How To Manage Your COVID-19 Risk

Malosh: I've been working in influenza, epidemiology and vaccine effectiveness for quite some time now. And one of the things that we've seen consistently with pandemics and if you look back at like SARS or MERS, there's this phrase that they always use when there's a new virus circulating and causing these kinds of diseases and its “cluster of pneumonia with unknown cause”. And so when I saw that phrase being used in December, I was starting to get worried because I'm not on any immunosuppressant drugs, but my immune system is not exactly 100% because I received a bone marrow transplant in March of 2019. I was diagnosed with leukemia in November of 2018.

I've had to be very cognizant of infections and I've been thinking about protecting myself as I go out into the world and mostly the way that I do that is not going out into the world, right? This is a known thing, right? If you wanna avoid infection, you don't come into contact with other people.

So for me, it was relatively easy to accept because it was life or death. I had a high perceived risk of infection, and so I stayed home. And if I was gonna go out into public and I wasn't sure if somebody was gonna be sick around me, I wore a mask. And if people were gonna come over to my house, my family or whatever, to see me, we asked them don’t come over if you have any symptoms.

So I was set to come out of isolation on March 9th, but the rest of the world sort of joined me at home instead. Obviously it was hard to have that extended, but in a sense I'm a little bit used to what we're all going through now because I've been doing it for a while. And there's a lot of people that are like me. They're not old. There's a whole host of different cancer survivors or otherwise immunocompromised people. Anybody who received a transplant of any kind is gonna be on some immunosuppression, just so that their body doesn't attack the new organs. And so I currently am very healthy. I don't feel sick. I don't look sick. You wouldn't necessarily know that I was a high-risk person for COVID-19 just by looking at me.

But you know, all of these things that we're doing to stay home and consider the risk that we might be putting other people at, that all is really helping protect me.

Speaker 1: Ryan Malosh is an assistant research scientist at the University of Michigan School of Public Health. In his work, he studies herd immunity and a respiratory virus epidemiology - tracing the ways diseases like COVID-19 travel in populations. And as a survivor of leukemia and a bone marrow transplant, Ryan and his family have first-hand experience managing infection risk, making the kinds of decisions we’ll all have to consider in the coming days, weeks and months.

Hello and welcome to Population Healthy, a podcast from the University of Michigan School of Public Health. This episode is part of a series of special editions of our podcast, focusing on the ongoing coronavirus pandemic.

Now that the weather is getting nicer and states like Michigan are beginning to loosen their restrictions on gatherings, retail shopping, and more, how do we keep an emphasis on safety? As the pandemic continues, how do we assess our own risk? And then the risks to friends and family, as we had out of our homes, looking to reconnect and return to public spaces.

Malosh: We have been given a strict set of instructions over the last couple of months - stay home as much as you can. The restaurants are closed, the bars are closed, most workplaces. And so it's very easy to follow those guidelines because they're so strict. Now that we are getting to the point where we're starting to see decreases in cases, particularly in states like Michigan, where we're starting to really see the case counts come down on a daily basis, those restrictions are necessarily gonna be relaxed.

And so without that strict guidance, we are gonna have to make decisions about what level of risk we're willing to tolerate. In anything that you do, going back out into the world, having contact with people is going to increase your risk at least to some extent because cases aren't gone, right? There are still cases of COVID-19 in our communities. Anything that we do, any time we leave our house, we're gonna increase our risk to some extent and so it's really gonna be up to us to decide what is gonna be a tolerable level of risk for ourselves and for the people that we care about because there's always the risk of onward transmission.

The stay at home orders, the things that we've been doing up until now, those are really geared towards reducing the rate of which people contact each other. So we're trying to minimize the number of contacts that people have. And by accounts that's been pretty successful, and that's still probably the best way that we have to prevent new infections. Stay away from all the people who might have it, right? That kind of makes sense.

But then there are other interventions that we have in our tool box. Those are geared at reducing the likelihood of transmission given the fact that there is contact between people. And so these are the things like face masks and hand hygiene which reduce the chance that two people coming into contact with each other will then spread the disease on.

There's been some research that has shown that universal masking where everybody wears a mask, regardless of whether they're sick or not, can actually reduce the force of infection to a pretty substantial degree. That's partly because we know that people can spread it before they have symptoms. If everybody wears a mask, then it doesn't matter if you're infectious or not, we're gonna reduce the likelihood that you spread it on.

Speaker 1: One way to picture how you can reduce your risk is available at your local deli counter. Picture a slice of swiss cheese and then another, and another, and another, and another.

Malosh: The idea here is that all of the interventions that we have are imperfect. Wearing a mask isn’t gonna reduce your risk to zero. Washing your hands isn’t gonna reduce your risk to zero. Asking people if they have symptoms or if they have been in contact with someone who has symptoms, isn't gonna reduce the risk that they're infected and passing it on to zero, and so on.

