Norovirus Sickens 125 on Ruby Princess Alaska Voyage

Updated July 4, 2026

Princess Cruises' Ruby Princess arrived at San Francisco's Pier 35 on July 2 after a 20-day Alaska and Canada voyage marked by a confirmed norovirus outbreak that sickened 102 of 3,032 guests and 23 of 1,144 crew members, according to Centers for Disease Control and Prevention figures. Princess said cases had decreased and remained low, and the ship would undergo comprehensive cleaning and disinfection before its next cruise.

The guest cases represent 3.4% of passengers onboard, above the CDC Vessel Sanitation Program's public reporting threshold. The CDC said its Vessel Sanitation Program was informed of the outbreak on June 28.

The outbreak is Princess Cruises' third CDC-reported norovirus event in 2026. No cruise line has more so far this year. Princess has recorded 478 sick passengers and crew members across the three outbreaks.

Cleaning measures changed onboard operations

The CDC identified norovirus as the causative agent after samples were collected. Sick guests and crew reported diarrhea and vomiting as the main symptoms. Ruby Princess crew members increased cleaning and disinfection, isolated ill passengers and crew, and consulted with the Vessel Sanitation Program during the voyage.

Princess said in a prepared statement, "Princess Cruises can confirm that a limited number of guests reported mild gastrointestinal illness during the 20-day June 12 Ruby Princess voyage from San Francisco." The company added, "Our crew responded promptly by implementing enhanced sanitation protocols across the ship, and cases have since decreased and remain low."

Princess also moved to cabin-level sanitation early in the sailing. A June 15 letter delivered to guests said, "some guests have reported experiencing gastrointestinal symptoms," and told passengers the ship would begin an enhanced cleaning and disinfection program. Ruby Princess has 1,542 guest cabins. Stateroom deep cleaning was scheduled over June 16 and 17.

Other onboard changes included crew-served buffet stations and added handwashing reminders before buffet entry. Crew stepped up cleaning of high-touch areas such as railings, elevator buttons and door handles. Morning stateroom service was suspended during the two deep-cleaning days, while evening turndown service continued.

The ship's activities, entertainment and shore tours continued during the voyage. Ruby Princess called at Alaska ports including Ketchikan, Wrangell, Juneau, Skagway and Valdez during the summer solstice sailing, and the voyage ended in San Francisco on July 2 as scheduled.

Passengers waiting to board the next Alaska sailing from San Francisco said Princess had informed them about the outbreak before embarkation. That next departure was scheduled after the additional cleaning and disinfection work.

Princess has three CDC-listed norovirus outbreaks this year

The Ruby Princess outbreak follows a May norovirus outbreak aboard Caribbean Princess that sickened 160 people and a March outbreak aboard Star Princess that sickened 193. Lindblad Expeditions has also had two norovirus outbreaks aboard National Geographic Sea Bird in 2026.

The CDC has logged seven cruise ship gastrointestinal illness outbreaks in 2026. Five were caused by norovirus and two by E. coli. In 2025, norovirus accounted for 17 of 23 cruise ship gastrointestinal outbreaks reported by the agency.

How the CDC counts cruise ship outbreaks

Under the Vessel Sanitation Program, cruise ships with foreign itineraries that include U.S. ports report acute gastroenteritis cases to the CDC before arriving in a U.S. port and update the agency when illness rates rise. The CDC publicly lists outbreaks when 3% or more of passengers or crew report gastrointestinal symptoms to the ship's medical staff.

Ruby Princess reported the outbreak to the Vessel Sanitation Program on June 28. The CDC said the program remotely monitored the outbreak, including review of the ship's response and sanitation procedures.

Norovirus typically causes vomiting and diarrhea and can spread through contaminated surfaces or food, according to the CDC. The agency says the virus can survive on surfaces for days or weeks. Cruise ship outbreaks account for only 1% of all reported norovirus outbreaks, the CDC says.

The illness totals are cumulative for the full voyage, meaning the 125 reported cases do not necessarily represent people sick at the same time. The CDC count remained 125 in reports after Ruby Princess returned to San Francisco.