Over 500 people have gotten sick on Royal Caribbean cruises since December

REUTERS/Joe Skipper

Royal Caribbean cruises have had over 500 reported cases of illness since December 2017.

• A Royal Caribbean cruise that departed from Baltimore on January 2 had 47 reported cases of "gastro-intestinal illness."
• The cause of the illness is not known.
• The outbreak follows over 500 reported cases of illness on Royal Caribbean cruises in December.

Passengers on a Royal Caribbean cruise have reported 47 cases of "gastrointestinal illness," according to a company spokesperson. The Grandeur of the Seas cruise ship departed from Baltimore on January 2 with 2,859 passengers and stopped in Charleston, South Carolina; Orlando, Florida; and the Bahamas.

The cruise was set to return to Baltimore on Thursday, but a mechanical issue has forced the ship to postpone its return until Saturday. The Royal Caribbean spokesperson also said that the guests who reported illnesses were treated by the ship's doctors.

Royal Caribbean does not know what caused the outbreak of illness.

"We're taking steps like intensive sanitary procedures to minimize the risk of any further issues," the spokesperson told Business Insider in a statement. "The ship will undergo special cleaning procedures before it departs Saturday for her next cruise."

Two Royal Caribbean cruises in December left more than 500 combined passengers sick, according to USA Today. A cruise from Singapore to Australia that ended on December 7 had over 200 reported cases of illness, and 332 cases of illness were reported on a cruise from Florida that returned on December 16.