Everything You Need to Know About COVID-19 Right Now

A Q&A with emergency medicine physician, Dr. Zachary Levine

When we last spoke to you in early March, we were still at the early stages of understanding COVID-19. Can you offer any more insight into how the virus is spread and the incubation period?

One of the few things that has remained stable is how we contract the virus. COVID-19 is spread by droplets that land on surfaces.

I think people still get confused between airborne and droplet because droplets are of course airborne for a little while before they fall to the ground. Respiratory droplets are not so small that they stay airborne for a long time like measles, for example, making them less transmissible.

The majority of people catch the virus by touching contaminated surfaces where droplets have landed, then touching their face. You could catch the virus if someone sneezes or coughs on you, but just walking by someone with the virus is not considered high risk.

In terms of the incubation period, we’re still estimating that to be 1 to 14 days between the time you catch the virus and show symptoms. The problem is that you can transmit the virus before you have symptoms.

How long can the virus live on surfaces?

Studies have shown that it can live on copper for up to 4 hrs, on cardboard for up to 24 hours, and on plastic and stainless steel for 2 to 3 days. This is why wiping things down is so important.

Have the symptoms of COVID-19 evolved?

The most common symptoms of COVID are still fever, cough, and shortness of breath. However, we’re recognizing that other symptoms can show up as well. I had an 80-something patient whose initial symptoms were that she felt weak and had one episode of diarrhea. She had none of the classic symptoms, so we didn’t initially test her. But when we did, she was positive for COVID-19.

It depends on where you live and what hospital you are at, but where I work (at the Montreal University Health Network – MUHC) many patients presenting to emergency are now being tested. We’re testing people with vomiting, headache, acute loss of smell, and diarrhea. We’re testing elderly people if they are experiencing weakness and loss of consciousness. I think it’s the right thing to do.

Testing many people, even those who are less sick, will give us a better idea of how many people have the virus, and how deadly it actually is. It will also tell us how many people are less sick but are still contagious, so we can protect the population better.

We’re still asking people not to go to emergency [with mild symptoms]. Whether it’s COVID, the flu or a cold, you need to stay home, stay away from others, and rest.

Can you explain what ‘flatten the curve’ means?

When we keep people apart (through social distancing and self-isolation), we reduce the likelihood of having a massive peak of people who are severely and critically ill at the same time which could overwhelm the [health care] system. If many people are sick at once, we will have to make the difficult and awful choice about who gets resources like ventilators.

Flattening the curve means we can treat everyone within our ability and within reason. The downside is that the distancing period ends up being longer. But, a more gradual rate of infection and fewer people infected at any moment of time means we can treat more people, and less will die.

How can people reduce their risk and their risk to others?

By staying home as much as possible, socially distancing by keeping 2 meters or 6 feet away from others, washing their hands properly, and not touching their face.

Masks have become a much-discussed topic. Are they necessary?

The mask argument has gotten more and more interesting. People are either very strongly for or against wearing them.

The reason for this is varied: [In some places] N95 masks are in short supply for health care workers. If they don’t fit properly, particles can still get in. If they get damp, they are not as effective. People wearing them can also be overconfident and not wash their hands or touch their face more often.

In my opinion, there is probably no harm in wearing a mask when you go outside. Even the cloth ones [that many people are making themselves] can offer protection by blocking some particles.

Centers for Disease Control and Prevention (in the United States) is now endorsing the use of cloth face coverings. But [as of now], I don’t wear a mask in public myself, and I only wear one in the hospital when I’m seeing a patient.

Masks are more important for people who have symptoms so they are protecting others, but I don’t condemn anyone who wears them, especially if it makes them feel more secure.

If you do decide to wear a mask, it’s crucial that you wash your hands and not touch your face. And unless you are a health care worker, you don’t need an N95 mask, especially when there are shortages in some places. If you make your own, use a thicker cloth – bandanas are thin and not as effective – and make sure you can wash it.

In the beginning, it was thought that immunocompromised and elderly people were most at risk for catching COVID-19. Is this still the case?

Adults generally catch the virus at the same rate, no matter their age. But, in terms of lethality it’s heavily weighted towards older people. The rates of infection between the ages of 50-80 seem quite similar, then seem to go lower with each decade under that. But the older you are, the worse it is. Also, more men are dying from the virus than women and we don’t yet know why.

