Officials have uncovered at least 57 positive COVID-19 cases in Ontario schools through the use of asymptomatic testing of students, staff and their families, the government confirms.

In late November, the Progressive Conservatives announced they would be starting voluntary, asymptomatic COVID-19 testing at certain schools in Toronto, Ottawa, Peel Region and York Region—four areas most impacted by the disease at the time.

They said the targets would be chosen in consultation with school boards. All students, staff and teachers within those schools would have the option to receive the on-site testing. In some cases, families will also be allowed to be tested.

To date, the province has conducted more than 4,500 asymptomatic COVID-19 tests in those areas. Fifty-seven positive cases were found, the government confirmed.

At least 26 cases of those cases were found in students and staff at Thorncliffe Park Public School in Toronto.

Since September, more than 7,000 lab-confirmed positive COVID-19 cases have been logged in schools across the province. More than 4,800 of those infections were in students.

COVID-19 infections have led to multiple school closures, with at least 12 schools in the Toronto District School Board (TDSB) shuttered as of Dec. 18.

Last week, staff at the TDSB called on the province to o stop in-person learning for the first two weeks of January and conduct asymptomatic COVID-19 testing in all the city’s schools.

“We believe that out of an abundance of caution. This request, these requests, should be taken very seriously,” Leslie Wolfe, president of the Ontario Secondary School Teachers Federation, said at the time.

“We are very concerned for high risk neighborhoods in the City of Toronto, for the kids that we teach in those neighborhoods, and of course for our own members.”

The calls have not been heeded so far by the Ontario government, who previously said they would not be extending the upcoming winter holiday break for students and teachers, and have repeatedly said that schools are safe places for children.

At the same time, government officials sent school boards a memo this week indicating they should be prepared to switch to remote learning if it is deemed necessary.