More than two months have elapsed since the first case of mumps was reported, yet the unpredictable outbreak rages on throughout the National Hockey League.
And despite heightened sensitivity about the issue and increased vigilance from teams to try to prevent transmission, it seems there is another case almost every day.
It's a strange thing, especially considering the relative rarity of incidents in the United States. Each year in the U.S., the Center for Disease for Control and Prevention in Atlanta receives anywhere from a few hundred to a couple of thousand reported cases. There were 438 confirmed cases in the U.S. in 2013, and more than 1,000 thus far in 2014, out of a total population of almost 320 million.
And although the vaccine-preventable disease -- which has symptoms such as swelling, muscle aches, fatigue, loss of appetite and fever -- has spread across college campuses (there have been four outbreaks this year at American universities), never has it run through a professional sports league. Once you've had the virus, you are immune to further outbreaks and are no longer contagious.
Most recently, the New York Rangers announced Thursday afternoon that forward Lee Stempniak will be isolated from the team for the next five days and will be tested for the mumps. It was the third such announcement of the day for the Rangers, as they were the first organization to reveal that the disease had reached the American Hockey League ranks as well. According to the Rangers, both forward Joey Crabb and head coach Ken Gernander of the team's minor league affiliate in Hartford, Connecticut, will be isolated and tested. Emerson Etem of the Anaheim Ducks was diagnosed last month while with the team's AHL affliliate Norfolk Admirals.
Currently, 16 NHL players -- out of a total of more than 700 -- have been confirmed as having had the mumps, with Penguins defensemen Olli Maatta being the latest, with the Rangers still waiting diagnoses for the aforementioned trio.
And the disease has not been limited to players. Two referees and one team's radio intern have also been diagnosed.
The NHL has few solutions beyond making its medical personnel available and providing support when needed. After issuing a memo to all 30 teams and their respective medical and training staffs in November, the league sent out an additional, more specific memo Tuesday that detailed the proper protocol and designating appropriate personnel to handle a situation if it arises.
More than anything, the memo was disseminated as an effort to raise consciousness about the virus.
"We drilled down to specific expectations in terms of putting someone in charge at the club level to make sure things are getting handled appropriately," NHL deputy commissioner Bill Daly told ESPN.com on Wednesday. "The basis of information hasn't changed. Everyone knows what the disease is, how it is transmitted and the steps that need to be taken to minimize outbreak."
Although Daly says the league is not fearful of players contracting more serious illnesses from the mumps virus, the puzzling phenomenon has cast a pall of confusion as the NHL tries to curtail the problem.
The Penguins, who also recently tested goaltender Marc-Andre Fleury (his results came back negative), have endured scrutiny in the past week, especially after superstar Sidney Crosby appeared before the media on Dec. 12. After the team's morning skate, Crosby was sporting a large swelling on the right side of his face, considered a hallmark symptom of the disease. The Penguins decided to hold Crosby out for precautionary reasons and later revealed that further tests confirmed he had contracted the mumps.
Not long afterward, teammate Beau Bennett was diagnosed, prompting fear about his recent visit to a local children's hospital that might have caused unnecessary exposure for some patients. Dr. Michael Green, of the Children's Hospital of Pittsburgh's pediatrics infectious diseases division, said during a conference call with reporters Wednesday that he did not believe Bennett was infectious at the time. Only two or three children who came into contact with Bennett had not yet received an age-appropriate dosage of the vaccine, Green said, but the hospital would continue to monitor accordingly.
Still, the specter of transmission, or at least the optics of the possibility, prompted several teams to cancel or postpone previously scheduled holiday hospital visits. The Carolina Hurricanes, Calgary Flames, Minnesota Wild and New York Islanders all decided to take such action.
Most teams have administered prophylactic vaccines to try to combat further transmission, although players cannot be forced to receive vaccines, and a few teams have had players elect not to.
Teams in the AHL are starting to administer booster shots as well: The Grand Rapids Griffins will be offered vaccinations Friday and both the Toronto Marlies and Milwaukee Admirals will receive theirs this weekend.
Teams are also taking extra precautions in sanitizing locker rooms and all surfaces, as well as discouraging players from sharing water bottles and towels.
Some teams have taken it one step further, as the Rangers confirmed to ESPN.com on Thursday that players would not share hotel rooms on the road while the team continues to deal with the situation. (Players get their own rooms after they've left the entry-level contract phase, as per the collective bargaining agreement.)
So, what happens next? That's very hard to predict, according to Dr. Greg Wallace, who leads the domestic measles, mumps, rubella and polio team at the CDC. The most difficult part of curbing the spread is that the virus has such a long incubation period that players might transmit the disease before realizing they have it.
And although most teams are trying to be proactive in administering boosters to players and staffers, the vaccine (when receiving the recommended double dose) is generally believed to be only about 88 percent effective.
"It's hard to predict how long this can fester on or how quickly it can burn out," Wallace told ESPN.com last week.
Wallace said the end of the outbreak cannot be confirmed until two full incubation periods, or about 50 days, elapse without any new cases.
And with new cases popping up each day, who knows when that could be?
The Wild's Keith Ballard was the first NHL player to miss a game with mumpslike symptoms, and that was Oct. 17. Eventually, five Wild defensemen were sidelined by the virus, leading some to wonder what sort of impact this could have on a team if the outbreak persists until the end of the regular season and perhaps into the playoffs.
Others assume the disease will eventually run its course. Daly points out that every season, several players contract nasty outbreaks of the flu, yet those rarely yield the same sort of media coverage.
Daly doesn't think the mumps poses a serious threat to the league beyond adding a bizarre storyline to the 2014-15 season.
"It's not this scourge that's going to end things for the league or force us to shut down," he said.