So the interventions here that we use are the slices of swiss cheese, and the ways that they are imperfect are the holes. And so this is an area where the virus is still able to get through and still able to spread. But if you think about swiss cheese, none of the holes are exactly lined up. As you start to stack those layers of swiss cheese one on top of the other, the holes will become covered and eventually, with stacking enough slices, you'll be able to substantially reduce the risk of infection that way.

So that's the thing to think about as we start to re-engaged, stacking these interventions one on top of the other, just like the layers of swiss cheese. If you're gonna go out to a restaurant to eat,  one of the inventions is keeping people 6 feet apart from each other. So hopefully, the restaurant is only maybe using 50% capacity or things like that so people can stay further apart from each other. Maybe they're doing symptom screening or temperature screening at the door. The restaurant staff are wearing masks or even the patrons are wearing masks, obviously not while they're eating, but when they're mingling around. All of those things as we stack them up, they can start to make a meaningful reduction in our risk.

Speaker 1: Throughout this pandemic, there has been an emphasis on personal accountability and shared responsibility. That's not gonna change as we emerge from stay-at-home orders. The difference now is that the first step is coming to terms with your own acceptance for risk, and then understanding that your situation is unlike anyone else's situation, and their situation is not yours. 

Malosh: There's a lot of things that we know about the way this virus transmits even though we don't know everything. We've seen out of China and a lot of other places that household transmission is a particularly high risk thing. What that tells us is that the virus spreads indoors pretty efficiently and that if people are gathered together inside in one location for long periods of time, that's the typical household type of contact that we think about right, people are indoors, they're living together, that that is a high risk activity.

And so what that tells us is that the reverse of that would be the lower risk interactions. So being outdoors, being able to stay further away from people, and maybe shorter term interactions, those are the things that are gonna be a little bit less risky. We've seen this also with the fact that there are major outbreaks in nursing homes, in prisons, all of these congregate settings where people are indoors and they're confined to a small area, and their high density, there's a lot of people in a small place.

The thing that everyone is gonna have to consider is just basically, what the level of risk they're willing to tolerate. And knowing what increases your risk will help you decide that. Knowing that being in a closed space with a lot of people is the highest risk thing that you can do, helps you kind of figure out how to reduce your risk.

My calculation is going to be a lot different than some other people's calculations because I am a high risk person, and so I'm willing to tolerate less risk of infection than most people might be. And I think everybody's gonna have to think about their own medical history and their own situation with their social networks, too, and how willing they are to pass it on to somebody in their life who might be a high-risk person. So, like my wife has to think about what level of risk she's willing to accept based on the fact that she could pass it on.

I think there's a lot of common sense things that everybody can do to sort of minimize their risk. The local public health authorities are really keeping a very close eye on circulation in the community and they can make the best local recommendations for what's acceptable in terms of getting together in small groups or going out into public in other ways, going to bars and restaurants and things like that. So I think it's really important that we all follow our local public health guidelines just because those are the people who are watching what's happening in our local area, and because this is such a local type of disease, I think that's gonna be really key.

I think getting together with friends who aren't sick is gonna be one of the things that everybody is looking forward to doing. Now that the weather's getting a little bit nicer, it's safest to do that outdoors. Obviously you wanna be able to have a conversation, you wanna feel that human connection again, but staying as far apart from each other as you can, so making sure that the space that you're in allows you to be at least 6 feet, maybe even further away from each other.

I think it's really important to be able to keep something nearby so that you can wash your hands. Hand hygiene is not something that we just picked up at the beginning of this and that are gonna discard as we go forward. This is all gonna be our new normal now, is to wash our hands a lot more.

And even keeping a mask nearby in case anybody has symptoms and you wanna be able to have a little bit of extra protection. I think keeping a mask nearby makes a lot of sense. Or even if you're unsure whether people have had exposure, that's just something that I think is a smart thing to have at the ready.

And then really don't share food or drinks. If you’ve prepared your own food, you know that you're not being exposed. Maybe not everybody thinks about that. They think having a burger at a barbecue wouldn't be such a big deal.

The other thing is, if anyone feels sick or has had recent contact with someone who feels sick, they should skip the gathering, stay home, follow the 14-day guidelines that a lot of public health authorities are early recommending.

And then I think if you're seeing someone at risk of severe disease, these calculations all have to change a little bit. This is an older relative or someone who has a compromised immune system. Then you just take extra precautions. Maybe everybody wears a mask. Maybe you stay more than 10 feet away from each other. Maybe you think about ways that you can connect with them in a different way with technology or whether they stay in the house and you're in the driveway or something like that. We're gonna have to sort of re-invent the way we connect with people who might be at high-risk.

Speaker 1: This has been a special edition of Population Healthy, a podcast from the University of Michigan School of Public Health. During the ongoing coronavirus pandemic, we’ll work to bring you analysis from our community of experts to help you understand what this public health crisis means for you. To stay up-to-date in between special edition episodes, be sure to check out our website publichealth.umich.edu, subscribe to our Population Healthy newsletter at publichealth.umich.edu/news/newsletter and follow us on Twitter, Instagram, and Facebook @umichsph.