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Monitoring development of the coronavirus with virus particles in wastewater

Virus particles end up in the wastewater through the faeces (stool) of infected people. At the waste water treatment plants, samples are taken from wastewater for RIVM. Researchers examine these samples for coronavirus particles. The results can be seen on this corona dashboard.

The wastewater research is one of the ways to track the spread of the virus, such as testing people for corona. Because there is less testing (at the GGD and through self-testing), wastewater research is an important indicator if the virus might revive again.

Questions and answers about wastewater research

Do we know with this research how many people are infected?
More virus particles means that the virus is more spread. This can be traced back to an area, but not to the number of infected people. However, it is very clear to see whether the virus is circulating more or less and where the virus mainly spreads.

How many people who are infected have coronavirus particles in their stool?
For about half of the people, the virus can be found in their stool. Some infected people have more virus particles in their stool than others, with or without symptoms. There are no indications that people have been infected by (working with) stool or wastewater.

Can we see a revival of the virus?
The results of the wastewater measurements could be an early warning of an upcoming revival of the virus. With this warning, the local GGD and municipality can do more research in advance. We now see that wastewater measurements during pandemic waves anticipated other characteristics, for example the number of positive tests and hospital admissions.

Can we see a decline in infections?
If the number of infections decreases, this is not immediately visible in the wastewater measurements. This is because people continue to have virus particles in their stool for a while.

This image gives a view on the process of the sewage research. The steps are in de following order: collecting the samples, take them to RIVM, make preparations for analysis, extract RNA, detect PCR and other research for COVID variants, data analysis and modelling, adding data to the Coronavirus Dashboard.