The African swine fever virus has been detected in a contagious state on Japanese soil for the first time, the government said Tuesday.
The government has in the past detected genes of the African swine fever virus in food brought from overseas, but never before has the virus been confirmed as being at an infectious stage.
The Ministry of Agriculture, Forestry and Fisheries said the discovery of an infectious form of the virus has prompted a decision to strengthen measures against illegal imports of livestock products.
The virus was discovered in sausages brought into the country from China in January, the farm ministry said Tuesday.
The virus only affects domesticated and wild pigs and boars, not humans, but there is no vaccine or effective treatment for the highly lethal virus, the ministry said.
The sausages were brought into Japan, apparently as souvenirs, by two passengers arriving separately at Chubu airport near Nagoya on planes from Shanghai and Qingdao on Jan. 12, according to the ministry.
So far no African swine fever infections have been reported in Japan and it is unlikely that food infected with the virus would cause an outbreak unless pigs were fed with the infected food.
Under the law on infectious disease control for domestic animals, people who bring unauthorized animal products into the country could face a fine of up to ¥1 million or imprisonment for up to three years.
To date authorities have only penalized serious violations, such as when unauthorized products were imported for sale, but the government now plans to tighten controls and take action against those who repeatedly import unauthorized livestock products.
African swine fever is more lethal than conventional swine fever, also known as hog cholera, with a number of outbreaks having been reported in parts of Japan since September — the first time the virus had been detected in the country for 26 years.
An outbreak of African swine fever was reported in China last year and has since spread to Vietnam and Mongolia. As of February, dozens of countries in Africa and Europe have also reported outbreaks.