Of the 851 cases confirmed as of 11 am Tuesday, 146 are either tourists from China or people who caught the virus in Japan. 691 are passengers or crewmembers of the Diamond Princess. The remaining 14 are people who were evacuated from the Chinese city of Wuhan on government-chartered planes.
As the total number of cases rises, the government has found it increasingly difficult to trace the routes of transmission. Infections have been reported among people from a variety of jobs and age ranges.
In Hokkaido, a school bus driver and a woman who delivered lunches to an elementary school are confirmed to have been infected. The Hokkaido board of education has instructed schools to cut down the duration and number of attendees of upcoming graduation ceremonies.
In Sagamihara City, Kanagawa Prefecture, an East Japan Railway employee who had been working at Sagamihara Station tested positive last Saturday. City officials say the man worked mostly inside the station office, so there is little risk that he infected passengers.
Controlling the spread
On Tuesday, the government released basic guidelines on how to avoid infection, calling on people to work from home if they have a fever or exhibit cold symptoms. The guidelines also call on organizers to consider cancelling or postponing events, though this is not mandatory.
Currently, when a new case emerges, the authorities attempt to identify the route of transmission, monitoring people who had come into close contact with the patient. But the new guidelines say that if the number of cases continues to rise, the government will shift its focus on keeping people indoors.
In the guidelines, the government says that the virus has been largely passed on through "spray or contact" and that airborne transmission was unlikely. However, it adds that the risk of spread remains. And, while the mortality rate of the virus is not as high as other infectious diseases, it does pose a higher health risk than seasonal influenza.
Prime Minister Shinzo Abe told reporters that the guidelines will help curb the increase of infections. He said the plan includes additional steps to prevent the spread in rural communities, and that he will work with municipal governments and medical institutions to quickly establish an adequate response and care system.