Weekly influenza update, week 48, December 2017
ECDC and WHO/Europe publish weekly influenza surveillance data in the report Flu News Europe.
- Influenza activity across Europe remained at low levels.
- Of the individuals sampled, on presenting with ILI or ARI to sentinel primary healthcare sites, 8.8% tested positive for influenza viruses, a higher proportion than the previous week (7%).
- Data from 16 countries or regions reporting to the EuroMOMO project indicated that all-cause excess mortality was within normal ranges for this time of year.
2017/18 season overview
- Since week 40/2017, a relatively low number of influenza viruses have been detected in sentinel and non-sentinel specimens.
- From sentinel sources, a slightly higher proportion of type B viruses compared to type A viruses has been detected. Approximately equal proportions of A(H1N1)pdm09 and A(H3N2) viruses have been detected.
- For type B viruses from both sentinel and non-sentinel sources, B/Yamagata lineage viruses have greatly outnumbered those of the B/Victoria lineage.
- While low in number, of the A(H3N2) viruses genetically characterized 61% belonged to clade 3C.2a, the vaccine virus clade, as described in the WHO recommendations for vaccine composition for the northern hemisphere 2017–2018, and 39% to clade 3C.2a1 of which the viruses are antigenically similar to those of clade 3C.2a.
Read more on seasonal influenza
Seasonal influenza is a preventable infectious disease with mostly respiratory symptoms. It is caused by influenza virus and is easily transmitted, predominantly via the droplet and contact routes and by indirect spread from respiratory secretions on hands etc.Read more
Surveillance reports and disease data on seasonal influenza
Surveillance reports and data: Disease data from ECDC Surveillance Atlas, Annual Epidemiological Reports, Surveillance reports.Read more