Outbreak of Bellyache Marred Royal Caribbean Cruise

An outbreak of gastrointestinal illness aboard a Royal Caribbean International cruise ship last week may signal the return of a seasonal virus that for the past several years has bedeviled the industry as well as other crowded places.

About 8.5 percent of the passengers and 1.7 percent of the crew aboard the Splendor of the Seas fell ill during the course of a 14-day cruise from Barcelona, Spain. The ship finished its cruise in Galveston, Texas, on Saturday.

The cause of the illness hasn´t been determined. While bacteria in food and water supplies was once the chief source of gastrointestinal illness on ships, since 2002 viruses have become a more frequent cause.

Passengers who show symptoms are typically confined to their cabins to prevent the spread of the virus.