Ontario reported a record 550 new COVID-19 cases among public school students and staff over the weekend and more than one fifth of all public schools have at least one active case for the first time this school year.

The Ministry of Education says that between the afternoon of Dec. 10 and Monday, 473 public school students and 61 staff members tested positive for COVID-19, along with 10 other people whose associations to schools were not disclosed.

Tuesday’s increase was the highest weekend count of new cases tied to schools reported in the 2021 school year.

There are 1,019 schools with at least one active case of COVID-19 and 28 schools are closed due to outbreaks or other operational reasons.

At this point in the 2020 school year, there were 889 schools with one active case and 18 were closed.

There are more than 2,400 active cases of COVID-19 tied to schools, representing about 20 per cent of all known active cases of COVID-19 in Ontario on Tuesday.

Across the Greater Toronto and Hamilton Area, school boards reported 1,411 active cases of COVID-19 on Tuesday, up approximately 40 per cent from one week ago.

At least 326 class cohorts are isolating at home due to exposures, but that number is likely an underestimate as several major school boards including the TDSB do not disclose class cohort isolation data.

A number of GTHA parents wrote on social media Tuesday that several school boards were advising them to bring all their children’s school materials home with them before the winter break in the event schools do not reopen in January.

There have been 10,093 lab-confirmed cases of COVID-19 in Ontario schools since Sept. 2021.

During the entire length of the 2020-21 school year, there were 15,292 lab-confirmed cases.

The majority of public school boards in Ontario end for the winter break this Friday.