Stomach Bugs, Not Hantavirus, Are the Bigger Threat on Cruises

Tourists disembark from a Royal Caribbean cruise ship in Cabo Rojo, Pedernales Province, Dominican Republic.

Photographer: Marco Bello/Bloomberg

Stomach bugs on cruise ships recently hit a nearly two-decade high as more people than ever board the vessels, underscoring how easily viruses spread on contained voyages.

While cruises are in a global spotlight after a rare hantavirus outbreak killed three people on an ocean liner since April, mild gastrointestinal illnesses are far more common on ships. They have risen for the last four years to the highest since 2007, according to data from the Centers for Disease Control and Prevention’s Vessel Sanitation Program. The data tracks ships with 13 or more passengers with foreign itineraries that dock at one or more US ports.