ST. LOUIS — In-school COVID-19 transmission is rare when schools follow public health precautions like masking and social distancing, according to a recent study in Missouri.
The study was aimed at identifying ways to keep elementary and secondary schools open and safe during the pandemic.
The study is part of a larger, ongoing collaboration with Centers for Disease Control and Prevention (CDC), Washington University School of Medicine in St. Louis, the Missouri Department of Health and Senior Services, the Missouri Department of Elementary and Secondary Education, Saint Louis University, the Springfield-Greene and St. Louis County health departments and school districts.
The Missouri school findings are similar to those of schools in other states, which demonstrate that COVID-19 prevention efforts can “significantly” curb the spread of the virus among students, teachers and staff, WashU said in a press release.
“This work is imperative because keeping kids in school provides not only educational enrichment but also social, psychological and emotional health benefits, particularly for students who rely on school-based services for nutritional, physical and mental health support,” said senior author Johanna S. Salzer, DVM, PhD, a veterinary medical officer with the CDC’s National Center for Emerging and Zoonotic Infectious Diseases.
The study involved 57 schools in the Pattonville School District, the Springfield Public School District in Greene County and two private schools in St. Louis County. All schools in the study required students, teachers, staff and visitors to wear masks while on campus or buses.
Other safety measures included hand hygiene, deep cleaning of facilities, physical distancing in classrooms, daily symptom screenings for COVID-19, physical barriers between teachers and students, virtual learning options and increasing ventilation.
For two weeks in December, schools notified the research team about students, teachers and staff who were either infected with the virus or quarantined due to being considered a close contact of someone who had tested positive.
In St. Louis, close contacts of students or teachers who tested positive were placed in quarantine. In Springfield, some of the close contacts were placed in a modified quarantine, meaning they could stay in school if they and the infected person were wearing masks when in close contact. The infected person still isolated at home.
Participants in the study included 193 people across 22 of the 57 schools.
Thirty-seven tested positive for the virus and 156 of their close contacts. Among participants who tested positive, 24 (65%) were students and 13 (35%) were teachers or staff members. Of the close contacts, 137 (88%) were students and 19 (12%) were teachers or staff.
“Among the 102 close contacts who agreed to testing for COVID-19 using saliva tests, only two people received positive test results indicating probable school-based SARS-CoV-2 secondary transmission,” WashU stated in the release.
No outbreaks were identified in participating schools despite high rates of community spread in December, even among the Springfield schools that followed the modified quarantine.
“Schools can operate safely during a pandemic when prevention strategies are followed,” said Jason Newland, a Washington University professor of pediatrics who led the pilot program with the CDC. “The pilot study demonstrates low transmission in schools and no student-to-teacher transmission — and this was during the height of the pandemic in December, with high rates of community spread.”
The findings of the study were published on March 19 in the CDC’s journal "Morbidity and Mortality Weekly Report."
Since mid-January, the CDC, Washington University and Saint Louis University researchers, St. Louis County and Springfield-Greene County health departments, three school districts from St. Louis County and three school districts in Greene County have been participating in a larger study to continue examining COVID-19 prevention strategies and quarantine policies.