Nova Scotia·Q&A

Why rapid tests should only be used when you have COVID-19 symptoms

Nova Scotia is expected to receive more rapid COVID-19 tests from the federal government this month, but how those rapid tests will, or should, be used has come into question, especially as the Omicron wave has changed the province's testing protocol.

Dr. Lisa Barrett says only rapid testing when symptomatic will help preserve and extend PCR testing

Nova Scotia is expected to receive more rapid COVID-19 tests from the federal government this month, but how they are to be used has come into question. (Submitted by Donna Lyall)

Nova Scotia is expected to receive more rapid COVID-19 tests from the federal government this month, but how those rapid tests will, or should, be used has come into question, especially as the Omicron wave has changed the province's testing protocol.

Portia Clark, host of CBC Radio's Information Morning Nova Scotia, spoke with Dr. Lisa Barrett on Friday, about how she thinks the rapid tests should be used in the province.

Barrett is an infectious disease specialist and a member of Nova Scotia's expert vaccine panel. 

Listen to the full interview here:

The federal government is sending 140 million rapid COVID tests across the country. Dr. Lisa Barrett explains how to best to use them, once they're here.

This interview has been edited for length and clarity.

There's some concern around the accuracy of rapid tests. People are wondering if they get a negative result, whether they could still have COVID? On the other hand, if you get a positive result, you most likely do have COVID. What's your take on that?

As we've always said, a positive — especially at a time when there's lots of virus around in the community — you should assume that you have COVID. There are instructions, depending on whether or not you have symptoms and what to do next, on the Public Health and Nova Scotia Health Authority website. 

A negative has never meant a negative forever, and it doesn't mean that you aren't infected. What it means is that you're very much less likely to be infectious at a given point and I think that's really important for people to understand. That's not Omicron specific, that's test specific.

Omicron has changed things a little bit in that it goes from low levels of virus to quite high and potentially infectious pretty fast and so truly, these days, people should remember that a negative is only negative for that day and if you do have symptoms, you need to retest … and staying home, staying away from others is very important at this point. 

We're supposed to use these rapid tests only if you have symptoms. What are your hopes for the new batches of tests when they come before the end of this month? 

It is true that we've changed to using them more in the symptoms-level range, and that's not unusual or unexpected. We change testing every time the situation with the virus changes.

When these [tests] come, it's going to depend on where we are in terms of how much virus is in the community, about where it's best to use them. As we go forward, the considerations are: how much virus [there is], whether we do have a lot of people who are having symptoms and [if there's] community spread. Then sticking most of our tests toward symptomatic testing makes good sense in order to preserve and extend our PCR testing over time.

There will also be opportunities to continue using them in spaces and places for people with fewer symptoms in situations where people are getting together, like in schools or in different places around the province where there's community spread.

But to be honest, that all needs to get figured out as we go and make sure that people have those tests when they need them for symptoms so [it's] a little bit of a shift. I think people have seen it as a restriction. I don't see it as a restriction. I see it as a change, based on what our community virus is doing. 

We expect the province is going to put those test kits into schools and send them home with students. How often, and when, should students be testing if we're still getting around 500 positive cases a day by the end of this month? 

The intent with the school program when it first started in the fall was to test kids who had either some or a bunch of symptoms, and that would be the same. The expectation would be that people would test if they had symptoms. 

If they have a positive test, then that would be a consideration that they are definitely positive and then if they're negative, the idea would be to retest again several days later. 

Dr. Lisa Barrett is an infectious disease researcher and clinician at Dalhousie University. (CBC)

So how that looks exactly in the upcoming days, weeks and months remains to be seen in terms of exactly how people use them, but I think the big thing for people to know is that, Nova Scotia has always valued testing and in particular, rapid testing — that hasn't changed, and the government has been very good at getting supply for us from the federal batch so people should feel good about that. 

I know there's lots of worry and concern about the distribution to other parts of the province, and there are some plans underway to address those concerns and issues. 

Should we be swabbing our throats, given that Omicron is showing up and multiplying really quickly in people's throats more than in their nostrils?

I'm careful with that information. TikTok tells me that's true, a few medical reports tell me that's true and there does seem to be some reasonable background medically that that may be true. 

Whether the throat is earlier or better than the nose, that's a good question. Some data suggest that's true, and multiple groups in the country are now going to do some really controlled testing to figure out whether throat versus nose or both is the best way to do that test.

Right now, I don't recommend people start swabbing random parts of their upper head and neck, including the throat, until we get those data out there, and, hopefully, we should have some of that soon and there's some efforts with our local lab group to to figure that out locally as well with our own specific virus in our own specific clinic.

On a more sombre note, Dr. Robert Strang, Nova Scotia's medical officer of health, said police officers have had to go to testing sites which speaks to this scarcity panic. What's your reaction to that?

I'm a little surprised. I think number one, people are worried [but] supply is coming and we will be getting at least our fair share in Nova Scotia of tests. You may not have all the tests you want, but you probably definitely will have the tests you need in the next little while.

Keep in mind that if you don't have as many as you want, chances are you're doing a little bit more activity and a little bit more going about than is recommended at the moment.

We do still have restrictions in place and a guidance to stick close to home for the next little while due to the level of community virus so I'd remind people of that. And to the policing, that's never my first response, but we do want our health-care workers and people delivering these kits to be safe. 

Is there anything else people should be keeping in mind right now?

Omicron is out there and it's around a fair bit so don't rely or wait for an exposure site to feel like you may run into the virus. So not just testing, but keeping a really well-fitted mask, some distance and keeping your unmasked indoor activity low still until the end of January [when] the restrictions change is really important in all of us doing our part still to keep virus at a manageable level. 

We really are still seeing people in hospital for either COVID or other medical problems that are related to COVID that aren't going as well, so please remember, stay up on both the testing, but also all those other public health measures that we know work so well and can't wait to see people getting out for those boosters and vaccines. 

With files from Information Morning Nova Scotia

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