More than 100 passengers on US cruise ship sick from suspected norovirus

More than 100 passengers and crew members aboard the Ruby Princess reported gastrointestinal illness during a 20-day cruise from San Francisco, and the CDC said the outbreak was caused by norovirus.

The CDC reported 102 sick passengers and 23 sick crew members on the ship, which carried 3,032 passengers and 1,144 crew members on the voyage to Alaska and British Columbia. Reporting based on the agency's outbreak data said illnesses were logged over the full trip, not all at the same time.

Princess Cruises said the ship returned to San Francisco on July 2 and was undergoing comprehensive cleaning and disinfection before its next departure.

Voyage and outbreak timeline

The Ruby Princess departed San Francisco on June 12 for the 20-day round-trip cruise. The outbreak was reported to the CDC on June 28, and the ship returned to San Francisco on July 2 for disinfection.

The CDC's Vessel Sanitation Program tracks gastrointestinal outbreaks on cruise ships because norovirus spreads easily in crowded settings and can move quickly through passengers and crew.

Princess Cruises told reporters it increased cleaning and disinfection, isolated sick passengers and crew, collected stool specimens, and consulted with federal health officials.

Why it matters

Cruise ships are closely monitored for norovirus because the virus is highly contagious and can spread through shared surfaces, food, and close contact. Public health officials use isolation, sanitation, and specimen collection to limit further spread.

At least some early reporting described the illness as suspected norovirus, but later coverage and the CDC identified norovirus as the cause. The case total reported across outlets was consistent at 125 people.

It was not immediately clear whether the outbreak count changed after the ship docked or when the next sailing would resume.