Tokyo, Jan. 23 (Jiji Press)–Pigs in the southernmost Japan prefecture of Okinawa were possibly infected with classical swine fever via food, an expert panel commissioned by the agricultural ministry said Thursday.
Leftovers, including pork infected with CSF in the country’s Honshu main island, may have caused an outbreak of the disease in Okinawa earlier this month, the panel said.
A genetic analysis conducted by the panel found that the gene type of CSF in Okinawa was similar to that in the central prefecture of Gifu and was not brought from abroad.
CSF-infected pork remains infectious for a while even after being processed into meat products unless it is heated sufficiently.
Pork from pigs that were resistant to the CSF vaccine or got infected with the disease but did not develop symptoms such as a fever before being processed may have been distributed in Okinawa.
The farm where the first CSF case in Okinawa was confirmed earlier this month fed pigs with unheated leftovers that were provided by restaurants and supermarkets.
Many farms in Okinawa feed pigs with food waste. “It’s important to be sure to heat” such feed, said Tomoyuki Tsuda, who heads the panel.
The ministry urged prefectural governments across the country to ensure pig farms heat food waste before being provided as feed. About 260 pig farms in the country use food waste as feed, according to the ministry.
At the farm where the first CSF case in Okinawa was confirmed, the number of pigs that have died has increased since late November.
One cause for the CSF outbreak in Okinawa was insufficient disinfection of vehicles that come to and leave pig farms, the panel said.
In Japan, CSF was confirmed for the first time in 26 years in the city of Gifu in September 2018.
The CSF virus is seen to have been spread in the Kanto eastern and Chubu central regions via wild boar. No CSF-positive wild boar has so far been detected in Okinawa.