The cruise ship Costa Atlantica sails out of Nagasaki Port on May 31 after all remaining crew members tested negative for COVID-19. (Motoki Nagasawa)

NAGASAKI--An Italian-flagged cruise ship docked here, which once had 149 cases of COVID-19 onboard in one of Japan's biggest cluster infections, departed Nagasaki Port on May 31 after all remaining crew tested negative for the virus.

The 86,000-ton Costa Atlantica arrived on Jan. 29 from China, where it underwent repair work from Feb. 20 at Mitsubishi Heavy Industries Ltd.’s Koyagi factory at its Nagasaki shipyard.

The ship carried 623 crew members from about 30 countries, including the Philippines and India, and two Japanese nationals.

On April 20, four crew members tested positive for the novel coronavirus. By May 4, a total of 149 had the virus.

Most crew members were quarantined in passenger cabins to prevent the virus from spreading.

The ship’s doctors, staff of the disaster medical assistance team (DMAT) and Nagasaki University, treated them.

Since early May, 495 crew members, including those who tested positive, were able to leave Japan after being closely monitored by health care workers and confirmed negative for the virus.

Crew members who are still hospitalized are expected to leave Japan as soon as they recover.

“We tried our best to provide the necessary medical support for the ship to prevent the virus from spreading into the city,” Nagasaki Governor Hodo Nakamura said at a news conference after he saw the ship off at the dock.

“I am relieved now that the departure day has come,” Nakamura said.

The outbreak had raised concerns among local residents and health care workers over the virus spread in Nagasaki.

Many of them joined the governor to bid the ship farewell and echoed his relief over the ship's departure, when it left the Koyagi factory just before noon.

As the ship left port, crew members onboard held up a banner reading, “Thank you very much,” to which medical staff onshore who had treated them for about a month flashed their own sign saying, “Buon Viaggio” (Bon Voyage) and waved at the crew.

Around 20 people including Hiroshi Yatsuhashi, the National Hospital Organization Nagasaki Medical Center's assistant director, bid farewell to the ship from Megami Ohashi, the longest cable-stayed bridge in Kyushu, which offers a panoramic view of the factory.

Yatsuhashi, 61, waited two hours to get a shot of the departing ship with his camera mounted on a tripod.

The medical center, located in Omura, Nagasaki Prefecture, had sent about 30 doctors and nurses to the dock to treat the sick crew members. The facility was prepared to accept those with severe symptoms, by postponing scheduled operations and taking other measures.

“It was really tough, but we didn’t lose anybody,” Yatsuhashi said. “It’s great that this day has come. The departure is an emotional closure of sorts. I wanted to see it through for myself.”

Yatsuhashi also treated passengers of the virus-hit Diamond Princess cruise ship, that had docked in Yokohama Port since February under quarantine.

He said he can't forget how many of its passengers worried if they could ever go home and how the public would perceive them.

Based on that experience, Yatsuhashi knows how the Costa Atlantica’s crew members who were isolated in cabins for more than a month felt.

“It must have been enormously hard for them mentally,” he said.

Also on the bridge, waving goodbye to the ship, was a 53-year-old Nagasaki woman employed in the social welfare industry.

“I was scared hearing that some crew members went out in the city, but I'm glad the virus didn’t spread,” she said. “I hope the crew members don't have a negative view of Japan.”

The woman said she once took a cruise on a ship run by the company that operates the Costa Atlantica.

“When will we feel safe and be able to travel again?” she wondered.

Sixty or so residents came out to see the cruise ship sail out in the city’s Doinokubi district, which lies across from the Koyagi factory.

“I was involved in shipbuilding, and I was worried about the (Costa Atlantica),” said a man in his 70s who worked at the factory until about 15 years ago.

“Medical staff and crew members reacted to the (outbreak) properly. They did great,” the man said while staring at the departing vessel.

A 63-year-old Nagasaki woman said she walked a long way to see the ship with her friends.

“When I go for a walk in the evening, I always see the windows of the ship’s cabins lit up, and it was a beautiful sight. To think that I can no longer see it makes me feel sad,” she said.

The Nagasaki prefectural and city governments are expected to conduct a series of studies on the response by authorities to the outbreak.

Two hospitals in Nagasaki accepted 11 crew members including those who tested negative. Only one crew member developed severe symptoms, and the person is on the road to recovery.

Nakamura said the fact that most crew members were young helped the situation from getting worse.

The governments received valuable information and advice from doctors on the DMAT staff who assisted during the Diamond Princess quarantine crisis, Nakamura said.

Nakamura pointed out, however, that the Costa Atlantica likely did not recognize the city’s public health center as the contact point for infectious diseases.

That hindered prefectural officials’ access to the health conditions of crew members before the ship entered the dock.

Nakamura said the prefectural government will provide support to entice cruise ships and other vessels to the area to undergo repairs in the mid and long term only after tough measures to contain infectious diseases are well-established.

Nakamura said it would be “extremely difficult” if a similar outbreak occurs on a ship with passengers on board.

(This article was written by Mizuki Enomoto and Naoki Ogawa.)