Royal Caribbean said Thursday that 277 passengers and crew members were sick, but their numbers surged Friday.
Due to illness, the ship will return to Port Canaveral, Florida on Saturday, a day earlier than planned.
"All ship's guests will receive a full refund of the price of their cruise," said Owen Torres, spokesman for Royal Caribbean. "We think the good thing is to get everyone home rather than let the guests worry about their health."
"We left the port around 4 pm yesterday and started getting sick last night around 10 am We were confined to our rooms."
He shared a letter that he received in his cabin from the cruise company:
"During this navigation, there was a small percentage of guests on board who suffered from a gastrointestinal illness, considered a norovirus."
Officials from Royal Caribbean said they waited for lab results to determine whether it was a norovirus, the most common cause of acute gastroenteritis in the United States.
Haddap stated that when they arrived in Jamaica the next day, no one was allowed to leave the ship.
The Oasis of the Seas is one of the newest ships of the Caribbean Royal Fleet and can accommodate over 8,000 people. about 3% of the people aboard the ship became ill.
"From our balcony, we can see the climbing wall," she said, "and after each user, they actually clean each button from the climbing wall."
Royal Caribbean plans to completely disinfect the ship in time for the next navigation.
"Our customers are sailing with us for a great vacation, and we are sorry this cruise did not succeed," said Torres.
Tina Burnside of CNN contributed to this report.