MEDFORD —The news that more than a dozen National Hockey League (NHL) players and referees were recently diagnosed with mumps has caught some headlines.

A once common childhood illness, mumps has been nearly eradicated since a vaccine was introduced in the late 1960s. So why the comeback now?

Dr. Edward Butler, chief academic officer and hospital epidemiologist at Hallmark Health and chairman of the Department of Medicine at Lawrence Memorial Hospital of Medford said, “The mumps vaccine is very effective in the short term but after 10 years or so that effectiveness begins to wane.

“Several years after the vaccine was introduced, we began to see a number of pre-teens developing mumps and we realized that a “booster” was needed to ramp up protection.”

In the United States, the mumps vaccine is now given in two phases: Once at age 12-15 months and then again sometime between ages 5-10. There is, however, a generation of young adults who fell outside the window of receiving a booster. There are also a number of international players who may not have been exposed to the same vaccination program as those in the United States and, as a result, may never have received the vaccine.

“We’ve seen small outbreaks in the United States over the past few years,” added Dr. Butler. “Typically they occur among groups of similar types of people in close quarters, such as college students. NHL players sharing locker rooms could be another example.”

Mumps is an infection of the parotid glands, which sit between the cheek and the ear. Symptoms are similar to the flu, including painful swelling around the face, fever, sore throat, aches and pains, difficulty chewing or swallowing and nausea. In some extreme cases, meningitis and encephalitis can occur. There is no specific treatment for mumps because viruses cannot be treated with antibiotics but it typically runs its course in 10 to 12 days. The virus is spread through close contact with an infected person’s saliva and the long incubation period of one to three weeks makes it hard to pinpoint an exact source of infection.

According to Dr. Butler, there are typically about 500 cases of the mumps each year in the United States.

“Most of the cases seen are due to the waning of the vaccine or the fact that a small population remain susceptible despite the vaccine,” he said. “Regardless, it is important for all children to receive the vaccination as well as the booster. When it comes to fighting mumps, one dose is good but two doses are better.”