VANCOUVER -- Another 10 elementary and secondary schools in the Lower Mainland have had exposures to COVID-19 variants of concern, according to health officials.

Fraser Health said it's working closely with school districts in Surrey, Burnaby and Coquitlam to manage the latest exposures, and that seven full classes are in isolation as a result.

That includes two classes each at North Surrey Secondary and Woodward Hills Elementary, and one class each at Frost Road Elementary, Marlborough Elementary and Princess Margaret Secondary.

"As these are variants that are new to our communities and more easily transmissible, Fraser Health is working to identify any further connected variant cases to ensure immediate isolation and case management to prevent further transmission," the health authority said in a news release.

Seven of the latest schools with exposures – Frost Road Elementary, A.J. McLellan Elementary, Woodward Hills Elementary, Cindrich Elementary, North Surrey Secondary, Princess Margaret Secondary and Sullivan Heights Secondary – are in Surrey. Fraser Health said the others are Marlborough Elementary in Burnaby and Archbishop Carney Regional and École Maple Creek in Coquitlam.

The health authority did not specify which variant was involved in the exposures, but said it "does not interfere with the effectiveness of vaccines, nor our ability to test for the virus."

So far, the vast majority of variant cases in B.C. have involved the B.1.1.7 variant associated with the U.K. Earlier on Tuesday, provincial health officer Dr. Bonnie Henry confirmed a total of 182 cases involving variants of concern have been detected so far in B.C., and that 159 were B.1.1.7.

Only eight of the identified variant cases remain active, including one person hospitalized with the disease.

Most of the cases have been identified in the Lower Mainland, and most involve travellers or contacts of travellers – though a significant number have unknown origins.

"About 13 per cent are directly related to travel and 60 per cent are close contacts, but there are still 20 to 25 per cent – a quarter of cases – where we are not clear where they acquired the (infection)," Henry said.

Fraser Health said mass testing of entire classrooms was conducted at North Surrey Secondary, Frost Road Elementary, Woodward Hills Elementary, Princess Margaret Secondary, and Marlborough Elementary Schools. But only staff and students who were identified as close contacts of COVID-19 cases at Archbishop Carney Regional, A.J. McLellan Elementary, École Maple Creek, Cindrich Elementary and Sullivan Heights were tested, a decision the health authority said was made after "an in-depth assessment." Those students and staff have already been contacted, according to Fraser Health.