Japanese health officials reported on Thursday that the number of Wuhan coronavirus cases on board a Carnival Corp cruiseship quarantined off Yokohama has risen to 20.

The latest victims on board the 115,900-gt Diamond Princess (built 2004) include four Japanese, one Taiwanese, two American, two Canadians and one New Zealander. All are passengers who took part in a second round of testing on board the ship.

Yesterday Japanese officials revealed that the first group, nine passengers and one crew member, had tested positive and had been taken ashore.

The Diamond Princess, which arrived in Japan on Monday after a voyage from Hong Kong, is currently moored at a remote pier in Yokohama with around 3,700 passengers and crew on board.

Princess Cruises, the Diamond Princess’s operator, has stated that the ship’s next two cruises have been cancelled and it will be offering all passengers a full refund and a 100% credit on a future cruise.

The company has also provided passengers currently on board the ship with free telephone and internet. Many have taken to social media to vent their frustrations at stuck in their cabins with nothing to do.

In Hong Kong, Genting Cruise Lines’ 150,000-gt World Dream (built 2017) remains quarantined alongside a pier at the Kai Tak Cruise Terminal with one suspected coronavirus case diagnosed with having only come down with a bad dose of the flu.

Dream Cruises, its operator, said in a statement on Thursday that the in Hong Kong on Wednesday morning with 1,871 passengers.

Around 30 crew members had claimed various minor symptoms including coughs and sore throats, with three crew also claiming fever in their health declaration forms.

“Of the 30, one crew member had tested positive for influenza, but temperature screenings this morning returned no recordings of fever from these crew members. As a precaution, the three crew members who had claimed that they felt feverish have been sent to public hospitals for further testing,” the company said.

The other crew who reported feeling unwell are being kept in isolation and tested on board the ship.

Genting did not give any indication on when the quarantine order against the World Dream would be lifted.

“Port health officials are currently administering health checks for the remaining passengers and crew on board World Dream. However, due to this situation, no passengers or crew will be allowed to disembark from World Dream until the test results from the affected crew members have been confirmed.”

The quarantine order will likely delay plans to redeploy the ship to Taiwanese waters, a move that was scheduled to take place next week.

No matter when the quarantine order is lifted, Taiwanese authorities yesterday announced that they would not permit any ship to dock in a Taiwanese port if it has called in Hong Kong, Macau or mainland China within the past 14 days.

However, unconfirmed media reports emerging from Taiwan on Thursday indicated that the Taiwanese government was planning to ban all cruiseships from calling at the island’s ports for the foreseeable future.

Royal Caribbean International has called off plans to deploy its 169,000-gt Spectrum of the Seas (built 2019) to Taiwan for a two-month period.

A company spokeswoman told TradeWinds that while the ship’s future sailings from Shanghai have been cancelled, it is still considering where to deploy the ship in the future.

The vessel is currently sailing off the Japanese coast.