How ECDC collects and processes COVID-19 data

EU/EEA countries - weekly reporting (TESSy)

The primary source for weekly COVID-19 data on cases and deaths in the European Union (EU) and European Economic Area (EEA) countries is the data submitted by Members States to The European Surveillance System (TESSy). If case data are incomplete in TESSy, data collected from official sources (see below) may be used.

As of 20 June 2022, ECDC has discontinued the data collection and publication of the weekly updates from non-EU/EEA countries on the number of COVID-19 cases and deaths.

Please refer to the World Health Organization (WHO) data on COVID-19 and the WHO Weekly Epidemiological and Weekly Operational Updates page for data and epidemiological updates for non-EU/EEA countries.

From 20 June 2022, ECDC will continue to update downloadable data files every Thursday for the EU/EEA countries only. The worldwide data collected by ECDC until 20 June 2022, continues to be available in an archived format.

Since the beginning of the coronavirus pandemic and up until 20 June 2022, a team of epidemiologists screened up to 400 relevant sources from 196 countries to collect the latest figures on the number of COVID-19 cases and deaths reported worldwide. This was initially done on a daily basis and was scaled down to a weekly basis in December 2020. The data screening followed ECDC’s standard Epidemic Intelligence (EI) process in which every single data entry was validated and documented in an ECDC database. An extract of this database, complete with up-to-date figures and data visualisations was published every Thursday on ECDC’s website, to ensure a maximum level of transparency.

EU/EEA countries - daily reporting (collected from official sources)

Since the beginning of the coronavirus pandemic, ECDC’s EI team has collected the number of COVID-19 cases and deaths, based on reports from health authorities worldwide. This comprehensive and systematic process was carried out on a daily basis until 14 December 2020. (See the discontinued daily dataset).

From 11 March 2021, ECDC’s EI team started publishing the daily number of COVID-19 cases and deaths for EU and EEA countries only.

On 26 January 2022, the data collection process was automatised to enhance data quality and allow for historic corrections of the timeseries. As of 5 February 2022, COVID-19 situation updates for the EU/EEA will not be published on weekends or bank holidays. Data will still be collected for those days through an automated process and will be available on the next working day. The processing of these data follows ECDC’s standard EI process and the data are validated by a team of epidemiologists. The data are then shared in the daily situation update on the ECDC website and are used for visualisations on the ECDC dashboard.