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. 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.
Increased influenza activity started in week 51/2014 this season when the percentage of influenza positive laboratory tests crossed the 10% threshold. The season lasted for 21 weeks until week 19/2015, when the positivity rate dropped below 10%. The peak of the season - with the highest proportion of specimens tested positive (55%) - occurred in week 07/2015. The peak varied between countries, occurring in week 04/2015 in Bulgaria and Portugal, and between weeks 05/2015 and 08/2015 in most central European countries.
The 2013–14 influenza season was mild and dominated by influenza A viruses, with a co-circulation of A(H1N1)pdm09 and A(H3N2) viruses in most countries. Only two countries reported higher syndromic notification rates compared with the previous season.
In September/October 2013, the European Reference Laboratory Network for Human Influenza (ERLI-Net) conducted an external quality assessment (EQA) for the rapid detection of influenza virus, its isolation and culture.
WHO/Europe has been holding annual influenza surveillance meetings jointly with the European Centre for Disease Prevention and Control (ECDC) since 2011. This meeting brought together epidemiologists and virologists – the national influenza surveillance focal points – from 50 Member States to discuss national, regional and global surveillance related to seasonal influenza and novel influenza viruses, such as avian influenza A(H7N9).
This report presents the results of the influenza virus antiviral (AV) susceptibility external quality assessment (EQA) which was held for European reference laboratories.
Active circulation of influenza has started late in Europe in the 2013-2014 season, with a different timing across EU/EEA countries, states the annual ECDC risk assessment on seasonal influenza. The first countries affected have been Bulgaria, Greece, Portugal and Spain, where the A(H1)pdm09 influenza virus has dominated. Without any specific geographic pattern, influenza activity has since spread rapidly across Europe. In Bulgaria, Portugal and Spain, the season peaked in weeks 4 and 5/2014, while influenza activity still continues to increase in Greece.
The third annual joint influenza surveillance meeting was held in Istanbul. The meeting focused on virological and epidemiological aspects of influenza surveillance, influenza vaccination, and new developments in the field of influenza prevention and control.