Mumps continued its winning record against the NHL players this weekend, being officially credited for a TKO of Pittsburgh Penguins superstar Sidney Crosby and also reappearing on the New York Rangers roster.
It's a dirty, rotten opponent with underhanded tactics. Anything capable of taking down Corey Perry must be.
With the official diagnosis of Crosby and Derek Brassard, even without counting the possible case of Beau Bennett, there have been 14 confirmed cases in the league on five different teams. That does not include the St. Louis Blues, who are not admitting to having patient zero but did have at least five players miss time with a mystery illness that caused facial swelling back in October, or the Montreal Canadiens, who have one rumored player with the mumps.
With just the confirmed cases, two percent of the NHL's approximately 700 active players and 17 percent of the league's teams have had to deal with the condition this season. The Dallas Stars haven't been among the infected yet, but they and everyone else in the NHL would be right to worry.
Mumps may be a fun word to say or to work into punny sentences, but it is not a fun disease to have.
About half of the people infected have the characteristic facial swelling, which can occur on one or both sides of the face - for an example, see the picture of Crosby that made the rounds on Friday.
The right side of Sidney Crosby's face was ... different ... today: pic.twitter.com/8gVmXU8c19— Seth Rorabaugh (@emptynetters) December 12, 2014
Fever, headache, fatigue and loss of appetite are also extremely common.
The reproductive tract can also be affected, with a small percent of post-pubescent women suffering from inflammation of the ovaries and around 20 percent of adolescent and adult men suffering from orchitis. Both complications can cause fertility issues. Other nasty complications include mild forms of meningitis, pancreatitis, encephalitis and very occasionally deafness. Some of those complications can be fatal, though again, those are rare outcomes of rare side effects.
Even so, while the vast majority of cases of the mumps are self-limiting in nature and resolve on their own in a few weeks, there are good reasons to vaccinate for it. Most of the population, thankfully, is vaccinated, including the majority of the players in the NHL.
So why, then, is the disease burrowing its way around the league? There are two main factors at play - the vaccine, while by far the best option to prevent the disease, is not perfect, and the very infectious nature of the disease itself.
Let's start with the latter and talk a little about epidemiology. Back when Dallas was a little panicked about Ebola (and the Flyers were being asked how worried they were to come and play the Stars), NPR had a great article about the relative contagiousness of diseases and the value doctors use to compare that, R-nought, which is the number of secondary cases that occur from a primary case on average.
Measles, at least in an vaccinated population, is one of the most contagious diseases we know of. The average person with measles, according to NPR, infects 12-18 others because measles can live in the air for up to four hours after an infected person has left. If you walk into an elevator that carried a person with measles three hours prior, there's a decent chance you've been exposed.
On the other end of the scale, a person with HIV infects an average of four others through the course of the disease. People with Ebola infect two others. Those diseases are considered, at least in a place with proper hygiene precautions and good medical care, quite containable.
Mumps falls more towards the measles end of the spectrum with an R-nought of 4-10, depending on your source. That's in the neighborhood with pertussis (whooping cough), smallpox, polio and rubella. It's higher than SARS and true influenza.
The trick mumps uses to spread so readily is it is contagious well before symptoms start showing, from about a week before symptoms begin to at least five days after symptoms start to show. People who have no idea they're sick can be inadvertently spreading the disease to those around them.
Which brings us to another reason mumps is cruising around the NHL so quickly - the method of transmission.
Unlike Ebola, HIV and hepatitis, which are primarily spread through bodily fluid, mumps (and influenza and SARS as well as many others mentioned above) are spread via airborne droplets. There is plenty of opportunity to exchange that not only in a locker room environment but also on the ice to an opponent or official. Players and officials are constantly in each other's personal space on the ice, and all sorts of possibly infected fluids are flying around. As Deadspin wrote today, it's the perfect environment for this type of disease to spread quickly.
Vaccination, then, is likely the reason the whole league hasn't come down with the mumps just yet. But vaccination is not perfect. Again, depending on your source, the mumps vaccine in the typical MMR delivery mechanism is about 85 percent effective. But science has recently discovered that the effectiveness declines with the age of the vaccine for mumps and a few other notable diseases (including whooping cough). People are still protected, but that protection level wanes somewhat. That's why teams with confirmed cases (and hopefully those without cases as well) have been offering booster shots to players and sometimes staff.
Of course, that only works if your players take the shots (Ryan Suter, I'm looking at you). While good handwashing and healthy habits can contribute to a strong immune system and lower chances of contracting any illness, it won't prevent one from picking up an airborne droplet from a well meaning teammate. Herd immunity, or the idea that if everyone who can be is vaccinated, there will be enough people with totally immune systems to help protect those for who the vaccine was less effective, comes in to play as well.
Everyone's body responds to vaccinations differently. Another personal anecdote - I was vaccinated with the MMR as a baby and had a serious reaction, bad enough that my parents were told to avoid that particular booster in the future (though I have had everything else). Because I volunteer at a hospital, I had to have my titer levels checked for all three diseases to know whether or not I could come to a shift if there was a patient with any of those diseases admitted. And 28 years after my original vaccination without any boosters, I still had high levels of antibodies to all three diseases.
On the other hand, Crosby reportedly received an MMR booster in February before the Olympics and still caught the mumps. Biology is weird.
So given all that mess, should the Stars be concerned? Absolutely.
Mumps is a very contagious disease with a good but not perfect vaccine, one that we know tends to lose effectiveness with time. Hockey is a sport ripe with the type of close quarters for an airborne droplet-transmitted disease to spread. There are no cases on the Stars yet that we know of, but teams they have played both repeatedly and recently have confirmed cases.
There's no good method of preventing the mumps except vaccination, so I'd hope the Stars and every other not-yet-infected NHL team have offered boosters to the staff and players. Good hygiene practices, such as not sharing water bottles or sweaty towels, are always a positive as well, though you'd hope those were in place regardless of a mumps outbreak or not.
[Ed note: The great Mike Heika asked around the Stars locker room on Monday and found out the team got MMR boosters two weeks ago. They also sanitize regularly during flu season. Both are great steps, though as Crosby's case shows, you can take all the right steps and still get stuck with mumps.]
And of course, if a player starts showing some of the classic symptoms, even in the aftermath of something else that could cause them like a brawl with a blow to the side of the face and with inconclusive test results, it's probably better to err on the side of caution and isolation until you know for sure. If social media outrage is what eventually leads you to a proper diagnosis, you might be handling the medical side of things wrong.