THE POOCHES WHO COULD PAWS CORONA
They can famously sniff out disease in humans. Now, as Helsinki airport trials Covid-hunting hounds, meet the clever British dogs being trained to come to our rescue here
PICTUre the scene: dawn breaks and at Heathrow more than 500 bleary- eyed passengers emerge from a long-haul flight. As they stream into the arrivals hall to wait at passport control, a uniformed officer walks up and down the queue. By his side is a spaniel, sniffing the air as he goes.
Suddenly, the dog stops and sits down stock-still. It’s directly opposite a middle-aged man, casually dressed and carrying a backpack. The official gestures for the traveller to leave the queue and follow him and his canine companion.
The man’s fellow passengers look on shocked, assuming they’ve just witnessed a sniffer dog identifying a drug smuggler. But the reality is very different. This dog has been trained to detect the unique scent emitted by someone infected with the coronavirus.
Such is his sense of smell — dogs can detect odour concentrations of around one part per trillion, the equivalent of one teaspoon of sugar in two Olympic- sized swimming pools — that he can pick out those carrying the virus even before they show symptoms.
Once identified, the man will be formally tested and, if confirmed positive for Covid-19, immediately quarantined. He, his family and anyone who had contact with him can then be prevented from spreading the infection further.
Sound fanciful? In fact, thanks to the work of pioneering British charity Medical Detection Dogs (MDD), it could become reality in the UK in a matter of months.
Set up more than a decade ago, the charity has trained dozens of dogs to use their super-powered noses to sniff out the odour of diseases such as cancer and Parkinson’s from urine samples or sweat swabs.
Others have become medical alert assistance dogs, capable of detecting minute changes in their owners’ personal odour triggered by conditions such as diabetes. If an attack is imminent, the dogs alert their human companions to help prevent a medical emergency.
Now scientists say the dogs could be deployed on the frontline in the battle against the coronavirus. They believe the animals could be taught to identify the unique scent given off by those who have Covid, first ‘learning’ the odour from face masks, T- shirts or socks that have been worn by patients with the illness.
Once trained, the dogs could be deployed at borders and airports to help prevent infections spreading. They could also be used to check key workers at hospitals and schools, avoiding the need for mass testing and allowing many to go back to work.
If you’re still sceptical, just look to Finland, which began using Covid sniffer dogs at Helsinki Airport this week in a four-month pilot scheme.
TRAINERS WORKING on the trial at the University of Helsinki, which saw the dogs trained to identify the virus using a total of 500 samples, both positive and negative, said the animals could detect the coronavirus with near 100 per cent accuracy.
At the airport, passengers are now asked to volunteer to dab their skin with a wipe, which is then put into a jar and given to the dog waiting in a separate booth. It takes a moment to sniff the wipe, before revealing the test results by lying down, barking or giving a scratch of the paw.
If the result is positive, the passenger is urged to take a standard coronavirus swab test to check the dog’s accuracy.
The researchers are now waiting for the first results of these tests to see if the dogs correctly identified the virus in the real-world setting.
‘The dogs are very specific,’ says
Professor Anna Hielm-Bjorkman, who led the training at the University of Helsinki. ‘They are finding the right patients.’
She says the dogs are now being prepared for other settings, including care homes and schools. She points out that the dogs are much cheaper than the standard swab tests, which can each cost £175 privately, and much quicker, too — it takes just one minute to test a passenger at an airport.
‘This new method seems to be really promising,’ she adds.
SO When could we be seeing sniffer dogs in our airports? The scientists leading the UK trial — from the London School of Hygiene & Tropical Medicine (LSHTM) in collaboration with MDD and Durham University — say it could be as soon as Christmas.
Thanks to a £500,000 grant from the Government, six dogs were selected to begin intensive training at MDD. The scientists hope the initiative will eventually mean 250 people are able to be screened every hour.
The pioneering dogs in question are cocker spaniels Norman, Jasper and Asher, labrador Star, labrador cross golden retriever Storm and labradoodle Digby. More canines have since joined the trial.
‘The aim is that dogs will be able to screen anyone, including those who are asymptomatic, and tell us whether they need to be tested,’ says MDD’s co-founder Dr Claire Guest. ‘This would be fast, effective and non-invasive and make sure NHS testing resources are only used where they are really needed.’
what makes the project so exciting is the charity’s proven track record of success.
