‘Close to 100% accuracy’: Helsinki airport uses sniffer dogs to detect Covid

Four Covid-19 sniffer dogs have begun work at Helsinki airport in a state-funded pilot scheme that Finnish researchers hope will provide a cheap, fast and effective alternative method of testing people for the virus.

A dog is capable of detecting the presence of the coronavirus within 10 seconds and the entire process takes less than a minute to complete, according to Anna Hielm-Björkman of the University of Helsinki, who is overseeing the trial.

“It’s very promising,” said Hielm-Björkman. “If it works, it could prove a good screening method in other places” such as hospitals, care homes and at sporting and cultural events.

After collecting their luggage, arriving international passengers are asked to dab their necks with a wipe. In a separate booth, the jar containing the wipe is then placed next to others containing different scents, and the dog starts sniffing.

If it indicates it has detected the virus – usually by yelping, pawing or lying down – the passenger is advised to take a free polymerase chain reaction (PCR) test using a nasal swab to verify the dog’s verdict.

In the university’s preliminary tests, dogs – which have previously been used to detect diseases such as cancer and diabetes – were able to identify the virus with nearly 100% accuracy, even days before before a patient developed symptoms.

Scientists are not yet sure what exactly it is that the dogs sniff when they detect the virus. A French study published in June concluded that there was “very high evidence” that the sweat odour of Covid-positive people was different to that of those who did not have the virus, and that dogs could detect that difference.

Dogs are also able to identify Covid-19 from a much smaller molecular sample than PCR tests, Helsinki airport said, needing only 10-100 molecules to detect the presence of the virus compared with the 18m needed by laboratory equipment.

Authorities in Vantaa, the city where Helsinki’s international airport is located, said the pilot programme, which is due to last four months, was costing €300,000 (£274,000) , which it said was significantly lower than for laboratory-based testing methods.

Although Covid-19 is known to infect mink and cats, dogs do not have the receptors necessary for the virus to readily gain a foothold and do not appear to be easily infected, according to Hielm-Björkman. There is no evidence that they can transmit the virus to people or other animals.

A Finnish organisation that specialises in training animals in scent detection, Wise Nose, is training a total of 16 dogs for the project, 10 of which are eventually expected to be able to work at the airport. Working in shifts of two, four of them – ET, Kossi, Miina and Valo – started on Wednesday.

Researchers in countries including Australia, France, Germany and Britain are reportedly working on similar projects but Finland is the first country in Europe to put dogs to work sniffing out the coronavirus. A similar trial started at Dubai international airport last month.