On March 12, only two months after the novel coronavirus outbreak, now known as COVID-19, started gaining traction in the Hubei province of China, the World Health Organization declared COVID-19 a pandemic. COVID-19 has now reached over 100 countries, including over 1,200 cases in the United States, prompting President Trump to declare a state of emergency on March 13.
In January, faculty from the Colorado School of Public Health convened an expert panel on coronavirus. Two panel members, Thomas Jaenisch, associate professor of epidemiology and pediatric infectious diseases, and May Chu, clinical professor of epidemiology, recently sat down to talk about what we know – and still don’t know – about COVID-19.
Jaenisch said, “Right now, we’re trying to buy more time – both to prepare vaccines and therapeutics, but also to slow the spread of disease and keep our healthcare systems from getting overloaded.”
Chu added, “You have to remember, we’ve only known about this virus for two months, and there’s still a lot we don’t know. So far, 80% of those infected develop only mild symptoms. About 20% of people are at high risk of developing more serious disease, usually those older than age 60 with comorbidities or younger people with underlying conditions.”
May Chu and Thomas Jaenisch, epidemiology faculty in the Colorado School of Public Health.
Topics covered include:
For those exhibiting symptoms of COVID-19, including low fever, headache and unproductive cough, Chu recommended they get tested if possible and then stay home. “You don’t want to be the gift-giver for COVID-19.”
Photo at top: Provided by the National Institute of Allergy and Infectious Diseases’s Rocky Mountain Laboratories.
Guest contributor: Shawna Matthews, a freelance writer specializing in science and healthcare.
Episode Transcript
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Shawna Matthews Welcome to CU Anschutz 360, a podcast about the CU Anschutz Medical Campus. We feature faculty, staff, and students, and their interesting and innovative work. I'm Shawna Matthews, a contributor in the Office of Communications at CU Anschutz. Today, we're talking about coronavirus. I'm here with two infectious disease experts from the Department of Epidemiology in the Colorado School of Public Health. Dr. Thomas Jaenisch is an associate professor of epidemiology and pediatric infectious disease. Dr. May Chu is a clinical professor of epidemiology. Thank you both for being here.
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So, back in January, you both served on an expert panel about coronavirus. About six weeks have passed since then, and quite a lot has changed in terms of coronavirus, now known as COVID-19. There are now over 100 countries infected, including the United States, and there are even cases here in Colorado. So my first question to you is, were you surprised by the trajectory that things have taken?
Thomas Jaenisch Yes and no. So, at some point, it had to happen, and there's many other countries that have taken a quick road, and have many cases, and at some point it also would have to come to Colorado. I think the main message that we should all remember is what we are trying to do now is to slow down the epidemic and to buy us more time. To buy more time in order to get ready with [the] development of vaccines and therapeutics and drugs. But also so that the cases are spread out over a longer period of time and that we don't overwhelm the hospitals, especially the intensive care unit capacities that we have.
Thomas Jaenisch So, I want just to put up front as the underlying mantra of what we are saying and why these measures that are taken now by the officials in Colorado and elsewhere are reasonable and the right thing to do.
May Chu And you have to remember, as far as we know, the number of cases that we have: 80% of those who get the disease are really showing mild symptoms. And it is the 20% at the highest risk that need to be worried. And those at the higher risk are those 60 years or older, and with the underlying comorbidity of some sort. And/or is a younger person that has already pre-existing disease that will just make it more difficult for them to recover.
Shawna Matthews That's interesting that you bring up the fact that most people will have only mild symptoms, because it seems like there's sort of an environment that's pervasive across the country of fear and confusion. People don't know what they should be doing to prepare or how to protect themselves.
So, just to get it out upfront, in case our listeners have only a few minutes to tune in... can you each tell me what your main message would be surrounding the current outbreak, as well as what is currently on your shopping list?
Thomas Jaenisch Main message - hand-washing and keeping the grandparents safe.
May Chu Yes. Also that if they develop some type of symptoms like a cold, they should check with the doctor's office, and the doctor will go through a triage list of questions and help them determine whether they need to be seen or not. And I don't think you need to be fearful, but it's good to be careful. Because if you are sick with COVID-19, you don't want to give it to the highest-risk, like your grandparents.
Shawna Matthews And what's on your shopping list?
May Chu I don't really have anything on my shopping list. I think it's important to remember the message, as Thomas just said, is that you have to wash your hands often, wash it well. And the reason is because it's easy to transmit it from your hands to your face, where your mouth, nose, and eyes are entry points for the virus. So if your hands are clean, you're not gonna be able to infect yourself or touch somebody else and infect them.
Thomas Jaenisch And we just practice it - the elbow check. Maybe everybody, even if you can't see it, listeners you can imagine (chuckles), that instead of giving hands, shaking hands - you can check the elbows.
