Health officials say three more cases of measles have been confirmed in suburban Chicago, bringing the total number of cases to eight.
The Cook County Health Department said Monday that those infected include two adults and six infants, all of whom were not vaccinated. Seven cases are associated with a Palatine day care.
Officials say the overall risk of contracting measles in suburban Cook County is low, but that vaccination is critical to stopping the disease's spread.
They cautioned parents to consider limiting outings for children younger than 1 because infants are too young to be vaccinated.
Ninety percent of people who aren't immunized are infected if exposed to the virus.
Common symptoms include fever, runny nose, cough and a rash. Some people suffer complications including pneumonia and encephalitis.