Swine fever hits Aichi, Gifu, Shiga, Osaka and Nagano prefectures on Feb. 6. (The Asahi Shimbun)

TOYOTA, Aichi Prefecture--Pigs at farms in five prefectures tested positive for swine cholera following shipments from a hog farm here, the agriculture ministry said Feb. 6.

The viral disease, also known as classical swine fever, was confirmed for the first time in Japan in 26 years in Gifu Prefecture in September, prompting safety measures, including culling.

While the virus has since been spreading within the prefecture, it is the first time for cases to be confirmed outside the prefecture.

The virus was identified as the type found in Gifu Prefecture.

The cholera-positive pigs were first found at a farm in Toyota, Aichi Prefecture, and also discovered at farms in Nagano, Gifu, Shiga, Osaka and Aichi prefectures, to which the Toyota farm had shipped pigs.

A total of about 15,000 pigs are to be culled.