Keeping COVID-19 Rates Low in Schools: Advice From a Pandemic Expert
As the new school year gets underway, thousands of coronavirus cases have already been tied to in-person classes, despite the safety precautions in place. So far, infection rates in schools have been low, some data show—but fears around disease transmission still loom large in many educators’ and parents’ minds.
Many school districts, including about a quarter of the nation’s 100 largest, have recently reopened their doors, even as the pandemic continues. Schools have spent hundreds of thousands of dollars trying to keep the virus out of their buildings, but in some cases, outbreaks are occurring. Some districts have had to make an abrupt shift back to remote instruction. Across the country, teachers are scared of getting COVID-19 at work.
A new national COVID-19 school data dashboard, run by researchers at Brown University and school administrator groups, has found that over a two-week period, about 0.2 percent of students and 0.5 percent of teachers had a confirmed or suspected case of COVID-19. The dashboard has data from more than 550 schools that are both in-person and fully remote.
How can schools continue to keep transmission rates low throughout the fall semester? Which safety measures are essential, and which are not? To answer those questions, Education Week spoke with Dr. Mario Ramirez, a practicing emergency medicine physician who served as the acting director for the Office of Pandemic and Emerging Threats at the U.S. Department of Health and Human Services in 2015, during the Ebola outbreak in West Africa. Ramirez is now the managing director of Opportunity Labs, a consulting group that has issued guidance for school buildings to safely reopen.
Ramirez discussed the usefulness of temperature screenings, whether teachers should wear scrubs, and what the winter months will mean for schools. This interview has been edited for length and clarity.
How has our understanding of the coronavirus—particularly how that’s evolved over the last six months—influenced whether or how you think schools should reopen for in-person instruction?
First, compared to four or five months ago, we are getting a little bit more guidance and the more kind of granular details about what we think real community thresholds are for where it's safe to open school. And I think our understanding now of these outbreaks in schools—we recognize that it's more a function of what's going on in the community probably more than anything else.
The generally accepted threshold that most people are reporting is that you should have less than 30 to 50 new cases per 100,000 person-population over seven days. And if you have more disease than that in the community, it becomes more likely that you're going to have disease spread within your school, and then those are the situations where it's less safe to have your schools open.
The other thing, though, that I think has surprised a lot of us—I think four or five months ago, all of us working in disease epidemiology sort of presumed that the schools would report their outbreak data. There would be a push to present it in a uniform way so that we can all learn from each other, and we could have an idea for what was going on in one part of the country and what seemed to be working and what wasn't. And instead, what we've seen is that states have pursued a very disjointed approach. Some states don't report their data at all. It makes it almost impossible to really compare what's going on from one jurisdiction to the next.
It does seem like having an effective prescreening process in place is really helpful. I personally continue to believe that temperature tracking in school is not an effective screening tool. But what is helpful is good symptom screening. Trying to figure out [by asking parents] if a kid has a cough, runny nose, fever at home—those are things that are part of an effective screening regime and can help pull kids out before they bring [the coronavirus] into the classroom.
The other thing that does seem to be helping a lot are the personal protective barriers—things like masks, things like spacing. And then the last thing is some sort of cohorting approach, whether that's keeping kids in classes together or limiting class sizes. It's something that allows schools to isolate one or two case outbreaks to smaller numbers of people.
I know some schools are considering routine COVID-19 testing of teachers and students. How effective do you think that is in slowing the spread?
Right now, I think it's probably not yet at a place where we know how to use [routine testing in schools] really effectively. We are probably, I would say, 30 to 60 days out from having better information on this because we’ve seen a lot of variability [with how schools are approaching testing]. We still don't know what the sensitivity and the specificity of [antigen] tests, [rapid diagnostic tests], are going to be in the wild. [The Federal Drug Administration has said that antigen tests have a higher chance of missing an active infection than molecular tests, which can take a few days to deliver results.]
As far as testing in school goes, we know that there are a certain number of people who are going to get infected, and [some of] those people are pretty easy to pick up because they have fevers, they have coughs, they have symptoms—you can pull those people out easily. What you’re trying to prevent is people who don’t have any symptoms and come in as the silent spreaders. How accurate are the [rapid] tests for those particular people? Right now, at least, I don’t think we have enough information about [antigen] tests to make a definitive recommendation about using them [in a school setting].
