The agriculture ministry said Saturday that classical swine fever (CSF) infections have been confirmed at a pig farm in the city of Takasaki, Gunma Prefecture, marking the first outbreak of the infectious disease among farmed pigs in the country in about half a year.
It is the first classical swine fever case at a pig farm in Gunma since the first outbreak in Japan in 26 years was confirmed in 2018. The Gunma Prefectural Government will slaughter all of the roughly 5,400 pigs at the farm in accordance with the law.
In the prefecture, vaccinations started for farmed pigs in October last year, following the discovery of an infected wild boar. But the animals found with the disease at the affected farm, all piglets, had yet to be vaccinated.
Early this month, piglets at the Takasaki farm started to die after suffering from diarrhea, and the number of deaths has reached about 200, according to the prefectural government. The prefecture conducted tests on pigs at the farm following a report from its operator on Friday. Infections were confirmed in three piglets who were each about 70 days old.
Pigs are vaccinated around the time when the antibodies they received from their mothers disappear. The three piglets were covered by the vaccination program, but had yet to be vaccinated as they were showing symptoms of diarrhea, according to the prefecture.
The culling of the pigs at the affected farm will be conducted over three days from Sunday, with the prefectural government set to get help from the Self-Defense Forces and others for the task.
The prefecture and the central government will jointly work to investigate the infection route. A wild boar infected with CSF has been found around 5 kilometers from the Takasaki farm, according to the prefectural government.