Hi everyone. My name is Matt McQueen, and we're going to go through some public health measures as it relates to COVID-19. First of all, welcome. My name is again Matt McQueen. I'm epidemiologist, PhD trained. Actually, I'm undergraduate here at University of Colorado Boulder in the early '90s and went on to get my Masters of Public Health, the University of Washington, Seattle, and then did my Doctorate work at the Harvard School of Public Health. Most of my research has been focused on genetic and molecular epidemiology, less so with infectious disease epidemiology. But again, with the broad training we have through our graduate work, we obviously are focused on any of threats that emerge in the public health arena. COVID-19 obviously being most pressing matter given our times. I wanted to start quickly with how we approach different aspects of disease, how we approached the disease process, what we want to study, what do we need to understand? Understanding the natural history of disease is very important. As you can see here, there's a series of different steps that this kind of emerges from. We have this pre-pathogenesis period. We have a period of pathogenesis, and then we've got these different layers down here that refer to different forms of prevention. This pre-pathogenesis period is really, this is before individuals have become infected with the particular virus, agent, bacteria, whatever we happen to be studying. All of the things that we do at this stage here is really to try to understand what is it about the host being the human, the agent, in this case, it would be the virus. Of course, the environment in a certain context of time. How are those things coming together to then maybe increase your risk of actually catching an infection. That's an important feature. As we move forward from that, once you do get infected, we've got this early pathogenesis phase. We're in this early phase, you're infected with the agent, you may not know it yet, you may not show any symptoms, you may never any symptoms as we see in the context of COVID-19. But this pre-clinical phase, this is an important time for us in public health to establish maybe some opportunities to screen. When we say screen, we're saying we're trying to find people who may have a disease or may have an infection and yet they don't know that they have that infection. That's trying to catch the infection even before somebody knows they're sick. We see that in more chronic disease epidemiology. For example, when we're screening for things like certain types of cancers, we may screen for heart disease, measuring someone's cholesterol levels, that may be screening them to understand their risk of developing disease. Then finally we move into this next phase, which is the clinical phase. This red arrow here, where we're talking about now if it's an infection, you've got the infection and now you're starting to show signs of the disease. That's an important step because obviously now you may require clinical care. It may be severe. It may be something like you need to be hospitalized. It may be something like you need to isolate yourself. If it's something like heart disease, you could start showing signs of having some heart trouble, maybe shortness of breath, tightness in the chest, for heart disease. Then obviously this move towards different outcomes. The scariest and most concerning outcome we have obviously is death, people can die. We have disability, chronic disease. But then people also recovers, we're seeing a lot with something like COVID-19. Throughout this, we've got these stages. Different types of health promotion for the pre-pathogenesis period. This course itself, I would consider in this health promotion we're trying to educate for people to understand what's going on with COVID-19. Why is it concerning? What do we need to do? Why are we wearing masks? Why are we walking around trying to socially distance and things like that? Those are all measures earlier on in the phase where we're talking about health promotion. Again, we move towards more of the pathogenesis phase with clinical phase where we're talking about traditional clinical care. Most of medical clinical care focuses on treating people who are already sick, although there is a lot of preventative and secondary type prevention that goes on as well. If we look at this very specifically with COVID-19, we can see again now instead of just a generic agent we are talking about, the SARS-CoV-2 virus that causes the disease of COVID-19, the host, that's us, humans, environment, and time. Again, we know that an active infection doesn't necessarily race to the signs and symptoms. In fact, probably a quarter of all of you, even if we are infected, may not even know it, you would be completely asymptomatic. Some of you may have mild symptoms. "I got this headache, sore throat." Okay, those are very mild and may not necessarily be attributed to what you hear about as being more severe forms of the disease. Some of you then may progress, some of us may progress to something that's more sort of classic of COVID-19, shortness of breath, headaches. You may have a loss of taste and smell, these are more overt symptoms that are indicating at the start of the clinical phase. Then again, fortunately within COVID-19, many progress to recovery, although some we're seeing