Royal Caribbean 'cruise to nowhere' ends after passenger tests positive for COVID-19 but later confirmed negative

An elderly passenger on board a Royal Caribbean “cruise to nowhere” that departed from Singapore tested positive and later negative for COVID-19. As a result, the voyage was cut short and the vessel returned to port on Wednesday, one day early.

"In the last 24 hours, one guest aboard Quantum of the Seas tested positive for coronavirus after checking in with our medical team," Lyan Sierra-Caro, spokesperson for Royal Caribbean, told USA TODAY Wednesday.

After the initial positive test, the passenger was taken to a medical facility upon arrival in Singapore Wednesday for further testing and care, Sierra-Caro said.

There, additional tests indicated that the first could have been a false positive.

"His original sample has since been re-tested at the National Public Health Laboratory (NPHL), and has come back negative for COVID-19 infection," Singapore's Ministry of Health said in a statement. "A second fresh sample tested by NPHL has also come back negative. NPHL will conduct another test tomorrow to confirm his COVID-19 status."

On Thursday, a "final confirmatory test" showed that the passenger did not have COVID-19.

After the initial positive test, every passenger and crew member who had been in close contact was traced "immediately," isolated and tested, Sierra-Caro said.

"We have rescinded the Quarantine Orders of (the passenger's) close contacts, who had earlier been placed on quarantine as a precautionary measure while investigations were ongoing," the Ministry of Health said Thursday. "MOH will support the laboratory on board the Quantum of the Seas in its review of its testing processes."

Ultimately, all passengers and crew members were tested and their results came back negative. Those in contact with the passenger were given PCR tests while those who were not were given rapid antigen tests.

"The ship returned to port today in accordance with government protocols," Sierra-Caro said.

The 83-year-old passenger on the Quantum of the Seas tested positive for the coronavirus after reporting to the ship’s medical center with diarrhea, Annie Chang, director of cruise at Singapore’s Tourism Board, told The Associated Press. The passenger had tested negative before boarding, Chang said.

The ship had 1,680 passengers on board, and they began leaving the ship at 7:30 p.m. local time Wednesday.

"We have been working closely with the Singapore government to ensure that all guests currently on board Quantum of the Seas can disembark safely and smoothly," Sierra-Caro said. "As part of existing protocols, guests will undergo an antigen test at the terminal before departing. In addition, our entire crew will undergo PCR tests today."

After disembarkation is complete, the ship will undergo a deep cleaning and disinfection, and all the passengers who had to leave the ship early will be compensated for the day missed at sea.

Additionally, Royal Caribbean has canceled the next four-night cruise on the ship, which had been scheduled to depart Thursday. "The health and safety of our guests and crew are of utmost importance to us," Sierra-Caro said.

Singapore recently began a “safe cruising” pilot program allowing cruise ships to make round trips to Singapore with no port of call in between. Strict safety measures were imposed, including reducing capacity by half and testing passengers before boarding. Royal Caribbean is one of two operators licensed to run such trips.

More: Royal Caribbean, Norwegian, Carnival Corp. cancel cruises through the end of the year

Royal Caribbean has worked with the government of Singapore to "create a thorough set of protocols designed to mitigate risk," Sierra-Caro said.

PCR tests analyzed at labs have greater sensitivity and detect the virus' genetic material at even low levels. Positive lab tests might occur in the beginning or tail end of an infection, when someone is less likely to spread the coronavirus to others.

"The system is working as it is designed to," Sierra-Caro said.

Singapore, a small but wealthy city-state in Southeast Asia, has reported 58,285 coronavirus cases since the pandemic began. Twenty-nine people have died.

More: Royal Caribbean will restart with short cruises to private island, may seek volunteers for test runs

Contributing: Ken Alltucker, USA TODAY; The Associated Press

This article originally appeared on USA TODAY: Royal Caribbean Singapore cruise ends; cruiser COVID-19 test negative