Schools with face-mask requirements had fewer Covid-19 outbreaks, CDC study finds

by Sarah Toy | UPDATE Sep 24, 2021 04:32 PM EDT

Two studies suggest masks can help prevent classroom outbreaks and pediatric cases in the community

Face-mask requirements in schools significantly reduce the spread of COVID-19 among children, two studies published by the Centers for Disease Control and Prevention show.

Arizona researchers found that schools that did not require masking at the start of the academic year were more likely to experience an outbreak of COVID-19 than those that did not. A second study found that counties without mask requirements for schools showed a larger increase in the rate of pediatric COVID-19 cases than counties with school mask requirements.

CDC recommends universal indoor masking in schools for both students and staff, regardless of vaccination status. The agency and many public-health experts are pushing for a so-called layered approach that includes not only masking, but also social distancing, screening tests, better ventilation and handwashing.

In the Arizona study, researchers looked at two of the state’s most populous counties, where students began in-person learning in late July and early August. The researchers tracked which schools required students and staff to wear masks indoors and which did not, and they also noted when those mask mandates were implemented – at the beginning of the school year or Shortly after the start of classes.

The researchers then studied a database where all school-linked outbreaks in the state were to be reported and counted 191 school outbreaks between July and August. About 8% were in schools that implemented early masking requirements, 33% were in schools that required masking later, and just over 59 percent were in schools without masking requirements. Researchers found that schools that did not require masks were 3.5 times more likely to have an outbreak of COVID-19 than those that implemented the masking mandate at the start of the school year.

“Mistakes in universal masking contribute to the outbreak of COVID-19 in the school setting,” researchers wrote in a report published Friday.

In another study, CDC researchers looked at pediatric COVID-19 case rates in 520 counties, some with and some without masks. Taking into account factors such as age, race, pediatric vaccination rates and rates of community transmission, they found that counties with school mask requirements had a smaller increase in rates of pediatric COVID-19 cases than children without those requirements. Was.

“Masks work,” said Mobin Rathore, chief of infectious diseases at Wolfson Children’s Hospital in Jacksonville, Fla., who was not involved in the study.

He said the research reveals what he has seen in his community.

He said in Duval County, where Wolfson is located, there was no masking requirement for schools when classes reopened in early August. Data from the Duval County Public Schools COVID-19 Case Dashboard shows cases among students were high in late August. Then, on September 7, the county school board approved a 90-day mask mandate for all students.

“After that, the number of cases in the school system began to drop,” Dr. Rathore said. According to the dashboard, the cases among students have been trending downward since then.