More than a quarter of the passengers on a National Geographic-themed cruise ship were sickened with a gastrointestinal illness, marking the third outbreak on the ship in about two months, according to the Centers for Disease Control and Prevention.
The CDC’s Vessel Sanitation Program said on July 15 that 18 of 62, or 29 percent, of the passengers on Lindblad Expeditions’ National Geographic Sea Bird reported being ill. No crew members reported being ill.
The predominant symptoms of those who reported illness include vomiting and abdominal cramps, according to the CDC, which said the causative agent is unknown.
According to the CruiseMapper website, the ship departed from Juneau, Alaska, on July 15 before it made stops in several locations in Alaska. It’s due to arrive in Ketchikan, Alaska, on Monday.
The cruise vessel has reported three outbreaks among people on board three trips so far in roughly two months, according to the CDC. The first outbreak occurred on a cruise that lasted from May 31 through June 5. The second one occurred on a trip from June 5 through June 10.
The outbreaks in May and June were due to norovirus, a contagious virus that spreads in crowded conditions and causes vomiting, diarrhea, and fever. Norovirus has been the most common source of cruise ship-related outbreaks in recent years.
In all three incidents, the cruise operator told the CDC that it would increase its cleaning and disinfection protocols, isolate ill passengers or crew, and collect samples for testing.
It comes as the CDC said earlier this month that dozens of people on board a cruise ship were sickened by a norovirus outbreak in a separate incident. According to the agency, 102 passengers out of 3,032 total, and 23 crew members out of 1,144 total, on board the Princess Cruises’ Ruby Princess vessel reported being ill.
The ship’s voyage dates were from June 12 to July 2. The predominant symptoms reported by passengers and crew members were diarrhea and vomiting, the CDC said.
So far in 2026, the CDC has listed eight outbreaks of gastrointestinal illnesses on cruises. Norovirus was listed for the cause of five, two were caused by the bacteria E. coli, and one is unknown.
“Norovirus is often a cause of gastrointestinal illness outbreaks on cruise ships, but we don’t always know the cause of the outbreak when we begin an investigation. Finding the agent that caused an outbreak (causative agent) can take time,” the CDC says on its website.
While cruise ships are strongly associated with norovirus outbreaks, the vessels only account for about 1 percent of all norovirus outbreaks in the United States, the CDC says.
Outbreaks occur frequently in colleges, universities, schools, and daycares and other childcare centers, the agency said. That’s because “close quarters, shared spaces, and high-touch surfaces make it easy” for the pathogen to spread, it added.
Norovirus outbreaks on school and university campuses have led to campus closures.
Lindblad Expeditions did not immediately respond to a request for comment.
