Wednesday, November 11, 2020
Dr. Paul Byers is one of the leading epidemiologists in Mississippi and a key figure in the public-health response to COVID-19, including an expansive testing and tracing regime intended to prevent community transmission of the virus and identify clusters where it spreads.
Byers sat down with the Jackson Free Press on Nov. 4 to discuss the Mississippi State Department of Health's approach to the crisis, now in the early stages of a third spike that extends far beyond the borders of the Magnolia State. Only one day after the interview, MSDH announced 1,612 new cases of COVID-19 in a single day, an ominous reminder that the worst days of the pandemic may still be ahead.
NJ: We're seeing a nationwide rise in COVID-19 numbers. We have all been worried that this will be the result of colder weather, of gatherings moving inside. Mississippi is not seeing the catastrophic spike some northern states are seeing. What explains this? Climate? (Note: In the days since this interview, the seven-day average of cases has spiked from 665 to 1017, the highest rate since early August.)
PB: Certainly, we've seen that sort of phenomenon with the flu in past seasons. When you get more folks indoors, in a closed setting, and more people are interacting with each other—we have a tendency at holidays to interact with people who are outside of our nuclear family, that we don't normally see on a routine basis. Historically, we've seen flu transmit that way. There's a good possibility that we're going to see COVID be transmitted that way as well.
But you know, there's so much else that goes into it. And for sure, one of the big things is physical distancing: staying away from each other, doing things safely, making sure that you're wearing a mask and that you're being conscious—aware of where you are and where people are in proximity to you. (You have to) really act as if anybody around you may have COVID.
I think we have seen a spike here. Certainly it hasn't approached what we saw over the summer. It hasn't approached what we've seen in some of the other states as well. We don't know if it's going to level off, or if we're going to continue to see a climb, but I tell you that one of the things that we worry about as we move into the fall months, the cooler times, the holidays is are we going to see a bigger spike?
There's going to be cases, but the thing we really worry is the impact on deaths and hospital capacity.
What are you hearing and seeing from hospitals and clinics? Usually, we look out for syndromic surveillance ahead of hospital spikes. How is that looking right now?
Our syndromic surveillance is actually holding steady. We haven't seen any big increases in that. One of the big things that we look at from our syndromic surveillance is emergency department data. And we just haven't had a big spike in that surveillance like we saw over the summer. When we look at hospital capacity, our numbers are increased for folks who are currently hospitalized, in the ICU, or on a ventilator with COVID.
But not to the extent that we saw over the summer. That seems to be holding steady. However, some hospitals have reduced capacity because of hospitalizations for a number of reasons, not just for COVID. Right now, if we maintain where we are, it's not looking overwhelming. But our concern, obviously, is what's around the corner.
How will MSDH follow up on the election to watch for potential clusters arising as a result?
We investigate and interview every case that we get reported to us. We identify what potential exposures they have had that may have led to infection.
By and large, I saw pretty widespread mask use (at polling places). I was encouraged by that. I saw appropriate mask use, but I also saw people clustering in line and doing what people do: talking to each other, not really separated by more than 6 feet.
As we trace back on our cases, and we identify that there may be clusters that are associated with those sorts of activities, the best way to do it is to interview the patient and find out where they've been and what potential exposures they may have had, with an understanding that it can often be difficult to pinpoint exactly where an individual may have been affected. Because there can be multiple exposures.
And although we may have had people who are infected, who did stand in line for two hours, their exposure may have been (from) a family member. Their exposure may have (from) been a party two days prior to that, or some other event. Or just as general community transmission that's unrelated to being at the polling place. So a lot of those things are sometimes very difficult to tease out unless you see something that really stands out as multiple cases, in a small group, in people all in line with each other.
Contact tracing seems to differ country to country. Are you looking for where an infected individual has been since becoming infected, or do you go backwards seeking a cluster event that is behind a significant number of infections?
It's a combination of both. And when you do case investigation, or cluster investigation, both of those things that you described go hand in hand. Identifying where an individual may have become exposed or where they may have been infected can be a bit more complicated than moving forward from an identified time.
Identifying all those people that may have been in contact with (an infected patient), making sure that those people understand the level of their contact and the need for quarantine and testing—can be more intuitive than tracing back and trying to identify the actual source of an infection.
When you have a lot of infections and widespread community transmission, it can be much more difficult to pinpoint exactly where an individual may have become infected than if you have one or two cases of a particular disease ... identifying common source exposures is just part of case investigation. It's what we do with any case that we investigate: If we have more than one case where the folks get it (identify) what's the common source between them.
But it's important to understand that when you have a lot of cases, a higher percentage of folks who are asymptomatic, who show no signs of infection, who were never tested, who never realized they were infected, but yet can be infectious, it's much more difficult to pinpoint individual exposures.
When we have common exposures come up, we have teams out there that say, "I've just identified another case at X, Y and Z." That's an indication for us that there may be a cluster. The short answer, Nick, is that it's really both. It's gotta be a combination.
As our understanding of COVID-19 evolves, we see that super-spreaders drive transmission in many places: one individual, sometimes asymptomatic, mostly unmasked, attending a large gathering or event. And the result is not one or three infections, but 10 or 30—or more. Is that what we're seeing in Mississippi?