If you have certain health conditions, you are more likely to do poorly. These include high blood pressure, heart disease, morbid obesity, chronic kidney disease, liver disease, diabetes, COPD, and anything that makes you immunocompromised like being on chemo, having AIDS, or an organ transplant. The more of these illnesses you have at the same time, the higher your risk of death.

Could warmer weather kill the virus? Could it then come back in the fall/winter?

There’s certainly evidence that the virus responds to things like windspeed, temperature, and humidity. Viruses tend to prefer cooler weather for their survival. Having said that, the effect of temperature isn’t enough to completely take care of a pandemic. The Spanish flu, for example, peaked in the summer months. Climate will help but it’s not enough, we must still do everything we’re currently doing such as social distancing etc.

There is definitely a concern that it could come back in the fall. But, if we flatten the curve, open the borders, and people start to travel, it could come back and we could have another peak, regardless of weather.

How can people reduce their symptoms if they do contract the virus? (We have heard things like Advil and Elderberry can make it worse.)

In general we’re recommending Tylenol, rest, liquids, and a humidifier if you have a sore throat. Some French doctors were advising against ibuprofen (aka Advil), but right now this is only observational. Still, until we know for sure, I don’t recommend ibuprofen and recommend sticking with Tylenol.

I don’t have any evidence for or against elderberry, but I don’t recommend it.

There is a lot of research on treatments and [for more serious cases of the virus] we are trying things like antivirals and anti-malarial drugs. There is some evidence to support these as treatments, but it’s still too early to know for sure.

How concerned should we be about contracting COVID-19 through food and packages (i.e. cardboard boxes)? Should we wait 72 hours before opening packages and wipe down all of our groceries?

There is still no evidence of the virus being transmitted through food.

I don’t think you need to wait 72 hours before opening packages, but it can live on cardboard for up to 24 hours so I would get rid of cardboard and wash or wipe off packaging.

But the truth is, the greatest risk is from touching things like shopping carts and other surfaces so it’s important to wash anything you think could have been contaminated.

What has been the most common misconception that you’re seeing/hearing about the virus?

Some people think only old people can catch COVID-19 (not true, but they do have a higher risk of death).

Cats and dogs spreading the virus is not founded.

I’ve heard some people say you have to be with someone for 10 minutes or more to catch it. Yes, the longer you are with someone the more likely you can catch it, but you are more at risk if their viral loads are high, no matter how little time you spend with them.

If someone is exposed to COVID-19, what should they be doing?

They should isolate themselves, quarantine for 14 days, watch for symptoms, keep themselves away from other people, but most importantly, monitor for fever, cough, and shortness of breath. Keep yourself in separate part of house if you can.

If you’ve had COVID once, can you catch it again?

We don’t have a definite answer to this yet. Most people who’ve had a coronavirus seem to develop a short-term immunity, but it is mutating rapidly so it’s possible you could get another strain. If it’s not mutating fast, we could use the antibodies of people who have survived it to develop treatments. But we don’t know if you will be immune for life. The jury is still out on this.

Are we any closer to developing a vaccine or a treatment?

We’re likely a year away from a vaccine. As for treatments, I think we’re getting pretty close to finding something. Studies are ongoing and there are a lot of resources being put into this. Some treatments being looked at are hydroxychloroquine, chloroquine, anti-viral medications like remdesivir, and prophylaxis which could prevent you from coming down with it if you are exposed. In the hospital now we are using a combination of medications including antibiotics and antivirals that have shown some promise. I’m feeling quite optimistic we will get somewhere in the next few months.

What is it like for you and your health-care colleagues right now, working on the frontlines?

It’s a worrisome time. There are a lot of unknowns, we worry about bringing the virus home to our family. We are seeing a lot more people with COVID. The real concern are the ones who get sick very quickly and need to be in the ICU. If we see someone who needs 4L of oxygen we get ICU involved right away and that’s not how it was before.

The hospital I work at is paying close attention and dedicating a lot of time to planning for how we will deal with bigger numbers if they come. It’s a stressful time, but it’s nice to see people work together. We really appreciated the support we’re getting from the public. We’re doing our job, and I’m getting to see my family, but no one knows how it will go.

Still, we are hopeful.

Dr. Zach Levine is an emergency medicine physician at McGill University Health Centre and Associate Professor at McGill University’s Faculty of Medicine. Dr. Zach is passionate about educating people about their health and empowering them to take control of it. He appears regularly on television, radio, and print.