Severe norovirus-like outbreak hits Holland America cruise ship

Holland America’s Zuiderdam has been hit by an unusually large outbreak of what appears to be norovirus — the flu-like stomach bug that causes diarrhea and vomiting.

More than 12% of passengers on board the vessel — 224 out of 1,820 — came down with the illness during a 17-night voyage that ended Monday, according to the Centers for Disease Control and Prevention in Atlanta.

It’s the first time this year an outbreak has surpassed 10% of passengers on a ship — a rare occurrence.

The CDC says Holland America has sent additional staff to the Zuiderdam to help clean and disinfect it. The line also delayed the ship’s departure on Monday to allow for extra cleaning.

CDC officials boarded the ship Monday, and the CDC is now testing stool samples to determine whether the outbreak is, indeed, norovirus.

Holland America has struggled with gastro-intestinal illness this year on its ships, with six outbreaks documented by the CDC. Only two other lines have had more than one outbreak: Norwegian Cruise Line (4) and Princess Cruises (2). Three other lines — Carnival, Regent Seven Seas and American Canadian Caribbean Line — have each had a single outbreak.

Holland America also led the industry in gastro-intestinal illnesses in 2007 with five outbreaks (tying with NCL) and in 2006 with seven outbreaks, according to CDC statistics.

Sometimes called the “24-hour flu,” norovirus is the most common cause of stomach illness in the United States, accounting for around half of all cases, according to the CDC. It breaks out regularly in schools, nursing homes, hospitals, offices and other places people congregate.