The activity of seasonal influenza has increased substantially in a number of European countries, especially in north-western Europe, concludes the latest Weekly Influenza Surveillance Overview, Week 1, 2013.
Sixteen European countries have reported increasing trend of influenza transmission. Medium intensity of influenza transmission is reported by eleven countries, and one country reports high intensity. The geographic pattern is reported as widespread by ten countries.
Virological surveillance for the period shows that out of the 734 sentinel specimens tested across 20 countries, 44% (320) were positive for influenza virus. This relatively high percentage is similar to that seen in week 52.
Since week 40/2012, of all influenza virus detections in sentinel specimens, 44% were type A and 56% were type B viruses. Of influenza A viruses subtyped, 51% were A(H3) and 49% were A(H1). The virological pattern seen in Europe is different from that being reported in North America.
The composition of this season’s influenza vaccine matches well to the detected influenza viruses in Europe.
ECDC will continue to monitor and report influenza activity in Europe on weekly basis throughout the season.