More than 100 passengers and 23 crew members aboard the Ruby Princess, a Princess Cruises vessel, have fallen ill with suspected norovirus after departing San Francisco on 12 June for a trip to Alaska and Canada. The Centers for Disease Control and Prevention (CDC) confirmed the outbreak — triggered when illness rates exceed 3% of those on board — among the ship's 3,032 passengers and 1,144 crew members, with the vessel docking in San Francisco for disinfection. The incident marks the third norovirus outbreak on a Princess Cruises ship this year, highlighting the heightened risk aboard cruise liners where close quarters can accelerate the spread of the highly contagious virus, which causes vomiting and diarrhea.