Several years ago the charity teamed up with Durham University and LSHTM to see if it was possible to identify malaria from sweat samples.
The study saw 600 apparently healthy children aged between five and 14 in the Gambia asked to wear nylon socks overnight. At the same time, they were screened for the malaria parasite using a finger-prick test. This revealed which of the children had malaria, even though they were unaware of it.
The socks were then transported to the charity’s headquarters in Milton Keynes. There, a pair of dogs correctly identified 70 per cent of the malaria-infected samples and 90 per cent of the samples without malaria parasites.
research suggests that odours produced by chemicals called aldehydes make infected people attractive to the mosquitoes. Unlike humans, dogs can smell these sweet, fruity chemicals even at minute concentrations.
Since the study’s publication two years ago, Durham University’s Professor Steve Lindsay has been
pushing for malaria detecting dogs to be used at border posts between South Africa and mozambique. exactly the same, he says, could be done with Covid-19.
‘We know from other infections and cancers that there are specific odours that the dogs can pick up,’ he says.
‘Now, with Covid-19, you have damage to the lungs, probably from an early stage, and people are likely breathing out smells that come from that disease in the lungs.’
The latest trial has seen 3,500 NHS staff sign up to help train the dogs by contributing used masks and clothing.
Professor lindsay adds: ‘What we are looking at here is not necessarily the smell of the virus, but the smell of the breakdown product, of the damage that it is doing in a confined space in the lungs.’
The six dogs have already undergone initial training — known as ‘early scent training’ — in the charity’s bio unit. Researchers are now waiting to see which will make it through to the next stages. ‘We are re-deploying them to go on Covid work,’ says Dr Guest. ‘They are ready to go.’
The dogs will first be trained to pick out the Covid samples at the charity’s training centre, after which the samples will be hidden in people’s clothing so that they learn to ‘screen’ an individual to find what they are looking for.
However, so far the trial has been stymied by a samples shortage.
‘We need 675 negative samples, and 325 positive samples,’ says project leader Professor James logan, head of the Department of Disease Control at lSHTm.
‘Although it does not sound like a lot, it is hard because the numbers [of people with Covid] came down in the UK very quickly.’
EARLIER this month, the scientists had only ten positive samples, and are appealing to the public to help boost this number. Researchers are hoping to recruit thousands of people in england who have mild Covid-19 symptoms.
The volunteers will need to provide samples of breath and body odour by wearing a mask for three hours, and nylon socks and a T-shirt for 12 hours.
This month, Professor logan said: ‘Once we’ve got all the samples, it will take about eight weeks to train all the dogs that we have. Then we would be looking to deploy within weeks after that. ‘ We are still hoping that we will have the first dogs deployed before Christmas.’
Commenting on the Finnish trial, he added: ‘it’s fantastic that the potential for using dogs to detect Covid-19 is seen around the world, and there are some encouraging early signs from these studies.
‘Our trial aims to prove with all certainty that dogs can detect Covid-19 ... While initial indications of our trial look promising, we still need the public’s help to collect more positive samples to complete the study.’ While the dogs could also be used at train stations, sports stadiums and workplaces, airports remain the obvious place for them to be deployed. ‘i think if these dogs had been ready for those first flights coming in from italy [in February], it could have been very differently managed,’ says Dr Guest. ‘Those people coming off the flights with the virus could have very quickly been isolated.
‘it would have been a fantastic way of assessing the population as they were moving about — it doesn’t only give you the individuals, it would give you the percentages with, say, 10 per cent of a flight having it.’
Some UK airports, including Heathrow, have trialled thermal-imaging technology to scan arriving passengers to see if they have a raised temperature, which is a symptom of the coronavirus.
Yet this method can lack accuracy, and Professor lindsay is confident the dogs can do better.
‘let’s imagine the curve and the epidemic coming down and we are controlling it,’ he says.
‘What we don’t want is to have cases coming in from outside again. So how do you pick them up early? if the dogs are found to be able to do this job, why not use them?’
Which means that the likes of Storm and Asher could soon find their super-powered noses put to the ultimate test.
■ TO SUPPORT Medical Detection Dogs and their work on Covid‑19, visit medicaldetectiondogs.org.uk. For details on how you can volunteer to provide samples, visit lshtm.ac.uk/research/ centres‑projects‑groups/usingdogs‑to‑detect‑covid‑19#