Norovirus outbreaks aboard two cruise ships operating in Southeast Alaska, including stops in Wrangell, infected at least 145 people on board the ships, according to separate reports last week by the federal Centers for Disease Control and Prevention.

A norovirus outbreak infected 125 of 4,176 people aboard the Ruby Princess during a round-trip voyage between San Francisco and Alaska from June 12 to July 2 that included a stop in Wrangell on June 16, according to officials.

The outbreak was reported to the CDC on June 28. 

The agency’s report released July 1 may not include additional people infected before the end of the journey on July 2.

The other outbreak affected 20 of 95 people aboard Lindblad Expeditions’ National Geographic Sea Bird, which called on Wrangell on June 28 and reached Ketchikan on June 30.

It is the second outbreak aboard that ship this season, after 12 people were infected during a voyage May 26-31.

Wrangell is on the Sea Bird’s schedule for five more visits in July and August; the Ruby Princess is not due back until September.

The Ruby Princess reported a smaller outbreak of an illness causing “acute gastroenteritis” among crew and passengers, according to an email sent to Haines borough employees in advance of the ship’s scheduled arrival in that port city on Monday, July 6.

As of Sunday, six crewmembers and one passenger were isolating aboard the ship. Holland America reports that it is disinfecting areas more frequently because of the outbreak, according to an email from a Holland America representative in Juneau.

Norovirus is a gastrointestinal illness that is the most common virus reported on cruise ships, including 17 of the 23 outbreaks reported in 2025.

The CDC’s reporting threshold for outbreaks is 3% of the people aboard a ship. The Sea Bird is a 152-foot-long ship with room for 62 guests and 30 crew members.

A CDC report released June 30 for the most recent outbreak aboard the Sea Bird stated that 19 of 68 passengers and one of 27 crew members were infected.

The CDC report for the Ruby Princess stated that 102 of 3,032 passengers and 23 of 1,144 crew were infected.

In response to the outbreaks, workers aboard the ships “increased cleaning and disinfection procedures according to their outbreak prevention and response plan,” according to each of the CDC reports.

Also, workers isolated ill passengers and crew, consulted with the CDC about cleaning and reporting procedures, and took other measures.

The Chilkat Valley News in Haines contributed reporting for this story.