Cruise ship outbreaks hit 23 in 2025, norovirus the most common

Key Points:

• Cruise ship gastrointestinal illness outbreaks have been increasing, with 23 outbreaks recorded under the CDC's Vessel Sanitation Program in 2025 and three outbreaks reported so far in 2026, including E. coli and norovirus incidents.
• A cruise ship outbreak is defined as when 3% or more of passengers or crew report symptoms of gastrointestinal illness during a voyage, highlighting the vulnerability of these semi-enclosed environments to virus spread.
• Norovirus is the most common viral outbreak on cruise ships, reported 214 times from 2006 to 2026; it spreads through contaminated food, water, or surfaces and typically resolves within a few days without being life-threatening.
• A CDC study found that larger ships and longer voyages (over seven days for passengers and five days for crew) are associated with higher rates of acute gastroenteritis outbreaks.
• Separate from U.S.-jurisdiction outbreaks, three passengers died from a hantavirus outbreak on the British cruise ship MV Hondius in the Atlantic, underscoring the potential severity of some cruise ship illnesses.