Week 10/2019 (4-10 March 2019)
- Influenza activity was widespread in the European Region. Specimens collected from individuals presenting with ILI or ARI to sentinel primary health care sites yielded an influenza virus positivity rate of 42.8%.
- Influenza type A virus detections dominated with slightly more A(H1N1)pdm09 than A(H3N2) viruses. Very few influenza B viruses were detected.
- 28.3% of specimens from patients with severe acute respiratory infection (SARI) collected in week 10/2019 tested positive for influenza virus, and almost all were type A.
- Pooled data from 22 Member States and areas reporting to the EuroMOMO project indicated that the excess mortality observed in previous weeks continued to decline. Excess mortality was seen in persons aged 65 years and above and, to a lesser extent, in persons 15-64 years.
2018/19 season overview
Influenza activity in the European region, based on sentinel sampling, exceeded 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 are circulating widely, with co-circulation in some countries while others report dominance of either A(H1N1)pdm09 or A(H3N2) viruses.
Among hospitalized influenza virus-infected patients admitted to ICU wards, 41% of influenza A viruses were subtyped; of these 72% were A(H1N1)pdm09 viruses. Among influenza virus-infected patients admitted to other wards, 35% of influenza A viruses were subtyped and 63% were A(H1N1)pdm09 viruses.
Over 90% of influenza A viruses detected from SARI surveillance since week 40/2018 were subtyped and 81% were A(H1N1)pdm09 viruses.
In general, current influenza vaccines tend to work better against influenza A(H1N1)pdm09 and influenza B viruses than against influenza A(H3N2) viruses. Preliminary vaccine effectiveness estimates continue to support the use of vaccines. Early data suggest the vaccines are effective, but estimates vary depending on the population studied and the proportions of circulating influenza A virus subtypes. See data from a European study (six countries), Canada, Finland, Hong Kong, Sweden, and the United States.
On 21 February 2019, WHO published the recommendations for the influenza vaccine composition to be used in the 2019–2020 northern hemisphere season. The recommendation for type B lineages was unchanged, for A(H1N1)pdm09 it was updated, and for A(H3N2) the decision was postponed until 21 March 2019.
- A recent summary of regional activity from October 2018 to February 2019 was published in Eurosurveillance and can be found here.
- Circulating viruses remain susceptible to neuraminidase inhibitors supporting use of antiviral treatment according to national guidelines.