Requiring students to wear masks and follow other hygiene measures prevents the spread of most coronavirus cases within classrooms, according to preliminary study results released Friday by the Centers for Disease Control and Prevention and researchers from Washington University and St. Louis University.
The pilot study found just two cases of the virus spreading in-school after conducting contact tracing and follow-up testing for 37 cases across 57 schools. It also found quarantining infected students and staff to be important.
“We took people that were sick and were infectious in our schools, they were in the building, they were in the classrooms. And we saw that transmission was rare,” said Dr. Jason Newland, a Washington University pediatrician who led the study.
The pilot study was conducted in December, when the number of COVID cases was ballooning in Missouri and nationwide.
The findings build on prior evidence and studies conducted in the United States and other countries, all of which indicate that in-person learning is safe and does not contribute to COVID-19 outbreaks when schools implement safety measures.
While Missouri never implemented a statewide mask mandate nor required masks be worn in schools, all the schools in the study do have a mask requirement.
“I think we all underestimated how good people are” at wearing masks, Newland said, adding that for young people, “it’s like a part of life.”
Most classrooms in the study also took steps to improve airflow, but only 5% of classrooms in the study had upgraded their ventilation systems. Opening windows or doors were more common tactics.
The CDC on Friday revised down its recommendation of space between desks, saying seating students 3 feet apart is adequate, rather than the initial recommendation of 6. Newland said most classrooms in the study already spaced students less than 6 feet apart.
“This gives these other folks that are now getting back in school more reassurance of that decision, that they can have a little bit more students if that was one of their barriers to going back to school,” Newland said.
Ferguson-Florissant and Hazelwood school districts plan to bring students back to school for the first time later this month.
Rockwood, Pattonville and University City school districts in St. Louis County are involved in the full study, along with three districts in the Springfield, Missouri, area and two private schools.
The Springfield School District implemented a “modified” quarantine rule endorsed by the state education department that is less strict than CDC advice. Under the district’s rules, students do not need to quarantine after close contact with an infectious person as long as both people were wearing masks the entire time. Newland said that significantly reduced the amount of in-person school that students missed.
“I think that's the next question we have to answer. Because the preliminary report shows modified quarantine is fine,” he said. “And we need to learn from that more.”
The study also looked at extracurricular activities, such as sports, and found no evidence they cause outbreaks.
The findings were published in the CDC’s Morbidity and Mortality Weekly Report journal. Data collection for the full study, which includes more schools, is wrapping up soon, and results will be published later.
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