About one-third of customers canceled their cruise on the Celebrity Mercury sailing that arrived Sunday in Charleston, S.C., after three cruises in February and March were afflicted with norovirus outbreaks.
The sailing had 1,066 passengers, about 600 less than the usual number.
The Mercury arrived in Charleston with an almost-perfect bill of health, with only six passengers contracting gastrointestinal illness.
Celebrity gave passengers on that sailing the option to cancel and receive a full refund plus a future cruise certificate, due to the cruise being shortened and modified in order to conduct extensive cleaning after three sailings were hit with major outbreaks of norovirus.
Before the last cruise, the Centers for Disease Control and Prevention issued a "no-sail recommendation" for the ship.
The Mercury embarked on its current sailing Monday after Celebrity conducted enhanced sanitizing onboard the ship and within the Charleston cruise terminal, resulting in a two-hour delay in departure, said Celebrity spokeswoman Cynthia Martinez.
Martinez said the additional sanitizing was not required by the CDC, but was done "in an abundance of caution."
Celebrity will determine on a per-sailing basis whether to continue the enhanced sanitizing.