(CHICAGO) Authorities are investigating a possible case of mumps at an Andersonville neighborhood elementary school on the North Side.

Chicago Public Schools notified parents on Monday about a case of mumps at Helen C. Peirce School of International Studies, 1423 W. Bryn Mawr Ave., according to the district. The case has not been confirmed and the Chicago Department of Public Health considers it a preliminary diagnosis.

“CPS is supporting the Chicago Department of Public Health as it investigates a potential case of mumps,” a statement from CPS said. “A diagnosis has not been confirmed, and we will work with the Department of Public Health to institute any necessary precautionary measures.”

The notification comes in the same week that three cases of the highly contagious disease were confirmed at Barrington High School, along with a fourth unrelated case in the suburb, according to the Lake County Health Department.

Seven additional cases are considered “probable” and 20 more were deemed “suspect” at two high schools, two middle schools and elsewhere in the surrounding area, health officials said.

Mumps is passed through saliva and mucus, especially by sharing cups or other items, officials said. Up to half of people who contract the virus at first show mild or no symptoms, which include fever, headache, loss of appetite and tender salivary glands under the ears.