Week 21-32/2019 (20 May–11 August 2019)

  1. Influenza activity was low, at interseason levels.
  • Of 812 sentinel specimens tested for influenza virus, 7 tested positive (<1%). Of SARI specimens tested for influenza virus, 1.7% were positive.

  • This is the penultimate report for the 2018–2019 influenza season. The final report will be published on 4 October and weekly reporting will resume on 11 October 2019 for the 2019–2020 season.

2018/19 season overview 

  • Influenza activity in the European Region, based on sentinel sampling, reached a positivity rate of 10% in week 49/2018, exceeded 50% between weeks 3/2019 and 7/2019, and peaked in week 5/2019.

  • Both influenza A virus subtypes have circulated, with co-circulation in some countries, while others reported dominance of either A(H1N1)pdm09 or A(H3N2) viruses.

  • Among hospitalized influenza virus-infected patients admitted to ICU wards, 99% were infected with type A viruses, with 66% of those subtyped being A(H1N1)pdm09. Among influenza virus-infected patients admitted to other wards, 99% were infected with type A viruses, with 54% of those subtyped being A(H1N1)pdm09.

  • Of the clinical specimens from SARI surveillance that tested positive for an influenza virus, 99% were type A viruses, with 79% of those subtyped being A(H1N1)pdm09.

  • A summary of regional activity from October 2018 to February 2019 was published in Eurosurveillance and can be found here.
  • Current influenza vaccines tend to work better against influenza A(H1N1)pdm09 and influenza B viruses than against influenza A(H3N2) viruses. For more detail, see the Vaccine effectiveness section located under Virus Characteristics.

  • WHO has published recommendations for the composition of influenza vaccines to be used in the 2019–2020 northern hemisphere season. While recommendations for both type B lineages were unchanged, updated recommendations were made for both A(H1N1)pdm09 and A(H3N2) viruses.
  • The vast majority of circulating viruses in the European Region were susceptible to neuraminidase inhibitors, which supports use of antiviral treatment according to national guidelines.

Influenza intensity, spread and dominant virus type/subtype