By Sonia Fernandez, UC Santa Barbara
For about 15,000 years, dogs have been our hunting partners, workmates, helpers, and companions. Could they also be our next allies in the fight against COVID-19?
According to emeritus professor T Santa Dickey of UC Santa Barbara and his associate, BioScent researcher Heather Junqueira, they can. And with a review article published in the Journal of Osteopathic Medicine, they added a small but growing consensus that trained medical sniffer dogs can be used effectively to examine individuals who may be infected with the COVID-19 virus.
This follows a comprehensive investigation into the use of trained sniffer dogs to detect COVID. “The most striking result is that studies have already shown that dogs can identify people who are COVID-19 positive,” Dickey said of their findings. “Not only that,” he added, “they can do it non-intrusively, faster and with comparable or possibly better accuracy than our conventional detection tests.”
It is not surprising that the magic lies in the sense of smell of dogs, which gives dogs the ability to detect molecules in small concentrations – ‘one part in a quadrillion compared to one part in a billion for humans’, according to the newspaper. Add to that other optimizations for odor, such as a large nose area and the structure of their noses, which allow the inflow through the nostrils and outflow through nasal folds. Furthermore, with 125-300 million olfactory cells and a third of their brains devoted to the interpretation of odors, dogs are well equipped with the ability to sniff out the volatile organic compounds that indicate the appearance of COVID.
Professor Emeritus Tommy Dickey and one of his Great Pyrenees therapy dogs
“The dogs basically smell the sweat of the person,” Dickey said of a series of experiments by French and Lebanese researchers examining the ability of dogs to detect COVID infection. Although the virus itself has no odor, metabolic products secreted by COVID-positive individuals through their sweat glands were detected by the 18 dogs selected for the study (16 Belgian malinois, one German shepherd and one Jack Russell terrier) with an accuracy rate of 83 -100% after only four days of training. True failures, according to the study, can be attributed to ‘distracting external odors or movements by a TV movie crew’.
“One dog twice showed positive results that could not be confirmed,” Dickey said. “Two weeks later, they found that both people who gave the samples had to be hospitalized with COVID.”
Meanwhile, a German research group used eight odor detection dogs in a randomized, double-blind controlled pilot study. The group trained the dogs for a week and set them on sniffing 1,012 samples of saliva or tracheobronchial secretions. They have an average detection rate of 94% with a sensitivity (ability to detect a true positive) of 67.9% to 95.2% and a specificity (ability to detect a true negative) of 92.4% to 98.9%. This pilot study used positive samples from individuals who were severely affected and negative samples from people without symptoms. Future studies, according to the article, may focus more on identifying different phases of infection or detecting different phenotypes of disease.
The use of dogs to detect diseases is not new. In fact, co-author Junqueira previously published results showing that her scent dogs (beagles, basset hounds, and mixtures of the two) can effectively detect non-small cell lung cancer.
“Dogs can detect other types of cancer as well as malaria, Parkinson’s disease and diabetes,” Junqueira said, adding that “research on medical scented dogs over the past few years has actually only gained more traction and will require many more peer-reviewed articles. before the idea of using dogs to detect diseases hit the mainstream. ”
Dickey’s own interest in the subject was sparked during his work as a therapy dog handler for three Great Pyrenees (more than 3,000 therapy dog visits), a long-standing career he relied on after cancer forced him to join UC Santa Barbara’s Department of Geography. to retire. in 2013. ‘I loved UCSB,’ he said. “I loved teaching and always brought my therapy dogs to class. I just had life, what can I say? ‘
In fact, he could not stay away – he and his dogs were on hand to see the UCSB community through difficult times, offering their rugged coats, wet noses and calm demeanor through tragedy and tension. Upon retirement, Dickey has published three therapy dog books for children, some of which tell stories of their UCSB therapy dog adventures. In addition, he and his dogs hosted educational demonstrations at the California Science Center and the Los Angeles Public Library, which sparked his interest in the power of a dog’s sense of smell for medical detection.
When the new disease called COVID-19 hit, Dickey asked: Can dogs detect the new coronavirus? Obviously, there was little in the way of research on the subject, which is why he teamed up with Junqueira, who has already been doing her own COVID detection research with her scent dogs in Florida. “One of our biggest motivations was to write a peer-reviewed paper that basically gave a progress report,” he said. “Where are we? Are these things really possible?”
Dickey and Junqueira found that researchers use a variety of dogs. ‘There were many Belgian malinois used, and dogs trained in explosives and colon cancer. So they were pro sniffers, ”Junqueira said. “Other groups, such as the group behind a Colombian study, were motivated by the need to find a fast, accurate and cost-effective form of COVID early detection.” The Colombian group used a variety of dogs – four Belgian malinois, one Alaska-malamute-Siberian mix and an American pit bull terrier.
“The pit bull has been abused before,” Dickey said, “but they rehabilitated him, and he was very good at sniffing.” After nearly two months of training and thousands of samples later, this Colombian dog cohort performed with a remarkable 95.5% sensitivity and 99.6% specificity.
During the various blind, controlled experiments, the detection time was a matter of minutes or less. Such speed is a huge asset in real world scenarios. In particular, a UK-based research group outlined their plans to train and eventually deploy dogs at UK airports and gateways as part of the COVID-19 screening process.
With all the sniffing in the presence of an air sickness, it is natural to worry about dogs being able to catch and transmit COVID-19. According to the newspaper, it is still the subject of ongoing research, but evidence indicates a low probability of transmission, although precautions must be taken to protect all involved.
“Current research supports the use of odor detection dogs for COVID-19 research studies involving people at locations such as airports and sporting events,” Dickey said. “In addition, the JOM article points out that another line of research could be used to detect medical scent dogs that include the development of medical electronic noses.
In principle, according to the researchers, you do not even need a dog to sniff out COVID if you do not smell, smell and process it the way it does. They said that using sensors and artificial intelligence could one day adjust a dog’s performance by using portable electronic noses, similar to wristband sensors, to report the heartbeat and patterns, blood pressure and oxygen, which can monitor a person’s sweat for metabolite biomarkers that may indicate diseases such as COVID-19.
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