Japan's swine fever epidemic is spreading, with local authorities in five central and western prefectures saying Wednesday they are struggling to contain the highly contagious virus that was first reported in September.

"We are facing an extremely serious situation," farm minister Takamori Yoshikawa told a meeting at his ministry in Tokyo while instructing officials to take thorough countermeasures. The ministry also set up a special task force in Gifu Prefecture to step up containment efforts.

Spreading from farms in Gifu, the hog cholera virus was newly detected by prefectural and local authorities at farms in neighboring Aichi as well as in Osaka, Shiga and Nagano prefectures.

The government held a Cabinet meeting Wednesday to discuss rapid responses with officials from the prefectures.

"We must prevent the spread of the virus through tighter cooperation between the government and relevant local authorities," Chief Cabinet Secretary Yoshihide Suga said at the meeting, asking ministries including the Ministry of Agriculture, Forestry and Fisheries to work closely and respond to requests from the prefectures.

"We also ask relevant parties to start an information campaign so that consumers will not be worried," said Suga.

The total number of pigs to be culled at affected farms is expected to reach 15,000.

"It worries me that we don't know how the disease is spreading," said a pig farmer in Iida, Nagano Prefecture. "The only thing we can do is to thoroughly manage hygiene."

(Workers in hazmat suits take part in an operation to cull 6,600 pigs at a pig farm in Toyota, Aichi Prefecture, central Japan, on Feb. 6, 2019.)

The disease does not affect humans even if meat from an infected animal is consumed, but it is fatal to pigs and boars.

Around 130 wild boars in Gifu and Aichi prefecture have tested positive for infection despite experts' initial assumption that the disease would not spread among the animals, which typically do not live in large herds.

Although there is a vaccine to counter classic swine fever, using it could prevent Japan from regaining its World Organization for Animal Health status as a CSF free country, hindering Japan's plan to expand pork exports. The organization already suspended Japan's status after the outbreak in September.

Yasuhiro Ozato, a senior vice farm minister, expressed reluctance to use the vaccine, saying, "We will seek to resolve this by sticking to hygiene control standards."

The Aichi prefectural government began culling around 6,600 pigs at a farm in the city of Toyota with the help of the Ground Self-Defense Force, while banning shipments from six other farms located within 10 kilometers.

The farm in Toyota had shipped pigs to six facilities in Nagano, Gifu, Aichi, Mie, Shiga and Osaka prefectures since January. The ministry has not detected the virus in Mie and the prefecture's government said that all of its tests on hogs from the farm in Toyota were negative.

The farm in Toyota reported to the Aichi government on Monday that pigs were showing symptoms of infection, including loss of appetite, and the prefecture detected the hog cholera virus in five pigs the following day. Detailed tests by the central government confirmed the infection on Wednesday.

The Aichi government said the farm in Toyota shipped pigs to a Nagano Prefecture farm Tuesday morning even after noticing hog cholera symptoms among them as prefectural authorities suspected another illness and did not stop shipments.

Of the 80 pigs brought to the farm in Miyada, Nagano, 79 were found to have been infected with the virus, according to the Nagano prefectural government.

Six hogs sent to a farm in Osaka Prefecture tested positive for the virus, Governor Ichiro Matsui said, adding all hogs at the farm will be culled as soon as a location is determined. There are around 700 hogs at the farm, according to the prefecture.

Matsui also said that he will discuss methods with the farm ministry.

A man involved in pig farming who lives near the Toyota farm said, "There was a vet at the company (managing the farm). I thought they were taking thorough preventive measures."

Hog cholera was detected at a farm in the city of Gifu in September, the first such discovery in Japan since 1992. The country declared the virus eradicated in 2007.