A norovirus outbreak was reported aboard a Holland America Line cruise ship during a recent Caribbean voyage, affecting nearly 90 passengers and crew members, according to the CDC.

The outbreak happened on the Rotterdam, which was sailing a 13-day Panama Canal and Caribbean cruise departing from Fort Lauderdale, Florida, on December 28 and returning on January 9. The illness affected 81 of the ship’s 2,593 passengers or just over 3 percent, and 8 of its 1,005 crew members.

Holland America Line reported the outbreak to the CDC’s Vessel Sanitation Program on January 8, one day before the voyage concluded. Passengers and crew who became ill primarily experienced gastrointestinal symptoms, including vomiting and diarrhea.

In response, Holland America Line implemented a series of outbreak prevention and control measures. These included enhanced cleaning and disinfection procedures in line with the ship’s outbreak response plan, isolation of symptomatic passengers and crew, and the collection of stool samples from affected individuals for laboratory testing. Results confirmed the presence of norovirus.

Shipboard medical staff also worked closely with the CDC’s Vessel Sanitation Program to review and apply additional sanitation and reporting procedures aimed at limiting further transmission.

Norovirus is a common cause of acute gastroenteritis on cruise ships. The CDC defines gastrointestinal illness as three or more loose stools within a 24-hour period, vomiting, or vomiting accompanied by symptoms such as diarrhea, abdominal cramps, fever, headaches, or muscle aches.