Dog sniffs as good as RT-PCR? Research shows they could be

Can dogs sniff out Covid-19? A study from Finland shows that they can. And, quite accurately, especially if the infection is caused the wild-type virus that’s used to train them.
After training four dogs, researchers from the University of Helsinki tested 420 samples for which the RT-PCR reports were already known. They also tested 303 incoming passengers at the Helsinki-Vantaa International Airport-Finland.
The study found an overall accuracy of 92% as compared to the RT-PCR tests. “Scent dogs trained with wild-type SARS-CoV-2 virus also mastered identification of other variants, although less accurately, revealing their robust discriminatory power,” the study said. The study was recently published in the BMJ Global Health journal.

The Indian Army also trained two of its dogs to detect Covid-19 last year.
In the first part of the study, which was used for validation, the dogs were accurately able to identify 92% of the samples as either Covid-19 positive or negative. “Failure to identify a COVID-19 positive sample was associated with the SARS-CoV-2 variant status. The dogs indicated correctly…only 36% of the alpha variant samples,” according to the study.
As for the real-life scenario at the airport, the results of the dogs matched the RT-PCR report for 296 of the 303 people, meaning the accuracy stood at 97.7%. The only drawback of the real-life study was that there were very few positive cases – only three of the 303. To ensure that the dogs could sniff out Covid-19 even in such low levels of prevalence, the dogs were also given 115 known RT-PCR positive samples at the airport. They were able to correctly identify 98.7% of them as positive.
At the time of the study – the real-life airport study was conducted between September 2020 and April 2021 – variants were just emerging in the country. The study said, “Since variants did not emerge in Finland at the time of training, only wild-type samples were used. Many of the discrepant results were associated with the new variant. In the future, operational work skills should be kept up simultaneous training with samples of emerging virus variants.”