KITCHENER -- Millions of Ontario children will return to school in under two weeks, and with the date fast approaching, the provincial government has offered guidance on managing COVID-19 cases in schools.

Health experts agree that an increase in cases is all but inevitable, as the return to the classroom will be accompanied by the return of several high-risk activities.

"I think we can expect, with more social interactions, there will be more cases of COVID-19. There will be more outbreaks just because there will be more cases," said Waterloo Region's medical officer of health, Dr. Hsiu-Li Wang, during a news briefing on Tuesday.

During the briefing, Dr. Wang said that she was expecting more details on how to manage school outbreaks from the province imminently, and it appears she was right.

At his daily COVID-19 briefing on Wednesday, Ontario Premier Doug Ford was joined by Education Minister Stephen Lecce in revealing the province's guidance on managing cases in schools.

Cases known to be acquired outside of school

In cases where the case was known to be acquired outside of the school but the individual was in class during their communicable period, the case's cohort can be—but doesn't have to be—dismissed for self-isolation. A document from the province shows that there will be exceptions on a case-by-case basis by the local public health unit (or PHU).

"For example, if the case was known to have acquired their infection outside of the school and had very short or limited contact with the school while infectious, the PHU may decide on more limited dismissal," the document explains.

Testing would be done in those who were dismissed as soon as possible, and self-isolation would last for 14 days from the last exposure to the case unless any other cases emerge. The province recommends testing within five to seven days of their last exposure to the case.

Waterloo Region has four testing centres:

  • The Grand River Hospital-run drive-thru in the Catalyst parking lot;
  • The Cambridge-North Dumfries Community Assessment and Testing Centre at Cambridge Memorial Hospital;
  • The St. Mary's General Hospital COVID-19 testing centre; and
  • Kitchener-Waterloo-Wilmot-Wellesley-Woolwich (KW4) Community Assessment Centre.

Read more: Here's how you can get tested for COVID-19 in Waterloo Region

The province also listed a number of escalating measures if cases spread amongst students.

Acquisition source unknown, or likely to have come from school

If a case is identified but public health doesn't know where it came from, or if it is likely that it was acquired at school, the measures ramp up.

In this case, a case's cohorts would be dismissed for self-isolation, as would people identified as having high-risk exposure to the case. Those people should be tested as soon as possible, the province's guidance says, and that, even after a negative result, they should be tested again if symptoms develop.

The school should be monitored closely afterwards for symptomatic people, and these should be discussed with Region of Waterloo Public Health.

Managing secondary cases

If a case in a school leads to secondary cases, things ramp up even more. Along with cohorts being dismissed, an outbreak will be declared and public health units are advised to consider closing the school.

In the case of schools, an outbreak is defined as two or more lab-confirmed cases of COVID-19 with an epidemiological link within a two-week period, and where at least one case could have "reasonably acquired their infection in the school." That also includes transportation—like buses—and before- and after-school care.

Infectious disease expert Dr. Abdu Sharkawy told CTV Kitchener on Monday that full buses are an area of high-risk. Currently elementary students will be bused to school with up to 70 children per bus and three kids per seat. Even with masks, Dr. Sharkawy said that buses are not normally well-ventilated, and that options like opening windows aren't effective in the winter when the bus would get too cold.

READ MORE: These back-to-school activities are considered high risk. An infectious disease expert weighs in on how to fix them

COVID-19 risk level by school activity Aug 24 2020

The province's guidance showed that an outbreak can be declared over after two weeks with no evidence of ongoing transmission related to exposure in the school. An outbreak does not necessarily mean the whole school will need to close.

Closing a school

Public health officials are advised to dismiss a whole school if there is "evidence of potential widespread transmission within the school," like if several cohorts have been dismissed based on the above criteria.

Testing may be recommended for all school attendees as part of case finding, especially if the link between cases is not easily established. In that case, the province says public health units will need to coordinate with Ontario Health Region to ensure timely access and accessibility to testing options.

The school can reopen as cohorts that don't have evidence of transmission are identified. The outbreak does not necessarily need to be declared over to reopen a school.