Gastrointestinal illness outbreak on Seven Seas Mariner voyage from Miami sickened 27 people, CDC reports

What happened on the Miami-to-Honolulu sailing

A gastrointestinal illness outbreak was recorded aboard the luxury cruise ship Seven Seas Mariner during a 21-night voyage that sailed from Miami to Honolulu between January 11, 2026, and February 1, 2026. The outbreak was reported to U.S. public health officials on January 29, near the end of the itinerary.

Final case counts documented for the voyage show 27 people met the illness criteria: 21 passengers out of 631 onboard (3.3%) and six crew members out of 458 (1.3%). The predominant symptom reported was diarrhea. The causative agent was listed as unknown at the time the outbreak summary was posted, with specimens collected for testing and confirmatory results pending.

How outbreaks are tracked and when they become public

U.S. cruise ships calling on American ports are subject to the Centers for Disease Control and Prevention’s Vessel Sanitation Program (VSP), which monitors acute gastroenteritis. Cruise operators are required to report cases that meet the program’s case definition, and the VSP posts public notifications when illness levels reach the threshold established for public reporting.

The case definition used for surveillance focuses on symptom patterns consistent with acute gastroenteritis, including multiple loose stools within a 24-hour period beyond a person’s normal baseline, or vomiting paired with additional symptoms. The reported totals reflect illnesses over the entire voyage and do not necessarily indicate that all affected people were sick at the same time.

Response measures implemented onboard

Control steps reported for the Seven Seas Mariner included enhanced cleaning and disinfection procedures under the ship’s outbreak prevention and response plan, isolation of ill passengers and crew, and collection of stool specimens from cases for laboratory testing. Ship personnel also consulted with the VSP regarding sanitation procedures and illness reporting requirements.

Public health monitoring in this incident was conducted remotely, focusing on review of the ship’s outbreak response and sanitation procedures.

Context: gastrointestinal illness on cruise ships

Gastrointestinal illness outbreaks at sea can occur for a range of reasons, including viral and bacterial causes, contaminated food or water, or person-to-person transmission in congregate settings. Norovirus is a frequent cause of cruise-associated outbreaks, but investigations do not always identify a causative agent immediately, and laboratory confirmation can take time.

What travelers can do

• Report symptoms promptly to onboard medical staff to support case detection and control measures.
• Follow isolation instructions if ill to reduce the risk of spreading infection to other passengers and crew.
• Maintain strict hand hygiene, especially before eating and after using the restroom.

The outbreak summary does not provide patient-level details on recovery outcomes, and the publicly posted figures represent the final illness totals for the completed voyage.