A Ruby Princess norovirus outbreak sickened 125 passengers and crew members during a 20-day cruise from San Francisco to Canada and Alaska, federal health officials said. The Princess Cruises ship returned to San Francisco on Thursday, July 2, after the illness spread during the voyage.
The Centers for Disease Control and Prevention reported that 102 passengers and 23 crew members became ill. The ship carried 3,032 passengers and 1,144 crew members during the trip.
Ruby Princess Norovirus Outbreak Reported to CDC
The Ruby Princess departed San Francisco on June 12 for a round-trip cruise to Canada and Alaska. The outbreak was reported to the CDC during the voyage.
Health officials said the illness did not affect all sick passengers and crew at the same time. Some people became ill earlier in the trip, while others reported symptoms later.
The CDC lists the causative agent as norovirus. The agency tracks cruise ship gastrointestinal illness outbreaks through its Vessel Sanitation Program.
Cruise ships must report certain illness cases to the CDC. Public outbreak notices are posted when at least 3% of passengers or crew report gastrointestinal symptoms on voyages under CDC jurisdiction.
Symptoms and Health Concerns
Norovirus is a highly contagious stomach virus. It often spreads through contaminated food, surfaces, water, or close contact with an infected person.
Common symptoms include vomiting, diarrhea, stomach pain, and nausea. The CDC says symptoms can also include fever, headache, and body aches.
For many people, norovirus symptoms last a few days. However, the illness can be more serious for older adults, young children, and people with underlying health conditions.
Dehydration is one of the main risks. Health officials urge people with severe symptoms to seek medical care, especially if they cannot keep fluids down.
Princess Cruises Responds With Cleaning Measures
Princess Cruises said crew members responded by increasing sanitation measures across the ship. The company also said the vessel would be thoroughly cleaned and disinfected before its next departure.
The CDC said outbreak response steps can include isolating sick passengers and crew, collecting health samples, and reviewing cleaning procedures. Cruise lines may also increase disinfection in high-touch areas.
The Ruby Princess outbreak is one of several cruise ship gastrointestinal illness outbreaks reported by the CDC in 2026. Most listed outbreaks this year have involved norovirus.
The CDC also reported recent norovirus outbreaks on other cruise ships, including the Caribbean Princess and Star Princess. Both are also operated by Princess Cruises.
How Travelers Can Reduce Risk
Health officials say handwashing remains one of the best ways to prevent norovirus. Soap and water work better than hand sanitizer alone against the virus.
Passengers should wash their hands after using the restroom and before eating or drinking. They should also avoid sharing utensils, cups, or food with anyone who feels sick.
Travelers who develop symptoms should report them to the ship’s medical staff. Quick reporting helps crews limit the spread of illness.
The Ruby Princess norovirus outbreak serves as a reminder that stomach viruses can spread quickly in crowded settings. Passengers preparing for summer travel should follow health guidance, report symptoms early, and take basic precautions before and during a cruise.