According to the study, sniffing dogs detect Covid better than the actual tests
So far, the strongest evidence suggests that barking dogs detect Covid even better than tests.
Throughout the pandemic, researchers have said that the sharp sense of smell in dogs can be used to detect carriers of the virus.
But promising laboratory results – from exposing dogs to samples in highly controlled situations – had to be replicated under real conditions.
New results from the University of Helsinki show that Labrador retrievers and white shepherds can detect up to 97 percent of positive cases.
And trained dogs are 99 percent accurate when they confirm who is viral among airport passengers, the study claimed.
By comparison, studies show that lateral flow tests detect up to 72 percent of cases, while PCR tests are believed to be 85 to 98 percent accurate.
Finnish researchers said dogs can be a “valuable tool for curbing a pandemic” when used at airports and other rallies.
Researchers at the University of Helsinki trained four dogs – Labrador retrievers Silja, Rele and Kosti and a white shepherd named ET (pictured at Helsinki-Vantaa Airport) – to smell Covid in the spring of 2020.
The results show that dogs can detect up to 97 percent of positive cases. And trained dogs are 99 percent accurate when they confirm who is viral among airport passengers, the study claimed. Pictured: Kosti at Helsinki-Vantaa Airport
New results from a study by the University of Helsinki show that dogs can detect up to 97 percent of cases and are 99 percent accurate when they confirm who is viral. Pictured: White Shepherd ET inside the test room, showing the sample in the middle, number two, positive for Covid by placing one paw on it
The researchers said their findings suggest that dogs that can smell malaria with Parkinson’s and cancer may serve as a method of virus screening when tests are not available – for example, in the early stages of a pandemic. Pictured: purpose-built booths at Helsinki-Vantaa Airport, where dogs sniffed samples from passengers
Dogs have never been used in the UK pandemic response. But as part of experiments where they could be transported out at airports, they were deployed at Paddington station in London.
Snuff dogs are already used to warn of epileptic seizures, cancer and Parkinson’s disease.
Dogs can pick up the scent at as low as one fraction per trillion – the equivalent of a teaspoon of sugar in two Olympic-sized pools.
They are believed to be able to detect compounds that the body quietly releases when it is ill.
The Helsinki team trained four dogs – Labrador Retrievers Silja, Rele and Kosti and a white shepherd named ET – to smell Covid in the spring of 2020.
Dogs were exposed to skin samples – cotton swabs taken from the neck, forehead and wrists – from 114 virus-positive volunteers.
They were also exposed to samples from hundreds of Covid-free individuals.
During the training, the dogs detected the infected 92 percent accurately and 91 percent confirmed that someone was Covid-negative.
The dogs reported the positive case either by offering their paws or by sitting.
And their sniffing skills were almost as good even if the sample had become asymptomatic (89 percent).
By comparison, studies show that side-flow tests bypass 20 to 80 percent of positive cases.
To test the dogs in the real scenario, they sniffed 303 arriving passengers at Helsinki-Vantaa Airport between September 2020 and April 2021.
Each passenger had also taken a PCR test.
Results, published in BMJ Global Healthshow detection of dogs and PCR result corresponded 98 percent of the time.
Previous studies by British researchers at the University of Durham and the London School of Hygiene and Tropical Medicine have shown that dogs were able to detect up to 94 per cent of cases, making them significantly more accurate than rapid lateral flow tests.
Researchers in the UK said the two dogs were able to examine 300 passengers leaving the plane for Covid in just 30 minutes. Pictured: A medical identification dog and a handler show how dogs can be used to detect Covid in public places.
Dogs have never been used in the UK pandemic response. But as part of tests to see if the dogs could smell the disease effectively and which used £ 500,000 in taxpayer cash, the dogs were sent to Paddington Station in London (pictured with Matt Hancock, Duchess of Cornwall and former Health Minister).
Dogs sniffing samples in purpose-built lockers at the airport confirmed that 296 of the 300 passengers were covid-negative (99 percent success rate).
However, they did not find the only three passengers who were PCR-positive.
But the researchers said one of these passengers was negative in the second PCR, and the other was positive but no longer contagious.
Experts said some of the differences in dogs ’sniffing skills were due to the fact that they were trained to detect the original virus strain, not the alpha.
Due to the low positivity at the airport, dogs were given 155 samples from those infected with Covid. Dogs correctly identified 99 percent of these cotton swabs.
Combining airport and positive sample tests, dogs were detected in 97 percent of those infected and 99 percent of those without the virus.
The researchers said this shows the “solid distinctiveness” of the dogs’ sense of smell and that they should be trained to detect any rotating variations.
They said the dog could be retrained to detect a new strain in just “a few hours.”
In a separate analysis, the researchers modeled how accurately dogs sniffed the virus if four in ten people became infected – in a hospital during a pandemic, for example – and when only one percent became infected, as at the airport.
When the incidence is high, they estimate that dogs would engage in 88 percent of positive cases and 94.5 percent of negative cases.
If the prevalence of the virus is low, dogs will detect about one in ten infected and confirm almost all negative cases.
The researchers said the results suggest that dogs can be used in screening with the goal of excluding people who do not need a PCR stick to save time and testing capacity.