Sweden’s National Veterinary Institute has confirmed that a case of African swine fever (ASF) has been detected in the country for the first time.

The highly contagious viral disease of domestic and wild pigs was confirmed from a sample of a dead wild boar found southeast of Fagersta – 145km from Stockholm.

The country’s National Veterinary Institute (SVA) said seven wild boars have been found dead in the Fagersta area since August 25, 2023.

Samples from another wild boar are on their way to the veterinary institute for testing, it said.

The boar leg sample that was analysed at SVA. Source: Erik Ågren

SVA said it is currently not clear how the disease came to Sweden, but that it is assumed it has been introduced through human activity and not wild boar.

Lena Hellqvist Björnerot of the Swedish Board of Agriculture said: “The contingency plan we have had for a long time is now being implemented.

“We are also taking note of experiences from other countries that have been in a similar situation.”

SVA said relevant authorities are now working intensively to localise, contain and control the infection.

Prevention measures

SVA said one of the first measures introduced to contain the disease is for the responsible authorities to work with the hunters’ organisations to find out how large the affected area is.

This will be done by searching for dead wild boar within the range of where the positive case was found.

All access to this area will be prohibited, as the disease can spread by being carried on shoes, tools and vehicles.

Karl Ståhl of SVA said: “At present, we do not know how the infection was introduced but it is a long-distance jump from the nearest infected area in Europe and we therefore assume that it has been introduced through human activity and not wild boar.

“There is currently an extensive spread of infection in Europe. There are countries that have succeeded in eradicating the disease and that is our national goal.”

African swine fever

According to the World Organisation for Animal Health (WOAH), ASF has become a “major crisis” for the pork industry in recent years and is responsible for massive losses in pig populations and drastic economic consequences.

“Currently affecting several regions around the world, and with no effective vaccine, the disease is not only impeding animal health and welfare but has also detrimental impacts on biodiversity and the livelihoods of farmers,” it said.

WOAH said the disease can have a mortality rate of 100%.

The is currently no effective vaccine against ASF. It does not pose a threat to human health, but can be easily spread by humans across country borders.

“The virus is highly resistant in the environment, meaning that it can survive on clothes, boots, wheels, and other materials. It can also survive in various pork products, such as ham, sausages or bacon,” WOAH said.

“Therefore, human behaviours can play an important role in spreading this pig disease across borders if adequate measures are not taken.

“ASF continues to spread worldwide, threatening pig health and welfare. The disease has reached multiple countries across Asia, the Caribbean, Europe, and the Pacific, affecting both domestic and wild pigs.”