A suspected norovirus outbreak is reported aboard Princess Cruises’ Ruby Princess, which is docked in San Francisco for disinfection. The U.S. Centers for Disease Control and Prevention (CDC) says the outbreak affects passengers and crew. According to CDC figures cited by multiple outlets, 102 of more than 3,000 passengers have become ill, along with 23 crewmembers. Another report says the total number of people sick reaches about 125, consistent with the broader description of more than 100 passengers being affected. The CDC received notice of the outbreak more than two weeks into the voyage. The CDC defines a norovirus outbreak using a threshold of 3% or more of passengers becoming ill. The Ruby Princess set sail from San Francisco on 12 June for an itinerary to Alaska and Canada, with a scheduled return on 2 July. Despite the outbreak and the ship’s disinfection activities, the vessel returns to San Francisco as scheduled, according to one report. The incident is described as the third norovirus outbreak for Princess Cruises vessels within the year.