CALGARY -- Alberta teachers and school-based staff members should be tested for COVID-19 before classes resume at the beginning of September and again throughout the year, the province's medical officer of health recommended on Wednesday.

"This is entirely voluntary," said Dr. Deena Hinshaw during Wednesday's regular update. "However, asymptomatic testing of staff in school settings will help us with a baseline understanding for school re-entry and ultimately help us even more closely monitor the virus in the coming year."

There are about 90,000 teachers and school staff members in the province, meaning it will take a monumental effort to test each one, said Hinshaw.

"Our testing capacity has expanded greatly, but no province in Canada can collect  and process that many tests all at once," she said. "I am asking teachers and educational staff to arrange testing proactively. Do not wait until the day before you are set to return to school."

Testing is available to all Albertans and Hinshaw said she is asking those who are asymptomatic to hold off to allow room for teachers and school staff members.

"To be clear, if you have any symptoms, no matter your occupation, you can and should still get tested," she said. "If you have no symptoms but you are a close contact of a case of COVID or part of an outbreak, you can and should still get tested. If you feel completely well and have not been in contact with a confirmed case, we are just asking you to consider waiting until after Sept. 1 to book a test."

Children should only be tested if they are symptomatic or have a pre-existing medical condition said Hinshaw.

"This is because in students, our priority is to make testing available to all those with ongoing mild symptoms that may mimic COVID-19, such as allergies," she said. "Parents should book all such tests through Alberta Health Services."

Under provincial guidelines, students in Grades 4 to 12 will be required to wear masks in common areas and on school buses when they return to classes. Hinshaw said last week the mask recommendation is the result of the detailed review of the latest medical evidence.

Alberta recorded 121 new cases of COVID-19 on Wednesday, bringing the province's total to 11,893. One more Albertan has also died, a woman in her 90s who lived at the Good Samaritan Southgate Care Centre.