Sniffer dogs are not a novel concept since we see dogs frequently used around airports and public places to sniff out drugs, weapons, or explosives. Previously a one-of-a-kind project was announced to have trying to find a way for medical detection dogs to assist COVID-19 testing by sniffing out 750 people per hour.
Now, we have more proof that dogs can be trained to detect COVID-19 and they do so by sniffing human sweat, according to a proof-of-concept study.
The study was published in the journal PLOS One.
Dogs were trained to sniff out COVID-19 from sweat samples
177 patients, 95 who had tested positive for COVID-19 and 82 negative, from four hospitals, participated in the research with their sweat samples. Researchers based in France and Lebanon took sweat samples from the underarms of the patients, and per the study, the samples needed to come from the same hospitals for the dogs to not be confused by the particular hospital odor.
The researchers trained 14 dogs, who have been working in explosive detection, search and rescue, or colon cancer detection, using the sweat samples. In order to do that, they asked the dogs to detect a positive COVID-19 sweat sample from three to four cones that contained negative, or mock, samples, CNN reports.
The dogs were able to pick up on a specific scent produced by volatile organic compounds that are generated by catabolites which are produced by the replication of the virus. They escape the body through sweat, which can then be picked up by sniffer dogs.
The findings show promise
The results were astounding. "The success rate per dog (i.e., the number of correct indications divided by the number of trials) ranged from 76% to 100%," wrote researchers in the study.
Moreover, two samples which had been said to be negative by the hospitals were marked repeatedly by the dogs. When the hospitals were informed, further testing showed that the individuals were actually positive.
The results need to be confirmed in larger studies, however. "Even if trained dogs are able to correctly discriminate symptomatic Covid-19 positive individuals from asymptomatic negative ones, they should not be considered a perfect diagnostic test -- but rather a complementary tool, " the study said. If further reinforced with other studies, trained dogs could provide a non-invasive alternative to currently available tests.
Sniffer dogs' jobs might be at stake though. Back in May, Airbus announced they were going to deploy "electronic jellyfish-like devices", which use living biological cells to sniff out dangerous chemicals and bombs at the airport and might even be able to detect viruses such as COVID-19.