VANCOUVER -- The president of the union representing B.C. teachers is demanding that the province restrict the number of students in classrooms to 15 in the Fraser Health region.

In a letter to Premier John Horgan, Teri Mooring says that skyrocketing cases in the health authority are a concern for teachers, staff and students.

“I am writing to urge you in the strongest possible terms to instruct the Ministry of Education to respond swiftly to the dramatic rise in cases of COVID-19 in the Fraser Health region by reducing class sizes to no more than 15 students,” the letter states.

Mooring writes it is “virtually impossible” to maintain physical distancing in some classrooms because of how large the class sizes are now.

She says other school districts, like the Vancouver School Board, have already reduced class sizes to 15 in high schools and she would like to see the education ministry work with Fraser Health to implement the same limit.

“We've seen more teachers being diagnosed; we see more students being diagnosed. And so these preventative measures need to be put in place immediately,” she tells CTV News Vancouver, adding teachers have been asking for a mask mandate and smaller class sizes since August.

The renewed call comes as a Surrey elementary school teacher who tested positive for COVID-19 took a turn for the worse Friday.

An online fundraising campaign has been set up for Darlene Lorenco, who’s described as a “beloved music teacher.” 

“She has an amazing talent for teaching and shares her passion for music with our children daily. Even when schools closed in the spring, Darlene went above and beyond to create online music experiences for the families at home. She is loved so much by all who know her,” the campaign reads.

The campaign does not say how she contracted the virus.

In a social media post, a teacher shared a photo showing a classroom of two dozen students to highlight “what an actual classroom looks like” in the Fraser Health Region.

A Langley mother whose daughter has just tested positive for COVID-19 is also urging the province to take measures to address the teachers’ concerns.

“I think a classroom of 15 should have been done in the beginning. And I think a way to alleviate the class sizes and the crowdedness would have been to offer online learning to those parents that could do it and have the resources to do it from home,” Kristina said. She declined to provide her last name.

Her daughter was in two classes where an exposure at R.E. Mountain Secondary School took place.

So far, her daughter is the only family member who’s tested positive; she is experiencing some mild symptoms.

“It’s definitely not something you want to hear. It’s so scary because you don’t know what long-term effects she’ll have from this,” Kristina said. “I had mixed feelings letting them go to school. But I thought, ‘If they say it's safe, if they say they have all these rules in place, it should be OK.’ … I feel like they failed our kids.”

In a statement to CTV News, the B.C. Ministry of Education says the health and safety of students and staff are a priority.

“We know there are growing concerns about COVID cases in our province, especially in Fraser Health and Vancouver Coastal Health regions,” the ministry says. “We continue to consult the provincial health officer and local health authorities on the best approach going forward and any changes would be under the direction of public health. And we hope that the collective efforts of new regional public health orders will flatten the curve for the benefit of students, staff, schools and communities throughout the Lower Mainland.”

Without any new measures, Kristina has enrolled her daughters in online learning with a school district on Vancouver Island because the online classes offered in Langley were full.