Whether a return to school will worsen the COVID-19 pandemic is an experiment playing out across Tennessee and the nation, and it begins in Hamilton County this Wednesday.
Whether to go back to in-person education or use a hybrid online system and how to do so safely are hotly debated topics, complicated by a lack of data and understanding of the role children and schools play in spreading the coronavirus.
In Hamilton County, the milestone comes as officials are cautiously optimistic that a mask-in-public mandate amid coronavirus is helping slow the spread of the virus. That improvement could bring renewed confidence for a return to school, but could also be wiped away with a resurgence brought on by new transmissions.
Hamilton County and Knox County are Tennessee's two largest school districts attempting any form of in-person learning before Labor Day. Still, neither district is sending all their students physically back to the classroom, and Knox County has delayed the first day of school twice.
Despite differing academic approaches, the scientific community is unified in the stance that keeping the community transmission rate of the coronavirus low is key to K-12 schools reopening. Otherwise — if transmission rate is too high — schools could become hot spots for outbreaks.
"Opening schools in person when there is high community spread is risky. There absolutely will be infection in those schools if there's a lot of community transmission," said Melissa McPheeters, a health policy research professor at Vanderbilt University Medical Center.
Although Hamilton County has seen a decline in transmission throughout early August, McPheeters said the question is, "is it low enough?"
"Remember, the virus doesn't just stop at the schoolhouse door. If you have a high level of community prevalence, that prevalence is going to exist in the school," McPheeters said. "Children will come into the school with cases of COVID that may not be visible so they could then potentially spread to other students and to faculty and staff, as well, and then back into the community."
Educators and pediatricians agree that in-person learning is best for students when it can be done safely because of the vital services that schools provide and the role they play in both childhood and economic development.
Countries such as Denmark, Germany and Norway sent students back to the classroom and managed to avoid major spikes in new COVID-19 cases by following strict social distancing and hygiene protocols. However, the pandemic was much better controlled in those countries at the time than it is now in the United States.
On the other hand, health officials in Israel blamed a large resurgence of new cases in June on schools reopening. They did not enforce class size limitations or face masks, and the number of new cases jumped from less than 50 per day to 1,500 per day nationwide, according to The Wall Street Journal.
Many leading agencies and experts recommend aiming for a COVID-19 test positivity rate of 5% before resuming face-to-face activities such as school.
"That doesn't take into account other things that are going on in the community, and what kinds of safety precautions any particular school system might be able to put in place to mitigate some of the spread, but that's an important metric to keep an eye on," McPheeters said. "And then, of course, having that consistent reduction in cases is really important."
Most school districts in the state, including Hamilton County, have a phased reopening plan dependent on the current trajectory of the outbreak in their area.
Local reporting of COVID-19 testing data has been inconsistent throughout the pandemic, making calculating test positivity rates a challenge. But starting July 16, the Hamilton County Health Department began releasing the total number of negative tests along with its daily updates of new positive cases, so that important metric can now be tracked.
The average percentage of positive tests in Hamilton County since July 16 is 8.8%, according to health department data updated Friday afternoon. As new cases have declined over the past week — possibly due in part to the public face mask mandate — Hamilton County's average test positivity rate fell to 6.7%. Tennessee's seven-day rolling average test positivity rate during the same timeframe was 8.6%, according to the COVID-19 tracking project.
To start the year, Hamilton County adopted a more restrictive in-person schedule for the first two weeks of school. Students who opted for in-person learning will attend on alternating days and learn at home in between.
The district will monitor the county's average daily number of positive cases, hospitalizations and number of COVID-19 patients in the intensive care unit to determine whether to keep the current plan, move onto the next phase or dial back reopening by Aug. 31 and throughout the semester.
No matter the reopening phase, at least 30% of Hamilton County families have opted to participate online, further reducing the number of students physically in schools.
Dr. Tina Tan, a professor and pediatric infectious diseases specialist at Northwestern University's Feinberg School of Medicine, said during a recent webinar that even with low community spread, it's paramount for people in schools to practice social distancing and use personal protective equipment, wash hands and sanitize surfaces.
Schools also must conduct proper screening, isolation and contact tracing when needed. That's because as long as the coronavirus is circulating in a community, there will be a risk of spreading the virus anytime people convene, she said, and the risk increases inside buildings with poor ventilation.
"Based on current data, the rate of infection among younger school children and transmission from students to teachers has been low, especially if you have mitigation protocols in place and precautions are followed and transmission in the community is low," Tan said.
A spokesman for the Hamilton County Department of Education said that public health officials from the Hamilton County Health Department are working with the district to track issues that may arise with COVID-19. The department provided 14 contact tracers to work exclusively with the school district, he said. Schools will also screen staff and students before school each day.
President Trump has suggested that children are "almost immune" to the coronavirus, but Tan said "anyone can be infected with COVID-19," although there do appear to be some differences in how the disease presents in youngsters.
"When the symptoms are present, they are similar in adults and children," she said, adding that asymptomatic children can still transmit the virus. "Children, however, tend to either have mild symptoms, with cough and fever being the most common, or no symptoms when they are infected."
Tan said a lack of research and data on COVID-19 in children makes predicting what will happen when teachers and students reconvene a challenge. But so far, studies seem to indicate that children under 10 years of age are less effective transmitters of the virus and infrequently serve as the first identified case in family clusters and in community spread.
"However, children 10 years of age and older have similar transmission kinetics as adults and are as likely to transmit to others in the household or in the community, similar to what we see in the adult population," she said.
Children with underlying health conditions and infants less 12 months old are more vulnerable to serious and deadly COVID-19 infection, and Tan said it's important to remember that schools are not just filled with children.
"Schools include a lot of adults," she said, "and many of the studies that have looked at possible school transmission have actually found that it's the adults in the schools that are bringing the virus into the school setting and getting the students and other teachers infected."
Contact Elizabeth Fite at firstname.lastname@example.org or follow her on Twitter @ecfite.