Royal Caribbean International’s beleaguered Explorer of the Seas returned to its Bayonne, N.J., homeport Wednesday afternoon after a 10-day Caribbean cruise cut two days short by an outbreak of gastrointestinal illness.

The Centers for Disease Control and Prevention (CDC) said 630 passengers out of 3,071 — 20.5 percent — fell ill during the cruise, which departed Bayonne’s Cape Liberty on Jan. 21. Fifty-four crew members (4.6 percent) also reported symptoms that included vomiting and diarrhea. The CDC has not pinpointed the cause of the symptoms, but Royal Caribbean has indicated they are consistent with norovirus.

When the ship arrived back in port, it also was carrying a CDC Vessel Sanitation Program (VSP) epidemiologist, one contract epidemiologist, and one VSP environmental health officer, who all boarded the ship in St. Thomas. The team was conducting an environmental health assessment and evaluating the onboard response to the outbreak.

The team will continue the investigation through the boarding of new passengers for the next voyage, scheduled to depart on Jan. 31. One more VSP environmental health officer was to board the ship upon its arrival in New Jersey to assist with the evaluation of the disinfection process, the CDC said.

Meanwhile, Bayonne Mayor Mark Smith consulted with Dr. Arthur Diskin, vice president and global chief medical officer at Royal Caribbean Cruises Ltd., who “has assured him that the cruise line and CDC have the situation under control,” according to a statement from the city of Bayonne. “Dr. Diskin reports that the number of active cases has declined significantly since the original outbreak and that the company has made arrangements for passengers with active cases to be assisted with transportation and medical care upon arrival.”

The city also said representatives of the New Jersey State Department of Health and Senior Services were expected on site when the ship arrived. “We have been assured by Royal Caribbean and the Port Authority that the situation is under control,” said Smith said. “We intend to have our own state and medical local professionals confirm that our community is safe as the ship arrives.”

Royal Caribbean said the next cruise is scheduled to depart as planned Jan. 31 on a nine-night cruise to San Juan, St. Thomas, Labadee and Samana, Dominican Republic. Until then, the ship will undergo “a thorough barrier sanitization program … to make certain that any remaining traces of the illness are eliminated.

"It will be the third aggressive sanitizing procedure the ship has undertaken since we became aware of the issue, and will additionally provide a window of more than 24 hours where there are no persons aboard the ship, which is a significant help. Guests scheduled for the next cruise on Explorer of the Seas can be confident that all possible measures will have been taken to prevent further problems.”

Passengers on the shortened cruise will get a 50 percent refund and a 50 percent credit on a future cruise. Sick passengers who were confined to staterooms will get an additional credit of one future cruise day for each day of confinement. The line said it also will reimburse airline change fees and accommodations for guests whose travel home was complicated by the shortened cruise.

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