Weekly influenza surveillance overview, week 40/2013

Surveillance report

​Week 40/2013 was the first week of the influenza surveillance season. During week 40/2013:• All 26 reporting countries experienced low intensity of clinical influenza activity, 22 countries reported no geographic spread and 21 countries reported stable trends.• Of 132 sentinel specimens tested by 15 countries, 3 (2%) were positive for influenza.• One hospitalised laboratory-confirmed influenza case was reported by Ireland.During the first week of the 2013–2014 influenza season, there was no evidence of any significant influenza activity in Europe.

Executive summary

​There is no evidence of any significant influenza activity in Europe, concludes the Weekly influenza surveillance overview for week 40, which covers the period from 30 September to 6 October 2013. From week 40, ECDC restarted weekly reporting on seasonal influenza activity in Europe, based on data provided by experts, virologists and doctors throughout Europe.

ECDC weekly updates on influenza provide a clinical and virological overview on a weekly basis as well as of the whole season by each reporting country. Maps on influenza activity in Europe by week are available for download on the ECDC website. More detailed information on influenza virus characterisation is provided on a monthly basis.  

Influenza comes to Europe every winter, but its impact and timing varies. Each year, around 10% of the population are infected, and influenza-related complications cause hundreds of thousands of hospitalisations all across Europe. Young children and older people, as well as those with chronic conditions, suffer the most, but even perfectly healthy young people are at risk of developing serious complications, such as pneumonia, myocarditis, encephalitis, and may even die as a result.