In 2024, gastrointestinal illness outbreaks on cruise ships surged to their highest level in over a decade, according to the latest report from the US Centers for Disease Control and Prevention (CDC).
The CDC’s ‘Outbreak on Cruise Ships in VSP’s Jurisdiction’ report recorded 18 outbreaks of gastrointestinal illness on cruise ships within the jurisdiction of its Vessel Sanitation Program (VSP) at US and foreign ports.
For comparison, pre-COVID-19 outbreak numbers rarely exceeded 15 cases annually with outbreaks stabilising at around 11 cases per year between 2016 and 2018.
The majority of the outbreaks in 2024 were attributed to norovirus. December saw several outbreaks, including two separate incidents on Cunard Line’s Queen Mary 2, as well as reports of norovirus on Holland America Line’s Rotterdam; Princess Cruises’ Ruby Princess, and Holland America’s Zuiderdam.
Norovirus was not the only onboard illness recorded in 2024. In September, Royal Caribbean’s Radiance of the Seas experienced a salmonella outbreak and in March, Silversea Cruise’s Silver Nova had an E.coli outbreak. There were also cases where the cause could not be identified.
The report highlights outbreaks on cruise ships with 100 or more passengers, for itineraries lasting between three and 21 days. For an incident to qualify as an outbreak, at least 3% of passengers or crew must be affected.
Furthermore, in April and June 2024, the CDC confirmed two Legionnaires outbreaks occurred on unnamed ships.