DuPage County reports first measles case of 2026, with exposure at Chicago O'Hare Airport

DuPage County has reported its first measles case of 2026, and said the patient traveled through Chicago O'Hare International Airport.

The count said the case is in a vaccinated resident who recently returned from an international trip DuPage health officials said anyone who was at O'Hare Terminal 5 on Thursday, Oct. 15, between 4:20 p.m. and 7 p.m. should contact their local health department to report they may have been exposed.

Because the case is in a vaccinated person, DuPage health officials said the risk to the public is low. Vaccinated individuals who catch measles typically have a milder illness and are less likely to experience complication. They also may be less likely to spread the virus to others

The MMR vaccine – which covers measles, mumps and rubella – is considered protection for life against measles and rubella, though the CDC says it may become less effective against mumps over time. If you've had two doses of the MMR or were born before 1957, you're considered protected.

Breakthrough measles infections in vaccinated individuals are uncommon but possible, health officials said.

If you may have been exposed to measles, you should monitor for symptoms for 21 days. Symptoms include fever, cough, runny nose, red and water eyes and a rash that typically starts on the face and spread downwards. The rash typically appears three to five days after other symptoms start.

So far in 2026, the Illinois Department of Public Health has confirmed 24 cases of measles, with the case in DuPage County being the only confirmed in the past week. Most of the cases are linked to an outbreak in Douglas County, which is south of Champaign and east of Decatur, where 11 cases have been confirmed.

The rash appears as pink, red or reddish-brown flat spots and small raised bumps on light skin tones, and darker, dusky or purplish-brown areas on darker skin tones. The rash can be more subtle on darker skin tones, but a bumpy or textured feel is often present. If you have questions about whether a rash may be related to measles, call your doctor immediately.

Cook, DeKalb and DuPage counties have all had one confirmed case of measles so far this year. Kane County has had two, Madison County has had three and Moultrie County has had five.