A Norovirus outbreak affected more than 70 people aboard the Royal Caribbean ship Serenade of the Seas during a 13-night voyage from San Diego to Miami. The U.S. Centers for Disease Control and Prevention (CDC) reported that 71 passengers and one crew member, about 3.9 % of those onboard developed gastrointestinal symptoms.
The cruise departed San Diego on September 19, 2025, and the illness was first reported Sunday, September 28. The vessel is scheduled to dock in Miami on October 2.
Once the outbreak emerged, the ship’s medical team isolated the sick individuals and collected stool samples for laboratory testing. Royal Caribbean increased cleaning and disinfection procedures. The ship also consulted the CDC’s Vessel Sanitation Program (VSP), which is reviewing sanitation practices and monitoring the outbreak response remotely.
Norovirus is a leading cause of acute viral gastroenteritis. It spreads rapidly in enclosed environments, such as cruise ships through contaminated food, water, surfaces, or person-to-person contact. 1
Typical symptoms include:
Diarrhea
Vomiting
Abdominal cramps
Nausea
Occasionally, low-grade fever, headache, or muscle aches
Symptoms usually appear 12 to 48 hours after exposure and generally last 1 to 3 days. In healthy individuals, the disease is self-limiting, but in vulnerable populations (young children, older adults, immunocompromised), it can cause dehydration and require medical support. 1
Because norovirus can persist on surfaces and resist many cleaning agents, thorough disinfection with agents effective against nonenveloped viruses is essential. Hand hygiene using soap and water is more reliable than alcohol-based sanitizers for norovirus elimination. 1
In 2025, the CDC has recorded 19 gastrointestinal illness outbreaks on cruise ships, of which 14 were attributed to norovirus.
A notable prior case involved the Navigator of the Seas in July 2025, where 134 passengers (3.4 %) and 7 crew members (0.6 %) reported similar symptoms. The ship increased disinfection, isolated affected individuals, and engaged the VSP in oversight. 2
Cruise ships are high-risk settings for gastrointestinal outbreaks due to close quarters, shared facilities, and the volume of food service operations. Prompt reporting by passengers and crew is critical. The CDC emphasizes that when individuals notify onboard medical centers of symptoms, it enables earlier outbreak detection and containment.
Isolating ill individuals, sanitizing communal areas, and consulting with health authorities are standard protocols in outbreak management. Compliance by passengers, such as staying in cabins while symptomatic and following hygiene guidance is also key.
References:
1. Centers for Disease Control and Prevention. “About Norovirus.” CDC. Last reviewed April 24, 2024. https://www.cdc.gov/norovirus/about/index.html
2. Centers for Disease Control and Prevention. “Norovirus Outbreaks: Basics.” CDC, July 24, 2025. https://www.cdc.gov/norovirus/outbreak-basics/index.html.
(Rh/Eth/TL/MSM)