Is the testing strategy under pressure? The antigen test turned out to be not as effective as thought shortly after infection with the Covid virus

The result of the rapid antigen test appears to be less reliable than expected during the first two days after infection with Covid-19. This was reported by scientists from KU Leuven and UZ Leuven and technology company imec. They conducted a study with previously unused molecular tests on aerosols.

This indicates that the amount of exhaled virus (the so-called measure of infection) peaks before rapid antigen test Really reliable. To put it succinctly: People can actually transmit the virus soon after infection, while a rapid test still reports ‘negative’.

consequences

This does not come with consequences. so it is rapid antigen test An additional tool to combat the epidemic, it has also been considered by policymakers as a complete test. He. She Quick test result In the meantime, it was also acknowledged boarding the plane or attending the events. The test is almost on par with the PCR test in terms of efficiency. Only this turned out to be incorrect.

A specially designed sample of imec was used for the study, which can detect the number of SARS-Cov-2 in exhaled air. The test involved 58 high-risk contacts, 11 of whom developed an infection. All subjects were monitored daily for 2 weeks, with nose, saliva, respiration and antigen tested.

• During the first two days of infection, half of the rapid antigen tests gave false negative results.
• Polymerase chain reaction (PCR) tests, performed on nasal swabs, showed a lower viral load in these first two days.
• PCR tests on breath samples showed a high viral load.
• A high viral load was also measured during exhalation. This is the first indication that the virus is easily transmitted within the first two days after infection.

Advisory Committee and Christmas

The question everyone is probably asking now: What about Christmas? Experts and politicians have been calling for a quick test for weeks before visiting friends or family. “This is the only way you can be sure” has been suggested. Unfortunately. There is a new advisory panel on the agenda Thursday between the GEMS advisory group, the Federal Core and the chief ministers of federal states.

It is expected that this study will also be discussed in detail there, and that it may eventually contribute to the tightening. Although all the numbers are going in the right direction, tightening appears to be the only option, as virologist Marc van Ranst and Federal Health Minister Frank Vandenbroek (Forweet) have already indicated.

(LL)