Singapore's Ministry of Health said that two subsequent tests performed on the passenger on Royal Caribbean International's Quantum of the Seas who initially tested positive for Covid-19 were both negative for the virus.
The ministry said the passenger, an 83 year-old male Singaporean, had reported to the ship's medical center with diarrhea and, as part of the protocols, was tested for Covid-19 using a PCR test on the ship.
But the agency said that his original sample was retested and came back negative for Covid-19 and that a second, fresh sample also came back negative. Another test will be conducted tomorrow.
The Quantum of the Seas had begun a series of short cruises-to-nowhere earlier this month as the first Royal Caribbean International ship to sail since the global cruise shutdown in March; the case occurred on its third sailing. In accordance with Singaporean protocols, it had returned to Singapore after the initial positive test and had identified and isolated guests and crew who had close contact with that person. Each of those individuals subsequently tested negative for the virus.
The line said it was working closely with the Singapore government "to ensure that all guests currently onboard Quantum of the Seas can disembark safely and smoothly. 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."
Every passenger on the ship is wearing a tracing wristband, called the Tracelet, in order to monitor social distancing and enable contract tracing.
In a report published on Cruise Critic, Heidi Sarna, a Singapore-based journalist and co-founder of the Quirky Cruise website, was onboard the ship and said that passengers were required to "check in" by tapping their key cards at various spots around the ship as a way to further enable contact tracing. PCR tests were required to be taken by passengers 48 to 72 hours before sailing, she said.
Royal canceled the ship's next sailing, a 4-day cruise that was supposed
to depart Dec. 10, and said it would thoroughly deep-clean and
disinfect the entire ship after all passengers disembark. The line has
not yet decided on whether it will continue with sailings beyond that.
"Under the guidance of the Singapore government, we have created a thorough set of protocols designed to mitigate risk, including PCR and antigen testing of all guests and crew before boarding," Royal said in a statement. "Being able to identify this single case and act on it immediately demonstrates the system is working as it is designed to."
Royal's European brands, Tui Cruises and Hapag Lloyd, along with other lines sailings in Europe this summer and fall, were able to contain Covid-19 cases that came onboard, preventing them from becoming outbreaks and allowing the cruises to continue.
This report was updated Dec. 9 with new information throughout.