Ontario’s publicly-funded schools are reporting their highest single-day number of new COVID-19 cases so far this year as the number of active infections in students and staff surpasses 2,000 for the first time since the third wave of the pandemic.

The Ministry of Education says that there were 252 new school-related cases confirmed over a 24-hour period ending Tuesday afternoon.

That is a 36 per cent increase on the previous single-day high from this time last week when 185 new cases were reported.

The number of active infections associated with the public school system now stands at 2,016, up 30 per cent week-over-week.

In the 2020-2021 school year it took until March 26 for the number of active infections to exceed 2,000, and less than two weeks later schools across the province were switched to remote learning.

Of course, that closure order came with the vaccine rollout still in its infancy and school-aged children not yet eligible to roll up their sleeves.

This time around more than 22 per cent of children aged five to 11 have received one dose of COVID-19 vaccine and the hope is that the number will reach 50 per cent by the end of this month, providing schools some level of protection upon the resumption of classes in January.

“Our schools should be the first to open and the last to close and we're doing our utmost to ensure that they are protected and with this extra level of immunization that does give me further confidence that we can improve on the safety of our schools through a robust immunization strategy,” Chief Medical Officer of Health Dr. Kieran Moore told reporters on Tuesday when asked about the rise in cases. “If you just compare the secondary schools with the elementary schools, the number of outbreaks in the in the secondary schools are fewer, they are smaller and the length of time that students have had to be out of school is less. So I hope we'll have the same benefits as we improve immunization rates in our elementary sector.”

School-related cases of COVID-19 were stable through most of September and October but have been steadily rising since then, often outpacing the growth in case counts in the broader community.

As of Wednesday a total of 860 of Ontario’s 4,844 public schools have at least one active case of COVID-19. Of those schools 260 have active COVID-19 outbreaks, approaching the all-time high that was recorded at the height of the third wave of the pandemic on April 14 when 264 schools were dealing with outbreaks.

There are also 10 schools that are currently closed due to COVID-19 outbreaks or for operational reasons related to the pandemic.

Meanwhile, at least 209 individual classroom cohorts are self-isolating in the Greater Toronto and Hamilton Area following positive cases. That number is likely an underrepresentation when it comes to the disruption to in-person learning as only some boards publicly report the data.

On Tuesday, Moore said that his office is “working diligently with the Ministry of Education to review whether we have to put any other public health measures in place in schools to further protect them and keep our schools safe.” But he did not provide any further details.

There have been a total of 8,879 school-related cases confirmed by the ministry since students returned to classrooms in September.