By Melanie Lieberman
February 14, 2014

Cruises have been hit hard this season by the notorious norovirus. In January, a Royal Caribbean voyage was cut short when nearly 700 passengers and crew were sickened by norovirus, and a Caribbean Princess ship aborted its itinerary when 189 cases were reported. An unidentified agent also caused a norovirus-like outbreak on the Norwegian Star in early January.

Because this gastrointestinal virus is so easily transmitted—it spreads from person to person, or via contaminated food and water—cruise ships (with their close living quarters) can act as powerful incubators. The U.S. Centers for Disease Control and Prevention (CDC) identified the particular strain on the ill-fated Caribbean ships as GHII, a new(ish) Sydney-based norovirus that has been associated with more severe symptoms, and may have a higher rate of infection.

In 2013, the CDC reported 7 incidents of norovirus on cruise ships, involving 1,238 passengers. Last month alone nearly matched that number. But before you cancel your next dreamy tropical trip, it’s worth noting that in recent years the overall the number of people infected with norovirus aboard ships has been declining—even as the number of cruisers rises. This year, though, may prove the exception. The norovirus season is only halfway over—it typically runs from November through March or April.

David Peiken, the Director of Public Affairs for Cruise Lines International Association, says that CLIA’s members are well versed in prevention and treatment of norovirus. “In the uncommon instance of an outbreak, [members] have shown they are able to immediately employ numerous practices to mitigate its spread and treat ill passengers and crew.” Extensive ship-wide sanitation is one of those protocols, and includes sterilizing everything from door handles to poker chips.

Bear in mind that the overwhelming majority of norovirus outbreaks occur on land—in hospitals, college dorms, and other confined spaces. That also includes hotels, as the recent outbreak at the Mohonk Mountain House in New York’s Hudson Valley demonstrates.

If you are getting on a cruise, Bernadette Burden of the CDC has some advice. She recommends checking a ship’s inspection score in the CDC Vessel Sanitation Program database before booking a holiday, and reading up on healthy tips and practices prior to embarking. These include washing your hands often, especially before eating, and opting for on-board dining facilities that utilize staff, rather than self-service.

If you experience symptoms, report them immediately and recuperate in your cabin or, if possible, the ship’s infirmary. That way, you don’t become the person responsible for sinking an entire cruise.

Melanie Lieberman is an editorial intern at Travel + Leisure.