Frequent Testing Helps Prevent Transmission in Schools

Interventions after students receive a positive test were ineffective at preventing more infections.

A recent study conducted by investigators from Simon Fraser University has found that proactive, frequent COVID-19 testing all students is more effective at preventing transmission clusters in schools.

Findings from the study were published in the journal PLOS Computational Biology.

“During the COVID-19 pandemic many jurisdictions closed schools in order to limit transmission of SARS-CoV-2. Because school closures are costly and damaging to students, schools were later reopened despite the risk of contact among students contributing to increased prevalence of the virus,” the authors wrote. “Early data showed schools being mostly a low-risk setting, but occasionally large outbreaks were observed.”

For the study, the team of investigators tested the efficacy of 2 transmission control strategies.

The first strategy sent a student home if they developed symptoms and were then tested using a PCR test. If the result was positive for COVID-19, control measures were introduced into the classroom.

In the second strategy, all of the students in the classroom were regularly tested using a rapid test. If one of the students tested positive, control measures were introduced.

Findings from the study showed that the first control strategy was typically too slow to try and prevent more transmission from occurring. However, the second study led to the prevention of large outbreaks.

The investigators believe that their research is also applicable to other settings where groups of people spend multiple hours together.

"When schools have reopened during the COVID-19 pandemic, in some places there have been large clusters of infections, and in others very little transmission," Caroline Colijn, an author on the study said. "In our simulations, we explored what factors affect cluster size, and what interventions can be used to prevent large clusters."=