May Chu And, you know, in Asia, they often say, this is why they bow respectfully - because they don't have to touch anybody, and still show their respect.
Shawna Matthews That's interesting. So you heard it here first. Touching elbows is the new way to say hello.
All right, so I'm glad you brought up symptoms, because that's the next place I wanna go: really getting into the nitty-gritty of the symptoms. So, it seems like the common symptoms that are associated with coronavirus are pretty common to a lot of things that happen, you know, colds and viruses that happen at this time of year. Low-grade fever, unproductive cough... How do people know if they should see their doctor versus just having some kind of bug that they picked up out in the world?
May Chu So I mentioned that if you're worried, you should check. It doesn't hurt you or harm you to check. And that if you have traveled outside where there's transmission of coronavirus, which seems to be more and more places, you should also check with your doctor. And if you have been in large congregated places where people are there together you may want to also let your doctor know that might be the cause of your worry.
Shawna Matthews So if a patient is tested, do you know how quickly they'll get their results?
May Chu It depends. Generally they'll tell you 24 hours, because that's the best way to do it. A test like this can be performed in a few hours, but they often also will do it twice to be sure, at this time, because the worst thing is to have a false positive.
Shawna Matthews Do you know how many people per day can be tested in Colorado?
May Chu I think in Colorado they have ramped up their ability at the state, and they can test up to 160 as of, I think, today. But generally, that's gonna be much more now commercial laboratories and other academic labs may also be providing the test. So it could be up to the thousands in a day.
Shawna Matthews So, early in the outbreak, there were a lot of stories about stigma and discrimination against Asian-Americans. Now the epidemic is in more than 100 countries. I'm curious what you feel your message is, related to the country of origin for outbreaks like this.
May Chu I could take that answer. I'm Asian-American, and at the very beginning, when it's unknown, and people are fearful, they like to ascribe the blame on something or somebody. And it seemed very easy to just castigate the Chinese for having been the source of this virus, for the eating habits and others. But I think as we learn more and more about it is that: this virus doesn't care what race, what ethnic group that you are, what age you are. It will infect you if your body accepts it. So it's really not that it came from China, it could've come from elsewhere and would've been something else. And I don't know if you wanna say, Thomas, anything about the Mexican H1N1 and how that started.
Thomas Jaenisch About origins of emerging infections, new viruses: each of them has their own story. And I remember when I was in med school, that we were taught that the integrated pig-duck farming in China would be the source where new influenza strains would emerge, because of that special, very developed agriculture. But it's not true, actually. The 2009 pandemic, if you remember, came from the Western hemisphere, likely Mexico or [the] United States. And the most devastating influenza epidemic of all times, the 1917 so-called "Spanish flu," originated also here in the Western hemisphere, probably in Kansas. So, it's actually not true to blame, or it's not fair to blame these people, or origins, or countries for their viruses. And in the end we have to deal with them as a global community.
Shawna Matthews One of the important things about this virus is that it seems to have a prolonged incubation period, where people who are infected are actually capable of transmitting the virus without knowing that they carry it. So, how has that complicated efforts to control its spread?
Thomas Jaenisch Well, if you imagine people with a temperature scanner at the airport, trying to picture who is infected or not - this won't work if people don't have symptoms. So if people don't have fever, they can still be infectious, they will not show up on any temperature scanner. And this is different for this virus compared to other viruses in the past. So this is a problem, or a challenge, that makes this virus much more difficult to control.
And that also contributes to the judgment of many of us in the field to say that we think this will likely further spread around the world. And that the length of this period, if it's two days or three days or four days, is not conclusively investigated right now. Maybe it's around two to three days. That will definitely be enough for this virus to have an extended spread.
Shawna Matthews So for the germaphobe listeners out there, how long can COVID-19 survive on surfaces?
May Chu So, you have to realize that this virus came upon us just two months ago. So there's a lot of studies that just are begging to be carried out so that we understand better, one of which is environmental survival. But if you look at the 2003 SARS coronavirus outbreak then, some studies were done in controlled laboratory settings and the virus has been shown to survive as long as eight hours on a surface. But it really is dependent on the surface, and the substrate that it's in.
May Chu Generally, I think sunlight and outside air dilution will mitigate the length that it will survive. So if it's something on a surface, and it's in the hot sun, it essentially will desiccate, and it will not survive very long. So I think prudence here, and being careful, is important, so that you clean the surfaces, and you wash your hands so that - if you touch something, you wash your hands so that you don't contaminate yourself.
Shawna Matthews So, Denver has the fifth-busiest airport in the country. Should we be worried about traveling by air? Should we stop flying places?
