Millions of people board cruise ships each year seeking relaxation, but some vessels are hiding filthy secrets below deck.
The Centers for Disease Control and Prevention (CDC) has listed at least 17 cruise ships that reported disease outbreaks between January and May 2025.
Cruise lines, including Holland America, Princess Cruises, Viking and Cunard, have seen multiple vessels impacted by epidemics in recent months, prompting renewed scrutiny for onboard sanitation and food safety protocols.
Norovirus, often referred to as the ‘cruise ship virus’ due to its rapid spread in close quarters, was the most common culprit, cited in 13 of the incidents where 1,568 guests and crew members fell ill.
The virus is highly contagious and causes vomiting, diarrhea and stomach cramps.
Silver Ray, operated by Silversea Cruises, reported an outbreak caused by E. coli, and Sea Cloud Spirit was presumed to have had a ciguatera outbreak, an illness linked to eating reef fish contaminated with toxins.
Four other cruise ships, Seven Seas Explorer, Zuiderdam, National Geographic Sea Lion, and Silver Ray, were investigated for gastrointestinal illness outbreaks, but the specific causative agent remains unknown in those cases.
The CDC defines a cruise ship outbreak as when at least three percent of passengers or crew report symptoms of gastrointestinal illness during a voyage.
Holland America Line reported six outbreaks this year, five of which were linked to Norovirus. One was classified as ‘unknown’
These outbreaks are monitored through the agency’s Vessel Sanitation Program (VSP), which tracks and investigates health issues on ships sailing into US ports.
The program inspects ships for water and food safety, hygiene practices, waste management, and pest control.
Despite the recent outbreaks, all affected vessels received satisfactory scores, 85 or higher, on a 100-point scale.
Holland America Line reported six outbreaks this year, five of which were linked to Norovirus. One was classified as ‘unknown.’
Norovirus is highly contagious and spreads easily in the close quarters of a cruise ship, often via contaminated surfaces, direct contact, or food prepared by infected crew. The virus can survive for days on surfaces, making it difficult to contain once onboard.
Between January 4 and May 3, 658 of 10,748 guests and 73 of 4,172 crew members across multiple voyages were infected.
The affected ships included two separate Eurodam excursions, Volendam and two separate Rotterdam sailings.
The case deemed ‘unknown’ was reported on Holland America Lines Zuiderdam in April, which saw 56 of 1,149 guests and 14 of 751 crew members fall ill.
The CDC shows that the predominant symptom was diarrhea.
The Queen Mary 2 (pictured) departed from Southampton on March 8 for a 29-night voyage visiting ports in the eastern Caribbean and New York City. It will return to England on Sunday
Viking Expedition Operations’ Viking Polaris, Seabourn Cruise Line’s Seabourn Encore, Cunard Line’s Queen Mary 2 and Princess Cruises’ Coral Princess also experienced Norovirus outbreaks this year.
As did the Royal Caribbean International’s Radiance of the Seas and Viking Ocean Cruises II’s Viking Mars.
However, the outbreak on Queen Mary 2 hit at least 224 passengers and 17 crew members.
The Queen Mary 2 departed from Southampton on March 8 for a 29-night voyage visiting ports in the eastern Caribbean and New York City, and 10 days into the journey, a norovirus outbreak was reported to the VSP.
Nearly nine per cent of the 2,538 passengers onboard the ship have fallen ill, as well as 1.4 per cent of the vessel’s 1,232-person crew.
Norovirus, often referred to as the ‘cruise ship virus’ due to its rapid spread in close quarters, was the most common culprit, cited in 13 of the incidents where 1,568 guests and crew members fell ill
The CDC said that affected travellers are predominantly displaying symptoms of diarrhoea and vomiting, which are common to norovirus infection.
In response to the norovirus outbreak, the Queen Mary 2 crew has increased cleaning and disinfection procedures on the ship by the vessel’s outbreak prevention and response plan.
Silversea Cruises’ Silver Ray was hit with a spate of E. coli on January 10, which infected 51 of 681 guests and five of 532 crew members.
The ship quickly implemented enhanced sanitation measures, as well as isolating both passengers and crew members who reported the illness.
Several cruise ships have yet to determine what caused their guests and crew to become sick.
The National Geographic Sea Lion, owned by Lindblad Expeditions, reported an outbreak on April 21 after nearly 12 percent of its 43 guests and five percent of its 37 crew members were hit with vomiting, fever and diarrhea.
Regent Seven Seas’ Seven Seas Explorer also suffered an ‘unknown’ outbreak in May, leaving 24 guests and crew members sick with diarrhea and vomiting.
In response to the outbreak, Regent Seven Seas and the crew aboard the ship collected stool specimens from gastrointestinal illness cases for testing and isolated those who reported symptoms.
