The DeKalb County Health Department says there are five cases of mumps in Northern Illinois University students.
According to a news release, outbreaks have been common across college campuses in the past year.
It says up to half of people who get mumps experience mild symptoms, so they may not know they're infected.
Typical symptoms include swollen glands under the ears, fever, headache, and a loss of appetite; it can take up to 25 days for symptoms to appear in an exposed person.
Mumps is a viral disease, so health officials encourage frequent handwashing, and to avoid touching your nose, eyes, and mouth.