Minnesota Wild’s Ryan Suter is the latest NHL player to come down with the mumps. (Elsa/Getty Images)

The mumps have made an unfortunate comeback among NHL players this season, with players from the Anaheim Ducks, St. Louis Blues and New York Rangers all coming down with cases. Minnesota Wild defensemen have been hit particularly hard, however, with a total of five players — Ryan Suter, Jonas Brodin, Keith Ballard, Marco Scandella and Christian Folin — all with confirmed cases of the viral illness that was all but eradicated when a mumps vaccine was introduced in 1967. Before then, roughly 186,000 cases of the disease were reported each year, the Centers for Disease Control and Prevention reports.

So, what’s the deal? Why is the NHL seemingly a hotbed of a virus that saw a 99.9 percent decrease in prevalence since the vaccine was invented?

One theory is that the players weren’t vaccinated adequately. Until recently, the CDC recommended just one-dose of the MMR vaccine, which is a combination shot that inoculates against the measles, mumps and rubella viruses. Today, health officials recommend kids get a booster before entering kindergarten.

“I’m guessing for a lot of people, they haven’t had a second dose,” Director for Infectious Disease at Minnesota’s Department of Health Kris Ehresmann told Minnesota’s WCCO-4 this week.

However, even with the two proper doses, the vaccine is still only effective roughly 88 percent of the time, meaning it’s possible for outbreaks to occur given the right conditions, such as while playing hockey. This brings us to the second theory, as laid out by the CDC (emphasis ours):

Mumps outbreaks can occur any time of year but often occur in winter and spring. A major factor contributing to outbreaks is being in a crowded environment, such as attending the same class, playing on the same sports team, or living in a dormitory with a person who has mumps.

Just this year alone, there have been four reported outbreaks of mumps on university campus, including Ohio State, Fordham, University of Wisconsin-Madison and University of Illinois-Champaign.

The mumps is spread through respiratory functions, and specifically through “droplets of saliva or mucus from the mouth, nose, or throat of an infected person, usually when the person coughs, sneezes or talks,” the CDC writes. Sharing glasses, cans and other items that might come in contact with infected saliva and mucus can also transmit the virus.

Luckily, the mumps isn’t dire in people with otherwise healthy immune systems. It is, however, annoying, uncomfortable and generally not a conducive to going about your daily activities, let along playing hockey. (In rarer cases, however, the disease can cause inflammation of the brain, testicles, ovaries, meningitis and/or deafness.)

“Even though you look like a chipmunk you’re not having a good time with mumps,” Ehresmann said.

One of the telltale symptoms of infection is a swollen neck and face. Sufferers might also get a fever, headache, muscle aches, lose their appetite and feel generally fatigued. Symptoms tend to appear just over two weeks after contraction of the virus, but have been known to incubate in people’s systems occasionally for up to 25 days.

There is no magic cure, so sufferers just need to wait it out, as one might also wait out a common cold.

Unfortunately, for NHL teams, the illness means players will miss games. The Minnesota Wild knows this well: Scandella’s missed two games; Folin’s missed five; Brodin’s missed seven game; and Ballard’s missed eight. Suter missed Wednesday night’s game against the Montreal Canadiens (the Wild still won, 2-1), but Coach Mike Yeo has not ruled him out for Friday’s game against the Ducks, according to Star Tribune reporter Michael Russo.

As far as action plans to contain the outbreak, boosters for team are recommended. Yeo said everyone on the Wild was offered a booster shot after the first players were diagnosed. The locker room was also disinfected and equipment cleaned, Russo reports. Just like recovering from the symptoms of mumps, making sure no one else as contracted it is a waiting game, too.

This has players on teams that haven’t been infected yet worried.

“It is very bad. Right now, we have a lot of people that don’t feel very well. The last thing we need is to have the flu or mumps in our room,” New Jersey Devils winger Steve Bernier told New Jersey Advance Media on Thursday. “To be honest, I never heard about mumps until this year. Now it’s going all over the league. I’m not worried to the point where I’m thinking about it every day, but it’s in the back of my mind for sure.”