The European Influenza Surveillance Network (EISN) consists of contact points for influenza surveillance (epidemiological and virological) nominated by the Competent Bodies for surveillance of the Member States. Epidemiological and virological surveillance data on influenza are collected through The European Surveillance System (TESSy). As of 2008, the responsibility for the former activities of the European Influenza Surveillance Scheme (EISS) has been transferred to the European Centre for Disease Prevention and Control (ECDC).
By analysing the data on a weekly basis and issuing a weekly report, ECDC aims to provide to decision makers in Member States and national public health experts the basis to better assess influenza activity in Europe and to make available more accurate epidemiological and virological information to their governments, health care professionals and the general public.
The activities aim to contribute to reducing the burden of disease associated with influenza in Europe and include collection and exchange of timely information on influenza activity, contribution to the annual determination of the influenza vaccine content, provision of relevant information about influenza to health professionals and the general public and contribution to European influenza pandemic preparedness activities. ECDC also operates the influenza reference laboratory network: Community Network of Reference Laboratories for Human Influenza (CNRL).
Data collected for the surveillance of influenza are:
- Aggregate data of influenza-like illness (ILI) or Acute Respiratory infections (ARI) by age groups reported by sentinel practices in primary health care facilities.
- Qualitative indicators: intensity, geographic spread and trend.
- Virological data: types and syb-types of influenza viruses collected from sentinel and non-sentinel sources, genetic and antigenic characterisation of tested viruses, antiviral susceptibility and detections of the respiratory syncytial virus (RSV).
- Hospitalised severe influenza cases reported with severe acute respiratory cases (SARI) caused by other pathogens. These cases are reported with other variables: age-groups, causative influenza (sub-) types, vaccination status, underlying conditions.
Weekly analysis of influenza surveillance is available in the Weekly Influenza Surveillance Overview (WISO) from week 40 to week 20. During off-season, i.e. from week 21 to 39, the bulletin is available on a fortnightly basis.
The situation of influenza elsewhere in Europe is available at the WHO Europe report: Euroflu. For information about the influenza situation in the world, see WHO influenza updates.