obviously have died, and then beyond that, we are seeing some long-term disability. Let's go through some of these for COVID-19. We know in the pre-infection stage, the transmission dynamics of SARS-CoV-2 is fairly contagious. Is it as contagious as something like measles? No, but on average, you've probably heard of this R_0, it's an R with a little 0 subscript next to it. This R_0 is telling us something about how quickly it can spread through a population. With SARS-CoV-2, depending upon the environment, depending upon the time you're spending with somebody who's sick, that R_0 can be anywhere from two, maybe up to five. Measles, again, given the right conditions, can have something like 14. What that means is that one person who's sick can infect 14 other people on average. That's remarkably contagious, measles is. SARS-CoV-2 is somewhere in that two to three range, on average, for most people. Things that we do to protect ourselves, to stay far away, wearing masks, washing her hands, right. All that is doing is trying to suppress that R_0 to a level that's more manageable in terms of an outbreak and epidemic. What are some of the host factors? So those are the agent factors. Some of the host factors, we know that for whatever reasons severe illness seems to impact males more than females. Age is an incredibly strong predictor of both actual symptomatic infections but also more severe illnesses and death. Underlying medical conditions, this has been written about in research papers and so on. Individuals with certain types of underlying medical conditions, chronic, uncontrolled respiratory conditions, cardiovascular disease, type two diabetes, preexisting cardiovascular factors as well, those seem to predispose one to more severe outcomes of the infection. Obviously, you've seen a lot of socio-economic and occupational factors. We've seen this fall along lines that sort of uncover, right, related to this course. Some pretty severe racial, ethnic-racial, disparities in terms of health, and this is no different. This is something that is impacting communities of color at a higher rate and severe illnesses, deaths tend to be falling on individuals of lower socioeconomic status compared to others. What about the environment? Well, we know now, that indoor crowded, poorly ventilated spaces, we talked about it. If you're in a space and it's loud and you're talking loud and, people aren't wearing mast and you're crowded around other people, that's probably the wrong space to be in terms of risk for SARS-CoV-2. So indoor crowded, poorly ventilated spaces are, the environment has a huge role in the transmission, and certainly, we know now that it can, not just droplet, but also through aerosols, can spread from person to person. Time is absolutely important as well. Extended periods of exposure, there's likely a dosage aspect to this with the virus where the more kind of virus that you're exposed to, the higher likelihood that you are to get infected, the higher likelihood that infection may move towards more of a clinical illness and severity and so on. Unprotected health care workers very early in this pandemic were hit very hard because they were not properly protected by PPE and so on. That led to some early tragic deaths of health care workers among otherwise healthy individuals, and it's likely because their dosage to the amount of virus that they are exposed to is so high and for an extended period of time. As we move into the activity of infected, we talked about this, but approximately anywhere from 25 to 75 percent of infected individuals will be asymptomatic or just very mild symptoms. Now, when we go back and look at that and you really prod and you drill down, some people will say, "well, I actually had a headache, or I had some gastro-intestinal distress." But not the classic, ''my chest is heavy, I can't breathe'' and so on, and so forth. Those are some factors that we are still unpacking. The real stickler with this virus is that you're probably the most infectious, about one day before you develop symptoms if you are going to develop symptoms. That is a nightmare because you don't know you're sick, and so you're out actually spreading this to others. Which is why masks are so important because wearing a mask, you don't know if you're sick, so you might as well be careful and cover yourself up, it's important. Into the more clinical phase, again, those experiencing symptoms anywhere from ten to 30 percent will require hospitalizations. Both of these are strongly influenced by host factors. Underlying medical conditions, age, those types of things. The younger you are, the less likely you are to exhibit symptoms, obviously, it's no guarantee there are people, young people, who have gotten very sick with this but it is more rare, compared to individuals who are older, 75-80 years old. Outcomes from this? Again, people are dying from this, of all ages. The more likelihood of severe illness and death tends to aggregate in the older ages and people with multiple underlying medical conditions. They're also seeing some potentially long-term cardiovascular effects as well. For example, myocarditis, which is an inflammation around the heart. Looks like it's part of this process of recovery, which again, you can recover from. The inflammation of the heart is something that happens potentially with