Without Rapid Tests, COVID Will Be Hard To Control In Schools, Says UF Expert
It currently takes an average of 48 to 72 hours to get coronavirus test results in Florida.
Schools are reopening across Florida, with a range of safety measures in place to guard against coronavirus. But one key component is missing: the ability to quickly get test results for students and staff.
WUSF's Kerry Sheridan spoke with Dr. Glenn Morris, director of the Emerging Pathogens Institute at the University of Florida, about why that's a critical concern.
Kerry Sheridan: With schools reopening, I was hoping to get your perspective on what issues are still out there with regard to COVID testing, and what pitfalls may come?
Glenn Morris: "Obviously, testing is a key component of any type of prevention mitigation effort for something like coronavirus. Clearly, testing is a critical component for any effort to contact trace, ie to identify individuals who are infected and make certain that they are isolated in the context of quarantine. There are issues in Florida, in part because our underlying level of infection is high enough that it's hard to really be able to do top notch contact tracing."
"The prevention of illness or the minimization of illness within a school setting is really dependent on two factors. One is the level of disease within the community. At least here in Florida for a number of counties, there is substantial disease transmission still occurring. And so under those circumstances, there is reasonable likelihood that kids are going to show up in school who are infected."
"The other component is the mitigation approach, which is, if a kid does show up at school who is sick, what do you do? And so I think, in a setting such as Florida, where there are concerns about level of transmission within the community, a key component is having in place a really tight mitigation strategy. And there, testing becomes absolutely critical."
"You need to be able to have a setting where individuals who come in who may be infected can be quickly tested, ideally in the school nurse's office, right there on campus and find out within a very reasonable time period. Ideally within a couple of hours."
"If you've got a kid who's infected, and you're not going to get a result back for a couple of days, so you don't really do anything until you get the results back, then you really open up the possibility of initiation of rapid transmission within the school system."
KS: Local health departments are saying the average turnaround time for a COVID test is 48 to 72 hours. Is that fast enough?
GM: "No, to put it bluntly. Particularly in setting where you have fairly substantial transmission within the community, and you know that you're going to be getting infected kids in school, in order to be able to open the schools, you've got to have the ability to rapidly test."
"You've either got to have a very low transmission environment, or if you do have transmission within the community, you've got to be able to quickly identify the kids who show up at school. And 48-72 hours is not going to do it. It basically significantly enhances the likelihood that one is going to start seeing transmission within those schools."
"Your ultimate concern is you want to minimize the risk that you're going to get transmission within the schools themselves. Obviously, there's a lot of disease circulating within the community. Florida numbers are getting better, but they're still not that good. There's still a lot of cases which are occurring on a daily basis, particularly in some of the smaller counties, we're seeing lots of lots of cases. And under those circumstances, then to have even a degree of comfort in trying to open the schools, one needs to be able to rapidly identify kids with the virus."
KS: When schools closed in March, there was a lot of talk about rapid testing, and that by the time we reopened, we would probably have some rapid tests in place. What happened? Why haven't we gotten there?
GM: "I'm not sure you want me to go into all the political issues, but it hasn't happened. This gets back to leadership issues and a variety of other things, but we have not got in place a system that allows us to do the type of rapid testing which would give me a greater degree of comfort in trying to open up school systems. It's not there."
"The equipment's out there. There are three tests, both antigen-based test and also genetic-based, which can turn around results in a matter of hours. The problem is the availability of those tests."
"And so what we're really dealing with is not so much that the testing systems don't exist. What we are dealing with is the logistics issue. Getting the testing systems purchased, in place, with adequate supplies, so that one can do the types of rapid testing that are critical to things such as reopening schools."
KS: We've heard about saliva-based tests and pool testing and some different approaches. How close are those to being deployable in schools?
GM: "You're probably not going to gain that much by doing a saliva sample versus a nasal swab for a kid. You're still going to have to process the sample in some way. So the sample source is not necessarily that critical."
"There are potential advantages to having saliva-based tests. Here at the University of Florida, we have several investigators who are working on saliva-based testing. I don't want to say it's not that big a deal, but that's not going to be the major breakthrough."
"The real problem is having machines that can do the testing."
"We do pool testing here at UF. I mean, that's not a big deal. That's been out there for months. What it allows you to do is to screen large populations when you expect a high rate of negatives, so you can combine a lot of samples and hope that they're all going to be negative. The problem is, if you have a fair number of positives in that collection, then the whole collection is going to be positive. And so you're going to have to test each one individually and you end up using more resources than less. So pool testing has very specific uses, when you want to test large populations that are you're fairly confident are going to be almost all negative. That doesn't really fit the school situation."
"In the school situation, you want to know whether Johnny who's not feeling well and who just walked in the school nurse's office -- you need to know quickly whether or not he's got COVID-19 because if he does, then that's going to require some fairly rapid action to get him home and isolated to get other people in the class, you know, notified, potentially tested to make decisions about quarantine. There are a whole series of issues and a whole series of actions that need to be taken quickly to minimize the risk that Johnny's infection is going to pass on to another 50 kids in the school. And you can do that if you know quickly what's going on. If you have to wait three days for those results, you're not going to be able to take the rapid action that you need to be able to do."
KS: That means there would be a likelihood of quite fast community spread when schools reopen? Is that what you're saying?
GM: "Well, not so much community spread but spread within the schools. Kids are kids. And so you're not going to get everybody standing six feet apart wearing a mask. There is going to be ample opportunity for transmission within a school. The key is rapidly identifying individuals who are infected and to be able to pull them out from the school to minimize the number of individuals that they might in turn, infect. So again, to my mind, the critical a critical component to any school based mitigation effort is going to be having a rapid testing capacity, ideally at the school, with the school nurse."
