Dogs, specially trained to detect things beyond human perception by scent, have been successfully trained to detect coronavirus reliably from skin swabs. This could lead to improved detection in public places of viral infections.
The research, demonstrating the canine prowess, comes from the University of Helsinki. This was demonstrated through an experimental set-up at Finland’s Helsinki-Vantaa International Airport.
The study showed the accuracy of the dogs in identifying the samples to be 92 percent. Furthermore, there were only small differences in accuracy between individual dogs.
This strong results outcome was based on a triple-blind, randomized, controlled study. The design was such that none of the trio involved: Dog, dog handler or researcher knew which of the sniffed skin swab samples were positive and which negative.
The primary and most accurate diagnosis of SARS-CoV-2, the coronavirus infection that leads to COVID-19, is based on a PCR test. While this works on a small scale, PCR tests are ill-suited for screening large masses of people. This is based on the practicalities of testing large numbers, the time to result, and the high cost.
The approach involved dogs being taught to discriminate the skin swab samples of coronavirus patients from those of volunteers who tested negative. The second phase of the study used four trained dogs who completed a validation test to prove their discriminatory ability.
This involved each dog being presented with a series of 420 samples over a period of seven days. Here each dog received an identical set of 114 coronavirus patient samples and 306 control samples for sniffing. The positive or negative data was verified by PCR.
The third phase of the study was conducted by screening passengers and staff at Helsinki-Vantaa Airport in a real-life situation. The scent dogs correctly identified 98.7 percent of the negative samples. The low number of coronavirus-positive samples in real-life testing prevented a proper assessment of the dogs’ performance with positive samples. This absence of data will be boosted through further assessments.
According to lead researcher Anna Hielm-Björkman, the research was robust, making the case for the use of sniffer dogs to detect specific viral pathogens: “The sample sizes were sufficiently large, and all dogs sniffed an identical set of samples, allowing comparison of their performances.”
It is anticipated that other diseases can also be assessed for using dogs, based on their excellent sense of smell.
The research is titled “Scent dogs in detection of COVID-19: triple-blinded randomised trial and operational real-life screening in airport setting” and it appears in British Medical Journal Global Health.
