Coronavirus infection source usually impossible to trace: Health service director

It is usually not possible to find out where a new coronavirus patient contracted the virus, according to health service GGD director Sjaak de Grouw. "In the majority of cases you do not know the source," he said in an interview with AD. The 25 GGDs are in charge of doing source and contact tracing for every person that tests positive for Covid-19, the respiratory disease caused by the novel coronavirus.

"If someone says: I went visiting, went cycling and sat on a terrace, then you cannot say where the source is," De Grouw said to AD. "There are only a few options where you can be sure of that: for example if someone stayed inside for 14 days and only went outside once."

Public health institute RIVM considers "source and contact tracing an essential part of the fight against the current Covid-19 epidemic". Other countries also keep track of who got the coronavirus where. According to De Grouw, the Netherlands does not do this at a national level. "We see no reason to analyze that. That does happen at a municipal level. But there is no national registration, because in the majority of cases you do not know the source."

According to doctor-microbiologist Bert Mulder of the Canisius Wilhelmina hospital in Nijmegen, doing national research into the results of source and contact tracing is important. "The conclusion that you don't always succeed should not discourage you from continuing to investigate," he said to AD. "Any source you find will help to contain the virus better. You want to be able to stomp out every peat fire and that is only possible if you know where it is."

"Whether you know the sources of 6 or 60 percent [of infections], that is all information that can be used. We must immediately adopt everything we can learn from Germany or New Zealand,' Mulder said.