Health professionals confirmed three more measles cases in suburban Cook County, Illinois, on Monday.
This makes a total of eight measles cases in the county, which includes Chicago.
The measles cases include six infants and two adults, all of whom had not receive measles vaccines. Seven of the cases have a common connection at the KinderCare Learning Center in Palatine, Illinois.
Measles is a very contagious illness with 9 out of 10 unvaccinated people exposed to the virus contracting measles, the Cook County Department of Pubic Health said.
Initial symptoms include a runny nose, cough and a low-grade fever, causing many people to mistake measles for the common cold. It is only when patients' eyes become red and itchy, and a rash begins to develop that they realize they have measles.
To minimize exposure to the illness, anyone with measles symptoms should call their doctor’s office instead of going to see their health care provider.
Health professionals remind the public that vaccines are important in preventing measles from spreading. Children should receive their first dose between the ages of 12 and 15 months old. The second dose should be administered between the ages of 4 and 6 years old.
Cook County residents who have not received their measles vaccine should get one immediately. The health department said the two-dose measles vaccine, which includes strains of mumps and rubella, is 99 percent effective in fighting measles.