TY - JOUR T1 - European all-cause excess and influenza-attributable mortality in the 2017/18 season: should the burden of influenza B be reconsidered? JF - Clinical Microbiology and Infection Y1 - 2019 A1 - Nielsen,J.K. A1 - Vestergaard, Lasse S A1 - Lukas Richter A1 - Schmid, Daniela A1 - Natalia Bustos Sierra A1 - Tommi Asikainen A1 - Ramona Trebbien A1 - Denissov, Gleb A1 - Innos, Kaire A1 - Virtanen, Mikko J A1 - Fouillet, Anne A1 - Lytras, Theodore A1 - Kassiani Gkolfinopoulou A1 - Matthias Van der Heiden A1 - Linus Grabenhenrich A1 - Helmut Uphoff A1 - Paldy, Anna A1 - Bobvos, Janos A1 - Domegan, Lisa A1 - O'Donnell, Joan A1 - Scortichini, Matteo A1 - de Martino, Annamaria A1 - Mossong, Joel A1 - England, Kathleen A1 - Jackie Melillo A1 - van Asten, Liselotte A1 - Marit de Lange A1 - Ragnhild Tonnessen A1 - White, Richard A A1 - Susana P. da Silva A1 - Rodrigues, Ana P A1 - Larrauri, Amparo A1 - Clara Mazagatos A1 - Farah, Ahmed A1 - AnnaSara D. Carnahan A1 - Junker, Christoph A1 - Sinnathamby, Mary A1 - Pebody, Richard G A1 - Nick Andrews A1 - Reynolds, Arlene A1 - Jim McMenamin A1 - Caroline S Brown A1 - Adlhoch, Cornelia A1 - Penttinen, Pasi A1 - Mølbak, Kåre A1 - Krause, Tyra G KW - Excess mortality KW - Surveillance AB -

Objectives

Weekly monitoring of European all-cause excess mortality, the EuroMOMO network, observed high excess mortality during the influenza B/Yamagata dominated 2017/18 winter season, especially among elderly. We describe all-cause excess and influenza-attributable mortality during the season 2017/18 in Europe.

Methods

Based on weekly reporting of mortality from 24 European countries or sub-national regions, representing 60% of the European population excl. Russia and the Turkey part of European, we estimated age stratified all-cause excess morality using the EuroMOMO model. In addition, age stratified all-cause influenza-attributable mortality was estimated using the FluMOMO algorithm, incorporating influenza activity based on clinical and virological surveillance data, and adjusting for extreme temperatures.

Results

Excess mortality was mainly attributable to influenza activity from December 2017 to April 2018, but also due to exceptionally low temperatures in February-March 2018. The pattern and extent of mortality excess was similar to the previous A(H3N2) dominated seasons, 2014/15 and 2016/17. The 2017/18 overall all-cause influenza-attributable mortality was estimated to be 25.4 (95%CI 25.0-25.8) per 100,000 population; 118.2 (116.4-119.9) for persons aged 65. Extending to the European population this translates into over-all 152,000 deaths.

Conclusions

The high mortality among elderly was unexpected in an influenza B dominated season, which commonly are considered to cause mild illness, mainly among children. Even though A(H3N2) also circulated in the 2017/18 season and may have contributed to the excess mortality among the elderly, the common perception of influenza B only having a modest impact on excess mortality in the older population may need to be reconsidered.

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