A University of Southern Maine student has been diagnosed with mumps, the state’s first case since 2013 and the first reported on the school’s Portland campus since an outbreak in 2007.

The Maine Center for Disease Control and Prevention on Thursday confirmed the diagnosis of a case in Maine, but John Martins, a spokesman for the Maine Department of Health and Human Services, would only say that the person who contracted the virus is between the ages of 15 and 24 and lives in Cumberland County.

Martins also did not say whether the person had been vaccinated, citing patient confidentiality rules.

But Bob Stein, USM’s spokesman, said the university learned on March 1 that the results of a state lab test on one of its students came back positive for mumps. The student lives off campus, according to Stein.

An email was sent to students and staff Wednesday and a letter was posted on USM’s website explaining the situation. Stein said USM has been working with Maine CDC officials to make sure everyone on campus is aware.

“We are writing to notify you that there has been a student identified with mumps here at USM,” Lisa Belanger, USM’s director of Health Services, said in the letter. “After coming in contact with the mumps virus, it takes 12 to 25 days before symptoms appear. Mumps can be spread for three days before and five days after symptoms begin. The symptoms most commonly include swollen glands under one or both ears, fever, headache, muscle aches, fatigue and a lack of appetite.”

Stein said that the university contacted, either by email or phone, 155 students who might have come into contact with the infected student. His name, age and class are not being released.

Those students may have taken a class with the person, participated in an extracurricular activity, or lived with him – he has at least one roommate.

Stein and Belanger said the student is no longer considered contagious and has been cleared to return to classes.

Belanger said that of the 155 college students who might have been exposed, only four had not been vaccinated. Blood tests revealed that three of the four do not have mumps and the fourth’s test results were expected Friday.

Belanger said the last case of mumps reported at USM was in 2007 when the university had to deal with an outbreak. Belanger, who did not work for USM at the time, was uncertain how many students were infected, but it is not uncommon for outbreaks to occur on college campuses.

Belanger said some students are granted vaccination exemptions on religious or philosophical grounds when they enter college.

Most people receive vaccinations when they are infants before getting a booster shot at the age of 4 or 5. No additional vaccinations are required, Belanger said. In children, mumps is usually mild, but adults can have more serious complications.

A review of statewide data by the Maine Sunday Telegram in 2015 found a relatively high number of Maine elementary school students whose parents opted against having them vaccinated against mumps and other diseases. In the schools most at risk, unvaccinated children account for more than 10 percent of kindergarten and first-grade students.

In some schools more than 20 percent of students are unvaccinated, threatening to undermine what health experts call ‘herd immunity.’

A mumps patient is most contagious within the first five days, and there is no specific treatment. The virus is spread by mucus or droplets from the nose or throat of an infected person, most commonly when that person coughs or sneezes.

Doctors typically isolate the patient for five days to prevent further spread of the virus.

There have been reported cases of mumps recently at other universities and colleges including Harvard University.

The Boston Globe reported Thursday that six cases of the viral infection have been identified among the student population at Harvard University. Two of the students are enrolled at the Harvard Divinity School – one is an undergraduate and the second is a graduate student.

Martins, the Maine CDC spokesman, said the state is investigating a possible connection between the case in Maine and a mumps outbreak at a New Hampshire college. St. Anselm College in New Hampshire recently confirmed two cases of mumps with three other cases classified as suspect.

“We are investigating a potential link to mumps cases in New Hampshire and are in contact with our public health colleagues in that state,” Martins said in a statement. The case was confirmed by the Maine CDC on Wednesday.

There was a single case of mumps in Maine in 2013, none in 2012, and at least two cases reported in each year from 2007 to 2011. In 2007, 24 cases were reported in Maine, according to data provided by Martins.