VANCOUVER -- Following the release of new data on transmission of COVID-19 at schools, Vancouver Coastal Health says their information indicates the rate has been low so far this school year.

The health authority says its evidence supports the province's decision to keep its schools open through the pandemic.

In a statement Thursday, VCH said data show there has not been a "significant increase" in cases of the novel coronavirus among school-aged children since the start of the school year.

This is in relation to other age groups, VCH said.

Kids between the ages of five and 17 accounted for six per cent of cases within the region since the start of the pandemic, VCH said. That age group makes up about 10 per cent of the total population in the area.

About 700 students and staff per 100,000 population were diagnosed with the disease during the first term of the school year, VCH said.

This is consistent with data presented by provincial officials last month, during which it was suggested that fewer than 0.7 per cent of students in B.C. have been diagnosed. 

Of those cases in Vancouver Coastal, 90 per cent did not lead to school-based transmission, according to the health authority. Most caught COVID from home or in other social situations outside of school, it said.

Data analyst Jens von Bergmann said he was surprised to see VCH make such bold statements.

"It's a frequent thing where they've said, 'New data has been released,' and all we get is a graph, which maybe one can scrape some data out of this graph," von Bergmann said.

He said there is a 40 per cent spike in COVID-19 cases among school-aged children compared to other age groups, and VCH's claim that there have not been significant increases is troubling.

"We can't talk about transmissions in schools and what is happening when we are actually not going in and systematically testing in schools," he said.

Von Bergmann said many kids are asymptomatic and unless all students in a school are tested, like what's happening in Norway and Austria, many COVID-19 cases go undetected.  

Anyone who gets tested is told to isolate until they get their results, VCH said, and they and any of their close contacts are told to self-isolate in the event of a positive test.

VCH Medical Health Officer Alex Choi said the purpose of releasing the information was to reassure those in school communities that they are a "safe and low-risk environment."

The doctor noted a "moderate increase" in COVID cases among young people since the end of October, but said this is reflective of the overall increase in cases in B.C.

Still, many parents and staff members have raised concerns, especially as schools in other provinces remained closed after the winter holidays: would online learning be safer?

The province's top doctor has been asked several times, and her answer has been consistent. Dr. Bonnie Henry, the provincial health officer, says plans are in place to keep schools as safe as possible, and that schools are essential for development.

Not everyone is satisfied by that response, however, and others are calling for increased safety measures if in-person learning is to continue.

Last week, a dozen local presidents from the B.C. Teachers' Federation called publicly for improvements in the Fraser Health region – the province's most impacted by the pandemic. 

Members of the BCTF are calling for mandatory masks indoors, smaller class sizes to allow for physical distancing and the prioritization of vaccines for teachers and school staff.

CTVNewsVancouver.ca kept track of school exposures during the first term of the school year, and noted more than half reported at least one exposure between September and December. 

There were exposures at at least 491 of the Lower Mainland's 974 public and private schools.

Only a handful of outbreaks were reported.

When it comes to schools, the term "outbreak" is used when multiple people have lab-confirmed COVID-19 infections and transmission is likely widespread within a school.

"Exposure" or "exposure event" is a term used when a single person known to have coronavirus attended school while they were infectious.

Vancouver Coastal Health says an exposure at a school does not mean COVID-19 is spreading through the building.

"In the vast majority of cases, there is no transmission in the school setting," VCH says. "However, notifications are distributed out of an abundance of caution."

With files from CTV News Vancouver's Angela Jung