Experts say schools can be the perfect setting for a “superspreader” event of COVID-19.
They note that the number of confirmed cases of COVID-19 among children is rising across the United States.
They say schools need to put in preventive measures such as masks, physical distancing, staggered class schedules, and ventilation.
They add that the amount of COVID-19 spread in the town where a school is located is also an important factor.
We’ve seen COVID-19 spread like wildfire through some bars, churches, and other public gathering places.
Now that many schools are reopening, parents are holding their breath.
Experts tell Healthline that schools — especially those situated in states where cases are rising — can be the perfect setting for what’s called a superspreading event.
“There are some estimates that at a 1,000-student school you might have between 10 and 15 students show up on the first day who are infectious and that’s pretty representative of a typical high school,” said Dr. Marybeth Sexton, a former public school teacher who is now an assistant professor of medicine in the division of infectious diseases at Emory University in Georgia.
“If you don’t have masking and distancing regulations in place, and each one of those people goes on to infect two to three other people, and then they infect two to three other people, and they infect two to three other people, very quickly you’re going to have a situation where you’re going to have to shut a school down,” Sexton told Healthline.
As students in Georgia, Florida, and other states embark on an uncertain school year, Healthline asked experts where superspreading events typically occur, just how soon it will be clear whether schools have succeeded or failed in their reopening efforts, and how likely is it that schools will become superspreaders.
The perfect setting for spread
One of the earliest examples of a superspreading event took place at a March choir practice in Skagit County, Washington, where 52 people subsequently developed COVID-19 — three choir members were hospitalized and two died.
The list of examples goes on and includes children’s camps and schools.
In fact, more than 97,000 children tested positive for COVID-19 in the final 2 weeks of July, according to a study from the American Academy of Pediatrics and the Children’s Hospital Association.
In addition, the number of children diagnosed with COVID-19 in Florida has more than doubled in the past month.
“(School) is an indoor setting. It is an area where lots of people congregate, where there is shouting and yelling and close contact,” said Maureen Miller, PhD, an infectious disease epidemiologist and adjunct associate professor at Columbia’s Mailman School of Public Health in New York. “These are exactly the conditions that we basically closed down for the rest of the country — political conventions, casinos, offices. It’s the same scenario, only it’s with children.”
Sexton explained that superspreading events in places such as restaurants or churches tend to have a few things in common.
“(If) you do get unlucky enough to have somebody who is particularly contagious, and then you get a lot of people in a small space that’s not well ventilated and they don’t have masks on,” she said. “Then you really could infect an entire classroom if you were looking at this in a school setting.”
Exponential spread through a student body and the faculty can happen when people come to school who are already infected because of spread in the community.
If safety measures aren’t in place, “you do have the potential within a classroom to have a superspreading event, where an overwhelming majority of the people get infected,” Sexton said.
“It’s a huge experiment that we’re going to risk our children to see what happens,” Miller added.
Indeed, some schools that opened this month have subsequently closed again.
Last week, a viral photo put the spotlight on a school in Paulding County, Georgia, where students were seen crammed into hallways between classes.
Over the weekend, the school announced it would close for 2 days after nine people tested positive for the virus.
In addition, 260 employees in Georgia’s largest school district have either tested positive for the virus or were exposed after an in-person planning day.
In New Jersey, a summer preschool program closed after two employees tested positive.
Even as these stories fill the news cycle, New York’s governor announced schools there will open for the 2020 school year, citing how every region is “well below our COVID infection limit.”
It’s a decision that has everyone wondering how the big city will fare.
“New York City is actually pretty low. It has a pretty low positivity rate, one of the lowest in the country right now,” said Miller. “I would not do a full reopen of any school, definitely mixed model, some virtual learning and some in person. But with all these caveats, it’s staggered, there’s social distancing, and once an uptick is observed then you have to decide (whether to close).”
Measures can mean everything
The specifics are critical when assessing whether a school will succeed or fail in its reopening efforts.
Experts reiterate that mask wearing, physical distancing, and reduced class sizes can help.
“The details matter,” Dr. Michael S. Saag, a professor of medicine in the division of infectious disease at the University of Alabama at Birmingham, told Healthline. “If the schools are opening like the school in Paulding County, Georgia, it will not go well. Careful planning is required with attention to details.”
Saag said that a minimum all students, faculty, and staff need to wear a mask at all times in the school with the exception of the cafeteria, which ideally should incorporate outside eating.
“Keeping distance in the classroom and the hallways, and having anyone who feels ill stay at home. Ideally there should be sentinel testing, but that is not feasible,” he added.
Miller hopes that schools will eventually have access to rapid testing, which will help catch cases more frequently.
She also approves of staggered models of school attendance, where capacity is reduced and in-class learning is spread out over certain days.
Miller believes ventilation is an issue that schools need to tackle.
