CHICAGO (CBS) — The number of confirmed and suspected cases of mumps in the Northwestern suburbs is rising.

Officials say there are now 34 confirmed, suspected and probable mumps cases.

All but one is in Lake County. Officials say the lone case in Cook County is of a student in Arlington Heights.

Most of the cases involve students and staff in the Barrington 220 school district. However, there is one suspected case of a Libertyville High School student and an adult in Lake Zurich.

Last week, Barrington School District 220 sent out a letter to its community. “We’ve communicated with parents, students and staff daily,” said Morgan Delack, Director Of Communications.And on Friday, school officials addressed the issue to the press to state that the issue is under control.

“We spoke with our cleaning crews earlier this week and just asked them to reemphasize — making sure that we are disinfecting high-touch surfaces; door knobs, desk tops, hard surfaces,” said Barrington High School Principal Steve McWilliams.

[graphiq id=”axnYGQ895IN” title=”Mumps Vaccination Costs for the 2015-16 Season” width=”600″ height=”561″ url=”” link=”” link_text=”HealthGrove | Graphiq” ]