Toronto's top public health official is urging residents to remain vigilant and not let their guard down as the city continues to see a high number of new COVID-19 cases.

"Whatever happens, wherever you may or may not go, no matter how long the pandemic lasts, the single biggest mistake you can make is letting your guard down in terms of protecting yourself from COVID-19," Dr. Eileen de Villa said during the city's briefing Wednesday afternoon.

"So please, don't let your guard down around your co-workers. Don't let your guard down around your extended family or your friends. Don't let your guard down when you notice you're experiencing symptoms of COVID-19 – get tested."

With some restrictions expected to be lifted in the city next weekend, the doctor warned that it will result in an increase of virus spread, which she said is the biggest risk to public health at this time.

The province introduced a new tiered system for COVID-19 restrictions on Tuesday.

"Now we have a formal provincial framework with measures that will guide the decision-making process at the policy level, at Toronto Public Health we will do absolutely everything in our power to facilitate the safest reopening possible," de Villa said.

"And, as I've done throughout this pandemic, if I feel that additional measures or interventions are required or that more time is required, I will tell you.

Dr. de Villa joined CP24 to answer your COVID-related questions.

CP24: Peel's medical officer of health said today that he strongly discourages private social gatherings at private residences. Could we ever have this kind of situation happening in Toronto?

De Villa: I think that the circumstances, whatever is happening in your own community at the time, is really what dictates is the best course of action to take. And not being in Peel Region, I can't speak to the specifics there. But I do appreciate and understand that each jurisdiction has to take its own decisions around what makes the most sense, based on their data and based on the COVID situation that they're experiencing at the time.

CP24: On contact tracing, you mentioned how you are doubling down on that. Can you explain that to us?

De Villa: I don't know that it's doubling down. I think we've always been really interested in making sure that we're doing the best that we can in case management and contact follow-up. We know that that's one of the key elements as part of public health response. The challenge, of course, has been for us is that when case counts get really, really high and when doubling rates get really, really high. It doesn't just happen here. This is everywhere. The benefit of doing that case and contact management on every single case and following up all the contacts starts to lose its benefit because the numbers get too high, and you'll constantly have to keep adding stuff, and you'll never be able to keep up. What happens then in those circumstances, whether it's COVID-19, or influenza or any other pandemic, what you do is you focus your resources on where you can get the most effect for the resources that you're putting into play. But what we want to do is bring the case count down so that we can then do more fulsome case and contact management, bring all the public health actions on board and really do the best we can to protect the health of the residents of Toronto. That's really what we're aiming for.

READ MORE: Toronto continues to work on resuming full contact tracing as gyms, indoor dining set to reopen next week

We've gone from 50 to 700. And on top of it, we're adding another 200 this month, and we're partnering with other agencies. The provincial government has offered us some help. We're working with local hospitals and their health care professionals to see what they might be able to do to help us. So, we're pulling out all the stops to see what we can do. And to make sure that we're putting our best effort forward, including the use of technologies and other innovations, and putting our good learnings to good use, as we've learned quite a bit over the course of the pandemic.

CP24: The province unveiled its new tiered restriction guidelines on Tuesday. We know Toronto isn't going to go into it for another 10 days, getting an extra week over the other hot spots across the province here. Why does Toronto need the extra week? Are you worried that the 10 per cent positivity rate some people are suggesting is too forgiving?

De Villa: It's good that we have a framework. I think it's important that people know and understand what the provincial government is looking at as they seek to control and do the best they can in and around COVID-19. I think it's important that people understand what the considerations are. I think the other thing that's important here is that, yes, in Toronto, we are in a unique circumstance. We are the largest jurisdiction in the province. And when it comes to the many businesses that we have, we're literally in the thousands of restaurants, to say nothing of gyms and the other businesses that exist. We want to make sure that we move forward and move towards reopening in as safe of fashion as possible while we know that COVID-19 is with us. That requires some effort. And it requires some time. We want to know what the regulations are so that we can communicate them properly with all the business stakeholders and our communities so that everybody knows and understands what they need to do to make sure that reopening is being done as safely as possible and that we can be as successful as possible.

CP24: Do you worry that the threshold is a little too high?

De Villa: I think that, again, we're all focused on how we adjust public health measures so that we can reopen as safely as possible. These are really complicated circumstances, and we are learning a lot. And we continue to learn about how to manage COVID-19 in our community. My real focus is on figuring out how best do we help the people and the businesses of Toronto navigate our current environment, using this framework to be as successful as possible in opening and reopening our businesses in a safer manner possible.

CP24: A restaurant owner asks, the restaurant industry as a whole has spent millions of dollars on safety. How does it make any sense only to allow small groups of people to come into the restaurant and close at 9 p.m.? The government is crazy if they think that all the 22 to 50-year-olds will go home at that time.

De Villa: I think you also when you can hear the frustration and the concern, and I completely appreciate how very challenging this whole experience has been for many business owners, including those in the hospitality industry. There's no easy way around COVID-19. It has just been very, very challenging. And while the specifics of the regulations and the requirements are under the purview of my provincial counterparts, I think the important thing here is this -- the issue is, is that in bars and restaurants, by definition, you are bringing people into closed spaces, especially when we're talking about indoor dining, which is a necessity at this time of year. Close spaces in close contact with other people engaged in an activity, eating and drinking where you can't really wear a mask. It creates the conditions that give rise to virus spread. I think that's the reality of COVID-19. We ask people to do the best they can to try to minimize the risk to engage in those self-protective behaviours. But the challenge is at bars, restaurants, and the hospitality industry have circumstances that just put them at higher risk for virus spread.

CP24: Now, with gyms scheduled to reopen in 10 days, we find out that the maximum capacity is 50 people per gym. Now initially, back when we first entered stage three, it was higher. So why were the max allowable lowered in the first place when three per cent of known outbreaks in the city are traced back to gyms?

