Risk assessment update: seasonal influenza, EU/EEA, 2016–2017

Risk assessment

European Centre for Disease Prevention and Control. Risk assessment of seasonal influenza, EU/EEA, 2016–2017 – Update, 25 January 2017. Stockholm: ECDC; 2017.

Most countries with high influenza activity have reported appreciable numbers of cases with severe outcomes. These case numbers place a high burden on hospitals. This updated risk assessment provides an overview of the current influenza situation in Europe.

Executive Summary

Influenza season yet to peak in most of Europe

The ongoing influenza season appears to be particularly severe due to the circulating A(H3N2) strain. The A(H3N2) virus disproportionately affects the elderly and they are also sub-optimally protected with the current vaccine.

While peaks of influenza activity have been reached in some countries, such as Portugal and Italy, others, such as France, Greece and the United Kingdom (Scotland), are still experiencing increasing influenza activity and excess deaths concludes the updated rapid risk assessment on seasonal influenza . EU Member States falling in the latter category should critically assess the healthcare resources necessary to provide care to influenza patients at risk of developing severe disease in order to minimise severe outcomes and consider addressing any gaps in resources as a matter of urgency.

Continued vaccination of the elderly and other at-risk individuals at this time is likely to have a major impact only in EU countries, where the season has not yet peaked, as full immunity is not developed until two weeks after vaccination.

The timely administration of neuraminidase inhibitors, also known as antivirals, ideally within 48 hours of symptom onset, for probable or laboratory-confirmed cases of influenza infection should be considered for vaccinated and non-vaccinated patients in at-risk groups. In addition, prophylaxis of high-risk contacts should always be considered.

Preparing for next season

Efforts to improve vaccination coverage should start immediately after the current season, particularly for the elderly, other at-risk groups, healthcare workers and children – if nationally recommended for the 2017–2018 season.

It is also of critical importance that all EU Member States collect and can share information that enables rapid risk and impact assessments to be undertaken. This includes surveillance of laboratory-confirmed influenza cases admitted to intensive care units and mortality monitoring, as well as data sharing these data with ECDC and EuroMOMO. Any EU Member State that has not implemented laboratory-confirmed influenza monitoring in hospitals and is not submitting virus-based data should consider doing so, as this would improve the real-time assessment of the current influenza season and future epidemics or pandemics.

All EU Member States have committed to achieving 75% vaccination coverage rates among the elderly, the risk groups and healthcare workers. ECDC monitors influenza vaccination policies and coverage through annual surveys with the VENICE network. A notable discrepancy between having recommendations and the ability to monitor and report vaccination coverage among those groups exists in many Member States.