Discrimination between SARS-CoV-2 infection and other viral respiratory infections by working dogs – Presented by Nele ten Hagen

In the SARS-CoV-2 pandemic testing of symptomatic and especially asymptomatic individuals is one of the main strategies to stop infection chains. Because of their outstanding sense of smell, dogs could be an essential asset in mass screening testing strategies. Previous research demonstrated dogs’ ability to detect SARS-CoV-2- infections but has not investigated whether dogs can distinguish between SARS-CoV-2 and other viral infections. To address this question, a study was performed with swab from individuals and samples from cell culture, each infected with one of 15 viruses causing acute respiratory symptoms. We trained twelve dogs to detect SARS-CoV-2 positive samples. In the first test (scenario I) swabs from individuals with a variety of viral respiratory tract infections were presented and the dogs achieved a mean diagnostic sensitivity of 73.8% (95% CI: 66.0–81.7%) and a specificity of 95.5% (95% CI: 92.6–97.7%). When using cell culture supernatant from different coronavirus infections (scenario II and III) the dogs detected SARS-CoV-2 samples with a mean diagnostic sensitivity of 61.2% (95% CI: 50.7–71.6%) and 75.8% (95% CI: 53.0–98.5%), respectively. The specificities were 90.9% (95% CI: 87.3–94.6%) and 90.2% (95% CI: 81.1–99.4%), respectively. The results demonstrate dogs’ ability to differentiate viral respiratory tract infections by their odor. Nevertheless, compared to earlier studies the diagnostic sensitivities were found subpar. To deploy COVID-19 detection dogs, as a reliable screening method, a variety of samples from different viral respiratory tract infections should be included in dog training to ensure a successful discrimination process.