The Ministry of Agriculture, Forestry and Fisheries reports PED spreading across the country, causing high mortality in affected piglets, according to Asahi.
Since the outbreaks started last autumn, more than 30,000 animals in 19 prefectures are reported to have died (up to 18 March). By 7 April, 21 regions had been affected.
On 8 April, the Ministry announced new measures to farmers to prevent the spread of infection.
The virus does not infect people.
Asahi also reports the Ministry of Agriculture saying the first outbreak in Japan for seven years occurred in October in Okinawa Prefecture.
It then spread around Kyushu, killing an estimated 20,000 pigs in the prefectures of Kagoshima, Miyazaki (9,300 animals), Oita (1,400 animals), and then to central Shikoku and Kanto.
In addition to the 21 prefectures known to be affected, suspicious cases are being investigated in Shizuoka, Ishikawa, Gifu and Tokushima prefectures.
There were about 16.75 million pigs in Japan in 2012.
So far, reports Asahi, there has been no effect of the PED outbreaks on the price of pork.
