Measles in Cook County: Two cases confirmed, here's what we know

CHICAGO - Two adults—one in Chicago and one in suburban Cook County—have been diagnosed with measles, marking the first confirmed cases in the county this year.

What we know:

According to public health officials, the Chicago case involves an adult who had traveled internationally through O’Hare Airport earlier in April. That person had received one dose of the MMR vaccine and developed a rash on April 25. They have been isolating at home since diagnosis.

The suburban case involves an adult whose vaccination status is unknown. That person sought medical care on April 28 and was quickly isolated at a hospital.

The Cook County and Chicago health departments, along with the Illinois Department of Public Health, are investigating both cases and working to notify people who may have been exposed.

Where exposures may have occurred

Officials have identified several possible exposure locations, including:

• April 22–23: O’Hare Airport, 10 a.m.–8 p.m., especially Terminal 1
• April 25: Aldi in Lyons (7235 39th St.), 10 a.m.–12:30 p.m.
• April 27: Shell gas station in Stickney (3901 S. Harlem Ave.), 10 a.m.–12:30 p.m.
• April 28: Mobil gas station in Berwyn (2945 S. Harlem Ave.), 10:20 a.m.–1 p.m.

People who were at these locations during the times listed should monitor themselves for symptoms, which could take up to 21 days to develop.

What you can do:

Health officials say the best protection against measles is two doses of the MMR vaccine, which is about 97% effective. The first dose is typically given between 12–15 months of age and the second between 4–6 years old.

Free vaccinations are available at Chicago Department of Public Health clinics, and appointments can be made through getvaxchi.chicago.gov. Suburban Cook County residents can call 833-308-1988 to schedule a vaccination.

Dr. Sameer Vohra, Director of the Illinois Department of Public Health, said in a statement that "being fully immunized remains the best and most effective way for everyone to protect themselves and those they love."

The state’s new Measles Outbreak Simulator Dashboard helps parents and schools assess vaccination coverage at individual schools, part of a broader effort to prepare for potential outbreaks.

What's next:

Chicago and Cook County's health departments will continue tracing contacts and monitoring the situation.

Residents who may have been exposed should stay alert for symptoms and call their healthcare provider before seeking medical care if symptoms develop.

For more information about measles, visit the IDPH or CDC's websites.