Paris (AFP)

The ability of dogs to detect the Covid-19 virus in human sweat gives "very promising" results, according to a French study whose conclusions are published Wednesday.

The study, conducted from March 16 to April 9, compares two screening methods for Covid-19: the reference RT-PCR test on nasopharyngeal swab and the canine olfactory test, explain its initiators in a press release published Wednesday.

Just over 300 volunteers aged 6 to 76 participated, as well as nine trained dogs and French firefighters from the United Arab Emirates.

The participants - people who came to be tested in several Parisian screening centers - put compresses for two minutes under their armpits.

These compresses were then locked in jars and then sniffed by at least two different dogs, who were not in contact with the volunteers.

The detection experiment was done "blind", the handlers not knowing which compresses were positive.

The study was launched at the initiative of the National Veterinary School of Alfort (EnvA), as part of the "Nosaïs-Covid-19" project led by Prof. Dominique Grandjean, and of the clinical research unit Necker-Cochin by Prof. Jean-Marc Tréluyer, at the Assistance publique - Hôpitaux de Paris (AP-HP).

Of the 335 people tested, 109 were positive on the baseline nasopharyngeal PCR test.

"The sensitivity of the canine olfactory test", that is to say the ability of the dog's nose to detect true positives, "is 97%" and "the specificity", the proportion of true negatives detected, "is 91% ", the study concludes.

"These are excellent results, comparable with those obtained with the reference test," Pr Tréluyer told AFP.

"But the test with dogs is not meant to replace it, but rather to target people who should benefit from virological screening and facilitate mass screening because of the rapid response of dogs," adds he does.

"These results scientifically confirm the ability of dogs to detect an olfactory signature of Covid-19", underlines the AP-HP, specifying that this study, not yet published in a medical journal, is "the first of this type carried out in international level ".

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