(Chicago)  Two more suburban Cook County children have been diagnosed with measles, bringing the total number of confirmed cases to 13 in Illinois, officials said Friday.

Both of the two new cases confirmed Friday are children under one year old who were both associated with KinderCare Learning Center in Palatine, according to Divya Mohan Little, a spokeswoman for the Illinois Department of Public Health.

All 13 cases reported statewide are from Cook County, health officials said. Of those cases, 12 have been tied to the suburban daycare center, most occurring in children too young to be vaccinated.

Illinois health officials are still trying to figure out how the people became infected with the measles virus. No ties have been found to the December outbreak at Disneyland in California, health officials said.

None of the people infected so far in Illinois had been vaccinated for measles, health officials said.

Measles is a highly contagious respiratory disease that can cause severe health complications, including pneumonia, encephalitis and death.

The Centers for Disease Control and Prevention says children should be given the first dose of measles, mumps and rubella (MMR) vaccine when they are 12 to 15 months old. The second dose usually is given before the start of kindergarten at 4 to 6 years of age.

The DuPage County health department had warned of possible exposure at three locations, but the state health department has not confirmed any cases there as of Friday afternoon.

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