We've seen some of that, but it's not an either-or. Certainly, super-spreaders have been shown to account for a high level of transmission.
And we have seen events that have occurred where we have one or two individuals present during their infectious stage, and we have a high number of (resulting) cases that are identified. Sometimes it's difficult to say if that's a super-spreader event, or if you've had a lot of people who had very, very close contact with somebody while they were most infectious.
But we also have transmission that occurs outside of super-spreader events. We have transmission that occurs within families where one family member will become ill, bring it home, and (infect) several more family members. We see a whole lot of transmission that way as well. It's really a combination of both.
The reason I bring this up is that, in addition to causing some of these shocking increases, (super-spreaders) can also throw off some useful metrics. We talk about r0 (r naught)—in layman's terms, this measures how many additional infections the average infection creates. But explosive transmission from a few sources can unbalance that average. How are we accounting for that in our reporting?
It can (unbalance the average.) We think of the r0 with COVID as typically somewhere around three: but that takes into account that we are seeing super-spreader events as well.
It's not a static number. It is dependent upon the situation. And when you look at the r0 for a state, it's important to understand that a state is not a static environment. We have people who leave the state and become exposed. We have people who come into the state while they're infectious.
It's a very difficult dynamic to get your arms around, trying to determine what a true infection rate may actually be. It's difficult to account for where super-spreader events may be and how they impact what the transmission is.
But the reality is the transmission is the transmission. We know what needs to be done to limit it. And we also know that if an individual is wearing a mask and the people around them are wearing a mask, then you can greatly reduce the risk of even having a super-spreader event. Super-spreader events occur. Individual transmission occurs. I think what we have to do is decide 'what are the measures we want to put in place to prevent those kinds of things?'
Is it possible for MSDH to provide specific data on the types of events where transmission is occurring? Whether those are house parties, or church events, or after-school gatherings. Would that help us understand what exposures are really driving the spread in the state?
Yeah. I think we've done that, to a large extent, with the caveat that you're not always going to be able to identify, for many of the cases, the exact source of transmission. We've put information on our website about cases that are associated with jail outbreaks, and with what we feel like is community transmission, whether that's in long-term care settings or other outbreaks. And we do break that down by county.
I expect that we're going to have more information to be able to share on our county snapshots in the future about sources of transmission. Certainly, I agree that this can help, because the goal with information is not only just to publish numbers, but for people to have an awareness of where we are—and to have an understanding of the risk that is associated with certain activities.
Our basic message from the beginning, as we've learned more, has been modified, and it may be modified in the future as we learn more about the virus, its transmission, and certainly about what kind of long-lasting immunity there may or may not be. (But) the basic message and information that we want people to have is all about doing things safely.
The take-home message in all of this is that transmission can occur anywhere, at any time that you are in close contact with an individual. (When that happens) there can be transmission that occurs. I think it's important for everybody to understand that. And it's hard, man. It is. It can be difficult. And I know people have got COVID fatigue.
But when we wear a mask, we wear the mask to protect the person who's sitting across from us. And they're wearing a mask to protect us. They're staying more than 6 feet away to protect us. We're doing the same to protect them. And it also protects us (too), by the way.
If we can just use that standard in everything that we do. Don't have big gatherings with more than your nuclear family. Don't go to big parties. Don't go to (events) where you're not wearing a mask. When you go out in public, wear a mask. When you're at work, wear a mask. These are all the sort of standard things that we need to be doing regardless of where we're seeing individual transmission now.
And I can tell you it is a little bit worrisome. Because we've gone through cycles. Early on, we had a lot of transmission in long-term-care facilities. Then here was transmission in some businesses. Then we saw (clusters) in churches and weddings. Now we're starting to see transmission in small gatherings again. We just keep going full circle.
If we can just find some consistency in all of our actions, I think we can demonstrate (how to) reduce transmission, save the people who are most vulnerable, and (protect) hospital capacity, until we have a safe and effective vaccine that can interrupt transmission.
I think what's confounding many people is that we don't have much new information about how to stop the virus. It's the same information: masks, social distancing, avoiding large groups, sanitizing surfaces, washing hands, keeping rooms ventilated. But we're still in the holding pattern; still in the cycle. Do people need a timeline? An expectation of when this is over? Or do we need to communicate things differently?
No, I think that you're on the right track. A lot of it is that we've been doing this for a long time, and we still can't give anybody a concrete answer as to how much longer we need to do this.
And I know for folks who are out there living their lives now, it feels like we're going to be doing this forever. Where's the light at the end of the tunnel? When is this going to loosen up for us? When can we go back to normalcy in our lives? That's what keeps us going. That hope.
What we need to do is to stay the course. If we do that, and we do it together with a will for preventing transmission in our brothers and sisters, we know that we are going to get a vaccine at some point. And when we get a vaccine, it's not going to be immediate. It's going to take a couple of doses. There may be limited doses to begin with, but we're going to get there.
If we have any message to give, it's don't lose hope. We've all been in this together. We've all done some remarkable things together. As a population we have demonstrated that we can make a difference. We can reduce the transmission. It's simple, but it's not easy. We ask folks to hang in there. Don't give up hope.
Read the full interview at jfp.ms/byers. Email tips to state reporter Nick Judin at [email protected].