TORONTO -- Toronto Public Health (TPH) has dismissed all students from a high school in Etobicoke where there is currently a COVID-19 outbreak and is recommending that the entire school be tested for the virus.

In a news release issued Monday evening, the health unit said it took the decision to dismiss all students from in-person learning and activities at Silverthorn Collegiate Institute following “a careful and detailed investigation, newly reported cases over the weekend, and potential exposures at multi-grade events.”

All students who attend the school, located at Burnhamthorpe and Mill roads, will be moving to remote learning starting Tuesday, the Toronto District School Board said.

TPH said it is making the move in order to protect students, staff and the school administration.

“TPH continues to investigate this COVID-19 outbreak, including following-up with close contacts, providing guidance, and recommending whole-school testing,” the health unit said in its release. “TPH is also encouraging vaccination for the entire school community including family members of students, if they have not already been fully vaccinated with two doses of COVID-19 vaccine.”

A letter to parents from TPH obtained by CP24.com said take-home PCR test kits will be available at the school and should be completed by all staff and students. Alternatively, members of the school community can also get tested at a COVID-19 assessment centre.

TPH did not say exactly how many cases are currently associated with the outbreak at Silverthorn C.I., but a note to parents from the school’s principal obtained by CTV News Toronto said there were 11 cases.

Students and staff identified as close contacts in the affected classes and activities have been notified, TPH said in its letter.

As of Friday, there were three confirmed student cases of COVID-19 at the school, according to provincial data.  However those data have not been updated since Friday because of the Thanksgiving Holiday. An outbreak is considered to be two or more lab-confirmed cases linked within a setting within 14 days.

“This means that there is at least one case that could have reasonably acquired their infection in school, which includes transportation, extracurricular activities and before and after school care,” TPH said.

As of October 8, there were 21 active school outbreaks and 30 active investigations in 122 school settings in Toronto. The health unit said finding COVID-19 in school settings “is not unexpected, given that the virus continues to circulate in Toronto and how transmissible Delta variant is.”

“TPH continues to closely monitor all COVID-19 activity in schools and take action as needed to protect students and staff,” the health unit said.

In a statement to CP24, the TDSB said it is not clear how long the dismissal will last.

“We’re working closely with Toronto Public Health and helping in any way we can,” the statement read.  “While we hope students can return to in-person learning shortly, it’s not yet clear how long the dismissal will last as that will depend on the TPH investigation. In the meantime, all students will be moving to remote learning.”

TPH said the dismissal could last for around 10 days, but it depends on how the investigation progresses.

The Ford government has repeatedly insisted that schools are safe and that the best way to protect them is to reduce COVID-19 transmission in the community.

Bending to mounting pressure recently however, the government did say that it would deploy rapid tests to schools in areas that have seen abnormally high levels of COVID-19 transmission.

In its letter to the school community, TPH said that it is recommending a mobile vaccination clinic for the school and asked everyone who has not yet been vaccinated to do so.

Data on the city’s vaccine dashboard indicates that 73 per cent of those 12 and up in Markland Woods, where the school is located, have been fully vaccinated. That lags behind the overall rate for full vaccination in Toronto’s 12+ population, which sits at 81.6 per cent.

Members of the school community are also being advised to continue to monitor for symptoms.

“All staff and students should continue daily COVID-19 symptom screening using the TPH COVID-19 symptom screening tool,” the TPH letter said. “If you develop symptoms, the person with symptoms should self-isolate and use a PCR home test kit from the school or go to a COVID-19 Assessment Centre.”