More than 120 passengers and crew members aboard a Princess Cruises ship that docked in San Francisco on Thursday were infected with norovirus, a highly contagious stomach virus, federal health officials said.
The Ruby Princess was on a 20-day round trip journey from San Francisco to Canada and Alaska when 102 passengers and 23 crew members became ill, according to the U.S. Centers for Disease Control and Prevention (CDC).
Norovirus is often spread through contaminated food or surfaces, particularly in crowded environments. Symptoms typically include a sudden onset of vomiting, diarrhea, and stomach pain that can last for up to three days. While often short-lived, the illness can pose a greater risk to individuals with underlying health conditions, young children, and older adults.
The outbreak was reported to the CDC on Saturday. Officials noted that not all infected individuals were sick simultaneously, nor were they all ill upon the ship's arrival or departure.
The Ruby Princess had 3,032 passengers and 1,144 crew members on the voyage that set sail on June 12. Princess Cruises stated that the ship's crew implemented enhanced sanitation protocols and that the vessel would undergo thorough cleaning and disinfection before its next departure on Thursday.
This incident marks one of several illness outbreaks reported on cruise ships under the CDC's jurisdiction this year, with norovirus being the most common cause.