KS: And are you aware of any schools in the state that have that capacity in place?
GM: "Well, actually here in Alachua County, we have made similar recommendations serving. I'm on an advisory committee to our county health department. And we basically I've given the health department a similar set of recommendations as to what I've just described, which has been given to the school board. And essentially, we have been working very closely with the school with the health department. They are making certain every school has got a school nurse. They're hiring additional personnel to assist the school nurse to assist them in particular in contact tracing and working through mitigation if an infected kid is identified. And through the university, we are working to get our turnaround time to hopefully less than 24 hours. But again, that's a special instance where there is a close partnership between a local health department and the university."
"I would say that outside of sort of this special window here in Alachua County. In the U.S., that is what is needed for other school systems. I feel that for every school system, there needs to be the rapid testing capacity. And this gets back to, you know, what did the state provide?"
"I think what's critical is that if as a state, we are mandating the schools open, part of that is an ability that to allow schools to adequately prepare themselves. And it's not just making sure that all the seats are six feet apart. It's also having a rapid testing capability."
KS: So schools are reopening. What would you suggest they do without this rapid testing?
GM: "It's going to be very difficult to control spread within the schools. I think there may be some problems which arise."
"Now, again, the machines are available. It's not like we're asking for something that hasn't been invented. It's more a matter of getting the resources to the schools and prioritizing, you know, at a state level, recognition at the state level, that if we're going to do this, we really need to provide necessary equipment for the schools. And that includes not only the ability to separate desks, but also the ability to do rapid testing within the school."
"I mean, the President (of the United States) has the capability of rapid testing. Why can't we get it within our schools?"
"I think that comes down to a question of dealing with what is possible for the state to try to arrange. My understanding is that machines that are able to do rapid testing are being sent to nursing homes in multiple parts of the state. My understanding is those are coming directly from (U.S. Department of_ Health and Human Services. But somehow we can't seem to get rapid testing machines into our schools."
KS: I have asked Governor Ron DeSantis’s office about that. We haven’t received an answer yet. Let me ask you about what the governor has been saying about a “surgical approach” to contact tracing in schools. He and Education Commissioner Richard Corcoran have both mentioned that they don't think that the whole class should have to quarantine if they have a positive case in a class. Perhaps only the children right next to that student who are within six feet of that student for more than 15 minutes. What do you think of that?
GM: "I think that it is very difficult to come down with a one-size-fits-all approach. I think that potentially in high school, that might be possible. But then again, the problem is kids in high school are changing classes all the time. They’re in the hallways, and it starts getting a little difficult. I think in elementary school, it becomes very difficult, particularly with some of the younger grades, because, you know, kids are all over the place. If the class sizes are small if you're using a pod type approach, which is where you designate certain pods where kids stay within that pod, but if you've got an open classroom, you know, it's going to be hard to know, through the course of a full school day, which kid has or has not had 15 minutes of contact within six feet? I just think from a practical standpoint, that's going to be difficult."
KS: So is it now just sort of up to the individual contact tracers within a certain county to decide whether a whole classroom is at risk or not? How confident do you feel about the ability of the system as it is to effectively trace contacts within schools?
GM: "For a number of counties, there is already a shortage of contact tracers. You really need school-based contact tracing, which is essentially what we are trying to make sure we can implement here in Alachua County. Because you need somebody in the school, who is familiar with the operation of the school, and you need rapid results. If it's a contact tracing system that's been run by the county health department, you've got a contact tracer who's really not that familiar with the school, and doesn't get results till three days later, I'm not sure that's going to be that helpful."
KS: What's your advice for parents who are nervous about this whole thing?
GM: "Ask what the mitigation strategy is for their school system. Is there a plan? What does the plan look like? Does it carefully outline exactly who's responsible for each step of the way? And does it look like it's a workable plan that can move quickly? Speed is a key element. Because if you leave the kid in school for the rest of the school day, you're going to get the potential for further transmission."
"To backtrack a bit, I think we're becoming increasingly aware of the importance of aerosols in transmission. There's nothing magic about the six-foot distance. There is a decreasing degree of risk, the farther away you move from an infected person, six feet is the number that's just sort of decided on."
"But there's still a risk at 12 feet. Actually about a quarter of the risk than there is at six feet. But again, every three feet, you decrease your risk by half, but the risk is still there. And we're becoming increasingly aware of aerosols in the air, which makes masking even more critical. So there are a lot of variables that have to be taken into account."
KS: Some college students are having to come in with a negative test. Is that enough? Coming into school with a negative test that might have been done days or weeks before?
GM: "I'm not sure that's necessarily useful. It excludes people who may have had a prior infection. But again, keep in mind that usually within 10 days of onset of symptoms, we say that they're clear and probably not capable of further transmitting. So if you have a test that was done a week ago, it may not be that useful."
"I am concerned that there are a lot of schools that have not thought this through carefully. I mean, everybody's focused on the metrics, can we or can we not open schools? Just as important, is what does the school system do when the inevitable first kid gets infected? What is the strategy? How are they approaching it? Is it rational? And is it based in reality?"
"Again, if you're not going to get test results back for two to three days, then that needs to be figured into your mitigation strategy. And that may well mean that you're going to end up quarantining a whole lot more kids, because you don't really know whether or not somebody has the virus."
KS: So does it make sense to you, from a policy standpoint to say, since we don't have the rapid testing that we need, then if there is a suspected case in a classroom, even just a suspected case, the whole classroom should quarantine for two weeks?
GM: "Well, unfortunately, that's sort of what you're left with. But unfortunately, that also means that you're going to end up with a whole lot of school kids who are being sent home."