A dozen people—nine passengers and three crew members—fell ill during a gastrointestinal-illness outbreak on the National Geographic Sea Bird. The CDC says symptoms included diarrhea and vomiting, the cause is unknown, and the ship has stepped up cleaning and
On the National Geographic Sea Bird, the first signs of trouble were all too familiar: diarrhea and vomiting spreading through close quarters on a voyage that began late May.
The CDC has documented an outbreak of gastrointestinal illness during a National Geographic-Lindblad Expeditions sailing. Among the 66 passengers aboard the ship, nine reported being ill. Three crew members also reported symptoms.
The health agency said the cause of the outbreak is unknown. The CDC listed the voyage dates as May 26 through May 31, and the ship is currently operating in Alaska, according to CruiseMapper.
For now, the reported pattern is concentrated and direct—vomiting and diarrhea—without a confirmed culprit. In response, the crew implemented heightened disinfection and cleaning measures and isolated sick guests and employees, steps the CDC described as part of the ship’s containment effort.
National Geographic-Lindblad Expeditions did not immediately respond to a request for comment.
The outbreak arrives as the CDC tracks more cruise-ship GI events that meet its threshold for public notification. This year, the CDC has logged five outbreaks of gastrointestinal illness on cruise ships that met that threshold—two caused by E. coli and two caused by norovirus.
In 2025, there were 23 outbreaks publicly notified, including 18 caused by norovirus. The year before, 15 of 18 total publicly notified outbreaks were linked to norovirus. Norovirus is often associated with cruise ships, but the CDC notes that those cases account for only 1% of outbreaks reported.
The broader issue is how quickly illness can be noticed—or missed. Sarah R. Michaels. an assistant professor at Tulane University’s Celia Scott Weatherhead School of Public Health and Tropical Medicine. previously said outbreaks often take place within communities and that “we don’t know that they’re happening.” She added that close-contact settings. including day care facilities. nursing homes. and cruise ships. make it more likely that illness is diagnosed. reported. and brought to attention.
On this voyage. at least. the response was immediate: the crew increased disinfection. tightened cleaning. and isolated sick passengers and employees. Still. with the cause remaining unknown. travelers will likely be left with the same lingering question that follows every outbreak like this one—what. exactly. made people sick in such concentrated conditions?.
CDC norovirus cruise ship National Geographic Sea Bird gastrointestinal illness Alaska outbreaks