There is a virus that goes mump in the night, and it’s penetrating college campuses around the country.

Mumps isn’t part of routine health conversation in the way flu or whooping cough are; the youngest generations can’t even remember a time when not everyone was vaccinated against the virus. But the contagious illness, once common among babies and children, is making a comeback, largely at universities. And people are concerned.

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“Mumps kind of sounds like this archaic thing,” University of Missouri sophomore Caroline Brown, who contracted the virus around Thanksgiving, told PBS. “We get vaccinated for it; it just sounds like something that nobody gets. So I just didn't think that it was possible that I would get it.” Almost 200 mumps cases have been reported there, and more than 4,000 nationwide — “nearly triple the number in 2015 and the largest increase in 10 years.”

The symptom that most characterizes mumps is swelling in the salivary glands, which will cause the jaw area to hurt and make the cheeks puff up, according to the Mayo Clinic. “In fact, the term ‘mumps’ is an old expression for lumps or bumps within the cheeks.” Two to three weeks after exposure to mumps, infected people will also have a fever, headache, muscle aches, fatigue, and loss of appetite.

The virus is highly contagious, with outbreaks most often happening “where people have had prolonged, close contact with a person who has mumps, such as attending the same class, playing on the same sports team, or living in the same dormitory,” the Centers for Disease Control and Prevention say. “It spreads through saliva or mucus from the mouth, nose, or throat.” That could mean talking with an infected person, someone with the virus coughing or sneezing nearby or touching something healthy people also touch, as well as sharing things like cups and forks. “Mumps likely spreads before the salivary glands begin to swell and up to five days after the swelling begins.”

To help stop the virus from spreading, the Mayo Clinic recommends informing your doctor’s office ahead of time “so that you won't have to wait so long in the waiting room, possibly infecting others.”

There is a vaccine to prevent mumps that is largely effective — “since the pre-vaccine era, there has been a more than 99 percent decrease in mumps cases in the United States,” the CDC says — although even vaccinated people have a small chance of contracting it at any time of the year.

Some officials are questioning whether the vaccine is not effective enough, according to the PBS report, given outbreaks at places like the University of Missouri, where students are required to be immunized. Dr. Dirk Haselow, epidemiologist and medical director of outbreak response in Arkansas, where mumps cases in children and young adults account for a large portion of the year’s nationwide numbers, told PBS that many of the infected people were vaccinated. “We are concerned that the outbreak may indicate something unusual,” he said. The vaccine was made in the 1960s to combat a specific virus strain but “we are wondering whether the circulating strains have evolved away from the vaccine,” as the new cases of mumps are caused by a different strain from the original.

Regardless, the vaccine still protects against many cases of mumps and can prevent rare but serious complications, like swelling in the brain, testicles, ovaries and spinal cord, as well as deafness.

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