[ad_1]
A lab technician points out the results of rapid COVID-19 tests. Image: keystone
Now comes the 15 minute crown quick test, but there is a problem
Tourism experts and family doctors await the new corona rapid tests that are now hitting the market. But this is not a test to do at home.
What would otherwise take several hours with a conventional PCR corona test may now be possible in a quarter of an hour. Because this week Roche’s new rapid antigen test received certification in Switzerland, as well as other European countries.
“It will soon be available in Switzerland,” says Nina Maehlitz of the Basel pharmaceutical company. The rapid test is associated with some hope in the fight against the pandemic.
A change in the epidemic law is necessary
General practitioners, for example, expect rapid tests, which can then quickly give their patients certainty. But things have not progressed that much. “To do this, the corresponding ordinance in the Epidemic Law would have to be changed,” says Daniel Dauwalder of the Federal Office of Public Health.
At the moment, doctors can only make swabs for conventional PCR tests, which then need to be evaluated in a laboratory.
The Florida Army National Guard is already conducting rapid tests. Image: keystone
Several companies will launch rapid antigen tests on the Swiss market in the coming weeks. In addition to Roche, for example, one from the Swiss company Ender Diagnostics, which takes 30 minutes. “These tests will then be validated by the Swiss reference center and other laboratories. This validation is important to examine key properties such as sensitivity and specificity of these tests, ”explains Dauwalder.
The sensitivity indicates the sensitivity, in what percentage of patients the disease is actually detected. The specificity the precision, that is, if healthy people are really recognized as healthy people. After this validation, it is determined where these tests can be used sensibly.
“The FOPH will include rapid tests in its testing strategy and will define more precisely in which settings it makes sense to use these tests and who should perform the tests,” says Dauwalder. For example, they could help increase winter testing capacity.
These clarifications are currently in progress and have not yet been completed. Funding for rapid tests is also not clear yet. Until now, health insurance companies only reimburse for PCR tests if ordered by a doctor. The Federal Council must decide whether rapid tests will also be adopted.
Also, these quick tests are not self-tests. “Our antigen test is easy to use because it does not require any laboratory instruments or diagnostic equipment, but it must still be performed by medical specialists. The reason is to take the sample, ”explains Nina Maehlitz from Roche. And Patrick Barth from the Basel pharmaceutical company adds:
Oliver Nolte from the Center for Laboratory Medicine (ZLM) in St. Gallen also confirms this: “In general, we don’t see antigen testing as self-testing. Both clinical and analytical sensitivity are highly dependent on good swab collection, ”says Nolte. And the collection of swabs should only be in trained hands.
Laboratory medical care is part of it
Since it is not a self-assessment, the question remains how long the test person has to wait for the result despite the 15 minute test. That fundamentally depends on the strategic application of the tests, says Nolte. You cannot give an exact time.
“If the test is performed in a laboratory, the transport time from acceptance to arrival at the laboratory or device is critical,” explains Nolte.
If the results are to be available even faster and in a decentralized manner, for example at an airport, such a test is run without diagnostic devices immediately after the smear has been taken on site. For Nolte, however, it is clear that medical laboratory support for self-tests would have to be arranged.
Swiss company works with Switzerland
Roche’s antigen testing simplifies rapid, decentralized testing or testing in areas where there is not enough laboratory infrastructure, says Roche’s Barth. Ender Diagnostics Company sees a precisely defined location for your quick test. She works with Swiss with the goal of testing all long-range crew members on Sars-CoV-2.
“The test is designed in such a way that rapid tests can be performed on site and in emerging laboratories in various environments, for example at airports and cruise ships,” the Swiss company writes.
Due to the simplified workflow, up to eight times more tests could be processed than conventional PCR tests, for example at airports and cruise ships. This is a promising step towards mass screening, explains Hans-Peter Frank of Ender Diagnostics.
No test without trained specialists
Tourism experts, in particular, look forward to its use at airports. But Nolte is careful. At least rapid antigen tests are concerned with the detection of a reportable pathogen.
“In this context, we would consider it problematic if, for example, a test is carried out at an airport without the expertise of a medical laboratory. However, it is certainly conceivable to establish testing centers that are operated or supervised by laboratory medicine. “
Rapid tests are not as accurate as conventional PCR tests. “The sensitivity is significantly lower than that of a PCR test,” says Nolte. However, the Roche test showed a sensitivity of 96.52 percent, a PCR test has around 99 percent.
And according to Barth, the specificity was even 99.68 percent. “These results were obtained from two independent study centers in Brazil and India,” says Barth. But of course, the PCR test is considered the “gold standard”.
Nolte sees the difference in quality for weakly positive samples, which occur, for example, at the beginning of an infection, but also when the infection subsides and can be missed in the rapid test. That is why Nolte says:
Roche will initially be able to perform 40 million tests per month. “This number will double by the end of the year,” says Barth. The tourism industry’s hope that rapid tests will shorten the quarantine is not very great at the moment.
According to the current “Covid-19 Quarantine Instructions”, a negative PCR result does not shorten the quarantine period. This also applies to rapid tests at the moment. (cki / chmedia)
