The CDC says the uptick in the number of cruise ship gastrointestinal outbreaks in the past few months could point to a new strain of norovirus.
Outbreaks on land have seen a ‘newly dominant strain’ recently which could be replicated at sea.
“While the number of recent cruise ship outbreaks has been higher than in years prior to the pandemic, we do not yet know if this represents a new trend,” the health agency said.
“However, CDC data show a newly dominant 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.”
The rate of ship illness outbreaks has accelerated in the past few months since late 2024.
Before the pandemic gastrointestinal outbreaks were declining.
Throughout last year, there were 18 outbreaks, while a dozen specifically norovirus outbreaks have been recorded on ships so far this year.
There are various other factors which could be the reason for more frequent outbreaks.
“Among passengers, acute gastroenteritis incidence rates increased with increasing ship size and voyage length,” a report stated.
“For crew members, rates were significantly higher on extra-large ships.”