Thomas Jaenisch One has to make one distinction here, between the population and the individuals. So on the population level, airports will definitely help the virus traveling everywhere. And airports, train stations, and crowded places, soccer stadiums, or football stadiums - will help propagate the virus.
Thomas Jaenisch However, on the other side, if you ask me, "What is the chance that I can get coronavirus if I travel by air from Denver tomorrow?" It's likely gonna be very small. And, those two are two different perspectives on the same problem.
Thomas Jaenisch I think what we see right now is that many institutions, our university as well, has instituted travel restrictions now. To protect the workers so that they can keep on working, but also to slow down on average that spread of the virus.
Thomas Jaenisch Should we stop flying? Yes, we should maybe fly less. I think that the personal risk of catching the virus when we fly right now is still small. On the other hand travel restrictions that are implemented now will help slow down the epidemic.
May Chu And I also think that if you're in the high-risk group, like you're 60 years and older, and you've got some underlying comorbidities - you should consider staying put for a while and not fly. Because you're the highest risk.
May Chu We also are aware that Colorado has a huge ski industry, and huge recreational industry that depends on travelers from all over. And it's certainly shown in especially our first case and a few of the other cases of patients under investigation - are those that came from afar, up in Pitkin County and Summit County, which is our high ski season area.
May Chu So, there is the risk. But I think Thomas is right, that if you are personally in the age group, the risk of you getting it is low. The risk of somebody who gets on the airplane who may have been exposed and then decides to travel, and then becomes the vector of the virus, then that's something different. So, you do take a risk traveling, and you do wanna make sure that you stay away from people who seem ill.
Shawna Matthews So, we are heading into the end of ski season, it's March, it's getting warmer outside. Do you think that as we head into the spring months, that will slow the spread of the virus?
Thomas Jaenisch Personally, I think yes. But there's a large uncertainty. We don't know enough about this virus. We have to make assumptions, and we compare it with other viruses that we know better, like the influenza virus. And we know that the influenza virus is transmitted by airborne droplets and by direct contact. And the transmission via airborne droplets is depending on the temperature, on the moisture in the air, whereas the direct contact is not. It's more depending on people's behavior - if they wash their hands, if they touch door handles.
Thomas Jaenisch And the mix of these two transmission pathways, they make up the overall transmission. And if this virus behaves like the influenza virus, or other common cold viruses, then it will likely decrease when it gets warmer and drier. Colorado has quite a dry climate - and warm and dry together are the best conditions for the droplet transmission to slow down. But that's just speculation again. We can't be sure at this point.
May Chu Yeah, and another factor that might play into this is that this virus, as I mentioned earlier, appeared two months ago. So everybody has not been able to build up immunity to this virus. So generally, influenza and others that are cyclical and seasonal, most people have either had vaccines or have had one or two influenza episodes. So they have antibodies. That means that they get infected they can at least mitigate the transmission.
May Chu In this case, it may spread even further with or without conditions. So it may be that's not in Colorado, but it could be elsewhere where the conditions are just right. It could be chugging along, and then all of a sudden we have another outburst next year.
May Chu So, I think for scientists: it's hard for us to predict. It is also for us to be aware and be ready next season if it happens.
Shawna Matthews So, another occurrence in the spring is a lot of really big academic conferences, so tens of thousands of people congregate in a fairly small space. And so it seems like the fate of these is kind of up in the air. Some have already been canceled, some are just kind of hanging on a knife's edge. So, what do you think? Do you think they should be canceled? Or if they're not, what advice would you give to people who go?
Thomas Jaenisch Some of my meetings have already been canceled, where I was supposed to go. One by WHO [World Health Organization]. And I think it's reasonable it was canceled. Also because some of the people are working on different areas, and now have to concentrate on coronavirus and not work on another area for the next few months.
May Chu And I would say that canceling now is really about putting what we call a social distancing cordon around to prevent it, to take away the chances where it could spread. Because we just don't know who's coming, and who's gonna congregate, and where they came from. So I think [it's] best right now while there's so many hotspots around the world - it's good to be prudent, and not travel and not put yourself at risk.
Shawna Matthews So right now there are positive coronavirus cases in most states in the U.S., but not all. Do you think it will eventually reach every state?
May Chu Yes.
Shawna Matthews At least in the mainland? Yeah?
May Chu Yes.
Thomas Jaenisch I think so. Yes.
May Chu Mm-hmm (affirmative).
Shawna Matthews Dr. Jaenisch, you talked about protecting the grandparents. And so that comes down to populations that are particularly at risk for contracting COVID-19. So, can you talk a little bit more about the infectiousness of the virus? If you're in a room with someone who is infected with the virus - will everyone in the room contract it? Or are there certain populations that are more likely than others to develop that?
