What if our four-legged friends could play a key role in finding Covid-19?
In Corsica, the project was presented and submitted to the authorities for validation 15 days ago. It is part of an international initiative, led by Professor Dominique Grandjean of the National Veterinary School of Alfort. « _The dog is already used to detect and spot certain diseases on humans, colon, breast, lung cancer, Parkinson’s disease or malaria_, explains Aymeric Benard, veterinarian and commander of the Corse-du-Sud fire department. These diseases have one thing in common, they are not viral unlike Covid-19. But in recent years, especially in Alabama, dogs have been used to spot a viral disease in cattle herds. VOCs, volatile organic compounds, are produced in the context of these diseases, whether viral or not, and it is believed that this is also the case for Covid. «
First test this Thursday
There is of course no certainty at the moment but scientists believe the odds are good. If the tests were successful with dogs, then they should be validated with laboratory analysis. These analyzes will be carried out in Corsica, by the faculty of Corte which is associated with the project.
SIS 2A is the first to start the testing phase. To date only one other SIS has validated its participation in the project in France, it is SIS 77, which should start soon. At the international level, Lebanon and the Faculty of Beirut are also participating in the international study and other countries have already expressed interest and could join the project.
In Ajaccio, the trial could start this Thursday, as soon as samples will be taken from Covid-19 positive patients at the Mercy Hospital.
» The goal is to teach dogs the smell of positives, in parallel there will be samples from negative cases in order to teach dogs to differentiate them. “, Specifies Aymeric Benard.
Learning through play
» The principle of learning is always based on play, when the dog will « mark » the positive compresses, he will be rewarded by the game, with his favorite toy, which allows us to have a positive attitude towards the behavior of the dog and what allows us to move forward with him, says Brice Leva, head of unit at SIS 2A. «
The cynotechnical group of firefighters in Corse-du-Sud is already made up of dogs which are usually used to search for lost people in particular.
» Here we will ask the dog to target its search, not on a geographic space but on a presentation pot inside which will be the sample, so _we have to teach our dogs to sniff in these pots and then manage to make the dog « mark » the compresses that are positive_. «
A smell a thousand times more powerful than that of humans
The third phase of the project will be the statistical validation of the results. Are dogs able to mark compresses systematically? During this phase, the handler, that is to say the handler, will not know the location of the positive pads, in order to leave the total initiative to the animal.
Additional samples will also be taken and sent to the University of Corte to perform laboratory analysis, including gas chromatography and mass spectrometry, to try to characterize compounds that would be specific to people who test positive for Covid-19.
» The problem is that the dog’s smell is so powerful, a thousand times that of humans, that it may mark on compounds that will not be detectable in the laboratory., adds Aymeric Benard « .
If there is a possible marking of the disease, I am hopeful
For firefighters, the stakes are high even if they know that everything remains to be done.
» If we get there the idea is to offer a complementary solution not a replacement, notes Colonel Bruno Maestracci, fire chief of Corse-du-Sud. _Training and testing time should last from fifteen days to three weeks_. Today we are going to hire 6 dogs in training, knowing that as in any training there may be failures, it will depend on the dog and the ability to learn things. But if there is a possible marking of the disease, I am hopeful «
Samples will be taken by Ajaccio hospital and in its Eugenie annex, with the consent of the patients. They will consist in impregnating a little sweat on a compress placed under the armpits of the patients. The compresses will then be slipped into a glass jar topped with a sort of small funnel in which the dog comes to slide his truffle.
Nash, 3, Brice Leva’s dog, is part of the experiment, he has been training it for several days. » These are dogs that were recovered at the age of six months and then two years of training. We really need to channel the dogs, you see that when he marks, for the moment there is his toy and he tries to put his paw to recover it. We have to teach him to score without trying to catch what’s inside. «
From a technical point of view the dog is able to analyze 250 samples in one hour, and there will always be a double reading, that is to say that a second dog will pass systematically on each sample.
There is no risk for dogs. Samples will be kept 24 hours before being presented to dogs to reduce viral load. Thus the risk of contamination will be minimal, especially since we know that the dog does not develop the disease. Even if he can contract it, he has no symptoms and eliminates it very quickly.
The SIS 2B and the Corsican gendarmerie could also join this project, which was also made possible thanks to the support of the ARS and the Corsican prefecture.