Stomach bug cases on cruise ships are increasing due to a “newly dominant strain” of norovirus, says the US Centers for Disease Control and Prevention (CDC), where officials believe the outbreaks at sea might be linked to incidents of norovirus on land.
The gastrointestinal sickness typically causes stomach pain, nausea, diarrhoea and vomiting. Cunard, Holland America, Princess Cruises, Royal Caribbean, Seabourn, and Viking Expedition, have all played host to outbreaks in 2025.
Outbreaks set to double by end of 2025
Across 2024 as a whole, 18 stomach illness outbreaks were recorded by the public health agency. But with less than five months of 2025 gone, 16 cruise ship eruptions have already occurred, of which 75% have been found to be norovirus. E-coli has also been reported.
The CDC said “data show a newly dominant [norovirus] strain is currently associated with reported norovirus outbreaks on land. Ships typically follow the pattern of land-based outbreaks, which are higher this norovirus season.”
Resistant strains
Although the CDC recommends shipboard counter-measures, such as cleaning and disinfection protocols, food and hand hygiene measures, and placing infected people in quarantine, it nonetheless told the news outlet that “possible over-reliance on hand sanitizer on ships” could be behind the surge in instances.
The agency noted that strains of norovirus are increasingly resistant to disinfectant and can “persist on surfaces for days or weeks.” As well as passengers catching norovirus from contaminated water supplies or surfaces, someone can bring a pre-existing case with them on holiday and infect the ship.
These factors, the agency said, make norovirus particularly hard to control, especially given the close quarters in which cruise passengers and crew exist, and the sheer numbers of people sharing common areas and food arrangements.
#Norovirus is a very contagious virus that can cause vomiting and diarrhea. Anyone can get infected and sick with norovirus.
— CDC (@CDCgov) August 24, 2023
Don’t be that person—wash your hands to prevent norovirus.
Learn more about norovirus and ways to prevent it. https://t.co/ygIy3XyVUh pic.twitter.com/9Z189iEzP8
Surge coincides with federal cuts to CDC
In one recent episode on Holland America’s Eurodam, 60 guests suffered symptoms including abdominal cramps, vomiting and diarrhea, according to USA Today. And in March 2025, over 200 people aboard Cunard Line’s flagship Queen Mary 2, or around a tenth of the manifest, fell ill with vomiting and diarrhoea, as previously reported by Travel Tomorrow.
The US CDC is a federal body, responsible for safeguarding public health and safety through the control and prevention of disease, injury, and disability. It conducts research, develops and applies control measures, and provides information and education all designed to promote the health of US citizens. Since the start of President Donald Trump’s second mandate, it has announced staff cuts that have reduced its workforce by 3,500 to 4,000 employees.
