Island Health says a COVID-19 exposure has occurred at a Port Alberni high school, the first known exposure at a Vancouver Island school since classes restarted in September.

The health authority says the exposure occurred over five days in September at Alberni District Secondary School.

In a notice to families sent Monday, the school district says a member of the school community has tested positive and the dates of potential exposures to students and staff at the school are Sept. 14-15, Sept. 17-18 and Sept. 22.

Officials with Island Health are conducting contact tracing to identify any staff or students who need to self-isolate.

School District 70 Pacific Rim superintendent Greg Smyth and Cowichan Valley medical health officer Shannon Waters say staff and students will receive a phone call if they are identified as a close contact of the patient.

"If you do not receive a phone call or letter, continue to attend school and monitor for symptoms compatible to COVID-19 as per your school policies," the officials said.

"Due to privacy reasons we are not able to give out further information," Smyth and Waters said. "However, we want to assure you that our organizations are working together to maintain a safe and healthy school environment for students, families and staff."