Mumps is in no hurry to leave students at Pennsylvania State University alone.

The number of probable and confirmed cases has reached 68, said Shelley Haffner, infectious disease manager at Penn State's student health center.  She said she hopes the end of the school year — finals week is the first week of May — will break the cycle of exposures, but said outbreaks at some other colleges have lasted more than a year.

But the annual Blue-White weekend April 22 could increase mumps transmission.  The event, which centers on an exhibition game involving Penn State football players, draws alumni and students from other campuses to State College. Haffner said she hopes students will wash their hands, refrain from sharing drinks, and stay home if they're sick.

The first case was diagnosed Jan. 29.  There were 36 by March 3.

Haffner said there have been cases at another Penn State campus as well, but all were traced back to the main campus.

Justin McDaniel, a Penn State spokesman, said there were two confirmed and one probable mumps case at Penn State-Altoona.  The three students are no longer infectious and have returned to class.

Most of the students who have gotten sick with the virus had been immunized.  The university is suggesting that anyone who has not been immunized or got only one of the two recommended shots make sure they are fully vaccinated.  In some cases, it is notifying students who are in groups known to be at risk and suggesting they may want to get a third shot. Scientists are studying whether a third vaccine should be recommended for all college students.

Most mumps victims have been undergraduates.  Grad students, Haffner said, tend to have a "very, very different" lifestyle.

Mumps is a contagious disease spread through respiratory droplets.  Symptoms include swelling and tenderness of the glands just below or in front of the ear or jaw, fever, headache, muscle aches, fatigue, and lack of appetite.  They occur about two weeks after exposure to someone with the virus.  Infected people can spread the virus two to three days before they have symptoms.

The mumps vaccine is about 88 percent effective.