Thirty-one passengers onboard Viking Ocean Cruises, Viking Sea January 18–28, 2019 voyage, according to federal health officials.

31 of 925 passengers (3.35%) presented with diarrhea and vomiting, To date, no etiology has been identified.
Officials will board the ship in San Juan, Puerto Rico, on January 28 to conduct an epidemiologic investigation and environmental health assessment and evaluate the outbreak and response activities.
Viking Ocean Cruises and the crew aboard the ship reported the following actions:
- Increased cleaning and disinfection procedures according to their outbreak prevention and response plan.
- Collected stool specimens from passengers and sent them for testing.
- Sent multiple daily reports of gastrointestinal illness cases to the Vessel Sanitation Program (VSP).
- Consulting with VSP on plans for their comprehensive sanitation cleaning procedures in San Juan, Puerto Rico, on January 28, 2019.
Norovirus confirmed as cause of Oasis of the Seas outbreak