Chicago's O'Hare International Airport has been placed on red alert after a possible measles outbreak. The passenger was mainly confined to the airport's Terminal 1 area but had already exposed hundreds to the infectious disease, reports the Daily Mail.

The infected individual developed a rash on April 25. Despite receiving one dose of the measles vaccine, the person was diagnosed with a breakthrough infection and has been isolated at home since then. Health officials have advised residents to get two doses of the vaccine at least two weeks before traveling. A second case was reported in suburban Cook County, where the individual's vaccination status remains unknown.

Health authorities are urging anyone who may have been exposed to contact their healthcare provider for further guidance.

We'll be bringing you the very latest updates, pictures and video on this breaking news story.

For the latest news and breaking news visit: /news

Stay up to date with all the big headlines, pictures, analysis, opinion and video on the stories that matter to you.

Follow our social media accounts here on facebook.com/DailyExpress and @daily_express