Scent dog identification of SARS-CoV-2 infections, similar across different body fluids

Jendrny, Paula; Twele, Friederike; Meller, Sebastian; Schulz, Claudia; von Köckritz-Blickwede, Maren; Osterhaus, Ab; Ebbers, Hans; Ebbers, Janek; Pilchová, Veronika; Pink, Isabell; Welte, Tobias; Manns, Michael Peter; Fathi, Anahita; Addo, Marylyn Martina; Ernst, Christiane; Schäfer, Wencke; Engels, Michael; Petrov, Anja; Marquart, Katharina; Schotte, Ulrich; Schalke, Esther; Volk, Holger Andreas

Background The main strategy to contain the current SARS-CoV-2 pandemic remains to implement a comprehensive testing, tracing and quarantining strategy until vaccination of the population is adequate. Methods Ten dogs were trained to detect SARS-CoV-2 infections in beta-propiolactone inactivated saliva samples. The subsequent cognitive transfer performance for the recognition of non-inactivated samples were tested on saliva, urine, and sweat in a randomised, double-blind controlled study. Results Dogs were tested on a total of 5242 randomised sample presentations. Dogs detected non-inactivated saliva samples with a diagnostic sensitivity of 84% and specificity of 95%. In a subsequent experiment to compare the scent recognition between the three non-inactivated body fluids, diagnostic sensitivity and specificity were 95% and 98% for urine, 91% and 94% for sweat, 82%, and 96% for saliva respectively. Conclusions The scent cognitive transfer performance between inactivated and non-inactivated samples as well as between different sample materials indicates that global, specific SARS-CoV-2-associated volatile compounds are released across different body secretions, independently from the patient’s symptoms. Funding The project was funded as a special research project of the German Armed Forces. The funding source DZIF-Fasttrack 1.921 provided us with means for biosampling.