Hundreds of passengers have been taken sick aboard the Celebrity Mercury cruise ship, amid a gastrointestinal-illness outbreak.

The Carnival owned vessel has been hit twice by outbreaks in the past month, making this the third straight trip from South Carolina to be affected.

Because of the outbreak – blamed by the cruise line on the norovirus - the Celebrity Mercury will now miss Monday’s scheduled call at the British Virgin Islands and return to port in Charleston on Thursday morning.

This is a day earlier than scheduled.

Spokeswoman Cynthia Martinez confirmed some 350 of the 1,829 passengers on the vessel have been taken ill during the latest cruise, which had departed from Charleston on March 8th.

As a result of the latest outbreak Mercury’s next departure has been delayed by two days, and will now depart on March 21st.

The delay has been caused by planned “enhanced cleaning” to Celebrity Mercury.

With boarding now expected on Sunday, the vessel’s itinerary has been adjusted; now including Key West on Tuesday, Cozumel on Wednesday, Costa Maya on Thursday and Nassau on Saturday.

The U.S. Centre for Disease Control and Prevention recorded outbreaks aboard the vessel on February 16th and 25th, with both also blamed on the common norovirus.

Experts explain the virus can spread quickly in closed quarters and is hard to eliminate because people who have been exposed can reinfect places they frequent.

Symptoms include sickness and diarrhoea, but the virus is rarely fatal.