Do you have a sense of how often people in schools would have to be tested, or how many people would have to be tested, for that to be effective? Or is it still up in the air at this point?
It's still up in the air. I think we're getting better information about when people should get tested to really determine whether they're safe. I think the common mantra for at least what the public has internalized is if you have an exposure to someone and you go out and get tested the next day and your test is negative, then you're clear: You can go back to school or go back to work. And the truth is that's not accurate—the false negative testing rate for tests that are done the first 24 hours after an exposure are somewhere around 80 to 100 percent. You need at least three days before your test has any kind of meaningful accuracy.
My expectation is that the tests are probably going to be sort of pseudo-experimental, where we’re going to try to figure out how to use them in the best way possible, for at least another six months.
Schools are spending a ton of money sanitizing every surface, but I’ve seen concerns that deep cleaning can turn into “hygiene theater” and be overkill since COVID-19 transmission is thought to be mostly person to person. What are your thoughts on that balance?
I think now we certainly recognize that the primary route of infection is some sort of respiratory entry, and whether that's droplets or aerosol is still being debated. But it's certainly the case where somebody breathes it in, or you've got it on your skin surface and then you touch your nose and then you breathe that in. That is going to drive most of the infections in the country.
Now the data really suggests that the viral particles are infectious for 48 to 72 hours on hard surfaces if they don't get cleaned at all. There’s certainly value in cleaning and sanitizing. But there is a certain amount of—I wouldn’t call it theater, but there’s a question of, what’s truly effective in terms of reducing disease and where you get the most return on investment, for lack of a better word.
The most return on investment you’ll get in terms of reducing disease in your school is opening when it’s safe to do so, based on the community spread. And next I would say is effective screening. And after that, then it’s cleaning and sanitizing and making sure people are not touching their faces.
Stuff like spot temperature checks in the school—there’s not good evidence that that’s really helpful. Again, I would be wary of using the word theater, but it hasn’t been shown to effectively screen out people who are infected. I will go so far as to say that the NIH: National Institute of Allergy and Infectious Diseases where Dr. [Anthony] Fauci works actually discontinued temperature checks for people going into their office. So if that guy doesn’t think they’re valid, they’re probably really not valid for schools either.
You mentioned the importance of personal protective equipment earlier. Do you think teachers should be wearing eye goggles or face shields in addition to masks?
The evidence would show that wearing a face mask is by far the most efficient and cost-effective way to reduce the likelihood of transmission. It does seem like there's some small amount of infection that can theoretically occur through the eyes, but we've never been able to really prove that on a numerical or percentage level, because it's hard to track the route of infection. You can't say, “This person looks like they got it through their eyes,” versus, “This person looks like they got it through their nose.” It doesn't really work that way that often. I think things like face shields are helpful, particularly for folks who are at high risk of direct fluid contact. That's why we see people like doctors wearing goggles and wearing face shields because you're around patients who are coughing.
Teachers are less likely to have those kinds of exposures. That’s not to say that it can't happen, but at least based on our understanding of disease transmission, that seems to be much less likely.
As far as other PPE stuff goes, the question is, should teachers be wearing gloves? I think what is most efficient is making sure to wash your hands really regularly or disinfect with alcohol-based [sanitizer] more so than wearing gloves. Using gloves can be helpful, but it also generates a lot of bio-contaminated waste. It can be tricky to take those things on and off and not contaminate yourself.
I’ve also heard teachers wonder if they should be wearing scrubs or other disposable clothing.
I don't think so. Listen, the incidents of disease in schools, it's still really low. It's not like you're walking around a place where 100 percent of the people are infected with COVID. In outbreaks, we’ve had 20 or 30 cases. And as somebody who’s wearing scrubs right now, you gotta figure out how you're getting them off without contaminating yourself. It has to go in a bio-containment trash bin. It’s not like you can just walk out the door, take off your scrubs, throw them in your car, and not think you’re going to take that stuff out with you because you will. I don't think it's necessary for teachers based on what we understand of the disease right now.
