influenza; molecular; next generation sequencing; outbreak.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Amino Acid Substitution
  • Child
  • Child, Preschool
  • Communicable Diseases, Emerging / epidemiology
  • Communicable Diseases, Emerging / genetics*
  • Epidemics*
  • Female
  • Genetic Drift
  • Genetic Variation
  • Glycosylation
  • Hemagglutinin Glycoproteins, Influenza Virus / genetics*
  • Hemagglutinins / genetics*
  • Humans
  • Infant
  • Infant, Newborn
  • Influenza A Virus, H3N2 Subtype / classification
  • Influenza A Virus, H3N2 Subtype / genetics*
  • Influenza A Virus, H3N2 Subtype / isolation & purification
  • Influenza, Human / diagnosis
  • Influenza, Human / epidemiology*
  • Influenza, Human / virology
  • London / epidemiology
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Phylogeny
  • RNA, Viral / genetics
  • RNA, Viral / isolation & purification
  • Sequence Analysis, DNA
  • Young Adult

Substances

  • Hemagglutinin Glycoproteins, Influenza Virus
  • Hemagglutinins
  • RNA, Viral