TORONTO -- As the number of positive cases of novel coronavirus, now known as COVID-19, continues to rise on a cruise ship docked in Japan, questions are being raised about the ethics of keeping healthy passengers aboard under quarantine.

The 3,700 passengers and crew on the ship have been under quarantine since Feb. 4 when 10 guests tested positive for the virus. While sick passengers have been taken off the ship for treatment at local hospitals, new cases keep emerging with the total confirmed cases now at 174, including ten Canadians.

On Tuesday, Princess Cruises announced they had identified 39 new cases of COVID-19 on the Diamond Princess ship, which is currently docked in the port city of Yokohama, just outside Tokyo.

During the quarantine period, passengers have been confined to their rooms with their meals delivered by staff members wearing masks and gloves. Every day, segregated groups are allowed outside on the deck for an hour at a time for fresh air and exercise.

Alberta couple Mark and Jenny Rodrigue said the guests have been asked to stay a couple of metres away from each other when they鈥檙e out on the deck together.

On Monday, the Rodrigues said everyone was told to wear masks to accept their meals and to wash their room door handles after each delivery.

The quarantine period is supposed to last another week until Feb. 19, but Mark Rodrigue said he鈥檚 not confident that will be the end of it.

鈥淭hat鈥檚 still the current plan but the health authorities can change that, depending on their determination on how the virus is acting,鈥 on Tuesday. 鈥淭hey鈥檙e not going to put the country of Japan in any further danger than they already are. We鈥檒l just have to wait and see.鈥

Despite the precautions aboard the ship, bioethicist and University of Toronto professor Kerry Bowman said there are ethical concerns about the Japanese government鈥檚 decision to keep passengers on a ship where nearly 200 people have become sick.

鈥淭he quarantine ethics when you take healthy people and you鈥檙e putting them in with people who are unhealthy is radically different,鈥 he told CTV鈥檚 Your Morning on Wednesday.

Bowman said it鈥檚 difficult to know how dangerous the threat of contagion is to the outside world because authorities still don鈥檛 know the source of the infection aboard the ship, nor exactly how it is transmitted.

鈥淓ven if the argument could be made they鈥檙e not infecting each other, which is becoming a little hard to believe, the psychological and emotional stress, it鈥檚 very hard to justify that,鈥 he explained.

The bioethicist said Japanese officials could be violating healthy passengers鈥 fundamental rights by preventing them from leaving the ship.

鈥淨uarantine ethics are really, really tough going because in many societies you do not lose your fundamental civil rights without criminal activity so you really have to show cause that this is justified because of the potential harm,鈥 he said.

Bowman said guests could be put at risk by remaining on the ship, especially those with preexisting health concerns.

鈥淚 think there will be a lot of repercussions should they not be separated, pulled off, and moved into other areas,鈥 he said.

That鈥檚 the outcome Trudy Clement and her husband are hoping for after being trapped on the Diamond Princess cruise ship for more than a week.

In an interview with CTV鈥檚 Evan Solomon on Monday, the Canadian woman said 鈥渟tress levels are starting to rise鈥 among passengers.

鈥淎s nice as the room is, it鈥檚 not a nice place to be anymore,鈥 she explained.

While the scheduled end date for the quarantine is in sight, Clement said she鈥檚 not certain if they will even be allowed to leave Japan. She said they were told the cruise line is negotiating with Japanese authorities to help passengers make their way home after the quarantine.

鈥淲hich is what we wanted to hear because we had no idea what to do when they let us off or, you know, can we just hop on a plane, or are we going to be singled out that we can鈥檛,鈥 she said. 鈥淲e don鈥檛 know.鈥