Vancouver Coastal Health has sent out a letter to parents after a new case of the measles cases was found in connection to two schools.
Health officials are looking into possible measles cases at the French language high school Ecole Jules-Verne and elementary school Ecole Anne-Hebert in Vancouver.
Two unrelated cases were reported within the region earlier this week. One was caught locally, while the first case came from abroad.
Further details are expected to be released Friday afternoon.
A measles outbreak in Washington State and Oregon this winter has sickened 56 people so far, prompting lawmakers in Washington to revisit non-medical exemptions that allow children to attend school without vaccines if their parents express a personal objection. That, in turn, has provoked demonstrations from the public against having to vaccinate their kids.
Measles is highly contagious and spreads easily through the air when an infected person breathes, coughs or sneezes. The virus can survive in small droplets in the air for several hours.
Symptoms include a fever, cough, runny nose, and red and inflamed eyes, which typically start appearing seven to 14 days after initial exposure. These are followed three to seven days later by a rash, which lasts at least three days.