Dogs More Effective Than PCR Tests At Detecting COVID

Scientists and public health officials have been looking at all different kinds of alternatives to individual rapid COVID-19 tests to detect the presence of the virus, and in their search, they’ve landed on some strange alternatives. Some have resorted to testing poop in public sewers to detect traces of the virus, a method that has proven reliable in detecting outbreaks.

And as it happens, dogs – which have been used to sniff out everything from drugs to bombs – are also effective at sniffing out COVID-19, according to a new French study published by Bloomberg.

The dogs’ ability to detect the virus was clocked at 97% sensitivity, a level that puts this method on par with the most reliable rapid antigen tests. The sniffing method was also found to be 91% specific – a technical measure of the dogs’ ability to correctly identify negative samples. This ‘sensitivity rating’ is higher than that of many 15-minute antigen tests, which tend to be better at ruling out infection than at finding it.

And with Europe reopening its economy to vaccinated tourists on Wednesday, these study results couldn’t have come at a better time. As Bloomberg points out, virus-sniffing dogs could be widely deployed in airports, train stations or anywhere crowds amass to screen people, much like they’re used for detecting drugs or bombs. Using dogs also means COVID could be identified at just a fraction of a second in a non-invasive manner, and in an extremely inexpensive manner (in theory, it wouldn’t cost all that much to train the dogs, and the methods would be simple to those used to train drug and bomb-sniffing dogs).

The trial was carried out at France’s National Veterinary School, according to Bloomberg, which shared some more details about the trial.

The trial, which was conducted at France’s National Veterinary School in Maisons Alfort near Paris, collected sweat samples from the armpits of the participants with cotton pads that were locked into jars and gave them to at least two different dogs for sniffing. None of the dogs had prior contact with the volunteers. There were 335 people tested, of which 109 were positive in a PCR test that served as a control. Nine dogs participated, and the researchers didn’t know which samples were positive.

In July, German researchers showed trained dogs were able to distinguish between saliva sampled from people infected with the virus and those who were not more than 90% of the time. Finland, Dubai and Switzerland have started training dogs to sniff out infections.

The latest study was conducted between March 16 and April 9, and the Ile-de-France region helped fund the trial, contributing 25,000 euros ($30,500).

Efforts to train dogs to sniff out COVID are underway across Europe, and the world. In the UK, a team from the London School of Hygiene and Tropical Medicine are training six dogs in the hope that they will be able to detect COVID-positive people, even if they have no symptoms. In Finland, sniffer dogs have been working to detect infected travelers at Helsinki Airport since September.