2017 mumps cases as of May 1

A mumps outbreak at Penn State University's main campus in State College is up to 86 cases, according to the university's website.

Cases of the highly infectious disease were first reported there shortly before THON, the massive annual dance marathon that raises money for children fighting cancer.

The university urged students and others to be extra cautious around THON and spring break to avoid spreading the disease.

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Federal data shows that last year saw a marked rise in mumps cases nationwide, stemming largely from outbreaks on university campuses, with the two largest in Iowa and Illinois each involving several hundred students.

From January 1 to April 22 of this year, the U.S. Centers for Disease Control and Prevention said, 42 states in the U.S. reported mumps infections in 2,570 people.

Health officials say there's no specific treatment for mumps and most people recover completely in a few weeks, but that in some cases it can cause serious complications including deafness or inflammation of the brain.

"Mumps is a highly infectious disease passed through saliva and respiratory secretions. People with mumps are considered infectious from three days before swelling begins through five days after the start of swelling," the university said. "For most people, two doses of the measles, mumps and rubella (MMR) vaccine provide adequate immunity to the infection."

The CDC says there has been more than a 99 percent decrease in mumps cases in the United States since vaccinations for the disease began in 1967.

Mumps cases in U.S. by year through April 22, 2017