Overview of surveillance of influenza 2009/2010 in the EU/EEA
Reporting protocol for influenza data submission to TESSy
Overview of Surveillance of Influenza 2009/2010 in the EU/EEA
Background
ECDC has a mandate to operate and integrate EU surveillance networks and to identify, assess and communicate current and emerging threats to human health from communicable diseases.
In the context of the current pandemic influenza A(H1N1) 2009, disease surveillance based on reporting of the number of confirmed cases has become unsustainable in some of the most heavily affected countries, as their numbers rise exponentially. In response, and together with the EU/EEA Member States and WHO, ECDC has developed plans for how Europe can maintain an acceptable level of surveillance of the influenza A(H1N1) 2009 during the expected autumn wave of the pandemic.
On 14-15 July, ECDC held the 4th meeting of the Working Group on Surveillance and Studies in a Pandemic to discuss their experiences and plans for dealing with the expected autumn wave. This meeting brought together experts from ECDC, WHO and US-CDC, as well as experts from the equivalent bodies in Canada and Australia and from EU Member States. This work was originally initiated following ECDC’s review of all the national influenza pandemic plans in the EU, completed last year, which concluded that a common approach to disease surveillance in a pandemic would be highly desirable.
Approach
The document “Overview of surveillance of influenza 2009/2010 in the EU/EEA, August 2009” provides an overview of the surveillance activities and methods to be implemented by ECDC and the Member States in early autumn 2009. This document is supported by the “Reporting protocol for influenza data submission to TESSy”, which provides detailed guidance for national surveillance contact points on how to implement the surveillance components.
The proposed surveillance activities and methods reflect the importance of monitoring the demographics of the most severe cases, which will rely on surveillance of severe and fatal cases. For countries that are too overwhelmed to count cases, measuring qualitative indicators to understand the intensity of the geographic spread of the virus is suggested based on WHO guidelines.
Summary of Proposed Surveillance Activities
Four components are suggested for the quantitative monitoring of the pandemic influenza (H1N1) 2009. These are:
- Surveillance of influenza-like illness (ILI) or acute respiratory infection (ARI), to collect and provide timely information on influenza activity and estimate the ILI/ARI incidence in the population.
- Virological surveillance, to collect and provide detailed and timely information on circulating influenza virus strains.
- Surveillance of severe acute respiratory infection (SARI) and fatal cases related to the pandemic influenza, to better monitor the severity of the pandemic so as to detect indications of changes in the population groups affected by severe outcomes which may justify more robust public health measures and to monitor deaths
- Aggregate reporting of cases and deaths, to monitor the geographic spread, intensity and severity of laboratory confirmed pandemic influenza infections in Member States that are still counting individual cases.
- Qualitative monitoring of pandemic (H1N1) 2009 virus
Even in the absence of hard figures, most countries in the EU/EEA will still be able to make an assessment of the pandemic situation. The objectives of qualitative monitoring would be to monitor the geographic spread, trend, intensity and impact once the quantitative monitoring systems are no longer functioning. When country surveillance systems are overwhelmed, these more subjective assessments would be the only way of knowing how much countries are affected and whether the situation is improving or getting worse.
Mortality monitoring is another important indicator of the pandemic which can be monitored. Monitoring of all cause mortality and excess mortality is being set up by the EuroMoMo project. In response to the current influenza (H1N1) 2009 pandemic, EuroMoMo is providing an “emergency” mortality monitoring system which provides standardised indicators for comparison across Europe (http://www.euromomo.eu/).
Output
The main output of these combined surveillance activities will be a weekly influenza surveillance overview that will include not only the information covered by the current weekly bulletin, but will also provide a more comprehensive picture of the pandemic’s epidemiology and impact.