Norovirus Outbreaks on Cruise Ships Surge as Dominant Strain Spreads
A newly dominant strain of norovirus is fuelling outbreaks of the stomach bug on cruise ships, according to the US Centers for Disease Control and Prevention (CDC). The surge in cases has been linked to an increase in outbreaks on land, with the CDC warning that the highly contagious nature of the virus makes it a challenge to control on cruise ships.
The CDC has reported 16 gastrointestinal illness outbreaks on cruise ships this year, with 12 confirmed as norovirus. This is a significant increase from 2024, when a total of 18 outbreaks were reported, the most in over a decade. According to Yahoo News, which cited USA Today, the rise in norovirus outbreaks on land is believed to be influencing cases recorded at sea.
The dominant strain of norovirus is highly contagious, causing common symptoms including diarrhoea, vomiting, nausea, and stomach pain. The CDC has warned that the virus can be especially challenging to control on cruise ships due to the close living quarters, shared dining areas, and rapid turnover of passengers. When a ship docks, norovirus can be brought on board in contaminated food or water, or by passengers who were infected while ashore.
Measures are being taken to prevent the spread of the virus, including increasing cleaning and disinfection procedures, isolating ill passengers and crew, and encouraging good hand hygiene in passengers. The CDC’s Vessel Sanitation Program (VSP) is working with cruise ship operators to implement these measures, but the agency has also identified a possible overreliance on hand sanitizer on ships, which is not as effective against norovirus as washing hands with soap and water.
Several major cruise ship operators, including Holland America, Viking Expedition, Seabourn, Cunard, Princess Cruises, and Royal Caribbean, have experienced outbreaks of gastrointestinal illness on ships this year. According to the CDC, each year, there are about 2,500 reported norovirus outbreaks in the US, with cruise ships accounting for just a small number of these.
As the 2025 cruise season continues, norovirus cases causing sickness to passengers and crew members are likely to exceed last year’s figures. The CDC has advised passengers and crew to take precautions to prevent the spread of the virus, including washing hands regularly with soap and water, and avoiding close contact with anyone who is sick. As Yahoo News reported, the CDC has said that "norovirus can persist on surfaces for days or weeks and is resistant to many common disinfectants," making it a persistent threat to public health.
In response to the surge in norovirus outbreaks, the CDC has increased its monitoring of cruise ships and is working closely with ship operators to implement measures to prevent the spread of the virus. Passengers and crew can take steps to protect themselves by following good hygiene practices and staying informed about the risks of norovirus.
The CDC has confirmed that it is taking the outbreak seriously and is working to prevent further cases. As the situation continues to develop, Yahoo News will provide updates on the outbreak and the measures being taken to control it.
According to the CDC, "Repeated outbreaks on consecutive cruises may also result from infected crew or environmental contamination. This is because norovirus can persist on surfaces for days or weeks and is resistant to many common disinfectants."
The agency has encouraged anyone who is experiencing symptoms of norovirus to seek medical attention and to stay away from others to prevent the spread of the virus.
