Washington (AFP)

The United States on Tuesday authorized the marketing of the first Covid-19 test at home and without a prescription, which can indicate the presence of the virus in 20 minutes and will be sold for around $ 30.

The authorization of the test by the American Medicines Agency (FDA) is a "major step" in the fight against Covid-19, greeted its chief Stephen Hahn.

"We are helping Americans access more tests" and "reduce the burden on laboratories," he added.

This test is manufactured by California-based company Ellume, which plans to bring three million units to market in January and then millions more in the following months.

The test uses a nasal swab, not as long as those used in the medical setting;

it is therefore less painful to use yourself.

It must then be inserted into a small box, connected to the user's smartphone by Bluetooth.

The results are available in about twenty minutes on an application that must first be downloaded.

This asks users for their postal code and date of birth in order to transmit the data to public health authorities.

Providing your name and email address is optional.

This is an antigen test, which means that it detects a molecule on the surface of the coronavirus.

The technology used is similar to that of a pregnancy test.

PCR tests look for the genetic material of the virus.

If antigenic tests are less sensitive than PCR tests, many public health experts have been campaigning for their massive use for months.

Inexpensive, they could indeed allow people to test themselves several times a week as needed, and to have a result almost immediately, while an ultra-precise test whose result is known only five or seven days later is unnecessary, they argue, since the infectious period has usually passed.

According to the FDA, Ellume's test correctly identified 96% of positive samples and 100% of negative samples in people with symptoms.

In those without symptoms, the test detected 91% of positive samples and 96% of negative samples.

For symptom-free patients, the FDA recommends that positive results be "assumed to be positive until confirmed by another test as soon as possible."

Anyone with a positive result should self-isolate, the US agency adds.

To develop the test, Ellume received $ 30 million in funding from the US National Institutes of Health (NIH).

Another rapid test, produced by the company Lucira Health, had been approved by the FDA in mid-November, but it is only available on prescription from a doctor.

© 2020 AFP