Nearly 100 people came down with norovirus—also known as the stomach bug—during a recent cruise ship outbreak, the Centers for Disease Control and Prevention (CDC) announced Tuesday.
Here’s what you need to know.
On a 13-day voyage from San Diego to Miami, 94 passengers and four crew members on Serenade of the Seas, a Royal Caribbean ship, caught norovirus.
The ship set sail on Sept. 19, 2025, and nine days later, on Sept. 28, people started getting sick with diarrhea and vomiting.
By the time the ship docked on Oct. 2, the infection had spread to 5% of passengers and 0.5% of the crew.
According to the CDC, Royal Caribbean International, as well as the healthy crew members aboard the ship, responded to the outbreak with:
- Increased cleaning and disinfecting
- Collecting stool samples for testing
- Isolating sick passengers and crew members
- Consulting with the CDC’s Vessel Sanitation Program about cleaning and reporting procedures
It’s worth noting that Serenade of the Seas received a near-perfect sanitation score of 96 when the CDC inspected the vessel on June 25, 2025.
Norovirus outbreaks are common on cruise ships. In fact, this is the 14th norovirus outbreak aboard a cruise ship in 2025 so far.
That’s because the virus is highly contagious. It can survive on surfaces for weeks, and it’s harder to kill than other pathogens. (Norovirus is part of the 0.01% of germs that hand sanitizer can’t kill.)
In the close quarters of a cruise ship, the virus can spread quickly. Outbreaks are also easier to report and track on boats than on land.
People catch norovirus by swallowing the virus, usually from eating contaminated food or coming in contact with the pathogen, then touching their mouth.
The CDC has several tips for preventing norovirus on a cruise:
- Wash your hands often, and do not rely on hand sanitizer.
- Drink lots of water and get plenty of sleep.
- Leave the area if you see someone experiencing diarrhea or vomiting.
- If you’re feeling sick, tell the ship’s medical center right away.
