More than 400 passengers and crew were stricken aboard the Queen Mary 2, which sailed from New York Dec. 22, and the Emerald Princess, which returned to Florida Dec. 27 with more than 200 folks feeling ill.
The U.S. Centers for Disease Control said it was conducting lab tests this weekend to confirm the pathogen was the nasty norovirus.
Word from the QM2 was passengers being told to avoid buffets while a short-handed crew did its best to keep up with their duties, Britain's Sky News said.
"I have never felt as sorry for the staff as I do now. They are working round the clock battling this situation," one passenger wrote on the blog Cruise Critic.