Covid-19: are the millions of tests per week still useful?

Screening breaks records. Every day, according to data from Health Insurance, around 1.7 million people go to a dedicated center, laboratory or pharmacy to be tested. A strategy assumed by the executive. “Eight million tests in one week, there is almost no country that tests as much as us”, welcomed in early January the Minister of Health, Olivier Véran, on France inter. “Only intensive screening allows us to keep schools open”, he insisted earlier this week in the Senate.

For some scientists, these large-scale tests remain necessary to analyze the circulation of the virus. “We need to test a lot to continue to have a minimum lead on the virus”, Judge Anne Sénéquier, doctor and co-director of the Global Health Observatory at Iris. “If we don’t have the correlation between the number of cases and the number of hospitalizations, we also won’t have data on the true virulence of the Omicron variant.”

But, as a result, the queues are overflowing. The French sometimes have to wait several hours before being tested. And this intensive screening, reimbursed in almost all cases (except for adults who are neither vaccinated nor contact cases nor in possession of a prescription) represents a cost for the State. According to Health Insurance, the 170 million tests carried out in 2021 cost 6.7 billion euros.

For epidemiologist Catherine Hill, this situation should be ended. “We have never carried out the tests in a rational way: we track people who choose to go and get tested. It is not a strategy, and it is very expensive”, she laments to LCI. “Since the beginning of the pandemic, I think we only find one in three cases. Right now it may be a little more, but to control the epidemic, you have to find the contagious people before the development of symptoms.

Since the start of the crisis, Catherine Hill has been calling for the implementation of group tests: several samples brought together in a single sample. “In all schools and companies, group tests should be carried out twice a week with 20, 30 or 40 people”, she insists, a way according to her to fill the holes in the racket. “The sample would be collected in the same tube, which would cost much less. If the virus is found in the tube, it means that it is circulating. This system has been used a lot in American universities, in Switzerland or in Austria .”

In the meantime, the government wishes to pursue its strategy. According to its spokesperson, Gabriel Attal, the number of test centers will increase further in the coming days, with installation near vaccination centers. The executive is also relying on self-tests, in the light since the end of the year celebrations, to unclog laboratories without reducing screening.