Core Points - The Royal Caribbean cruise ship "Serenade of the Seas" experienced an outbreak of norovirus, with nearly 100 individuals infected on board [3][4] - As of October 1, out of 1,874 passengers, 94 reported symptoms such as diarrhea and vomiting, along with 4 crew members infected [3] - The ship had set sail from San Diego on September 19, visiting several countries before reporting the outbreak on September 28, when the number of cases exceeded 2% of the total onboard [3] - The CDC noted that norovirus spreads rapidly, primarily through contaminated food, water, or person-to-person contact, and while most patients recover within one to three days, it is highly contagious [3] - The cruise line has implemented immediate preventive measures, including isolating affected individuals and enhancing cleaning protocols [3] - This incident is part of a broader trend, with the CDC recording 19 similar gastrointestinal illness outbreaks in the U.S. cruise industry in 2024, 14 of which were caused by norovirus [4]