Cruise lines are reporting that the frequency of norovirus outbreaks has reached its highest point in a decade.
In the first half of 2023, 13 outbreaks were confirmed by the Centers for Disease Control and Prevention, the Miami Herald reports.
That's the most since 2012 when there were 16 confirmed outbreaks.
That marks the highest number since ships started sailing again in 2021 after COVID-19 restrictions kneecapped the cruise industry.
The outbreaks affected Royal Caribbean and Carnival lines, on Celebrity, Royal Caribbean International, Holland America, Princess and P&O ships.
The most recent outbreak occurred during a June 6-20 voyage of a Viking Cruises voyage from Iceland that docked in New York City. The CDC said out of nearly 840 passengers, 110 reported feeling ill.
The CDC says the highly-infectious virus is the leading cause of vomiting and diarrhea, and foodborne illness in the country.