The Illinois Department of Public Health (IDPH) reports that on October 10, a suspected case of measles was reported by Cook County Department of Public Health (CCDPH) to IDPH. The case, involving an unvaccinated individual with exposure internationally, was confirmed by the IDPH laboratory on October 11. IDPH is working with CCDPH to identify potential exposure locations in the U.S. The case’s rash onset was identified as October 9; therefore, the infectious period would be between October 5 through October 13. Prior to this case, the last measles case in Illinois was identified in 2019. Symptoms of measles include rash, high fever, cough, runny nose and red, watery eyes. After exposure to someone with measles, symptoms can take from seven to 21 days to show up. Individuals who develop symptoms of measles should contact a health care provider by phone or email before going to a medical office or emergency department. Special arrangements can be made for your evaluation while also protecting other patients and medical staff from possible infection. Measles can cause serious complications such as pneumonia and encephalitis (swelling of the brain). For more information about measles, contact your health care provider, or visit the Illinois Department of Public Health webpage on measles or the CDC’s measles site.