Covid-19 infection has its own distinct smell that can be detected by specially trained dogs with up to 94 per cent accuracy.
Research, which has not yet been peer-reviewed, was centred on six dogs who tested more than 3,500 odour samples donated by the public and NHS staff.
The canines were able to sniff out samples from people who were infected with Covid-19 but were asymptomatic, as well as those who had low viral loads. They were also able to identify infections caused by the strain that was dominant in the UK last summer as well as the Kent version which appeared later in the year.
Professor James Logan, head of the department of disease control at London School of Hygiene and Tropical Medicine (LSHTM), who led the project, said: “What was great was the dogs that have been trained on the original variant transferred to the new (Kent) variant.
“They could detect the new variant without any additional training. So this gives us real hope and really suggests that dogs are able to detect different variants of Covid.”
Dogs – Asher, Kyp, Lexie, Tala, Millie, and Marlow – from the charity Medical Detection Dogs took part in the trial. Neither the research team nor the dogs knew which of the odour samples came from those infected with Covid-19 and which were coronavirus-free.
The research, which was part-funded by the UK’s Department of Health and Social Care, showed that the specially trained dogs were able to quickly detect coronavirus-infected samples with up to 94.3 per cent sensitivity.
The next phase of the trial is set to test whether these “super sniffers” are able to detect coronavirus in real-world settings such as airports and sports events. Modelling suggests two dogs could screen 300 plane passengers in half an hour.
The researchers said using a rapid screen and test strategy, individuals who are identified by the dogs would then require a PCR test to confirm diagnosis.
Professor Steve Lindsay, from the department of biosciences at Durham University, said: “This is a very exciting result showing that there is a distinct smell associated with Covid-19 and, more importantly, that trained dogs can detect this with a high degree of accuracy.
“Dogs could be a great way to screen a large number of people quickly and preventing Covid-19 from being reintroduced into the UK."
Dr Claire Guest, chief scientific officer at Medical Detection Dogs, added: “These fantastic results are further evidence that dogs are one of the most reliable biosensors for detecting the odour of human disease. Our robust study shows the huge potential for dogs to help in the fight against Covid-19.”
