Summary of the influenza 2015–2016 season in Europe

Influenza in Europe, summary of the season 2015–16

The 2015-2016 influenza season has come to an end in Europe, with almost all countries now reporting low influenza activity for a number of weeks. 

Season’s dynamics

The season started in EU/EEA countries in week 52/2015, with the Netherlands reporting regional spread, while Sweden reported widespread activity. The season lasted for 22 weeks until week 20/2016, when the positivity rate dropped to 11%. The peak of the season - with the highest proportion of specimens tested positive (53%) - occurred in week 11/2016. 

Circulating viruses

Influenza A(H1N1)pdm09 and Victoria lineage type B viruses dominated the season. The A(H1N1)pdm09 virus was responsible for the majority of patients in intensive care units due to influenza; some 60% of those were in the 15–64 years old age group. This contrasts with the 2014–15 season where the predominant virus was A(H3N2) which affected the elderly more. 

 

The A(H1N1)pdm09 and A(H3N2) in the vaccine were likely to protect against the circulating viruses. The most prevalent type B viruses were of the B/Victoria lineage. A representative of this virus was in the quadrivalent-, but not the more commonly used trivalent-, influenza vaccine for this season.

Increased all-cause mortality during the season

Data from the 18 countries or regions reporting to the European monitoring of excess mortality for public health action (EuroMOMO) project suggested a pattern of excess all-cause mortality among those aged 15–64 years between the end of 2015 and week 14/2016. This may have been associated with influenza, as well as other factors. The level of excess all-cause mortality was similar to that of the 2012–2013 winter season and slightly lower than that of the 2014–2015 winter season.

Data on hospitalisations in reporting countries 

In the eight EU countries reporting hospital data, more than 8 500 hospitalised cases of influenza were reported this season, almost two-thirds of those patients were reported from intensive care units.

Flu News Europe

ECDC and WHO/Europe publish weekly data on Flu News Europe during the influenza season. Weekly online reporting for next season will start in week 40/2016. During the summer, weekly reporting to the European Surveillance System (TESSy) will continue, but bulletins will be issued monthly on 1 July, 5 August, 9 September and 7 October.