French authorities have ordered over 1,700 passengers and crew on a British cruise ship to stay on board due to a gastrointestinal illness outbreak. The Ambition, on a 14-night cruise from Belfast and Liverpool, reached Bordeaux on Tuesday. Up to 50 passengers showed symptoms, and those affected were isolated. A medical team is investigating the cause. The outbreak is not linked to a recent hantavirus incident on another ship. The U.S. Centers for Disease Control and Prevention notes a rise in cruise ship outbreaks, mostly due to a new norovirus strain.