Fraser Health is concerned as measles continues to spread in some communities in B.C.'s Lower Mainland, and the chief medical health officer is "disappointed" that those who are contagious aren't isolating themselves.

Dr. Paul Van Buynder said earlier this week that some people who have measles are refusing to quarantine themselves.

"We are disappointed that people who are showing symptoms of measles are not isolating themselves as requested by Fraser Health and as a result other people in the community are being exposed to this infectious disease," he said.

On Wednesday, he said a public school student and a worker in a community retail outlet were the most recent confirmed cases.

Lisa Mu, a medical health officer with Fraser Health, said measles alert notifications were sent this week to students who live on campus at the University of the Fraser Valley and to staff who worked at the Chilliwack Lions Club Music and Dance Festival.

"Through some of our contacts in the community, we've become aware of these particular individuals and I do think that they possess a risk to the rest of the community in that they are then going to be exposed to individuals who are then going to be incubating the virus."

The current measles outbreak has been concentrated in the Fraser East communities of Abbotsford, Mission, Chilliwack, Hope and Agassiz.​ About 100 cases of measles have been reported in the city of Chilliwack.

A measles warning was sent to some students and staff at the BCIT campus in Burnaby last week, after a student who attended classes there in early March was diagnosed with measles.

Health officials say anyone showing symptoms of the disease should quarantine themselves for the 21 day incubation period.