Artificial feeding of wild boar is increasing rather than reducing the spread of African swine fever (ASF) virus and fencing could be used as a control programme. These are some of the findings of EFSA’s scientific advice on control measures to reduce the spread of the virus among wild boar, delivered following an urgent request from the European Commission.
At the end of January 2014 two ASF cases were detected in the wild boar population in Lithuania, at the border with Belarus. After few days two further cases were reported in the wild boar in Poland, still in the border area with Belarus. The ASF virus detected in the wild boar in Lithuania has 100 % sequence homology with the one identified in Belarus in June 2013.
Many studies carried out in other ASFV infected areas in Europe, suggest that ASFV tends to disappear in wild boar populations, when the interaction with infected domestic or free range pigs is limited.
The report revealed that fencing is able to restrict wild boar movement, with an efficiency that is depending on the used fencing system. Wild boar-proof fences are described and have mainly been used to protect valuable agricultural or ecological environments or to facilitate shooting in Europe and elsewhere.
A recent simulation study indicated that preventing wild boar movement is at least as effective to prevent ASFV spread as 100 % wild boar depopulation, whereas movement barriers outperformed depopulation as a control measure when less complete depopulation was performed in the treatment area.
Furthermore, wild boar also quickly learn to avoid electric fences, and double-fencing with an animal-free exclusion zone is usually required to prevent close contact between wild boar and domestic animals. Altogether, a better knowledge on the ASF epidemiologic situation in North East Europe is required to identify the areas where fencing could be used as one element of a control programme and to assess the feasibility of its implementation.