“Open windows, open doors, taking classes outside. I think these are all things that could help,” Miller said. “There are high level ventilation HVAC systems that do remove virus from the air, and most of the school districts in the United States do not have that state of the art (system) and it’s not even really being discussed.”
Sexton agreed that advanced planning is important for schools as they reopen.
“The places that have more time to do it need to take advantage of it. To figure out how you avoid these situations where you have a couple hundred kids packed into a hallway,” she said. “Make sure that you really have plans. Are we really going to change classes? How are we going to change classes? How do we do this safely?”
“I think looking at the issue of whether masks are required in the building is a really important one for a school to have a decision on,” Sexton said, “and from an infection control standpoint the answer should be yes, absolutely.”
Location, location, location
Where a school is located also makes a difference.
“It really does depend on what the spread in the community is doing at the same time,” Sexton explained.
If cases are raging in a school district, that will impact how many people in the building on that first day of school pose a risk.
“If you had a student who showed up on the first day who had COVID, you will eventually see that spread through your student body and some of your faculty, but that could take weeks to be visible that that had happened because if you assume that somewhere between 25 percent, maybe up to 50 percent, in the young healthy population don’t have any symptoms or have very minor symptoms,” Sexton said.
States with a high number of cases such as Texas, Florida, Georgia, Nevada, California, and Arizona may face uphill battles as they reopen schools.
“Most of the southeastern United States and the Sun Belt into the lower Midwest is in that category of really seeing a lot of ongoing community spread and having the potential for a lot of infections in the building on day one,” Sexton said. “That I think you could see within a couple of weeks whether you’ve spawned a real problem as a result.”
Saag said that if he were a school superintendent in his state of Alabama he would postpone reopening schools and watch what happens in locations like Georgia that have decided to open.
“Based on my understanding of the virus, its high level of contagiousness, and the difficulty of implementing even the best plans, we will likely see outbreaks occurring in schools within 3 to 4 weeks of reopening, perhaps even sooner,” he said.
Miller recommended using Harvard’s COVID Risk Level Map to assess the level of risk in your area.
“Harvard has a really excellent site that takes it down to the county level and it’s looking at how many per 100,000 new cases are occurring and they also do a rolling average,” she said.
Schools as superspreaders
Experts told Healthline that if schools reopen to students without solid precautions in place they will most certainly be the site of superspreading events.
“Within schools that do not plan well, expect superspreaders to be commonplace,” said Saag. “The concern is for the older individuals, including the teachers, parents, and grandparents. It’s unclear how much virus will be ‘brought home,’ but I suspect that will occur commonly, re-igniting community spread like we had the month of July.”
The potential for superspreading events among children was confirmed this summer, Miller said, pointing to an outbreak at a Georgia summer camp, where hundreds were infected.
“This was outside and well over 200 kids got infected. This is a proxy of a school setting, only it’s outside,” she said. “They weren’t wearing masks. They weren’t all being asked to wear masks. There’s a lot of mask aversion in this country.”
Sexton reiterated that what’s happening in your area will impact the likelihood of a superspreading event at a school near you.
“It really depends what’s happening in the backdrop. That’s why there’s been this guidance that in areas with really high spread, it may not be safe to open or you may need to take significant safety precautions,” she said.
“Whereas, unfortunately,” Sexton added, “the few places left in the country that aren’t seeing that kind of spread in the community, you may have a little more leeway.”
Noting the outbreak among faculty in Gwinnett County, Georgia, Sexton said, “On the first teacher work day you had 260 people who either had COVID or had a high risk exposure to COVID on day one. Those aren’t people who got anything in school or at work. Those are people who got something out in the community.”
“Other locations that are having the community spread like we’re having in Georgia should take note of that, that they’re going to have a real problem on day one, potentially,” she advised.
Areas that haven’t yet returned to school have an advantage.
“We do know from watching New York, New Jersey, and Connecticut early on in March and April, that if you put really strict measures in place in the community you will see a significant decrease in cases, so that can make the schools dramatically safer by making the community safer,” Sexton said.
It’s not too late for struggling school districts to start again or for schools that start classes after Labor Day to put themselves in a better position for reopening.
“You have almost 4 weeks right now, this is the time to really drive hard getting those measures in place in the community,” said Sexton. “Because in 2 weeks you could see a benefit and in 4 weeks you could see a real decrease.”
If people in states that are getting hit hard by COVID-19 right now could stay home, wear masks when they’re out in public, distance when they can’t stay home, and avoid large gatherings, Sexton said, the fruit of their efforts would be a safer return to school.
“Parties, family reunions, all those things everybody likes doing in the summer, they’re really not safe right now and they’re going to impact our ability to have kids back in school,” she said.
It’s wise to take time to create a strong reopening plan with safety measures to protect students and faculty.
Alternatively, a school year beginning without safety in mind will not end well, Saag said.
“This is a giant experiment and no one knows what will happen even with the best planning. We do know what happens when the school system simply opens with no plans,” he said. “That will be a disaster.”