The Kane County Health Department has identified two locations where individuals may have been exposed to measles following a confirmed case in an unvaccinated person. The individual is no longer infectious.

The potential exposure sites include:

• Kaneland High School in Maple Park, during the school day on 18 August.
• Next Generation Pediatric Clinic at 107 S. McLean Blvd. in South Elgin, on 21 August between 12:30 and 4 p.m.

This is the fifth reported measles case in Illinois in 2026 and the first in Kane County since 2019. The health department stated that additional exposure information may be released as the investigation continues.

Guidance for potentially exposed individuals

The health department advised those at the identified locations to verify their immunity through documentation of two doses of the MMR vaccine, laboratory evidence of immunity, or confirmation of a previous infection. People born before 1957 are generally assumed to have immunity.

Anyone unprotected who was potentially exposed should quarantine at home for 21 days from the date of exposure unless they can provide evidence of immunity. Individuals developing symptoms should call a healthcare provider before visiting a medical office, urgent care, or emergency department.

“Our priority is identifying people who may have been exposed, making sure they receive timely guidance, and providing the community with accurate information as the investigation continues,” said Michael Isaacson, the Kane County Health Department’s executive director.

A call centre has been opened for questions regarding measles, symptoms, or vaccination. It is staffed from 9 a.m. to 4 p.m., Monday through Friday, at 331-240-3311.