The Illinois Department of Public Health has announced that the number of measles cases in Illinois so far in 2025 has reached six.
Two new cases in southern Illinois were confirmed over the weekend, adding to two in the Marion area that were identified in April. Two unrelated cases were previously confirmed in Cook County.
One of the new cases was confirmed over the weekend is in the Franklin-Williamson Bi-County area. This now meets the technical Center for Disease Control and Prevention definition of an “outbreak” in that area.
Another southern Illinois case may have visited locations in Missouri, including the St. Louis Aquarium.
Current information on potential sites where infected individuals may have exposed others can be found on the IDPH website at Measles Exposure Locations. This will be updated as the Department gets more information.
