- What if the coronavirus had a specific odor?
- In this case, dogs trained to detect this smell could, thanks to their scent, detect the virus in people who carry it.
- This is the subject of research carried out by veterinarians and firefighters, who hope to find through this trial « a reliable screening method and complementary to the tests already available, » explains Professor Dominique Grandjean, who supervises this work.
A formidable flair. Already capable of finding missing persons, detecting diabetes or even certain cancers, dogs may also have the ability to sense the
coronavirus. This is the bet of Professor Dominique Grandjean, professor at
the National Veterinary School of Alfort (Val-de-Marne) and head of the veterinary service of the Paris Fire Brigade (BSPP), which is launching a trial conducted jointly by veterinarians and firefighters.
This research plans to experiment with cynotechnical skills to detect Covid-19. The objective, « allow a reliable and massive screening for coronavirus, » hopes Professor Grandjean. If we can validate this experiment, the dogs will provide a complementary solution to the PCR and serological tests, which each have limits. ”
How did this essay come about? Does the coronavirus have a peculiar smell that the dogs’ scent would allow them to pick up?
We already know that dogs have the ability to smell certain diseases. We also know that some viruses do have a specific odor. This is what has been discovered by teams at Auburn University in Alabama, who have demonstrated the ability of dogs to detect mucosal disease in cattle, a virus for which there is no there was no reliable screening test. Specially trained dogs today have the ability to detect it.
We therefore wanted to reproduce this for the detection of SARS-Cov2. This research is part of the Nosais trial, a development project for medical detection by dogs. We have just launched the first tests, in which the Franco-Lebanese University of Beirut, the Fire and Rescue Service of Corse-du-Sud and the Seine-et-Marne fire brigade (SDIS 77) are participating ). The goal is to do the same thing as the Americans, but with the Covid-19, by banking on the fact that it leaves a specific trace in the organism, a trace that the scent of dogs can detect.
In the protocol you just launched, how do you train dogs to detect Covid-19?
A person with the coronavirus will eliminate traces of it, these are « catabolites » induced by the virus, which are found in urine, stool, tears, or saliva and sweat. Other countries have launched studies similar to ours, including urine or saliva, but the health risk in this case is higher.
Our test is about detecting the virus in sweat, because in sweat there is no virus shedding, so there is no risk of contamination. Especially since sweat characterizes each person, so if the test works, it can provide a very reliable detection mode.
In practice, we collaborate with hospitals, where axillary sweat samples are taken – under the armpits – from patients tested positive for coronavirus. Cotton swabs are placed for a few minutes under their arms, before being locked in airtight boxes for 24 hours to ensure that the samples no longer contain any virus particles. We work with fire dogs used to looking for missing persons, and with dogs from the company Diagnose, whose animals, trained in the detection of explosives in particular, have already integrated a catalog of dozens of specific odors. Here, it’s about training them to identify the characteristic smell that the Covid-19 might have. Or one more smell to the library of specific smells they have in memory.
The samples are placed in sterile jars and then in a small hatch near the dog’s favorite toy. Accompanied by his master, he comes to breathe this smell before recovering his toy. For him, smelling the virus becomes a game. Then, we submit a line of samples – one positive and several negative – to the dog’s flair, which will sit in front of the positive sample. Today, we are in this phase of training dogs to detect the smell of coronavirus. We started just a few days ago, but according to the first feedback we have, we can be sure that the coronavirus generates a particular fragrance that we find in sweat.
If this trial is successful, what could be the practical applications? How can this discovery be included in the French Covid-19 screening strategy? Have other countries already expressed interest in your work?
The first tests are encouraging, and we should have concrete results within three weeks. Then, it will be necessary to obtain the scientific validation of this protocol. If this virus detection method works, this will allow mass detection of Covid-19. A single dog could « test » several hundred people each day. This could be deployed at airports, on disembarkation of ocean liners, and even across certain municipalities. This would complement PCR and serological tests, which are not 100% reliable, which have a high rate of false negatives.
It is a fast device, which requires no sampling equipment, so no risk of shortage of reagent or swab! It is practical and inexpensive, which also makes it an interesting asset for the screening strategy of the poorest countries, which do not have a significant capacity for biological tests.
To date, several countries including Brazil, Belgium, Morocco or Switzerland, or even Quebec, have expressed interest.