Third measles case confirmed in suburban Cook County

CHICAGO (WGN) — Cook County Public Health has confirmed a third measles case.

Health officials announced Tuesday that the third confirmed case of measles this year is a suburban Cook County man whose vaccination status is unknown. Public health officials believe the illness was contracted through exposure connected to the county’s last reported measles case, announced on Tuesday, Sept. 16, 2025.

An Aldi store in the south suburban community of Crestwood may have been a point of exposure, health officials added. Anyone who visited the store, located at 4820 Cal Sag Road, between 5 p.m. and 7:30 p.m. on Thursday, Sept. 24, may have been exposed to the new case, according to CCPH.

Cook County Health used this incident to remind residents who have been exposed to measles of the following:

• Individuals who are unsure about their prior vaccination status should consult their healthcare provider if they may have been exposed. The health care provider will determine the need for testing if symptoms develop.
• If an exposed individual develops symptoms, they should call a healthcare provider before visiting a medical office or emergency department for evaluation, to ensure that special arrangements can be made to prevent possible exposure to patients and medical staff.
• Individuals who are unvaccinated against measles, mumps, and rubella (MMR) and are exposed should talk with their doctor about getting the MMR vaccine. It is not harmful to receive the MMR vaccine after being exposed to measles, mumps, or rubella, and doing so may help prevent the disease.
• Most individuals are vaccinated against measles routinely in childhood and are not at high risk. The best defense against measles is vaccination. Two doses of the MMR vaccine are 97% effective against measles and generally provide lifelong immunity.
  • The first dose should be given between 12 and 15 months of age
  • The second is between the ages of four and six.

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Measles symptoms typically appear within 21 days following exposure. They include rash, high fever, cough, runny nose, and red, watery eyes. The rash typically starts on the face and then spreads to the trunk. A person is generally contagious for the four days preceding and the four days following the onset of a rash.  

Complications from measles can lead to pneumonia, seizures, hearing loss, life-long brain damage, and death.