Evaluation of possible mitigation measures to prevent introduction and spread of African swine fever virus through wild boar

This scientific report has been prepared in response to a request for urgent scientific and technical assistance under Art 31 of Regulation (EC) No 178/2002, in relation to possible mitigation measures to prevent introduction and spread of African swine fever virus (ASFV). It was requested to assess the feasibility to drastically reduce the wild boar population by hunting or by the use of traps, and to assess if prevention of movement of wild boars by feeding or by artificial physical barriers reduces the risk of spread of ASFV. No evidence was found in scientific literature proving that wild boar populations can be drastically reduced by hunting or trapping in Europe. The main reasons are the adaptive behaviour of wild boar, compensatory growth of the population and the possible influx of wild boar from adjacent areas. Thus, drastic hunting is not a tool to reduce the risk for introduction and spread of ASFV in wild boar populations. Furthermore, wild boar density thresholds for introduction, spread and persistence of ASFV in the wild boar populations are currently impossible to establish, due to the uncertainty regarding the extent of the spread and maintenance of ASFV, the biases in population datasets, the complex population structures and dynamics. Furthermore, attempts to drastically reduce wild boar populations may even increase transmission and facilitate progressive geographical spread of ASFV, since intensive hunting pressure on wild boar populations leads to dispersion of groups and individuals. Artificial feeding of wild boar might increase the risk of ASFV spread. Fencing can restrict wild boar movements, however further knowledge of the ASF epidemiology and spatial distribution of wild boar is required to identify the areas where fencing could be used as one possible element of a control programme and to assess the feasibility of its implementation.