MIAMI, Florida (CNN) -- The Centers for Disease Control and Prevention said Monday that 197 passengers and 15 crew members aboard the cruise ship Oceana have come down with a gastrointestinal illness. A CDC field team boarded the ship Saturday in Barbados to gather more information on the outbreak. "We conducted interviews with passengers and crew members and gathered samples," said CDC spokeswoman Susan McClure. "The investigation continues." There are 1,859 passengers and 868 crew aboard, according to a statement released by the CDC.