Illinois Measles Concern Grows After Chicago, Kane County Cases, Missouri Traveler

Chicago, IL - Chicago health officials are investigating a potential measles exposure involving an out-of-state traveler who spent nearly 24 hours in the city, including time at Union Station.

According to the Chicago Department of Public Health, the traveler arrived from Sedalia, Missouri, at Union Station on Aug. 27 at about 10:30 p.m. The person stayed overnight in Chicago before returning to the station Aug. 28 at about 9 p.m. and departing for Rochester, New York.

Health officials are working to identify and contact people who may have been exposed. Symptoms can take up to three weeks to develop after exposure.

Dr. Alfredo Mena Lora, an infectious disease specialist at St. Anthony Hospital, reports symptoms may include fever, cough and a rash, typically appearing within one to three weeks.

The investigation comes as Kane County health officials examine a separate measles case involving a vaccinated individual. Officials described the infection as a breakthrough case, which can occur despite vaccination but remains uncommon.

Kane County Health Department officials had previously identified more than 1,600 contacts connected to an earlier measles case in the county.

Health officials said vaccination substantially lowers the risk of severe illness and remains the primary protection against measles, which is considered highly contagious.

People who are not vaccinated and are exposed may be asked to quarantine for 21 days. Those with confirmed immunity generally do not have to quarantine, according to Kane County officials.

Chicago previously investigated another measles exposure involving an international traveler who passed through O'Hare International Airport in late June.