The careful calculus of closing schools in a pandemic

As COVID-19 continues its steady spread through Ottawa's schools, administrators say they're leaning on public health officials to determine when to keep kids in the classroom, send some cohorts home or shut schools down altogether.

But how does Ottawa Public Health (OPH) reach that decision?

As of Thursday, 67 schools in Ottawa's four public boards and 18 schools in western Quebec had at least one case of COVID-19. One Ottawa elementary school, Monsignor Paul Baxter School in Barrhaven, remains closed after two staff and two students tested positive for COVID-19, as does Fellowes High School in Pembroke, Ont.

Initially, OPH said an outbreak would only be declared at a school where there were at least two cases that were epidemiologically linked — in other words, where transmission was determined to have occurred at the school, on the way to school or during some other school-related activity. Health officials would then determine which students needed to self-isolate.

With all the safety protocols in place — physical distancing, mandatory masks and a new cohort system designed to limit contact among students — many parents assumed that if a case was detected, only those few students or staff in direct contact with the infected person would be sent home.

However, at Monsignor Paul Baxter, which became the first elementary school in Ontario to close, that's not what happened.

"Although these [COVID-19] cases are all in the primary panel, OPH sends all students and staff home to be cautious," the school's principal, Mark Kennedy, explained in a letter to parents. "We continue to defer all medical and health related decisions to Ottawa Public Health."

No closures at OCDSB

Yet so far, the city's largest school board has avoided a closure. As of Thursday, the Ottawa-Carleton District School Board (OCDSB) was reporting nine cases, with no classes or cohorts sent home. (A school-by-school breakdown is available here.)

"Ottawa Public Health, as the lead health agency in Ottawa, is responsible for managing COVID-19 cases, including providing guidance to schools on confirming and controlling outbreaks," OCDSB spokesperson Darcy Knoll wrote in an email to CBC.

In an email to OCDSB families Friday, the director of education said should the board close schools, it will notify families as soon as possible through email and social media.

"Unfortunately, this could be as late as the morning of school. It is recommended that you prepare for this possibility in advance," wrote Camille Williams-Taylor.

Knoll's counterpart at the Ottawa Catholic School Board (OCSB), Sharlene Hunter, echoed the reference to Ottawa Public Health providing guidance to schools. (Click here for a breakdown of which OCSB schools are affected.)

"OPH decides which cohorts in the school should self-isolate by being most at risk from the outbreak," Hunter told CBC in an email. "If OPH advises that a class, cohort or school be closed, parents, students, and staff will be notified."

Assessing risk of spread

In an email to CBC, OPH confirmed it maintains authority over school closures, and indicated it looks at risk of spread on a case-by-case basis.

"Over the last couple of weeks, OPH is starting to see that some students and staff are now getting sick from interactions at school," OPH wrote. "If there is sufficient evidence to indicate that there is risk of spread to additional cohorts, there may be a decision to close the entire school in order to stop transmission."

You can see a sample of the OPH school closure letter here. If a single case or unlinked cases are found in a student or staff member, parents will receive this letter. If an outbreak is declared, parents will receive this letter. If a child is found to have COVID-19-like symptoms while at school, parents can expect this letter.