Can you have coronavirus and not feel sick? A doctor answers your COVID-19 questions

Dr. Allison McGeer, an infectious diseases specialist answers questions about when to practice social distancing, COVID-19 infections, and possible transmission routes.

Dr. Allison McGeer is an infectious diseases specialist at Toronto's Mount Sinai Hospital

Dr. Allison McGeer is an infectious diseases specialist at Toronto's Mount Sinai Hospital. (Craig Chivers/CBC)

As the COVID-19 pandemic continues to change nearly every aspect of life in Toronto, many still have questions about the virus and the risk it poses.

Dr. Allison McGeer, an infectious diseases specialist at Toronto's Mount Sinai Hospital who worked on the front lines of the SARS epidemic in 2003, took your questions on CBC Radio's Metro Morning on Wednesday. 

Q: Is it possible to be a carrier of the virus without being sick? And if so, how would the person know they're a carrier and what should they do?

A: Probably not. There is some evidence that people can get infected with this virus and not show any symptoms. Those people probably don't carry it for any length of time. Their immune system will respond to it and they'll get rid of it. The evidence so far is that those people are less likely to spread the virus than people who are sick. 

Part of the reason for all of this social distancing and keeping away from people is there is a possibility that you could have this and not know it. It won't harm you in that circumstance. There is a possibility you could pass it on to other people. 

Q: Once you get COVID-19 and recover, can you get it again? 

A: We don't know the answer to that question yet. We're only two and a half months into the outbreak with this virus. We've never seen it before so we're not going to know for sure until we've had enough people who have been exposed. I think there's good reason to hope that if you've had it once, you'll be protected at least for a few months or a couple of years, but we don't know that.

It's a very unusual infection after you recover from it, you are not protected for some period of time. We don't know that absolutely yet. This is different from something like Ebola where we know once you've recovered from Ebola virus infection that you're going to be immune.

Q: Is there a possibility of COVID-19 being a recurring annual flu? We get the flu every year as opposed to SARS which didn't come back. 

A: We don't know. If it is a recurring illness, it will likely be milder in subsequent years. It's just like flu pandemics. When it first comes and nobody has been exposed to it before, you get a more severe illness. If you get recurrent infections, generally it's not as bad. So if this is a virus that causes recurrent infections, it'll probably settle into being a seasonal problem like influenza. And of course, if we have vaccine then things will be much better. But again, we do not yet know the answer to that.

Q: I'm a 70-year old healthy adult, and I live on the 24th floor of an apartment building. I hear that I'm not supposed to go outside but I'm just wondering if that would mean I shouldn't go on the elevator in the lobby in my building and go for a walk.

A: I think each of us needs to do what we have to do to get by and not going out and not going for a walk is something that you might be able to keep up for a couple of days. The goal here is not that you stay inside. The goal here is that you stay away from other people. There is nothing wrong with going outside at all as long you're staying away from other people. 

When you live on the 24th floor, that means if you take the elevator down, there's likely to be other people in the elevator. This is a balancing act. For those of us who are over 65, getting out and moving and getting exercise is very important. So I think you just maybe want to limit how often you do that and try to travel at times when there's not going to be so many other people on the elevator.

Q: People have also been asking about when they live in condos and apartment buildings about ventilation. Is there any risk around the vents? 

A: As far as we know this is not transmitted over long distances in the air, so there's no reason to worry about airflow in your house or your apartment building or your condo.

Q: Why are we not just protecting the most vulnerable people and allowing everyone else to continue with life? Why are we closing borders and asking everybody to socially distance?

A: We're not doing that at the moment because although this disease is much less severe in younger people, it still can be very severe. This is disproportionately more dangerous for older and more vulnerable people. 

There are still lots of younger people in Italy and around and in China who have died. The challenge is that there's a lot more younger people. Although the proportion of people who are going to die who are younger is smaller, the number of young people who are going to die from this infection if we don't control it is still going to be a very large number. 

Q: I'm a nurse working in the community. Is it a good idea to isolate nurses, doctors and health care professionals in hotels so instead of putting our families and patients at risk, we keep ourselves isolated in a hotel. We can then go to work and come back to the hotel on a regular basis until everything settles down.

A: As long as people don't have symptoms, the chances that they'll pass it onto other people is either zero or very small. With healthcare workers, we are focused on making sure that they are not coming to work and if they have any illness that they get tested immediately. 

Healthcare workers in the hospital are using precautions all the time to protect themselves. Based on data we have so far from Hong Kong, as long as we're using those precautions, health care workers are not at substantial risk. So we're not worried about healthcare workers going home and infecting other people at home or infecting people in the community. We want to maintain things as normal as possible for people. So I think that's why public health has not yet imposed any other restrictions on health care workers.

Q: I have some family members who work in factories. Factories have hundreds if not thousands of people and they've stayed open. Is it a safe idea to go to work with people in close proximity in line and touching the same parts as other people?

A: It's important for every workplace and for workers to think about what they can do to protect themselves. So I would hope people would have instructions about washing their hands, alcohol hand rub, and that people would be talking about whether they need to do extra cleaning and space people further apart. 

We're trying very hard to slow the spread of this virus while doing as little damage to our lives as possible. But we're not doing a little damage; we're doing a lot of damage to a lot of people's lives. The province and the country are still trying to find the right balance with the least amount of damage. Some services are essential and some things we need to keep going. We need to look at the situation and say how do we make this as safe as possible.