Over 400 people has fallen ill to a virus after riding a cruised that sailed through the Caribbean earlier this month, federal health officials said Thursday.

According to Jay Dempsey, spokesman for the Centers for Disease Control and Prevention, they have taken samples from ill passengers and they have confirmed the presence of norovirus, a type of virus that causes gastroenteritis outbreaks. Its symptoms include diarrhea, vomiting and upset stomachs.

The virus is often found responsible for symptoms that get transmitted from person to person in closed quarters such as cruise ships.

The Celebrity Mercury left from South Carolina and is set to return to Charleston on Friday. Cynthia Martinez, spokeswoman for the operator Celebrity Cruise, said that the ship is carrying 2,600 crew members and passengers and 418 of them got sick.

Martinez added that 48 are currently in isolation as the sickness peaked earlier this week.