Region of Waterloo Public Health has confirmed a student at Huron Heights Secondary School in Kitchener has tested positive for the coronavirus.
The student was last at the high school on Thursday, September 17.
The Waterloo Region District School Board said in a release, the health department is in the process of getting in touch with all high-risk contacts of the positive case and will provide individual guidance to them.
High-risk contacts in the identified cohort will be directed to self-isolate until at least October 1, and longer if symptomatic.
The board says if you don't receive a call from the health department, your child is not considered a high-risk contact.
It's the fourth case of COVID-19 in one of the region's schools, and third in a student.
A case in a student at Riverside Public School in Elmira was also confirmed on Sunday evening.