CHICAGO -- Health officials confirmed a case of measles in Chicago on Saturday.The Chicago Department of Public Health says it's working closely with the highest-risk locations to contact exposed individuals.Exposures may have occurred on May 16 on the blue line from O'Hare International Airport to the University of Illinois Chicago campus, Millennium Park and retail stores on State Street between Monroe and Randolph Streets, and on South Canal Street.Official say on Saturday morning, exposures may have occurred at the UIC Student Center East."It's not uncommon for Chicago, because we are an international hub, to have travelers come in from other places who are infected with diseases like measles," said Chicago Department of Health Commissioner Dr. Julie Morita.Those who think they may have been exposed should check their vaccine records or contact their healthcare providers to determine if they need to be immunized."Measles is a serious yet preventable disease through a safe, effective and universally available vaccine," Morita said. "Chicagoans should make sure their children and family members are up to date on vaccines now. Vaccination is the best way to protect against measles."There have been great studies that have shown that the measles vaccine is very safe and very effective, and so the best thing parents can do for their children is to make sure they're vaccinated," Morita said. "And adults who haven't been vaccinated should get vaccinated."Officials report that Chicago has one of the highest rates of measles vaccination in the country.Symptoms of measles include fever, cough, runny nose, red eyes, diarrhea and a rash consisting of tiny, red spots. Pregnant people, those with weakened immune systems, and those who have not been vaccinated are at highest risk from measles."Measles when it becomes really severe can lead to serious lung damage. It can lead to brain swelling. It can lead to blindness if it gets really bad," Morita said.For more information about measles, contact your health care provider or visit www.cityofchicago.org/measles.