CHICAGO — Health officials in Illinois have identified the state’s first measles case of 2025.
On Wednesday, the Illinois Department of Public Health (IDPH) announced the first confirmed measles case of 2025 in Illinois, which was reported in an adult patient in far southern Illinois.
According to the IDPH, the case was confirmed through laboratory testing on Wednesday, though officials did not confirm the exact location.
So far, it is the only case that the IDPH is aware of and officials said it is not considered an outbreak. Officials added that the risk of community transmission for the general public in Illinois remains low.
The IDPH says it is closely monitoring the situation and supporting local health departments in southern Illinois.
“This first reported case of measles in Illinois in 2025 is a reminder to our Illinois residents that this disease can be prevented with up-to-date vaccination,” IDPH Director Dr. Sameer Vohra said. “With hundreds of cases being reported nationally, we have been working closely with our local public health and health care partners to prepare for any potential measles cases in Illinois. IDPH is urging medical providers to consider a measles diagnosis in patients with consistent symptoms and alert their local health department immediately if they suspect a case.”
Dr. Vohra also advised the public to seek out vaccinations if they are not already protected.
“The key to preventing measles is the highly effective measles/mumps/rubella (MMR) vaccine. Two doses of measles vaccine are 97% effective in preventing measles,” Dr. Vohra said. “I recommend that our Illinois residents make sure that they and their family members are up to date on the MMR vaccine and all other age-appropriate immunizations.”
The new case is the first to be reported in the state since an outbreak in Chicago last year resulted in 67 cases.
Nationally, the CDC has reported 800 cases of measles in more than 25 jurisdictions around the country, more than double the national total in 2024.
Potential exposure locations
The IDPH is currently working with health officials in the area where the case was confirmed to identify all potential exposure locations, though none were immediately identified.
According to the IDPH, the clinic in southern Illinois where the patient sought care is now working to identify any possible exposed patients and check the immune status of those who may have been in contact with the patient.
Healthcare workers at the clinic who were exposed were all wearing masks at the time and are also considered immune.
What do I do in the event of an exposure?
Health officials advise anyone who believes they may have been in a location that would have put them at risk of exposure to review their immunization records or contact their healthcare provider to make sure they are up to date on the MMR vaccine.
The IDPH warns anyone who may have been exposed to measles and is not immune to monitor themselves for symptoms like rash, high fever, cough, runny nose, and red, watery eyes. Symptoms can take from seven to 21 days to show up.
Health officials say those who develop symptoms should stay home and away from others. Symptomatic individuals should also contact a healthcare provider before the medical office or emergency department, so special arrangements can be made to protect patients and medical staff.
Am I protected against measles?
Measles, which is a highly contagious disease caused by a virus, can spread easily when an infected person breathes, coughs or sneezes, according to the World Health Organization (WHO).
Many in the United States are already protected.
The CDC said the measles vaccine, which has been used for over 50 years, is considered to be very effective. Two doses of the vaccine are about 97% effective at preventing measles if exposed to the virus, and one dose is about 93% effective.
Those who received the vaccine are usually fully protected for life after about two or three weeks, according to the CDC.
While the vaccine has historically proven to be highly effective, the CDC said about three out of 100 who get the vaccine will still have measles if exposed.
For more information on how to get vaccinated, call Cook County Health at 833-308-1988.
Illinois residents can view their immunization records on the state’s Vax Verify portal.
Gabriel Castillo contributed to this report
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Visit the IDPH website for more information on how to stay safe.