Dr. Kieran Moore, Chief Medical Officer of Ontario, warned in a public health unit memo to prepare for more cases and potential outbreaks of measles amid rising infection rates in Europe.

Moore said on Wednesday: "Currently, there are four active measles cases in Canada, two of which are in Ontario in the Peel region and the city of Toronto."

He added, "Given this significant increase in cases worldwide, Ontario's health system partners must prepare for continued importation and potential outbreaks."

The two cases in Ontario were children who recently traveled outside Canada, and in at least one case, a child was hospitalized.

With the March break approaching, healthcare practitioners should encourage vaccinations and report suspected cases.

Moore also mentioned: “Although measles is no longer considered endemic in Canada, outbreaks can occur when susceptible individuals (e.g., unvaccinated) travel to countries where measles is prevalent and return.”

Measles is highly contagious, and its symptoms include a red rash, fever, cough, runny nose, red eyes, and fatigue.

The viral infection spreads through the air and close contact, and symptoms can start appearing anywhere from seven to 21 days after exposure.