Norovirus Outbreak Sickens 125 Passengers and Crew on Ruby Princess Cruise from San Francisco

More than 120 passengers and crew members aboard the Ruby Princess cruise ship fell ill after a norovirus outbreak during a 20-day round-trip voyage from San Francisco to Canada and Alaska, according to the U.S. Centers for Disease Control and Prevention (CDC).

Federal health officials said 102 passengers and 23 crew members contracted the highly contagious stomach virus during the voyage. The ship, operated by Princess Cruises, returned to San Francisco on Thursday after completing its scheduled itinerary.

The Ruby Princess departed on June 12 carrying 3,032 passengers and 1,144 crew members. The outbreak was reported to the CDC on Saturday. Officials noted that the illnesses occurred at different times during the voyage, meaning not all infected individuals were sick simultaneously or when the ship arrived in port.

What Is Norovirus?

Norovirus is one of the leading causes of acute gastroenteritis worldwide. It spreads easily through contaminated food, water, shared surfaces, or close contact with an infected person. Cruise ships are particularly vulnerable because of the large number of people living in close quarters.

Common symptoms include:

  • Sudden vomiting
  • Diarrhea
  • Stomach cramps
  • Nausea

Symptoms usually appear quickly and last between one and three days. While most people recover without complications, norovirus can be more serious for young children, older adults, and people with weakened immune systems or underlying medical conditions.

Princess Cruises Implements Enhanced Cleaning

Princess Cruises said its crew responded immediately after the outbreak was detected by introducing enhanced sanitation measures throughout the ship.

The company also confirmed that the Ruby Princess would undergo a comprehensive cleaning and disinfection before departing on its next scheduled cruise.

CDC Reports Multiple Cruise Ship Outbreaks in 2025

The CDC said this is the seventh gastrointestinal illness outbreak reported on cruise ships under its jurisdiction this year, with most cases linked to norovirus.

Health officials continue to monitor cruise-related outbreaks and recommend strict hygiene measures to reduce the spread of infectious diseases onboard.