Last year, there were 16 outbreaks on cruise ships, from norovirus, salmonella, E. coli or other unidentified pathogens that cause gastrointestinal symptoms such as diarrhea or vomiting. That's the largest number of cruise ship outbreaks in 12 years.

In all cases combined, 781 passengers and 109 crew members had fallen ill as of Monday December 30, with symptoms including diarrhoea and vomiting. Norovirus — a highly contagious virus that causes stomach illness — is to blame in three of those outbreaks; the cause of the two most recent is still unknown, the CDC says.

2024 was the worst year for gastrointestinal illness outbreaks on cruise ships in over a decade, according to newly released data from the Centers for Disease Control and Prevention.