The Centers for Disease Control and Prevention on Monday reported an gastrointestinal outbreak on a cruise ship operated by a luxury cruise company.
In a notice on the agency’s website, the CDC said 21 passengers out of 631 and six crew members out of 458 reported being ill on the Regent Seven Seas cruise ship, the Seven Seas Mariner.
The causative agent that triggered the outbreak was not known, the CDC said, while the prevalent symptom was listed only as diarrhea.
The Seven Seas Mariner departed from Miami on Jan. 10 and made stops in Mexico and Central America before stopping in Hawaii in February. The ship will continue to make stops across a number of Pacific island nations before visiting Australia, Indonesia, Thailand, and other countries in Asia, after which it wll turn toward Africa and Europe, according to CruiseMapper. It’s scheduled to return to Miami on June 13, the site shows.
Regent Seven Seas responded to the outbreak by increasing cleaning and disinfection procedures, collecting stool samples for testing, and isolating sick crew and passengers. It also contacted the agency about its cleaning and sanitation processes, and reported cases to the CDC, the health agency said.
“Cases reported are totals for the entire voyage. It does not mean all people are sick at the same time, such as when they arrive or leave a port or ship,” the agency said.
While the causative agent hasn’t been determined, norovirus is considered the most common cause of outbreaks on cruise ships, according to the CDC.
The stomach virus “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,” the CDC says, noting that finding the cause of the outbreak “can take time.”
“When an outbreak occurs, people whose symptoms met the case definition are asked to provide stool or vomitus samples,” it added. “These samples are tested to determine the causative agent.”
Late last year, the CDC confirmed an outbreak of norovirus on the Holland America Line’s Rotterdam, sickening 81 passengers and eight crew members. The main symptoms reported during the Holland America Line outbreak to the CDC were diarrhea and vomiting, the agency said.
Under the CDC’s guidelines, cruise operators are mandated to report outbreaks to the agency.
According to a cruise ship outbreak list maintained by the agency, the Regent Seven Seas outbreak was the first of 2026 reported by the agency. For all of 2025, there were roughly two dozen outbreaks on cruise ships, with the majority being caused by norovirus.
Norovirus is the leading cause of food-borne illness in the United States, responsible for 58 percent of such infections acquired in the country each year, according to the CDC.
On average, there are around 900 deaths, mainly in adults aged 65 and older, 109,000 hospitalizations, 465,000 emergency room visits, and 19 million to 21 million illnesses caused by norovirus in the United States each year, the federal health agency states on its website.
Alongside vomiting and diarrhea, other frequently reported symptoms and signs of the virus include nausea, stomach pain, aches, headache, and fever. Young children, older people, and those with weakened immune systems are most at risk, with dehydration from vomiting and diarrhea the top concern.
The Epoch Times contacted Regent Seven Seas, which describes itself as an “all-inclusive ultra-luxury” line operator on its website, for comment on Wednesday and did not hear back by publication time.