- Researchers say regular screening of students and employees is the best way to prevent COVID-19 outbreaks at schools.
- They say once a student or adult becomes symptomatic, it’s probably too late to prevent a spread of the disease.
- One expert, however, says testing can be cumbersome and expensive for schools, so masking and screening may be more prudent alternatives.
Regular monitoring of everyone in a school setting may be the only way to prevent outbreaks of COVID-19 in schools.
That’s the conclusion of a study published today in the journal PLOS Computational Biology.
Researchers reported that through a simulation, they determined that in cases of high transmission, actions such as closing down a classroom after a student was symptomatic were not enough to stop a large outbreak.
“We found that waiting until a student develops symptoms and tests positive is too slow a response, even though this was the method used in many jurisdictions to prevent COVID-19 transmission,” Paul Tupper, PhD, co-author of the study and a professor and director of the Cognitive Science Program at Simon Fraser University in British Columbia, Canada, told Healthline.
“Screening students without symptoms works quite well in our model and could also be applied in workplaces or shared living accommodations,” he added.
The researchers examined the efficacy of four possible courses of action taken when a student becomes symptomatic.
In the first option, the symptomatic student stays home and no further action is taken.
In the second protocol, once a symptomatic student receives a positive test result for COVID-19, other students in their group are sent home.
In the third option, when two or more groups have a student with a positive result, this is declared an outbreak and all students go into isolation.
In the final option, if a symptomatic student returns a positive result, all students are isolated.
The researchers found none of these models were effective in stopping the spread of the coronavirus unless there was already a low transmission rate in the community.
“None of the mitigation protocols we modeled, initiated by a positive test in a symptomatic individual, are able to prevent large transmission clusters unless the transmission rate is low (in which case large clusters do not occur in any case),” they wrote.
“Among the measures we modeled, only rapid universal monitoring (for example by regular, on-site, pooled testing) accomplished this prevention,” they added.
Dr. Dean Blumberg, chief of pediatric infectious diseases at UC Davis Health in California, says rapid pooled testing may pose some problems.
“That can play a role if you have the resources for that. However, there are challenges to that. One is having the testing available,” he told Healthline. “Another is that children don’t like to be swabbed, and parents may not like their children to be swabbed on a regular basis. I just think that has limited appeal.”
“The best option is to use other tests rather than the deep nasal pharyngeal swabs, which can be very uncomfortable,” he added. “You can swab the anterior, the superficial part of the inside of the nose, and you can do saliva tests also. So those would be better ways of doing testing.”
Blumberg contends that the key factors in keeping schools safe during the pandemic are masking and screening protocols.
“We’ve found that, to date, schools are very safe places for children to be. There’s very little transmission, especially when the schools have masking, and there’s enough capacity for testing and screening children also. Those are the key points, and when those mitigation factors are followed, there’s very limited transmission at school,” he said.
“Masking works very well, and in studies of children masking in schools, more than 90 percent of children do comply with masking requirements,” Blumberg added. “Children are resilient, and they can understand the need for masking, and they can follow these kinds of rules.”
“If you screen children and if everybody’s very vigilant about children being symptomatic and keeping them home, then this can limit opportunities for transmission,” he added. “And if there are exposures, then testing those who are exposed can further limit transmission. To me, those seem like the key actions to take that can keep safe places for children and for staff.”