VANCOUVER (NEWS 1130) – Researchers at Simon Fraser University suggest there’s a better way to prevent more outbreaks of COVID-19 at schools in B.C.: regular and rapid testing.
Currently, any outbreaks at schools are dealt with by testing students and staff who are showing symptoms, and then notifying their close contacts if their results come back positive for the coronavirus.
While the researchers say that helps limit the size of clusters at schools, their modelling shows that regular, proactive testing of all students — even before anyone starts to show symptoms — was effective at preventing large clusters of the virus.
“Rapid regular universal monitoring is far superior in preventing large clusters to testing that is initiated upon detection of a symptomatic case, even if a whole class is then tested soon afterward,” the paper reads.
That’s because it catches individuals who may be carrying the virus and are infectious, but who aren’t showing any symptoms.
The study points out that early evidence suggested schools were low risk and children were unlikely to be very infectious. However, with a major COVID-19 outbreak reported at a school in Kelowna, and with many more exposure alerts being issued at schools across the Lower Mainland, it is becoming clear that young people can contract and transmit the virus at school and that clusters and outbreaks can be large.
About a third of school exposures in B.C. involve staff, Provincial Health Officer Dr. Bonnie Henry said Thursday. The remaining two thirds are students.
Q Kelowna outbreak details…
Dr H: Staff and students. some exposures like on school bus
In BC overall of 216 exposure events she says 1/3 are staff, 2/3 students (this is new was the other way a month ago)#bcpoli #bced @NEWS1130 #covid19
— LizaYuzda (@LizaYuzda) October 22, 2020
The researchers, whose findings have yet to be certified by peer review, suggest two other approaches to prevention.
For one, they say reducing community transmission can play a big role, adding “if exposures themselves are rare, the waiting time before a high-transmission introduction is likely to be much longer than if community transmission leads to frequent exposures.”
Finally, the study finds that taking step to address the environment and how it plays a role in transmission could also help.
“Indoor, crowded, loud, poorly ventilated environments with singing, eating and dining are recognized to be comparatively high risk [36, 38],” the study reads.
“However, data could now be gathered prospectively with a focus on schools: when there are exposures in classroom settings, these could be linked to data on the room size, ventilation, whether windows were open, numbers of students in the class and classroom organization, and then further linked to follow-up on cluster size.”school covid study2020.10.20.20216267.full
The researchers stress that if we are to keep schools open, it’s imperative we do what we can to prevent large transmission clusters, “even if they are expected to be rare.”
“The expected benefit of preventing large transmission clusters will naturally depend on the state of COVID-19 transmission in the community, with larger clusters likely to be amplified and spread onwards where community transmission is ongoing. Such settings will also have more school exposures, and the chance of an unfortunate high-transmission introduction to a school is correspondingly higher, creating a viscious (sic) cycle.”