BARRIE, ONT. -- Ontario's education minister announced students would return to "elevated" control measures following the April school break one day after Simcoe Muskoka's medical officer of health cautioned the third wave might force schools to close again.

Dr. Charles Gardner said there is the potential for cases to rise among students and staff and added it "may prove not feasible to keep school going if the third wave becomes quite severe."

The region's top doctor said he would support another postponement of the week-long school break planned for April 12 to keep infection rates down.

"We did see an increase in transmission of COVID-19 over the Christmas break related to children being at home and social gatherings that proved to be more transmitting of COVID-19 to children than in the school environment," he noted.

Currently, there are two active school outbreaks at Boyne River Public School in Alliston and Holy Trinity Catholic High School in Bradford. The outbreak at Andrew Hunter Elementary School in Barrie ended on Tuesday.

Education Minister Stephen Lecce said that the plan is to go ahead with the school break next month, adding that he hopes expanded safety measures will allow Ontario schools to remain open for the rest of the academic year.

"We are increasing our vigilance and corresponding action to make sure that when a child returns from that break, we can do so with confidence that they are not entering with potential cases," Lecce said on Wednesday.

"I believe at this point in time, it's an important thing to keep school going, and I do know that if we go on our break right now, we might end up with that surge, so I personally would be supportive of a further postponement," Dr. Gardner said.

"We might find that the third wave we would have to be discontinuing school regardless," he added.

On Wednesday, the Simcoe Muskoka health unit reported 46 new COVID-19 cases, including five virus-related hospitalizations.

There are currently 447 active infections across the region.

Simcoe Muskoka's top doctor says local infection rates had levelled off, with cases sitting at around 50 per 100,000 population, while weekly counts continue to fluctuate, calling it a "saw-tooth pattern."