other viruses as well. We know that, but again, with this virus, it's an indication that the immune system was fired up, and causing systemic inflammation, which then can impact the heart. That requires recovery. You're not just going to bounce back. Your lungs may require to recover. That's true of the influenza, that's true of other viral illnesses that we get. The body needs to recover, the body needs to get better. That can take time. Bodies to heal, it's going to require some time. Case fatality rate is probably lower than one percent, which is encouraging, but that strongly depend upon age. Case fatality rate can be pretty scary high among older populations, 10, 15 percent. The good news is if there is good news, younger populations tend to be much less affected in terms of death. What can we do? What are some primary prevention measures that we do that prevent individuals from getting infected with SARS-CoV-2, therefore preventing all these downstream issues as well. We can just reduce density. Just fewer people in the same place at the same time. That just robs the agent of host to infect. Plain and simple. Decreased social connectedness. We've done this thing where we're trying to cohort you, and you're trying to take classes with the same people. Unfortunately, we're trying to disentangle some of the social connections to where you have stronger, smaller cohorts that you're working with rather than being thrown out into the entire campus for this year. Wearing masks, of course. That's literally trying to prevent you, mostly from you infecting others, but again, two people wearing a mask, that's safer than anything else, whether one or the other is not wearing a mask. Washing your hands, cleaning surfaces. Making sure the ventilation in the building is changing air over at a rate that cleans out any viral particles that are in the air. Of course, courses like this, education and awareness, making you all aware that this exists. What can you do? How can you prevent infections? All of that stuff is very, very important. For active infections, we're trying to find, and many of you went through this. If you moved into the residence halls, you had to provide a tests, a PCR test as you are moving in or you got a test done right at moving. Why were we doing that, especially if you didn't feel sick or you don't have any problems? It's because we're trying to find the infection before you know, or you ever will know that you had it. That's the whole point of that. We're trying to pick things up in the pre-clinical phase. For some of you, if you were picked up by this, you may never progress towards symptoms. Why we did that is because we can identify who ends up asymptomatically ill to tell them, "Hey, you've got to slow it down. You could be infecting other people and you don't even know it." Even though you feel great, you feel fine, you don't feel any problems, you've got the virus, we can detect it in your nose, your saliva, therefore, you can spread it. That's that early types of things that we can do to really detect people who don't know they're sick, in this early pre-clinical phase. Other things we can do, we can just talk about symptoms, we can look at symptom screening. We can try to screen populations for, "Yeah okay, you got a headache but you don't feel any respiratory symptoms." We can do things with information that you're providing on the daily questionnaires and so on, to give us a sense, a pulse of what's going on on campus to understand. Is it presenting in a weird way on this campus? Is it presenting in a weird way among 17, 18, 19 year olds? That's a question that we want to address. When you get to clinical phase, obviously you need clinical care. Health care providers, this could have some mental health consequences if you're isolated, you feel alone. Then we manage the cases that come out. Who's getting sick? In terms of what do you need? Do you need food delivered, do you need face time Internet connection? How's your computer to connect if you need to take a class, all that stuff. Then lastly, this one here we have rehab, monitoring, and therapy. For those who had the infection and now recovering. They're convalescent phase, they no longer have the infection, but they'll still have some issues they may need to work out. You may need to watch for cardiovascular issues. Maybe you've got some neurological things, your sense of taste and smell are taking a while to come back. Those are some things that we're monitoring and obviously where appropriate would be provided therapy and care. The three domains, primary prevention. The goal of primary prevention is to prevent the infection from happening in the first place. Wear your mask, wash your hands. Don't pack into crowded spaces and yelling and screaming, primary prevention. Secondary prevention, we're trying to find people who are sick but don't know that they're sick. That's more with screening. Tertiary prevention. Okay, you're sick, and okay, you're showing signs of illness. How can we help you? How can we support your care and so on and so forth. When you look at these things, we hear a lot of this in the media. The vaccines are being developed, they're being ramped up quickly. Record pace. I'm hoping by the time you're watching this, there's even more encouraging news about vaccines coming down the pipeline. But