The Diamond Princess departed from Yokohama on January 20th, with an original passenger manifest of 2,666 travelers from 56 countries and regions, and 1,045 crewmembers. The health authorities say about half of the people on board were Japanese nationals.
The Japanese government decided to quarantine the ship on its return to Yokohama after an 80-year-old man who had disembarked in Hong Kong tested positive for the virus.
Since February 3rd, health officials have been conducting tests on passengers and crewmembers showing symptoms such as fever and coughing, or who have been in contact with infected people. Officials told reporters on Monday that ongoing tests have so far found that over 130 people have contracted the virus.
On board, the passengers seem to have been left largely in the dark about the situation. They are being required to stay mostly in their rooms for at least 14 days, the virus' estimated incubation period.
A man in his 60s told an NHK reporter that there is a general lack of information, and that he is worried because he has no idea when they'll be allowed to get off.
Others say conditions on the ship are quickly deteriorating, with crewmembers unable to clean rooms and no computer access for many passengers.
"There seem to be reports that things are okay but that is far from reality" said Tadashi Chida, a passenger representing the remaining people on board. "Counseling services only available in English. Steak for dinner, which many of the elderly can't eat. The situation is bad."
Another major concern is the dwindling supply of personal medicine. A man in his 70s told the NHK reporter that he ran out of blood pressure and cholesterol medication several days ago.
"I take two kinds of medication or else I can't sleep," he said.
The cruise operator announced on Sunday that the ship had received 600 packages of medicine, with specific instructions on how it should be distributed among the passengers.
But the health ministry says the delivery is not sufficient for everyone on board and that it is working to fulfill additional requests.
Apart from those who have tested positive for the virus, eight people have been hospitalized for unrelated health problems, possibly due to lack of medicine.
The Diamond Princess isn't the only cruise liner to be affected by the outbreak. The US-based Westerdam has been denied entry to several ports, including Okinawa in Japan, and as of Friday was "sailing on a southwesterly course off the coast of Taiwan."
The ship departed from Hong Kong on February 1st with more than 2,200 people on board. Taiwan denied it entry, citing the possibility of coronavirus infection, and Japan did the same shortly after.
"The ship is not in quarantine," the operator said in a statement, adding there is "no reason to believe there are any cases of coronavirus on board." It said passengers have enough food and that there is phone and internet access.