People with COVID have a subtle scent that dogs can detect in under a second

People who are infected with COVID-19 give off a subtle but distinct odor that dogs can recognize in less than a second, according to new scientific research. Physician Claire Guest and colleagues built on a prior study showing that dogs could be trained detect human bladder cancer by smelling a patient's urine. Guest is now CEO of Medical Detection Dogs, a charity organization that researches dogs' ability to detect Parkinson's, type 1 diabetes, malaria, and other cancers. From The Guardian:

[A golden labrador named] Tala is one of six dogs who took part in the Covid study, which has not yet been peer-reviewed. It found that dogs could detect Covid-19 on clothing worn by infected people with up to 94.3% sensitivity: they would correctly identify 94 out of every 100 infected people. This compares with a sensitivity of 58-77% for lateral flow tests, and 97.2% for PCR tests.

However, dogs beat PCR tests on speed, making a diagnosis in under a second. "This includes people who are asymptomatic and also people with a low viral load," said Prof James Logan of LSHTM, who co-led the study.

Tala was the most accurate sniffer, achieving 94.5% sensitivity, and a specificity of 92% – the proportion of uninfected people that he would correctly identify[…]

Gundog breeds such as spaniels, retrievers and labradors make particularly good detection dogs. "These are dogs that absolutely just love searching," said Guest. "They're also very friendly and they enjoy working in public places."

image: Medical Detection Dogs