Top Japanese government adviser says Diamond Princess quarantine was flawed

A top Japanese government adviser has admitted that the quarantine measures enacted on the Diamond Princess cruise ship in Yokohama may have allowed additional infections to spread among the ship's crew and passengers. At least 705 people contracted the virus during the quarantine, four of whom have died. For a time, the ship had the largest concentration of cases outside of mainland China, where the outbreak began.
In an interview with CNN, government adviser Dr. Norio Ohmagari said that the quarantine of the cruise ship "may not have been perfect."
He said a "tough decision" had been made by the Japanese government to allow the cruise workers to keep working aboard the vessel, despite the risk of infection, to ensure the smooth running of the cruise ship.
But by failing to isolate the crew of the Diamond Princess from the beginning of the quarantine, he said infected workers may have passed on "secondary or tertiary" infections to their fellow crew members and passengers, thereby exacerbating the deadly outbreak.
"We suspected some of the cruise staff may have already been infected, but ... they had to operate the cruise ship itself, they had to see the passengers, they had to deliver the meals," Ohmagari said.
"So that may have caused some close contact with the cruise ship workers and also the passengers."