More than 100 crew members on board the Italian-operated Costa Atlantica have tested positive for COVID-19.

The cruise line announced Monday that Japanese health authorities had completed testing of everyone on board and concluded that 148 people were infected.

The Costa Atlantica has been docked in Nagasaki, Japan, for repairs and maintenance by Mitsubishi Heavy Industry since Jan. 29. No passengers have been on board during the repair work.

There are 632 people on board of 36 nationalities, according to the cruise line.

The cruise line said everyone on board is currently staying in a single-occupancy cabin, and crew members delivering food and medical services to cabins are required to wear personal protective equipment.

“The health and safety of our people, along with compliance and environmental protection, is always our utmost priority, and we have been constantly monitoring the health of our colleagues on board during the ships’ stay in Japan,” Costa Cruises said in a statement Monday provided by spokesperson Roger Frizzell.

The outbreak on the Costa Atlantica surfaced last week when officials from Nagasaki and Mitsubishi Heavy Industry, which is in charge of repairs and maintenance on the ship, announced that a crew member developed a cough and fever.

Nagasaki officials have said ship crew members will quarantine themselves on board unless they develop serious symptoms. At least one person was medically disembarked after becoming seriously ill, Frizzell said.

“We are now working with the Japanese central government and Ministry of Health to define the plan and make repatriation arrangement for people tested negative, through charter or commercial flight in coordination with the relevant embassies,” the cruise line said in an earlier statement. “We have started the planning of the repatriation.”