The Chicago Department of Public Health released a public warning on Thursday, September 10, 2026, indicating that a person diagnosed with measles was present at Union Station. The agency says the individual passed through the transportation hub, creating a potential risk of measles transmission to other travelers and staff.
Measles is recognized as a highly contagious viral illness that spreads through respiratory droplets. Because of its ease of transmission, health officials advise anyone who was at Union Station during the time the infected person was present to remain alert for symptoms such as fever, cough, runny nose, inflamed eyes, or a characteristic rash. Those who develop signs consistent with measles are instructed to contact a health care provider promptly.
The department also reminds the public that measles vaccination is the most effective means of preventing infection. Individuals who are uncertain about their immunization status or who have not received two doses of the measles‑mumps‑rubella (MMR) vaccine are encouraged to consult a medical professional to determine whether vaccination is indicated. The alert does not specify the exact time frame of exposure, but it underscores the standard protocol of issuing warnings when a confirmed case is identified in a public setting.
Chicago health officials continue to monitor the situation and will provide updates if additional information becomes available. The department emphasizes that while the risk of widespread transmission is low when appropriate precautions are taken, vigilance remains essential to limit the spread of this contagious disease in high‑traffic venues such as Union Station.