A new outbreak of classical swine fever (CSF) has occurred at a farm in Gifu prefecture of Japan, and the virus has been detected in more wild boar.
Latest domestic pigs to be affected by CSF in Japan is a farm of almost 1,300 pigs in Yamagata city. Several pigs were off their feed in early March, and subsequent tests indicated the presence of the CSF virus.
This was the 11th outbreak of the disease in domestic pigs in the country since September 2018, according to the agriculture ministry.
Yamagata is in Gifu prefecture, where the outbreaks began and where most of the subsequent cases have been detected. Previously, outbreaks have been reported in Aichi prefecture, and the virus has also been detected in Nagano, Osaka, and Shiga — all on the main island, Honshu.
By tracking and tracing pig movements involving CSF-infected farms, 17 units have been affected by the latest wave of the disease, and the number of animals lost to CSF through mortality or culling now stands at more than 48,700, based on official reports to the World Organisation for Animal Health (OIE).
The CSF virus continues to be detected in Japan’s wild boar population. Between February 2 and March 6, the agriculture ministry reported a further 38 cases to the OIE. One of these animals was found in Aichi prefecture, but all the others were in Gifu.
Since testing of wild boar began in September 2018, 206 animals out of 859 sampled in Gifu have tested positive for the CSF virus, while in Aichi, 12 out of 80 tested were positive. The virus has not been detected in any of the 237 wild boar samples from 40 other prefectures.
In order to gain control over CSF among Gifu’s wild boar population, Japan’s agriculture ministry has invited experts in oral vaccination from Germany to demonstrate the procedure at an upcoming workshop.
After a brief absence, CSF was detected in wild boar in Russia one month ago, according to an official report from the country’s animal health agency to the OIE. Source of the infection is unknown, but there is no evidence to link it to the cases in Japan.