De Villa: I can't say that I know specifically what went into the deliberations at the province around setting the thresholds for the various businesses. I would imagine that the experience here or in other parts of Ontario, experiences around the world would have played a role in that. But just like we were talking about with bars and restaurants, the challenge with gyms is that you're in a closed space. We're talking about indoor gym facilities so, you're in an enclosed space with other people around -- that's close contact between people -- and engaged in activities that are difficult to do with a mask on consistently. Engaging in vigorous physical activity, which one tends to do in a gym, is difficult to do with a mask. I think on top of it because you're in physical activity, you're breathing heavily. You put all these things together, and you've got the conditions for virus spread. I'm sure these are the kinds of considerations that went into the specifics of the regulations and the levels and thresholds that the provincial government put as part of their framework for gyms.

CP24: If you had a choice in the matter, in a perfect world, would you ever advise to reopen gyms in a pandemic?

De Villa: Well, in a perfect world, we wouldn't be in a pandemic. I think we would all agree that if there were a magic wand or some fairy dust that we could sprinkle and make this whole thing go away. I'd be surprised if there was anyone who would vote against them. That would be my first wish on, you know, every opportunity that was afforded to me.

CP24: Dr. de Villa, do you have any idea when the strip clubs will reopen in this new tier system as they have invested a lot of money into the safety protocols as per the inspections by your office?

De Villa: I have to admit, I don't know that specific detail of the framework. But I'm sure if we take some time to take a look at the specifics of the framework and the regulations that will come out associated with it, we'll be able to see where that might happen.

CP24: Would you describe the strip clubs as the early super spreader events, a super spreader venue?

De Villa: I think actually any super spreader venue is one in which people have let their guard down. And sometimes that's happened within the context. We've had a strip club outbreaks for sure in this city. But we've seen outbreaks in lots of other places. And frankly, where it's happened is where people let their guard down. They're in close contact with other people not wearing their masks, and that's what gives rise to virus spread.

CP24: What do you make of the new mask guideline issued by Canada's chief medical officer of health? I don't know anybody who's got a three-layer mask.

De Villa: There are a number of masks that I've seen, and I have a couple of myself that are two layers of cloth, but with space, for one to insert a filter in. I think that's the kind of mask that we're talking about. Over the course of the pandemic, yes, we have seen changing advice as we learn more and more about the virus and how best to prevent its spread. So, I think what you're seeing here is updated advice based on the latest evidence, as assessed by our colleagues at the Public Health Agency of Canada. But again, we're still talking about the basic measures for self-protection. Watching your existence is still a really, really important way and one of the most important ways by which to do this. A mask actually helps if you're unable to maintain distance for whatever reason from other people. That just offers that protection there. And of course, there's washing your hands and staying home when you're sick. Fundamentally, the basic steps for self-protection are still the best things that we can all do.

CP24: The number of cases is increasing. I know it's hard to go back to stage one again, but wouldn't it be safer for Canadians, especially with the rise of cases? Also, is there any plan to have a lockdown if cases keep increasing?

De Villa: I can appreciate that many people would think about that and think that a lockdown immediately might be the best way to go from a virus spread point of view. But here's the thing, we know that health is more than just about virus spread. Let's face it: COVID-19 is the most important thing right now in terms of public health. But that doesn't mean that there aren't other aspects of health that we need to manage. And that includes people's livelihoods, their ability to make a living and have sustained income, mental health, and social health. There are many other aspects that we're trying to manage, and that's the really delicate balance that we're all constantly trying to strike. We've seen other jurisdictions, particularly in Europe, as of late, that are moving towards lockdown, much higher rates than what we're seeing now. In order to avoid that, though, the best thing that all of us can do here is to continue to follow the advice we've been giving in respect of the steps for self-protection and to really be sure, don't let your guard down. Please don't let your guard down. It's when we let our guard down when we get close to other people, our friends, our family members or co-workers, because we think that they can't spread COVID to us, or we can't get COVID from them. That's not true. That's exactly how it happens when we let our guard down.

CP24: Do you have an update on the pilot project by McMaster Health Labs, Air Canada and the Greater Toronto Airports Authority that tested international travellers on a voluntary basis?

De Villa: I'm afraid I might not be able to give you an update on that. I'm not sure what the Public Health Agency of Canada or the federal government has in mind regarding testing at the airport. I am certainly happy to follow up and close the loop with you after the fact. Because again, anything that has to do with the border, and even if it is Toronto's airport, which actually is located just outside of Toronto, is under the jurisdiction of the federal government. Okay, again, for people who are travelling, if you have symptoms, make sure you get yourself tested. Don't travel at that time. I think there are lots of good advice out there for those who are travelling for whatever reason.

CP24: Are we still trying to flatten, crush or bend the curve? That was a term we heard a lot six months ago, but are we now just sort of living with it and dealing with the 800 to 1200 cases across the province?

De Villa: It's a little bit of both. Obviously, when we're talking about the concept of flattening or crushing a curve, what we're trying to do and what we're speaking of is reducing the spread of the virus. And clearly, living with the virus in our midst means trying to do that as successfully as we can really rest on our ability to minimize spread. And those, of course, come back down to the measures for self-protection that you've heard me speak about so many times -- watching your distance wearing masks and washing hands.

CP24: In the two weeks prior to Thanksgiving, when the stipulations came in that we were told, don't expect the number to go down that much. But even since then, the case numbers, whether in Toronto or the province, have stayed about relatively the same level. Is that disappointing to you?

De Villa: It's not disappointing at all. We had said don't expect to see the cases go down. And in fact, what we're not able to show is what we prevented from happening. In fact, the case counts could have been much higher.

This interview has been edited.