After two young children contracted measles in the city, Toronto Public Health is hoping you make sure your immunizations are up to date.

Over the last ten years Toronto has seen an average of five cases of measles a year with only one case reported in 2012.

So far this year there have been 4 reported cases, the latest in pair of children, a three-year old and 18 month old. The siblings did not receive measles immunizations.

The children were at risk of passing the infection to others from February 20th to March 8th and anyone susceptible to the virus that came into contact with the children would be expected to show symptoms between February 27th and March 29th.

What Public Health says is troubling about these cases is that the children did not travel outside of Toronto and it's believed they contracted the virus here, possibly exposing others to the highly contagious virus.

"That's the real serious problem," said Associate Medial Officer of Health Dr. Dr. Vinita Dubey. "Even if you don't travel, if you're not vaccinated you're at risk for getting measles and measles can be quite severe."

The infections are a different virus type than the case reported earlier this month involving someone who traveled outside of the area.

Most children are immunized after their first birthday and need the shot in order to attend school.

One fifth of measles cases require hospitalization, knocking most people out for up to two weeks.

It can cause ear, lung, and brain infections, and in rare cases measles can be fatal.

Unless you are immunized or immune 90% of those people exposed to measles contract the virus.

Public Health says infants under the age of one are most at risk as well those with weakened immune systems, the elderly, and pregnant woman.

Anyone born after January 1st 1970 is being urged to check their vaccination records to ensure they've received two doses in order to avoid the virus.

Those born before 1970 are likely immune.

"Our concern is the other individuals that may have come in contact with these two children may be at risk for measles," said Dr. Dubey. "We want to make sure the other children they've played with, any family members they've been with, that they're protected as well because otherwise we're going to see the spread of measles in the city."

Find more about measles HERE