More than 100 passengers and 23 crew members aboard a Princess Cruise ship were sickened with norovirus during a 20-day voyage to Alaska and Canada. The Ruby Princess docked in San Francisco on Thursday, July 3, 2026, with a significant number of individuals experiencing vomiting and diarrhea.
According to the U.S. Centers for Disease Control and Prevention (CDC), norovirus, commonly known as the stomach flu, is a highly contagious virus that causes gastrointestinal illness. It can spread through direct contact, contaminated objects, or consuming contaminated food or beverages. Infected individuals can remain contagious for up to two weeks after symptoms subside.
The outbreak on the Ruby Princess was first reported on June 28. Approximately three percent of passengers and two percent of the crew reported symptoms. The cruise line stated that its staff implemented enhanced cleaning and disinfection protocols upon the outbreak's detection and isolated affected individuals. Staff also consulted with the CDC's Vessel Sanitation Program to manage the situation.
"Our crew responded promptly by implementing enhanced sanitation protocols across the ship, and cases have since decreased and remain low," a Princess Cruises representative said in a statement. The ship is undergoing comprehensive cleaning and disinfection before its next voyage.
This incident marks the third norovirus outbreak reported on Princess Cruises ships this year. Similar outbreaks occurred on the Star Princess and Caribbean Princess in mid-March and late April/early May. Additionally, Lindblad Expeditions has reported two norovirus outbreaks on its National Geographic Sea Bird ship in 2026. The CDC has also recorded two E. coli outbreaks on cruise ships this year, aboard the Regent Seven Seas in January and Oceania Cruises in April.
The CDC recommends frequent handwashing, thorough cooking of shellfish, washing fruits and vegetables, cleaning and disinfecting surfaces, washing laundry in hot water, and isolating oneself for two days after symptom resolution to prevent norovirus contraction.