Coronadashboard data explained
- Coronadashboard data explained

Contact tracing GGDs

Where do the numbers come from?

RIVM provided these figures as open data.

How are the numbers calculated?

GGDs performed the source and contact investigation (BCO) in people with a positive test result. The GGDs investigate, among other things, in which situation someone may be infected. The GGDs have named 21 possible situations of infections. For the overview on the dashboard, we divided these 21 situations into 8 categories. The overview below shows the eight categories with the situations that fall under the relevant category.

1. At home and visiting

2. Work

3. School and childcare

4. Healthcare

5. Gatherings

6. Travel

7. Restaurant, café or bar

8. Other

Adjustments and corrections

Source and contact tracing scaled down

In the event of a positive corona test, the GGD carried out source and contact research until the end of 2021. The GGD contacted the infected person to find out where they might have become infected and to find out who they had been in contact with. The source and contact investigation will be scaled down in the autumn of 2021. As a result, less and less data is available and the Source and contact tracing page is no longer updated. The maps on this page provided data on source and contact tracing in the security regions up to May 15, 2022.

Adjustments in the numbers

From 5 November 2021, GGDs have been working with a new form of source and contact investigation: customized BCO. With customized BCO it was more common that enough information was available to show the possible situations of contamination on the dashboard.

Just like in the 'old' system, customized BCO also has a phase model. This meant that if there were a lot of infections, the BCO went to a different phase and was carried out in a less extensive way. With customized BCO, the GGD worked with the color codes green, orange and red. In the green phase, custom BCO was fully implemented. Orange meant that BCO was carried out to a limited extent. In phase red, the person who tested positive was only called with the result and no further information.

In contrast to the old system, if one of the 25 GGD regions was in phase green or orange, sufficient data was available to display information about BCO on the dashboard.