A U.S. public health surveillance report looked at how often passengers and crew on cruise ships got sick with stomach illnesses, known as acute gastroenteritis. The report tracked these illnesses over a 14-year period, from 2006 to 2019. The data came from reports filed by cruise ships sailing from the United States.
The main finding was that the overall rate of these stomach illnesses decreased over the years studied. However, the report also found that illness rates were higher on larger ships and on cruises that lasted longer. This pattern was seen for both passengers and crew members.
It is important to understand that this is a surveillance report, not a controlled scientific study. This means it simply observes and reports patterns in data that was already being collected. It cannot prove that larger ship size or longer cruise length directly cause more illness. Many other factors could be involved. Readers should see this as a broad overview of trends, not as proof of specific causes or risks.