Health Canada approved a rapid test for COVID-19 this week, leading some to wonder what that could mean for provincial testing systems under heavy pressure.
The Canadian Press asked infectious disease experts Dr. Barry Pakes, a public health physician and professor at the University of Toronto and Dr. Gerald Evans of Queen's about the new Abbott Diagnostics ID Now tests, which delivers results in about 15 minutes and should start arriving in provinces in the coming weeks.
How does the rapid test work?
Pakes: It's a similar technology (to the current testing method), it's just a different platform. So really, the quickness of it is its point-of-care — there's a little machine there, and everything you need to get the answer while the patient is waiting.
Evans: What (the rapid tests) have done is remove the lab out of the equation but you still need (a medical professional) who would know how to do this kind of swabbing ... It's the same nasal pharyngeal swab to collect the sample, to put into the machine and then run the whole test.
Can this be useful in addressing the testing backlog we're currently seeing in parts of the country?
Pakes: It could, but it also might not...If five times the number of people now want to get tested, you're actually more behind than you were to begin with, right? So it's about a system. It's about the proper messaging about who should get tested, under what circumstances, what they should do when they get tested — making sure the data systems are there, making sure the followup is there. Because you could have a best-case and a worst-case scenario with any new technology in such an incredibly dynamic situation that we're in right now.
What would be the worst-case scenario?
Pakes: The challenge with point-of-care testing and rapid testing is when lots of people do this all the time, everywhere, you get a false sense of security, and then all of your other public-health measures go by the wayside. You look around the world where individuals are getting tested using these point-of-care tests, whether it's the United States or India or a number of other hard-hit countries ... when you do that and the data is not in the public health system — so public health folks can't do case and contact management — then it's not (effective)."
How do we make sure that doesn't happen?
Pakes: If it's rolled out in a systematic way, where people know who needs to get tested, where to get tested, and the people doing the testing have a system to send that information to the people who need to do the contact management, then this could be a real help. If it's done in a haphazard way, and people test positive and that's not shared with other people they may have had contact with, that's not going to help anyone.
How reliable is this rapid test?
Evans: From the data I've seen, it looks pretty good. The sensitivity, in other words the ability to find an infection when somebody is truly infected, looks sort of north of 90 per cent.
Pakes: This test is not entirely as good as the gold standard, but the reason it's approved and the reason we're going to start using it is that it is coming closer to the gold standard in terms of sensitivity and specificity.
What's the immediate impact of implementing these rapid tests?
Evans: It allows us to rapidly screen patients who might be coming in (to the hospital) with something else, so we can decide if they need additional precautions. The other thing that's going to be useful would be select groups like health-care workers and teachers and kids, where a rapid answer would give you an opportunity to let people continue to work because you know they're negative.
Pakes: The impact could be transformative if it's used properly as part of a system. If you can find out whether or not you're positive within a couple of hours of you having symptoms and you can self-isolate and prevent further spread, then you've effectively cut off a huge piece of the transmission. If you didn't hesitate when you had symptoms because you didn't want to stand in line, and you actually went and got tested, you're going to know sooner, you're going to expose fewer people, and we're going to have much better control of the pandemic.
What are the long-term implications and who else can benefit?
Evans: I think really, the long-term implications are the ability to very, very quickly examine certain populations to exclude them having the infection. I think who's going to invest heavily in this are groups that have a lot of money. So organized sports — I can see all of professional hockey, baseball, football, basketball (leagues) are going to jump on this because they can rapidly test (a player) and know within 15 to 20 minutes whether they have COVID or not.
How much of an impact can rapid tests have on the private sector?
Pakes: "There's certainly going to be a role for that, particularly larger corporations who want to protect themselves and protect the people that are using their services. So that's going to (help) ... in keeping some of these entire industries operating. And I think that's really important for the overall health of our economy and our mental health as well.
These interviews have been edited and condensed for clarity.
This report by The Canadian Press was first published Oct. 2, 2020.
The Canadian Press