The Netherlands seems to have declared the corona crisis over: on Wednesday the last measures, such as the mandatory mouth cap in public transport and access tests at events, expired. Even mass testing in the GGD test streets is seriously under discussion: how long does it make sense to test everyone with complaints if the virus does not lead to major problems? Minister Ernst Kuipers (Public Health, D66) will probably make a decision next week about the future of testing, if he comes up with a long-term approach to Covid-19.
In the latest advice, which was sent to the House of Representatives on Tuesday, the OMT emphasizes that it remains important to keep a ‘view of the virus’, also because it is then possible to monitor more closely whether the effectiveness of vaccinations decreases.
Professor of virology and OMT member Marion Koopmans says that the large-scale testing of the past two years has been an important way of keeping track of the virus and combating it at the same time. “If people who pick it up go into isolation and their contacts are quarantined, then that is one of the pillars of your fight.” Now that the Omikron variant is less sickening and disruptive, Koopmans can imagine that continuing to test everyone in the coming months – with better weather on the way – will be less necessary. Especially if people continue to use the increasingly well-established self-test.
It is very conceivable that we will have to deal with a wave or new variant
Letting go of the GGD testing, which provides a daily overview of the number of infections, also has risks, says Koopmans. “It is very conceivable that we will have to deal with a wave or new variant again. It now seems that China is no longer able to contain Omikron. When a wave sweeps through that entire country, you have to take global surprises into account.”
Sentinel stations
The question is what alternatives the Netherlands has for a good overview of the spread of the virus. Before the corona crisis, flu was always closely monitored via the Nivel sentinel stations at general practitioners, where samples were taken from patients with flu-like complaints. Such a system has yet to be set up for Covid-19, and the flu monitoring stations are now disrupted, says Koopmans. “Many people with flu complaints now report to the Covid test streets, so the picture through the sentinel stations is incomplete. We hope this will get better after the test lanes close, but you don’t know that.”
An alternative that is already being used is sewage water measurements, which can be used to identify a regional revival of the virus at an early stage. The question is whether that is sufficient or whether GGDs should, for example, continue to test certain groups on a random basis. “For that purpose, you could keep a number of test streets open to still maintain an image,” says Koopmans. “You could test low-threshold healthcare staff there, which also serves the purpose of protecting the vulnerable patients with whom they work.” The OMT also advocates this. The OMT also wants a ‘self-report portal’ to be established to pass on a positive self-test.
Insufficient information
These systems are necessary, but do not always provide enough information if there is an outbreak, according to Amsterdam virologist Menno de Jong. If there is an increase in, for example, the sewer system and the general practitioners, this is mainly a reason to find out what is going on. Is there a new variant, or an outbreak among young people?
De Jong believes that this should be done in a number of ‘smartly chosen regions’. This is already happening in Amsterdam, where a working group has been set up in collaboration with the local GGD. In December, that working group had the best picture of Omikron’s growth and a quick view of the effect in hospitals – it turned out not to be too bad.
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The working group still meets every week, among others modellers, microbiologists and doctors join in to analyze the data. Last week, data from China and South Korea were also discussed, where the number of infections is rising rapidly: is something going on there, which we should also do something about in Amsterdam?
If there is a worrying increase somewhere, a decision can be made: should more testing be done in a certain population, for example students? Or should it be looked at which variant travelers from a certain country are infected with? “It depends on the situation how action should be taken,” says De Jong.
That is ‘top sport’, says Mariken van der Lubben, head of the GGD lab in Amsterdam. This also became apparent in December, when in Amsterdam it was known within 48 hours of all positive tests on the largest test street in the city which variant it was. It takes at least a week for the national sample of the RIVM to get a clear picture.
The intensive monitoring that is done in Amsterdam does not necessarily have to take place throughout the Netherlands, says Van der Lubben. “But it would be good if this was also done in other regions. Amsterdam is a big city, do it somewhere in a rural area, or in Groningen and Maastricht.”
It also means that not all test streets can be closed, Van der Lubben emphasizes. “You may have to scale up all of a sudden, so you have to keep some of the infrastructure in case it’s needed.”