Thomas Jaenisch Those are two questions. One question is, how likely is it that I'm in the same room and have contracted the disease, and how many people on average will be infected by one person. And the third question, if I'm infected, how likely is it I'm getting a severe course of disease, or even die of that.
Thomas Jaenisch So, it has been estimated that: let's say between one to two, maybe three people are being affected by each case. So that we call the 'basic reproductive number,' in epidemiological terms. It's estimated between 1.5 to 2.5, or around 2. With that you can see easily if everybody infects another two people, the virus will propagate, and will cause a larger and larger epidemic. Until, on average, people are already sick and have become immune, and then they can't contract it anymore. And then this number drops below one, so that every person on average can infect less than one other person. Then the epidemic will die out eventually.
The other question is, if I'm in the same room, what are the probabilities of being infected. And that depends on, on the distance, on the social distance, or on the distance in the room. It seems that if I'm around one to three meters away, then the probability is very small.
May Chu So somewhere between three to six feet is sort of what they advised. And CDC's advising six feet from someone to keep the distance. Cause droplets travel about maybe three feet. Especially on a sneeze or where it drops. So, little bit beyond that is prudent.
Shawna Matthews What about kids and risk of COVID-19?
Thomas Jaenisch Yeah, kids seem to be safe. There have been some reports now showing that children on average don't get very sick - there's less severe disease in children. However, children are incubators. They can transmit the disease. And again, remember: if you have to go to work and the children can't go to school because the school is closed, and you ask the grandparents to have the children - that's putting the grandparents at risk.
Shawna Matthews So really the biggest fear with the COVID-19 is this mortality rate. That everyone is afraid that, what is it, one in five or one in six people will get really sick and, and some do in fact die of COVID-19. So, do you have the current best estimate for the worldwide mortality rate?
Thomas Jaenisch Oh, it differs according to region, it differs a lot. So I've heard various numbers. If you look at the official numbers, it seems to be around 2%. That might be an overestimation, because we don't know all the people who are infected but show very mild symptoms. And that reflects back to the capacity of testing. Because you can't easily scale up testing. And then what you end up doing, you test those that have more severe symptoms, so you test the more severe end of the population. And those that don't have any symptoms, or have mild symptoms, they go unnoticed. So it's most likely an overestimate.
However, it's clear that the case fatality rate - so the probability of dying once you're infected - is depending on other risk factors. And some of these risk factors have been mentioned. One is age, one is comorbidities, other diseases. We are not yet at the point where we can tease those apart and say what the independent effect is. And I wanna give one example. So it seems that the data from China shows that men are at greater risk as compared to females. At the same time, we know that in China, many men smoke. It might be that this factor is just due to the smoking in men, and not by the fact that they are males versus females.
And so, this work we still have to do, and we have to do it for many other risk factors in order to, um, to calculate or to estimate the individual contribution to that risk.
May Chu Yeah, and often this mortality rate gets sort of finalized years after an outbreak. Because then we really know what the exposure was, and how many deaths there were, and then we can calculate it. And for instance, SARS in 2003, the mortality rate was 10%. The reason that it's at 10% is because they identified about, 8,000-some cases, and then about 10% of them died. And then the disease disappeared. So then it stands at 10%. Were we able to follow it two, three years, and know who were exposed, then it would've been a lot lower.
So that comes to where you're talking about whether this is gonna stay or be seasonal. So if this because a seasonal, and it comes back again and again - we'll know better how to look at it. And when we count the cases of death due to this disease, it will be a lot less, because we have a lot more people infected.
But should this disappear tomorrow, then it is gonna be where it is. Because we won't know better.
Shawna Matthews All right, so, to wrap it up and to put it in a bite-sized package for people to walk away with - so what are your key 'do's and don'ts' in terms of reducing possible exposure to COVID-19?
Thomas Jaenisch Well, again, hand-washing, social distancing, avoid larger meetings. And if you can, cancel travel. Think about those who are most at risk and that need that protection. That is, as we said already, the elderly, but also people that have some kind of disease or immunocompromised. They need to be protected.
May Chu Yeah, and I think this is a time, if you're sick - you should stay home. You should not be the gift-giver of a disease to others.
Shawna Matthews Is there anything else either of you would like to add?
May Chu So I think we shouldn't worry so much about this immediate fear and impact. You know, other diseases will come too. For which we won't know how it will play out. And a lot of answers right now is our best guess, and we won't know. So we can't make people feel that comfortable. But be assured that 80% of people who do get the disease do not show serious disease. And that should be something you keep in mind.
Shawna Matthews Great. Thank you. Dr. Chu, Dr. Jaenisch, I think that's all we have. Thank you for your time today.
Disclaimer: Transcripts are generated using a combination of speech recognition software and human transcribers. It may contain minor differences from the audio, including some edits for clarity in print. Please check the recording and with the Communications team before quoting in print.
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