Cruise Ship Outbreak Season Kicks Off with a Bang

The 2025 cruise ship outbreak season is off to a fast and vomit-soaked start. Two separate outbreaks of gastrointestinal illness have affected over 100 people each, marking the sixth and seventh such outbreaks to occur aboard cruise ships visiting U.S. ports since January.

CDC Reports Outbreak on Holland America’s Rotterdam

The Centers for Disease Control and Prevention (CDC) detailed the outbreaks via its Vessel Sanitation Program. The most recent outbreak, reported on Monday afternoon, has affected at least 104 passengers and 12 crew members aboard Holland America’s Rotterdam during a two-week cruise, which began on February 2 from Fort Lauderdale, Florida, and is expected to land this Friday. The outbreak has been traced back to norovirus, a common cause of gastrointestinal illness on cruise ships.

Why Cruise Ships are a Breeding Ground for Outbreaks

Cruise ships are notorious for foodborne outbreaks due to the close living conditions and shared dining areas. However, 2025 is already shaping up to be an especially bad year for cruise vacations, gastrointestinal-wise. This latest outbreak is the seventh reported to the CDC this year and the second in February, well above the typical pace of recent years.

Comparing 2025 to Previous Years

For context, there were only two outbreaks reported through early February in 2024 and three in 2023, with a total of 18 reported outbreaks in 2024 and 14 outbreaks in 2023. The CDC has also reported another outbreak on Royal Caribbean’s Radiance of the Seas, affecting at least 160 passengers and eight crew members before the ship landed on February 8.

The Norovirus Connection

The Radiance of the Seas outbreak is also under investigation, but a smart bettor would put their money on norovirus being the cause. More than 90% of diarrheal disease outbreaks on ships are caused by norovirus, which can spread easily and quickly through contaminated food and water, close contact with infected people, or even from touching surfaces contaminated with invisible specks of an infected person’s poop or vomit.

Norovirus Beyond Cruise Ships

Norovirus, also known as the "cruise ship virus," is a common problem that affects virtually everywhere. Less than 1% of all norovirus cases in the U.S. are tied to cruise ships, according to the CDC. However, norovirus has been surging in the U.S. since last summer, with a higher number of outbreaks reported than in recent seasons.

Taking Precautions on Cruise Ships

According to the Cruise Lines International Association, the odds of getting sick from norovirus or any gastrointestinal illness aboard a cruise ship are "quite rare." However, given the unusual glut of outbreaks reported so far in 2025, it’s essential to take precautions. The CDC advises passengers to regularly wash their hands, leave any area where people appear to be visibly sick with a gastrointestinal illness, and report potential cases to ship staff if they’re not already aware.