Coronavirus rates are surging across much of the country again. That means school district leaders must prepare to make quick decisions about how they are operating.
There are two main ways to look at how much the coronavirus has spread in a community:
- the case rate;—or the number of people identified with COVID-19 for every 100,000 people in the community;—and
- the positivity rate, or the percentage of the tests given in a community that come back positive for the virus. If a community has limited testing, it is likely to have a higher percentage of those tests come back positive, both because more infectious people are not tested and thus not isolating themselves, and because those who do get tested are more likely to be those with more obvious symptoms.
According to the latest seven-day average from the Centers for Disease Control and Prevention, 22 states have an infection rate higher than 20 per 100,000 people. Four states—Montana, North and South Dakota, and Wisconsin—all have case rates more than 50 per 100,000, which the CDC considers moderately high risk for schools.
Johns Hopkins University’s Coronavirus Resource Center, which tracks coronavirus testing, finds the percentage of tests coming back positive for COVID-19 during the same seven-day period is rising in 33 states and is higher than 5 percent in 32 states. Both the CDC and the World Health Organization consider any positivity rate above 5 percent to mark high risk for outbreaks.
“Once you start to escalate above that 5 percent test positivity rate, then you know there’s an increased amount of transmission occurring in the community, meaning that there would be an increased risk for COVID in the school setting,” said Tina Tan, a pediatric infectious disease doctor at Lurie Children’s Hospital in Chicago and a coronavirus expert with the Infectious Disease Society of America.
“One thing to keep in mind is anybody who gets COVID can transmit COVID. So even though the majority of cases in children or asymptomatic, they are still able to transmit the virus,” said Tan, who has been working with districts on their remote- and in-person learning plans. So far, research suggests that infected children and adults have about the same amount of virus particles in their respiratory tracks, but for some as-yet unknown reason, children under age 10 appear to transmit the virus less than adolescents and adults.
“Some people are saying, why don’t we bring back, say pre-K to 3rd grade for in-person learning. And then we’ll do kind of a hybrid model for the kids that are a little bit older and then high school can be all virtual,” Tan said, “But whether or not it’s applicable will depend upon the resources that the school district has as well as what protective mitigation protocols they are able to put in place.”
She said all in-person schools, be they full or part-time should require universal mask-wearing for all students, teacher, and staff except when they are eating, along with six-foot social distancing and regular handwashing. Tan also recommended any in-person classes group students into cohorts and require students to eat lunch in their classrooms to avoid mixing different groups.
Now is also a good time for school leaders to double down on ensuring students and staff are up to date on vaccinations for all the other seasonal and childhood illnesses, following years of increasing outbreaks in measles, whooping cough, and seasonal flu.
“One of the unintended consequences of the pandemic has been a dramatic decline in the rate of routine immunizations,” Tan said, and while many precautions against COVID-19 can also buffer against things like the flu or measles, reduced immunizations will lower herd immunity against preventable childhood diseases.
While all public schools are required to track symptoms and have procedures in place to quarantine those who are sick, plans for universal COVID-19 testing may be less effective, researchers say. For example, San Diego Unified schools, which started in-school learning for small numbers of highly vulnerable students this week, requested enough COVID-19 tests from the state for every student and staff member in order to provide larger-scale in-person learning, but Tan said even rapid-response tests could miss many in the early stages of the disease, and results may not come back quickly enough to track and isolate those who are infected.
In fact, one recent Mathematica study suggests strong preventative measures including mask-wearing and social distancing can give schools a wide buffer to respond to potential outbreaks.
“It turns out that the delays in getting a test back matter a good bit, but depending on what you are doing,” said Brian Gill, lead researcher for the study of more than 400,000 school reopening scenarios at different grade levels, precautions, and community infection rates. “If you’re trying to run a school full time without precautions, if you were pretending that you could operate business as usual, then delays in getting tests back can substantially increase infection rates,” he said. Holding class fully in-person with precautions still can lead to outbreaks if test results take several days, but significantly fewer infections than in schools without precautions.
“Then when you get to the part-time, small-group hybrid approaches, it turns out the testing time doesn’t matter much, essentially because ... if you’ve got small groups, only a couple of days a week with masks and six feet of distance, then you’ve almost eliminated transmission occurring in the school anyway,” Gill said.
However, in the burgeoning number of communities—and at least five states—where 20 percent or more of COVID-19 tests come back positive, Tan warned, “that is a lot of virus that’s circulating in that community. And it probably is not a good idea to continue any in-person learning in that situation. ... No matter how small your hybrid group is, these kids don’t live at the school. So if community rates are really high, then that just increases the risk of someone bringing COVID in from the community to the school.”
“There’s ongoing research, but until we get a better handle on what the transmission dynamics are, we know that anybody with COVID can transmit the virus. So, I think you have to be very conservative and very safe.”
Chart Source: CDC COVID-19 Data Tracker
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