KITCHENER -- Wellington-Dufferin-Guelph Public Health’s top doctor announced Thursday that she had instructed school boards and private schools to extend online-only learning.

Before the holidays, the Ontario government announced that schools would stay closed beyond their normal holiday break, with students instead switching to distance learning after the holiday.

Elementary students in southern Ontario were originally supposed to return to class on Jan. 11, with secondary students due back in class on Jan. 25.

Now, WDG Public Health’s medical officer of health, Dr. Nicola Mercer, has asked schools in her area to extend online-only learning for all students until at least Jan. 24.

“The importance of in-class education on the overall health, well-being and development of our children remains the foundation of our education system,” said Dr. Mercer in a news release.

“However, with a significant rise in cases across our region and evidence of transmission among school-aged children, we must make this difficult decision to reduce the spread of COVID-19 and keep our region safe.”

Her decision came hours before the Ontario government announced it would take the same measures, keeping students at home with remote learning until Jan. 25 after new provincial data raised "significant concerns" about the spread of COVID-19 among school-aged children over the Christmas holidays.

Premier Doug Ford said the announcement would come from Chief Medical Officer of Health Dr. David Williams, who was scheduled to speak publicly via teleconference at 3 p.m., but the decision was announced during a press release issued just before 3 p.m.

"With the public health trends where they are across the province, our priority remains keeping students, teachers, school staff, and all Ontarians safe," said Premier Doug Ford in the release, which also outlined some alarming numbers about cases in children.

"Targeted testing done among students and staff in December 2020 confirmed that schools are not a significant source of transmission," the news release said.

"However, with students having been at home for several weeks and with reports of concerning behaviour over the holidays, the positivity rate among school-aged children has increased sharply."

The positivity rate among kids age 12 to 13, specifically, increased from about 5.4 per cent in early December to nearly 20 per cent by early January.

For Wellington-Dufferin-Guelph Public Health’s area, the instructions will be evaluated on an ongoing basis to determine when schools can safely reopen.