Scent dog identification of SARS-CoV-2-infections- a double blind study – Presented by Esther Schalke

The COVID-19 pandemic has rapidly spread across the globe. Rapid testing remains one of the main strategies to contain the spread. Scent dogs are capable of detecting disease-specific volatile organic compounds emanated from infected body cells and could support current testing strategies.

Methods – Results:

In a pilot study ten dogs were trained to detect SARS-CoV-2 infections in beta-propiolactone inactivated saliva samples. They were able to discriminate between samples from infected patients and negative controls. The cognitive transfer performance for the recognition of non-inactivated sample material and detection accuracy were tested on three different non-inactivated body fluids (saliva, urine, sweat) in a randomised, double-blind controlled study.

Dogs were tested on a total of 5242 randomised samples. Dogs detected non-inactivated saliva samples with an average sensitivity of 84% (95% CI: 62·5–94·44%) and specificity of 95% (95% CI: 93·4–96·0%). In a subsequent experiment to compare the scent recognition between the three non-inactivated body fluids, diagnostic sensitivity and specificity were 95% (95% CI: 66·67–100%)   and 98% (95% CI: 94·87–100%) for urine, 91% (95% CI: 71·43–100%) and 94% (95% CI: 90·91–97·78%) for sweat, 82% (95% CI: 64·29–95·24%), and 96% (95% CI: 94·95–98·9% ) for saliva respectively.

Conclusions

Detection dogs were able to transfer the conditioned scent detection of inactivated saliva samples to non-inactivated saliva, urine and sweat samples, with a sensitivity >80% and specificity >94%. All three fluids were equally suited for SARS-CoV-2 detection by dogs and could be used for disease specific recognition. Detection dogs may provide a reliable screening method for SARS-CoV-2 infections.