There are six confirmed cases at Barrington High School with more than a dozen other probable cases.
The district said schools are operating as normal and there has not been a major drop in attendance.
On Tuesday, the health department released an official count of mumps cases in Lake County:
Barrington High School: 6 confirmed, 16 probable, 2 suspect
Station Middle School (Barrington): 3 confirmed, 4 probable, 2 suspect
Prairie Campus School (Barrington): 5 suspect
Roslyn Road School (Barrington): 1 suspect
Fremont Intermediate School (Mundelein) 1 suspect
Libertyville High School: 1 suspect
Carmel High School: 1 suspect
Daniel Wright Junior High School (Lincolnshire): 1 confirmed case
Other Lake County cases:
1 confirmed (Barrington)
2 probable
3 suspect cases
For more information, visit: https://www.lakecountyil.gov/3875/Mumps