Infectious people

Where do the numbers come from?

Until 9 July the National Institute for Public Health and the Environment (RIVM) supplied data on the number of infectious people twice a week. This data is available as open data.

• See RIVM’s open data set on number of infectious people
• See RIVM’s description of the data set on number of infectious people

How are the numbers calculated?

Someone who is infected with coronavirus can transmit the virus to other people. How long they are infectious for differs from one person to another. The precise number of infectious people is unknown, but RIVM calculates the range within which this number probably lies using data from the Pienter Corona study and the number of hospital admissions.

• See RIVM’s explanation on calculating the number of infectious people
• See RIVM’s explanation of the Pienter Corona study

Adjustments and corrections

Changes in the figures
From 1 June 2020 until 12 October 2020 the number of infected people was estimated on the basis of data from the first round of the Pienter Corona study, the number of hospital admissions and the number of confirmed cases. As of 13 October 2020, this figure is estimated using data from the second round of the Pienter Corona study and the number of hospital admissions. In the second round of this study, a larger group of people was tested to find out if they were infected with coronavirus, and more insight was gained into the degree of people’s infectiousness.

From 9 July 2021, RIVM will no longer calculate the number of infectious people for the time being. This figure is based on the number of hospital admissions. More and more people have been vaccinated and fewer people are hospitalized as a result. The difference between the number of infections among people and the number of hospital admissions is increasing. Therefore, the number of infectious people is no longer calculated.