Amid a flurry of questions by lawmakers about the use of the rapid coronavirus tests, the health ministry on Thursday confirmed it had bought 7,951,000 of the test kits so far, but that this number is growing.

Test phases have launched in Luxembourg schools, hospitals and care homes, with hopes that the rapid tests will help locate infections sooner and break infection chains.

But the government is yet to present a wider strategy about their use. Employer organisations had previously said the tests could be used in jobs where people work closely together, such as on construction sites, or with customers, such as hairdressers or the hospitality sector.

Claude Muller, a virologist at the Luxembourg Institute of Health, said the rapid antigen tests are “one of the solutions to combat against covid. Their efficacy is between 85% to 90% for people who are symptomatic; it’s not 100%, but none of the measures taken during the pandemic is 100% safe.”

Muller in an interview said Luxembourg should have started using the self-test kits sooner. “Luxembourg had already received 75,000 in November, but they were so criticised at the time because people did not necessarily understand how they worked, that they were slow to be used.”

The tests work with a nasal or throat swab that users can do themselves, without the need of a medical professional.

“The tests are of great value to people with or without symptoms who visit their friends. If someone tests positive, the chance that they are really positive is very, very high, especially if the same test was negative a few days earlier,” said Muller. “I would say people should buy several tests in advance and test themselves frequently before visits or 4-5 days after suspicious contact.”

Rapid antigen tests are already available in supermarkets and pharmacies in Luxembourg, costing between €4 and €9 per test. A 17% VAT levied on the tests initially was dropped.

Thomas Dentzer, head of strategy at the department of health, mid-March had said doing a test once or twice a week would be ideal. “These tests only detect covid if you are at the peak of your infection. That is, four or five days after infection, then about another four days.”

PCR tests such as those carried out in laboratories or the large-scale testing programme are more sensitive and detect the virus over a longer period of time.

The health department, or Santé, is working on a list of recommendation on how to use the rapid tests, also to ensure effective contact tracing of people who test positive.

“Of course, their effectiveness will also depend on the discipline of people, how they use them. After a period of isolation, a positive test can be confirmed by a PCR test,” said Muller.

The health department has published a list of self-test kits it recommends online.

This article was first published in French on Paperjam and has been translated and edited for Delano.