An outbreak of the mumps caused chaos and confusion throughout the NHL in December, with some of Hockey’s leading stars falling victim to the virus.

Anaheim Ducks were the first team to report players suffering from the viral infection, which is spread by coughing and sneezing. More often seen in children, mumps affects the saliva glands and causes painful swelling on either side of the face below the ears; serious complications are rare, but in some instances infertility could result.

Emergency immunizations and quarantines have been implemented since the outbreak and reviews of the NHL’s infectious disease prevention guidelines are underway.

As of 22nd December, 18 players across the NHL had been infected. These included star players such as Sidney Crosby of Pittsburgh Penguins. Teams ranging from the Ducks, Pittsburgh Penguins, Minnesota Wild, New Jersey Devils and New York Rangers have all been affected.

Ironically, Rangers’ Derick Brassard missed the round of booster shots organised for the team at the end of November due to illness—he would later become one of those infected, along with forward Lee Stempniak, Tanner Glass, a minor league player and a coach.

The Rangers’ form has been barely affected, though. Their pre-Christmas 1-0 win over the Hurricanes completed their longest winning streak since 2011-12, when they managed 7-in-a-row. Demand to see the New York Rangers is always high, particularly over the holidays—and especially when on such a golden run of form, however, you can find here sold out tickets.

The US has seen large numbers of mumps cases recently: earlier in the year, there was a large spate of cases at Ohio State University. More than 100 students were infected. However, late 2014’s NHL outbreak is a rare occurrence in professional sport.

The NBA and NFL will be monitoring the situation closely. Not only to see whether precautions put in place are working, but also because many clubs across the various sports share the same arena or training facility.

In the meantime, Hockey has a busy holiday period to navigate—NHL tickets are available here.