As some Ottawa students return to class today for the start of the new school year, Ottawa's medical officer of health is warning parents to expect COVID-19 cases in schools.

"This is possible in the first week of school," said Dr. Vera Etches when asked on CTV Morning Live how soon we could see cases of COVID-19 in elementary and secondary schools in Ottawa.

"We have young children in our community right now where we're identifying people who turn positive for COVID-19, everyday there's school age children."

Dr. Etches made the comments on the first day of classes for students in Ottawa's French Catholic school board. Some students with Ottawa's French public school board also returned to class on Thursday.

According to Ottawa Public Health data, there have been 120 laboratory-confirmed cases of COVID-19 in residents under the age of 10 in Ottawa, and 210 cases involving residents ages 10 to 19.

Ottawa Public Health has released a screening tool for students. The screening tool will help parents and guardians make the decision of whether or not their child should attend school.

"What we're asking is that if people are sick, they stay home and the children are screened everyday so that if they're not well they stay home," said Dr. Etches on Thursday morning.

"But sometimes, this is a tricky virus and people don't always know they're carrying COVID and so that's something where it could happen and we have the plans in place to make sure that stops when one person is identified that it doesn't go further."

Dr. Etches visited École élémentaire catholique Horizon-Jeunesse for the first day of classes on Thursday.

CTV News Ottawa's Christina Succi asked Dr. Etches outside the school whether she foresees a point where schools are closed for a week or two due to a case of COVID-19.

"I doubt it. I think what the schools have been working hard to do is to find cohorts. So working really hard to be able to contain the number of close contacts that any child has," said Dr. Etches.

"So that's where we start, we start with the close contacts. Now, if we see something else linked across the school then we'll be looking at other measures."

Earlier in the day, CTV Morning Live host Leslie Roberts asked Dr. Etches what she will be looking for during her visit to the school.

"First of all, it's always the keeping people who are ill out, so maybe check in with some of the parents who are arriving asking them how did it go screening your child this morning," said Dr. Etches.

"I'll be looking to see what's happening as people are, hopefully they're not lining up close together, they're keeping distance as they get ready to go into the schools. There's hand sanitizer at the entrance."

Dr. Etches says she will also be looking at signage in the hallways directing traffic, distance in the classroom and how the older students are wearing masks.

"All of these little things are new behaviours that the principals have been working on, making sure their school environment shifts to the new COVID reality."

The medical officer of health says her team at Ottawa Public Health has been finalizing plans with the school boards to deal with COVID-19 cases in schools.

"We've been practicing, we've been doing that in scenarios with schools," said Dr. Etches about the drafting of a flow chart for dealing with COVID-19 cases.

"We know our outbreak team is going to be the superintendent, the principal, the facilities person who is in charge of cleaning, our school nurse and our outbreak team. These things we've gone through, but some of those quick references we're just finalizing yesterday."