Anyone who has mild corona symptoms can now test themselves with a self-test at home. Following an advice from the Outbreak Management Team, the Ministry of Health is relaxing the test protocol announced this afternoon. But some experts are critical of the adaptation; they warn that you risk losing sight of the pandemic.
It has been a mantra at press conferences for a long time: ‘if you have complaints, get yourself tested’. This testing had to be done via a test line of the GGD, which mainly uses PCR tests. But that’s exactly where things went wrong in recent weeks. Many test streets were at their maximum capacity, which created queues and not everyone was able to get in on time.
At the same time, it has become apparent in recent weeks that the willingness to go to the test line in the event of complaints is decreases. RIVM expects that people will test themselves more quickly if they have a self-test at home. At the end of November, the outgoing cabinet announced a change to the self-test policy, which led to today’s new advice.
Disadvantages of testing at home
But there are downsides to testing at home, experts say. To start with, self-tests that are available in the supermarket or drugstore are less sensitive than the PCR tests in the GGD test line. A self-test will therefore ‘let in’ more infections than a PCR test does. It is difficult to say exactly how reliable the self-tests are – studies do not provide an unequivocal answer. A major investigation into this is expected next week.
“People who are really ill can take such a self-test out,” says virologist Bert Niesters (UMCG Groningen). “But the problem is the people with mild cold symptoms.” And that is precisely the group that is advised to test at home.
Because self-tests are less sensitive, there is also a greater chance of incorrect results. A false positive test is rare, says Richard Molenkamp, molecular microbiologist and responsible for virus diagnostics at Erasmus MC. But it does happen the other way around: someone can see a negative self-test result, even though he is infected. Anyone who goes outside can pass on the virus.
In addition, the self-tests work especially well during the onset of an infection, when the amount of virus particles is highest. If you only test if you have had mild symptoms for a number of days, there is a risk that the test will be falsely negative.