COLUMBUS, Ohio (WTVN) -- The number of mumps cases at Ohio State University has grown to 40.

18 of the cases are female while 22 are male. 32 of the 40 cases are OSU students, 4 are staff, 1 is a family member, and 3 are people with close ties to the university.

Three of the cases required a stay in the hospital.

"That means that they had a lot of pain and were likely hospitalized for pain management," said Columbus Public Health spokesman Jose Rodriguez.

The vaccine against mumps is only about 80 - 90 percent effective. While that's high, Rodriguez says it leaves a good chunk of the public open to the highly contagious disease.

"The more people that are vaccinated in the community the less of a chance that each of us has to become ill or catch the infection," Rodriguez said.

More cases are likely to be reported. Mumps outbreaks are unpredictable. Rodriguez says they are looking into other cases outside OSU, but didn't know how many would be confirmed as mumps. Health officials plan to work over the weekend to try and confirm the cases.

Basic things like hand washing and covering your cough and sneeze are easy ways to prevent spread of the disease. Rodriguez says if you do have mumps you should remain isolated from others for at least five days.