Professor Kentaro Iwata said that the Japanese government's isolation of the Diamond Princess made the situation chaotic and violated the quarantine process.

"Yachts are a completely unsuitable place to control infectious diseases," Kentaro Iwata, a professor at Kobe University, a Japanese infectious disease expert, said in a video posted yesterday. The video today drew hundreds of thousands of views, as passengers and sailors on the Diamond Princess cruise began to land after a two-week isolation period off the Yokohama port.

Iwata said he was so concerned with what he saw on the yacht after visiting the ship that he had to isolate himself 14 days to avoid transmitting the virus to his family. "There is no distinction between the green and the red areas, showing the uninfected and potentially infected areas," Iwata added.

Japanese professor confirmed that he had a lot of experience dealing with infectious diseases, when dealing with Ebola epidemic in Africa, or SARS in China in 2003 and cholera in many other countries.

"I was never afraid of being infected. However, inside the Diamond Princess yacht, I was scared because there was no way to know where the virus was," Iwata said.

Diamond Princess recorded at least 542 cases positive for the corona virus, making the yacht the largest outbreak outside of China. Japanese officials have confirmed that infections on yachts primarily occurred before quarantine measures they deemed were effective.

Hundreds of passengers on board today were allowed to leave after test results showed they were negative for corona virus. Japanese government officials also rejected Iwata's criticism.

"Since February 5, we have taken thorough measures to prevent the spread of disease, including wearing masks, washing hands and using disinfectants. The truth is that we are trying do your best to prevent infection, "Japanese Cabinet Chief Secretary Yoshihide Suga told reporters today.

Japanese Health Minister Katsunobu Kato also defended the way the government handled Diamond Princess. "Specialists, members of the anti-infectious team, are monitoring the inside of the yacht. According to experts, the risk of infection is under control," Kato said.

The yacht carrying 3,711 passengers and crew were quarantined at the port of Yokohama, Japan since February 4 after a Hong Kong tourist once boarded a positive boat with nCoV. During isolation, Japanese health officials repeatedly discovered more people infected with nCoV on board.

The Covid-19 epidemic has so far killed 2,010 people and 75,184 people infected, mainly in the center of Hubei, China. Six deaths were recorded outside mainland China in Japan, Hong Kong, France, the Philippines and Taiwan.