Research results, Cooperation agreements

A large transnational research team of experts led by the University of Veterinary Medicine Hannover (TiHo) building on collaborative work with the Bundeswehr published a new study in the journal Frontiers in Medicine on medical scent detection dogs. The study showed for the first time that dogs can differentiate SARS-CoV-2 virus samples from 15 other viral respiratory pathogens with a high specificity. This study does not only confirm the growing scientific evidence that dogs can be a fast, rapid screening tool to spot SARS-CoV-2 infected individuals, but also that the changes in volatile organic compounds release are SARS-CoV-2 specific.

The study was conducted with twelve scent detection dogs with the aim to see if dogs can differentiate SARS-CoV-2 samples from other viral respiratory pathogens. The other viral pathogens included Influenza A and B, human respiratory syncytial virus, metapneumovirus, human parainfluenza virus type 1 and 3, rhinovirus, adenovirus and multiple human coronaviruses, including SARS-CoV-1 and MERS-CoV. Three test scenarios were performed to address the aim of the study. In the first test scenario, dogs trained with inactivated saliva samples of SARS-CoV-2 patients discriminated between SARS-CoV-2 and swab samples from patients infected by other respiratory tract infection viruses with a mean sensitivity of 74% and a specificity of 95%. As not all virus samples were readily available from infected people in the second test scenario cell cultures were used. Interestingly, dogs trained with inactivated saliva samples of SARS-CoV-2 patients were able to also differentiate supernatant of cell cultures of the different respiratory viruses. In the last scenario dogs were trained with inactivated cell culture material of SARS-CoV-2. Dogs performed similar as in the first scenario in discriminating SARS-CoV-2 cell culture samples from cell cultures of other viral pathogens. In the cell cultures the dogs also smell the volatile organic compounds. The cell cultures consist of human cells to which the various pathogens have been added.

Dr. Esther Schalke, EBVS® specialised veterinary behaviourist and major at the Bundeswehr Medical Service Headquarters said: “This study is another proof of the potential scent detection dogs could have in controlling the current pandemic. It is difficult to imagine, but canine scent detection is three orders of magnitude more sensitive than current available instruments.”

Prof. Holger A. Volk, EBVS® specialised veterinary neurologist, department chair of small animal medicine and surgery, University of Veterinary Medicine Hannover, said: “It is known that infectious respiratory diseases can release specific volatile organic compounds and this study highlights that dogs can recognize these unique SARS-CoV-2 volatile organic compounds pattern.”

Background information: Since the start of domestication, man has used canines’ exceptional olfactory capabilities for scent detection to hunt down prey, but also to be protected themselves from predators. Nowadays, dogs are also increasingly used in the field of medical olfactory recognition (Jendrny et al., 2021). They are able to detect infectious and non-infectious diseases like different types of cancer, malaria, bacterial and viral infections with a high level of accuracy. The dog’s olfaction is second to none and not to compare with olfaction of humans; dogs have more than 1000 genes related to olfaction, a higher nasal surface, better airflow for scenting, 40 times more olfactory receptor cells (200-300 million vs. 5-8 million in people) and an additional scenting system (vomeronasal organ) to name a few examples. To illustrate the tremendous canine olfactory sensitivity, a dog could detect the equivalent of one drop of a liquid in 50.000.000 litres of water (20 Olympic-size swimming pools).

Project partner
Hannover Medical School, Hannover, Germany
University Medical-Center Hamburg-Eppendorf, Hamburg, Germany
Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
German Center for Infection Research, Hamburg-Lübeck-Borstel-Riems, Germany
Centre for Biological Threats and Special Pathogens ZBS 1, Highly Pathogenic Viruses, WHO
Reference Laboratory for SARS-CoV-2 and WHO Collaborating Centre for Emerging Infections and Biological Threats, Robert Koch Institute, Berlin, Germany
Bundeswehr Institute of Microbiology, Munich, Germany
Ludwig Maximilian University of Munich, Munich, Germany
German Center for Infection Research, Munich, Germany
Bundeswehr Medical Service Headquarters, Koblenz, Germany
Military Medical Center, Bundeswehr, Fürstenfeldbruck, Germany
Bundeswehr School of Dog handling, Ulmen, Germany

Funding
The project was funded as a special research project of the German Armed Forces Medical Service (SoFO 02Z9-S-852121) and supported by the COVID-19 Research Network of the State of Lower Saxony (COFONI) through funding from the Ministry of Science and Culture of Lower Saxony in Germany (14-76403-184).

Original publications
ten Hagen, N.A., Twele, F., Meller, S. et al. Discrimination of SARS-CoV-2 Infections From Other Viral Respiratory Infections by Scent Detection Dogs Frontiers in Medicine (2021)
https://doi.org/10.3389/fmed.2021.749588

Background Information: Jendrny, P., Twele, F., Meller, S. et al. Canine olfactory detection and its relevance to medical detection BMC Infect Dis (2021) https://doi.org/10.1186/s12879-021-06523-8

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Wissenschaftlicher Ansprechpartner:
Prof. Holger A. Volk, PhD
University of Veterinary Medicine Hannover
Small Animal Clinic
Phone: +49 511 953-6202
holger.volk@tiho-hannover.de

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Originalpublikation:
https://doi.org/10.3389/fmed.2021.749588

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Weitere Informationen:
http://www.tiho-hannover.de/pressemitteilungen