Norovirus Sickens Over 120 on Princess Cruise Ship from San Francisco

More than 120 passengers and crew members aboard a Princess Cruises ship that docked in San Francisco on Thursday were infected with norovirus, the U.S. Centers for Disease Control and Prevention (CDC) confirmed.

The Ruby Princess, which completed a 20-day round-trip voyage from San Francisco to Canada and Alaska, reported that 102 passengers and 23 crew members fell ill with the highly contagious stomach virus. The ship carried a total of 3,032 passengers and 1,144 crew members.

Norovirus is a common cause of gastroenteritis, characterised by sudden vomiting, diarrhea, and stomach pain that can last up to three days. While most people recover without treatment, the virus can pose serious risks to young children, the elderly, and individuals with underlying health conditions.

The outbreak was reported to the CDC on June 27, with officials noting that not all infected individuals were sick simultaneously or when the ship arrived or departed ports.

Princess Cruises stated that crew members responded promptly, implementing enhanced sanitation protocols across the vessel. The ship was thoroughly cleaned and disinfected before its next scheduled departure later on Thursday.

So far in 2026, seven illness outbreaks have been reported on cruise ships under CDC jurisdiction, most caused by norovirus. The virus spreads easily through contaminated food, water, surfaces, or direct contact with infected individuals.

Health experts emphasise that frequent handwashing with soap and water for at least 20 seconds is the most effective prevention, as hand sanitiser alone does not reliably neutralise norovirus.