Are you concerned about the winter months for schools, especially when it might not be feasible to utilize outdoor spaces or keep classroom windows open?
I think anybody who studies disease transmission is worried. Certainly, the seasonal patterns for coronavirus—coronaviruses as a family, not just this coronavirus—would suggest that disease transmission should go up in the winter months. The viruses tend to last longer, both indoors and outdoors, they seem to be hardier in cold temperatures, people are clustered closer together. Those are all of the inputs that drive transmission.
The other question that people are really concerned about is whether or not the flu and coronavirus are going to collide in a really meaningful way. Interestingly, the disease rates of influenza in the Southern hemisphere for the earlier part of this year, which are kind of our bellwether for how the flu season is going to go, were much, much better than we've had in the last decade. A lot of people wonder if the PPE measures and the distancing measures that we took for coronavirus affected that, or this year's flu vaccine works better, or is it because this year's flu isn't that infectious, and nobody really knows.
If disease incidents really start to jump up in the next 30 to 60 days, that’ll be a sign that we may have to change what we're doing at school. But we're not there yet.
What is a good way to ensure ventilation or good air quality if schools do have to keep their windows shut?
The evidence would suggest that disease spreads the most in areas that are poorly ventilated, so I think the low-cost measures are things like fans [alongside] partially cracked windows that create a draft and move air through classrooms without creating static classrooms. In addition to that, there’s a lot of discussion about air filtration, and the American Society of Heating, Refrigerating, and Air-Conditioning Engineers has issued some interim recommendations about what sort of filtration should be used. There's a lot of discussion about MERV-7 versus MERV-13 filters and what do we really need in schools. The truth is that at this point, there's not a lot of well-accepted scientifically validated data to say what sort of filters people need to be using.
There's still a lot of debate about just how airborne the disease is and whether it's transmitting over really long distances or is it still a fairly close contact thing. I think most of us in medicine would acknowledge that there is some aerosolized spread, which would suggest that it can spread over larger distances, but the degree to which that breaks down versus close contact is still being determined.
I think the most important thing is probably keeping air moving through the building in a meaningful way. And then air filtration is a part of that, but there's still a lot of uncertainty about what the right filtration is.
I know that in some places where K-12 schools are remote only, day cares have reopened. I'm curious what the difference is from an epidemiological perspective, or if it's just a question of essentialness.
Yeah, it's a mix, right? There've been a couple of good studies that have come out that the [Centers for Disease Control and Prevention] has helped to amplify. Some of them are out of South Korea, other ones are looking at disease transmission in Europe, showing that the rate of transmissibility from kids to adults seems to be higher once kids cross age 10. That’s not to say that it doesn’t happen in younger groups. The CDC did release a study out of Texas that showed some disease transmission in preschool settings to their parents back home, but it does seem like the rate of transmission is much less than once you get to be older than age 10. I think if we're trying to moderate risk and trying to reopen society in a way that balances risk and necessity against what the risk of disease transmission is, there does seem to be a difference there in terms of kids under grade 2 and then those above grade 2.
Is there anything else you would want schools to keep in mind?
Public schools and vaccinations are about to collide in a really complex and meaningful way. I think it's critically important for people to get the flu vaccine this year. But the question is going to be, as we get into March and April of next year and a [COVID-19] vaccine becomes available, A, is it going to be adequately tested in kids? And then B, are schools going to be vaccine administration sites?
Schools have played a critical role in vaccine campaigns from 2009 H1N1 through pertussis through measles and mumps and chickenpox. It's certainly conceivable that schools could be asked to play a role in [COVID-19 vaccine] administration. And now I think is the time for teachers and educators to start getting a pulse in their local community. If we're gonna find our way out of this thing, a large number of people are going to have to take up the vaccine. Clearly, we're facing barriers to public belief in vaccinations and at what point they feel like the vaccine is going to be safe enough for them to do it. So rather than have the conversation [over] 10 days when the situation is thrust upon [schools], this should be something that we’re talking about now.
Vol. 40, Issue 08, Pages 14-15Published in Print: October 7, 2020, as Keeping COVID-19 Rates Low in Schools: Advice From a Pandemic Expert