'A game changer': Breath test for COVID-19 being developed by B.C. researchers
VANCOUVER -- A swab up the nose and gargling salt water are two of the ways people are now tested for COVID-19 in B.C., but researchers have been working on a fast and non-invasive option that would involve giving a breath sample.
Interventional respirologist Dr. Renelle Myers – who works at Vancouver General Hospital and BC Cancer and is also a clinician scientist at the BC Cancer Research Institute – told CTV News Vancouver her team had been preparing to study using breath samples for the early detection of lung cancer.
"When the pandemic hit, we knew the potential of breath, and thought let's change gears and see if we can diagnose COVID-19 through breath analysis, because it would provide a very rapid, non-invasive way to do it," she said, and added their work in relation to lung cancer will continue.
"You could imagine lining up at an airport, at an arena, at school, at work, and having the confidence of knowing everyone in there has been screened."
Myers said the technology is similar to machines used by airport security to scan for explosive or drug residue following a swab, and could produce a result within a minute.
"We've currently tested 300 participants in the study, from the hospital – either they're admitted with COVID-19 and have agreed to participate in the study – or from a testing site," she said.
Participants give two breath samples collected two different ways. The first involves taking a deep breath and then fully exhaling into a small breathing tube.
"When you feel like you're getting empty, we tell you to raise your hand, and we pull five cc's of air from the sampler and we pop that into the machine," Myers said. "Some people prefer to hold the tube themselves and blow out, and they know when they're getting empty, they can draw the sample. Or we'll just stand beside you and draw the sample when you're getting empty."
While the lab cannot be visited due to pandemic protocols, Myers demonstrated the breathing tube over a video call. The handheld, pipe-like device had a plastic syringe portion sticking out near the middle, which she pulled down to draw the sample as she breathed out for about eight seconds.
The sample is then analyzed by a small, portable machine on site. Myers said she has taken it to testing sites on the North Shore and in Whistler by just packing it up in the trunk of her car. It does need to be plugged into a power source, however.
The second type of breath sample is collected by having people blow air into a bag, "almost like blowing up a balloon.” That sample is then transferred into a special tube, which is transported back to the lab and tested by a much larger, highly sensitive machine.
The results from the two machines are then compared. Researchers are looking to pin down the specific volatile organic compounds that are markers for the virus.
"We have the capability, once we recognize that COVID signal, to program a portable machine to look for those signals and then it would be a yes, no. Yes COVID, no COVID," she said. "We have approximately five different compounds that have been consistent in COVID positive patients."
Myers said most people they ask have been happy to take part in the study.
"It doesn't hurt, it's quick, it doesn't take very long at all and people want to contribute because we all want this to get better," she said. "I think this technology, although we have a ways to go, would really be a game changer in bringing people back together."
The study has funding to test up to 1,000 people. Myers said they may not end up needing that many participants to get the answers they're looking for, but "more is always better.”
"What we don't need is a rapid test that gives high false positives or false negatives, so it's really important that we get it right," she said.
The study is being supported by funding from the Vancouver Coastal Health Research Institute, Vancouver General Hospital and UBC Hospital Foundation's COVID-19 research fund, and a donation from the Leung family and Beedie Foundation through the BC Cancer Foundation.