Virus World

In a Finnish study, dogs learned to recognize the distinctive odor of a coronavirus infection. In the future, dogs might be able to detect infected people in nursing homes or at airports. In a pilot study at the University of Helsinki, dogs trained as medical diagnostic assistants were taught to recognize the previously unknown odor signature of the COVID-19 disease caused by the novel coronavirus. And they learned with astonishing success: After only a few weeks, the first dogs were able to accurately distinguish urine samples from COVID-19 patients from urine samples of healthy individuals. "We have solid experience in training disease-related scent detection dogs. It was fantastic to see how fast the dogs took to the new smell," says DogRisk group leader Anna Hielm-Björkman. After only a short time, the animals identified the urine of people infected by the novel coronavirus, known as  SARS-CoV-2, almost as reliably as a standard PCR test. The Finnish scientists are now preparing a randomized, double-blind study in which the dogs will sniff a larger number of patient samples. Only then will the scent tests be used in clinical practice.

 

The very rapid and promising findings from Finland are also important for other research teams, such as those in Great Britain and France, who are training sniffer dogs to detect COVID-19. Fellow researchers from the German Assistance Dog Center (TARSQ) have also benefited from the Finnish results. "No one could tell us with certainty whether training with the aggressive virus is dangerous or not for humans and dogs. We wanted to gather more information first before we started training because the German virologists advised us against it — after all, so little is known about the virus so far," explains Luca Barrett from TARSQ.

 

It is still unclear which substances in urine produce the apparently characteristic COVID-19 odor. Since SARS-CoV-2 not only attacks the lungs, but also causes damage to blood vessels, kidneys and other organs, it is assumed that the patients' urine odor also changes. This is something which the dogs, with their highly sensitive olfactory organs, notice immediately. Certain diseases appear to have a specific olfactory signature that trained dogs can sniff out with amazing accuracy, Barrett says. "According to one study, dogs can detect breast cancer with a 93% probability, for example. And lung cancer with a 97% probability," she says.

 

See also study in BMC Inf. Dis. (July 23, 2020):

https://bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-020-05281-3