German researchers are teaching dogs to detect SARS-CoV-2 in human saliva. And the results are quite encouraging.
We know that some dogs, when trained, can detect the presence of cancers. Others can also smell the "smell" of epileptic seizures or malaria (by sniffing socks). More recently, some have also proven to be very effective in detecting yellow dragon disease, which ravages citrus crops.
Naturally, some researchers have recently wondered whether our four-legged best friends might also play a role in the fight against Covid-19.
With this in mind, several works are currently underway to explore how dogs could be trained to detect the novel coronavirus. Ultimately, these dogs could act as a first bulwark against the virus, allowing suspected cases to be filtered out in public spaces.
Earlier this year we looked at one such research project carried out in the UK. A second is also being conducted in France, led by Pr Dominique Grandjean, professor at the National Veterinary School of Alfort (Val-de-Marne) and head of the veterinary service of the Paris Fire Brigade (BSPP).
Researchers from the German University of Hannover are also on the case. The latter have just published their first results in the journal BMC Infectious Diseases .
As part of this work, eight tracking dogs were trained for a week to distinguish between SARS-CoV-2 infected saliva samples and uninfected control samples. Once trained, they were asked to sniff 1012 samples. Some were infected, some were not. Neither the researchers nor the handlers knew which tested positive.
In the end, the dogs correctly identified 157 positive samples and 792 negative samples . Conversely, they incorrectly identified 33 negative samples and rejected about 30 positives.
Overall, the team found an average sensitivity of 83% in detecting positive samples, and an average sensitivity of 96% in detecting negatives. By upgrading everything, it finally emerges an overall average detection rate of 94% .
"The results of the study are incredibly exciting" , enthuses Dr. Holger Volk, the main author of this work. This research, he says, will serve as a solid foundation for future studies to analyze what dogs actually smell. Ultimately, it will also be a question of understanding whether or not these can differentiate between the different stages of development of the disease.
