How dogs have been trained to sniff out the virus
Dogs can identify Covid-19's distinct smell with an accuracy of up to 94%, according to new UK research.
The study, led by the London School of Hygiene & Tropical Medicine in collaboration with Durham University, is based on six dogs who tested more than 3,500 odour samples donated by the public and NHS staff.
Both the dogs and researchers were unaware of whether the samples were positive or negative.
The research showed that the dogs were able to quickly detect coronavirus-infected samples with up to 94.3% sensitivity.
The dogs were able to sniff out samples from people who were infected with coronavirus but were asymptomatic, as well as those who had low viral loads.
They were also able to identify infections caused by the coronavirus strain that was dominant in the UK last summer as well as the UK (Kent) version.
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.”
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Six dogs – Asher, Kyp, Lexie, Tala, Millie, and Marlow – from the charity Medical Detection Dogs took part in the double-blind trial.
The scientists said the next phase of the trial will test whether these “super sniffers” are able to detect coronavirus on real people in real-world settings such as airports and sports events.
Meanwhile, preliminary analysis using mathematical 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.
They believe a combination of specially trained dogs, along with a confirmatory PCR test, could help detect more than twice as many cases and halt onward transmission, when compared to isolating symptomatic individuals only, or testing people with a lateral flow test and a PCR test.
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.
“Trained dogs could potentially act as a fast screening tool for travellers, with those identified as infective confirmed with a lab test. This could make testing faster and save money.”