Unusually high impact of influenza B during the early 2012-2013 influenza season in Wales--epidemiology and clinical analysis of the first 100 cases

Influenza Other Respir Viruses. 2013 Nov;7(6):1013-6. doi: 10.1111/irv.12151. Epub 2013 Sep 4.

Abstract

Background: Influenza B is often regarded as the milder form of the disease. The early 2012-2013 season in Wales saw the highest rate of influenza B-associated primary care consultations since 1994-1995 and considerable hospitalisations.

Objectives: This report summarises features of the first 100 confirmed cases during 2012-2013 in Wales.

Methods: Case information was sourced from routine laboratory testing and virological surveillance.

Results and conclusions: Influenza B (Yamagata lineage) viruses dominated, mainly affecting younger adults, admission to critical care was unexpectedly common. Low vaccine uptake amongst at-risk patients may have contributed to the burden of influenza in secondary care in Wales.

Keywords: Influenza; Wales; influenza B; severity; surveillance.

MeSH terms

  • Adult
  • Aged
  • Female
  • Hospitalization / statistics & numerical data
  • Humans
  • Influenza B virus / isolation & purification*
  • Influenza, Human / epidemiology*
  • Influenza, Human / pathology
  • Influenza, Human / virology*
  • Male
  • Middle Aged
  • Primary Health Care / statistics & numerical data
  • Vaccination / statistics & numerical data
  • Wales / epidemiology