We’ve all been following the National Hockey League mumps outbreak in the past few weeks. And by now, those of us who are known for opining on infectious diseases have been asked by our friends why even people who are fully and recently vaccinated are coming down with the disease. (Here’s the short version: Two doses of mumps vaccine are 88% (range: 66-95%) effective at preventing disease, so in an outbreak, a certain percentage of fully (2 doses) and partially (1 dose) immunized individuals are vulnerable to becoming ill, as are all the unvaccinated people exposed. For more information see Mumps Vaccine Effectiveness in Highly Immunized Populations and Mumps Outbreaks in Vaccinated Populations: Are Available Mumps Vaccines Effective Enough to Prevent Outbreaks?)
What are infectious diseases physicians saying about the NHL mumps outbreak?
History of Vaccines advisor and CHOP infectious diseases section chief Paul A. Offit, MD, appears in this video interview on WallStreetJournal.com. He discusses the mumps outbreak as well as Angelina Jolie’s ill-timed case of chickenpox.
Peter Lin, MD, medical columnist for Canadian Broadcasting Company, speculates about whether water-bottle sharing among NHL players might have contributed to some cases of mumps.
Gregory Poland, MD, editor of the journal Vaccine and head of the Vaccine Research Group at Mayo Clinic, was interviewed for a story on USAToday.com and noted that mumps outbreaks are not uncommon; in fact, he said “… if 13 students at a junior college in rural Arizona had mumps, you and I wouldn’t be talking. It gets hyped because it’s in [professional athletes].” Indeed, a large outbreak of mumps occurred earlier in 2014 at Ohio State University, with hundreds of cases on the campus and in nearby communities. That outbreak appeared in several national news stories but did not get nearly the attention that this NHL outbreak has generated.
Deborah Spicehandler, MD, at Northern West Chester Hospital in Mount Kisco, NY, is quoted here saying that she thinks the outbreak has likely reached its peak. Many NHL teams have offered booster doses of the MMR vaccine to players as well as antibody testing to check for vulnerability to disease.
Finally, let’s consider whether spectators are at risk from contracting mumps from infected players. The virus is spread via respiratory droplets, so a person would have to be close enough to an infected player’s cough, sneeze, or runny nose to be at risk. On the ice and in the locker room, there are plenty of chances for players to have that kind of contact. But even for a spectator sitting in the front row for a game, the chances that infected droplets would make it past the glass seem incredibly unlikely. So, if hockey is your thing, don’t worry about coming down with mumps from a player on the ice.
Off the ice is a different matter. Pittsburgh Penguins player Beau Bennett was diagnosed with mumps this week: he visited Childrens Hospital in Pittsburgh last week when he might have been contagious. Children at the hospital who might be vulnerable to mumps are being isolated and observed. Many NHL teams are cancelling holiday appearances at malls and other public venues so as not to put the public at risk outside the rink.