Paris (AFP)

The health authorities are suspended on its verdict: in just a few days, the Institut Pasteur in Paris has become the sentinel for detecting the Chinese coronavirus, a newcomer that the staff, already familiar with other respiratory viruses, handle under very high protection.

It was here that the first three cases in Europe, French people returning from China, were confirmed on Friday. When the positive curves were drawn on the computer screen "there was a great excitement because it validated the whole chain, from the hospital nurse who took the sample from the patient to the reliability of our + diagnostic-test + ", confides Vincent Enouf, deputy director of the National Reference Center (CNR) of Pasteur respiratory infection viruses.

The relief was all the stronger since this first test had been developed in record time. "A few days after the first cases, the Chinese had the very good idea of ​​doing a complete genome sequencing" of the new virus, he says.

This "new generation" sequencing was quickly disseminated within the scientific community and published on a specialized database. From this sequence, the teams at the Institut Pasteur were able to develop a reliable test.

Each day, the Institute receives around ten samples from French hospitals, at room temperature. These are "nasal-pharyngeal" swabs (nasal or throat mucus) - as with the flu - taken from "suspect" patients.

Above all, the samples should not be altered to avoid distorting the results - a false negative, for example, would remove a patient from the hospital when he is contagious. A specific ultra-secure protocol has therefore been implemented.

The virus is inoculated on inert cells. If the sample proves positive, it is communicated to the clinician and his patient, then lowered to a laboratory at level "P3", the highest level of safety of Pasteur - the highest degree (4) is used for Ebola but in other institutes.

- Full suit -

It is there, in full suit, FFP3 mask (as filtering as possible) and glasses, in a room where no particles come out, that the coronavirus is cultivated, in the hope of isolating and testing it .

"As the virus is alive and we do not know it, we protect the staff in the most drastic way", details Vincent Enouf, specifying that these conditions were the same for Sras and are always - very rarely - for the Sea.

Mélanie Albert, senior laboratory technician, says she is completely serene: the young woman is used to respiratory viruses, like the flu - against which she is vaccinated. All gestures, she knows them. "She has a green thumb," quips her superior.

"It is very important to call upon laboratories which are used to working in emergency conditions: we take additional precautions but the staff are completely ready, they are aware of what they are doing", congratulates Vincent Enouf.

And these days, his small team of seven people is "hyper motivated, because from the moment when the unknown is present, it makes us want to know," he says. "The days are much longer ... because it's exciting", agrees, enthusiastically, Mélanie Albert.

"Suspicions", as they call them, will likely continue to arise in the coming days. And the Pasteur Institute will distribute its test to other hospitals in France to be able to increase the number of sentries and detect more cases - if the epidemic spreads more in France, it will nevertheless be necessary to select the samples.

The challenge for the research institute is now to succeed in isolating the French virus, in particular with a therapeutic hope: developing a vaccine or treatments against this virus against which there is currently no treatment. They hope to be able to do so within a week.

© 2020 AFP