As of today, all primary schools will receive an initial supply of self-tests for their students in groups 6, 7 and 8. Students are required to take a self-test at home twice a week. Many employers also provide self-tests for their staff.
But, when should you do that self-test: if you have complaints, or if you have no complaints? In the spring this was stated in the brochure of the national government: ‘Self-tests are intended as extra certainty, for people who have no complaints’. This policy has since been amended. A tad confusing. Let’s get down to the facts.
Testing with complaints reliable
We call epidemiologist Carl Moons of UMC Utrecht. Together with three regional GGDs, two laboratories and the RIVM, he investigated the reliability of an antigen saliva self-test and an antigenic nasal self-test. “Our large-scale study shows that if you have complaints, the nasal self-test is very sensitive and reliable, compared to a PCR test at the GGD.”
The nasal self-test removes about 9 out of 10 corona cases in people with cold complaints and a lot of virus in the nose.
–
–
Testing without complaints is also a good idea
You can of course also test yourself without having any cold symptoms, as a kind of self-screening. But then the nose self-test is much less reliable, according to research by UMC Utrecht: 40 percent of people without complaints (but with a lot of virus in the nose) are detected by the self-test.
And yet it is wise to use the rapid test without complaints. Although the self-tests in people without complaints are less sensitive, they are not worthless. “With the antigen nasal self-test, four out of ten corona cases with a lot of virus in the nose are still detected in this group,” emphasizes Carl Moons of UMC Utrecht.
With repeated testing, for example testing twice a week, you may find even more corona cases with this nasal self-test, and you can rule out even better. “Only we have not investigated this repeated self-testing now.”
You detect infections earlier with it
RIVM’s behavioral research also shows that more people get tested if they have antigen nasal self-tests in house and also do this earlier than with a PCR test. An additional advantage is that people who (almost) never have themselves tested at the GGD, now at least do a self-test.
Nevertheless, doing a self-test if you have complaints remains the most reliable, do so as soon as possible after you have developed complaints. In the picture below from Nature can be seen why. The red line represents the antigen test, the gray the PCR test. The blue tests are tests for antibodies. The higher the lines go, the greater the chance of detection.
–
–
When will you be tested at the GGD?
At the GGD they can do a PCR test, which is seen as the most reliable. If you have a positive self-test, you should check it with the GGD: it is possible that you do not have corona at all – and it happens more often than you think.
Even if you want to know for sure whether you have corona, and you have been around someone with corona for a long time, it is wise to have a PCR test done at the GGD.
–
–
“And the current policy is also that people working in care, people with serious diseases and from other vulnerable groups, have themselves tested by the GGD,” says epidemiologist Carl Moons. “You don’t want to miss a corona infection with them.”
The scientist has another argument for visiting the GGD. “It is very nice if people have a positive rapid test confirmed. In this way we keep track of the epidemic, then you know how many people are infected. And because of the source and contact research that can possibly be started.”
–
–
Which self-tests are suitable?
Self-tests that are suitable for use can be recognized by a CE logo on the packaging.
Self-tests with a CE logo followed by a 4-digit number have been approved by an inspection body. Without a number? These self-tests are for sale thanks to a temporary exemption. Incidentally, there are also self-tests that do not have a grade but have already been approved, these are:
- Roche SD Biosensor SARS-CoV-2 Rapid Antigen Nasal Test
- BIOSYNEX COVID-19 Ag BSS rapid test
- Acon Biotech Flowflex SARS-CoV-2 Antigen Rapid Test
- MP Biomedicals Rapid SARS-CoV-2 Antigen Sante-Group
- Beijing Lepu Medical Technology Co., Ltd. SARSCoV-2 Antigen Rapid Test Kit (Colloidal Gold Immunochromatography) Orange Swallow
Waiver
The following suppliers have been granted an exemption to be allowed to market an antigen rapid test as a corona self-test:
–
–
