In a proof-of-concept study led by the School of Veterinary Medicine, dogs identified positive samples with 96% accuracy.
Many long for a return to a post-pandemic “normal,” which, for some, may entail concerts, travel, and large gatherings. But how to keep safe amid these potential public health risks?
“This is not a simple thing we’re asking the dogs to do,” says Cynthia Otto, senior author on the work and director of the University of Pennsylvania School of Veterinary Medicine Working Dog Center. “Dogs have to be specific about detecting the odor of the infection, but they also have to generalize across the background odors of different people: men and women, adults and children, people of different ethnicities and geographies.”
In this initial study, researchers found the dogs could do that, but training must proceed with great care and, ideally, with many samples. The findings are feeding into another investigation that Otto and colleagues have dubbed “the T-shirt study,” in which dogs are being trained to discriminate between the odors of COVID-positive, -negative, and -vaccinated individuals based on the volatile organic compounds they leave on a T-shirt worn overnight.
“We are collecting many more samples in that study—hundreds or more—than we did in this first one, and are hopeful that will get the dogs closer to what they might encounter in a community setting,” Otto says.
Through the Working Dog Center, she and colleagues have had years of experience training medical-detection dogs, including those that can identify ovarian cancer. When the pandemic arrived, they leveraged that expertise to design a coronavirus detection study.
Collaborators Ian Frank from the Perelman School of Medicine and Audrey Odom John from the Children’s Hospital of Philadelphia provided SARS-CoV-2-positive samples from adult and pediatric patients, as well as samples from patients who had tested negative to serve as experimental controls. Otto worked closely with coronavirus expert Susan Weiss of Penn Medicine to process some of the samples in Penn’s Biosafety Level 2+ laboratory to inactivate the virus so they would be safe for the dogs to sniff.
Because of workplace shutdowns due to the pandemic, instead of working with dogs at Penn Vet, the researchers partnered with Pat Nolan, a trainer with a facility in Maryland.
Eight Labrador retrievers and a Belgian Malinois that had not done medical-detection work before were used in the study. First the researchers trained them to recognize a distinctive scent, a synthetic substance known as universal detection compound (UDC). They used a “scent wheel” in which each of 12 ports is loaded with a different sample and rewarded the dog when it responded to the port containing UDC.
When the dogs consistently responded to the UDC scent, the team [ … ]