vaccines are primary prevention because you essentially create an environment where the agent cannot actually infect the host, because we have pre and planted immunity to this thing, to this particular virus before the virus even touches your nose or your whatever. That is truly primary prevention we're trying to ward off the infection before it can move to the infectious phase. You get infected with it, just like vaccinations for measles mumps rubella, other things, you won't even move to the active infection phase with the vaccine that works well. Rapid testing, you participate in this if you did move in testing, this is this RT LAMP antigen test, these are 30, 45-minute turnaround time. These are really important because we don't want to wait three, four days for results for the test we want to know now so we can act quickly. People who are becoming infectious, we want to tell them in 45 minutes, you are actually shedding virus, you're infectious, you need to be careful and not infect your friends and your classmates. That has to happen quickly rather than we test you, come back a whole day later, think about your life and 24-hours, how much you can do in 24 hours that ends up spreading it to others, so rapid tests are going to be a big part of this response. Then drug development you've heard about Remdesivir, Dexamethasone is another one where these are helping people recover, really to prevent the worst outcomes of this infection. To make sure that you're not going to disability or death or things like that, but that treatments help you recover and that's the drug development pipeline. This is convalescent plasma, convalescent plasma, things like that that are used to once you are sick and you're very ill and hospitalized, what are some drugs and therapies we can provide that essentially assist the recovery, towards recovery and not towards death. Some implications for this illustrated that the natural history of disease is incredibly important, whether you are talking about concussions, whether you're talking about cardiovascular disease, breast cancer, there is a natural history. The goal is in public health and epidemiology and so on is to identify stages of that national history that we can intervene to break up what would otherwise happen. We can do that through primary prevention, that's the best way a vaccine, no one gets sick. Great. Primary prevention, everyone eat well, exercise and so on, that will prevent, plaque formation in the arteries and prevent cardiovascular disease. But really we want to identify all chains and it's important, is that with the second here, we want to attack the natural history from all angles. We want to develop therapies, want to develop vaccines if it's infectious disease, we want to work on better ways to screen, isolate, find people who don't know they're sick. If we attack the primary, secondary and tertiary measures, we have a chance to keep things under control in terms of the worst outcomes, but also preventing people from getting sick in the first place, and once you do get infected, identifying them quickly in removing them from infecting others as well. I wanted to conclude, generally speaking, without any sort of content on the slide. I just want to talk through this stuff that, public health in this country. You're living through a time, 2020 as being in college and 2020, which is going to be one for the history books and in many different ways, I know it's hard, I know it's difficult to manage, everyone wants to get back to normal. You will look back on this year, I promise you remarking at what went down. This, I also will be a defining moment for public health in our country and I think the awareness that's growing, we could all probably understand that it had, we spent a little bit more time, effort money on preventing the pandemic, it would have saved a lot of money. The whole ounce of prevention is worth a pound of cure, that's exactly the primary, secondary, tertiary prevention. It's a lot easier, a lot cheaper to spend money and primary prevention, preventing things from happening than the cure, which is the tertiary prevention, that's very expensive, you're talking about life and death and so on. Try to embrace as much as you can what the time you're living in, I know that sounds crazy, you will tell your grandchildren about this, I promise you, this is one of these generational, we hope generational events that will be for the history books. If you're interested in public health, we started a public health certificate program a few years ago. Here's the website you can look it up or you can just google Public Health CU-Boulder, we have lots of courses that are interesting in this area. There's a whole certificate you can graduate with, that really compliments whatever coursework or interests you have on campus. We have sociology majors who are public health, we have engineers, we have folks in business, we have folks in obviously all the biologies, MCDB, E-bio, IFI, anthropology, international affairs, you name it. It's a very interdisciplinary program for good reason because public health, as I'm sure you're finding out, is incredibly interdisciplinary. It can't just be epidemiologists that can't just be docs and nurses, it can't just be policymakers and we all have to come together to fight this effectively. Thanks for your time.
