Mass coronavirus test: what the mass tests show in Graubünden – News

During the weekend, massive voluntary tests were carried out in three valleys in the south of Graubünden. About 15,000 people, or about half the population, were tested for ten years. The authorities are satisfied with the participation. One percent of those tested tested positive without symptoms. Scientific editor Christian von Burg explains how to deal with the findings of the massive test.

Christian von burg

SRF Science Editor

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The journalist, born in 1972, works for the SRF science department. It started with the newspaper “Der Bund”, first with the local editorial team, then in Germany.

SRF News: What is the conclusion after this massive test from your point of view? What did you bring?

The most concrete benefit is undoubtedly for the 150 infected people who did not even realize they had the virus. It is precisely this one percent that contributes significantly to the spread of the pandemic. The test also showed where the virus is particularly widespread, namely in the Bernina region. Now they know that it pays to take stronger action against the virus.

What are the limits of such action?

It is only an interim report. The deciding factor now is what you do with it. It would be wrong for everyone who tested negative to think they were safe and careless. Also, the image is incomplete because only half could be tested. Specifically, there are 150 other infected people in the region who do not know anything.

Rapid tests carry the risk of false positive results. Elsewhere, in neighboring countries, the positives have been retested. How many of the 150 who tested positive are not infected?

According to the manufacturer, it is around 8.6 percent, which would be around 13 of these 150. Follow-up tests, for example in a massive test in Vienna, showed that even more were false positives. I think the effort of a new test would be worth it. People would be more likely to be tested if they could trust that they won’t go wrong in being isolated.

In your opinion, should these massive tests be scaled up or repeated?

Surely that would be a possibility. But I think more specific tests would make more sense. For example, outbreak investigations in schools or companies where cases are already known. Or regular exams, called screenings, in nursing homes where people at particular risk live.

Interview by Marc Melcher.