External scientific report: alternative control strategies against ASF in wild boar populations.
Abstract
ASF is a devastating infectious disease of domestic pigs and wild boar, usually fatal. No vaccine exists to combat this virus. It does not affect humans nor does it affect any animal species other than members of the Suidae family. From the beginning of 2014 ASF has spread in Estonia, Latvia, Lithuania and Poland, mainly in the wild boar, causing very serious concerns. The European Commission requested EFSA to assess different wild boar management options taking into consideration its ecology in the Baltic States and Poland. Therefore, a simulation study was performed comparing control strategy alternatives using a spatio-temporally explicit individual-based model. The model was developed based on literature regarding wild boar ecology; ethology of the ASF virus recently circulating in Eastern Europe; wild boar density maps from the ASF affected regions and an expert consultation meeting. The model results did not reveal one single immediately effective control measure based on accepted wild boar management tools. Strategies using conventional wild boar management approaches - ban of feeding and targeted hunting of reproductive females - were found to become effective slowly over multiple generations of reproduction. Therefore, when applying the strategies, a width of 100-200 km is required as buffer zone surrounding the area with ASF detections in order to compensate the forward spread till measures become effective. Massive population destruction (i.e. about 80% of the population in the control area within 4 months with any available technique) or instantaneous removal of infectious carcasses could stop ASF spread already by limited buffer width of below 50 km. The equal outcome is reasoned by the avoidance of infectious carcasses when the population was destroyed. Centred on the effective and immediate exclusion of wild boar contacts with infectious carcasses, hybrid strategies including reasonably intensified conventional hunting may suffice to stop ASF spread using a practical buffer width (about 50 km) resp. time horizon (less than 3 years) for control while avoiding destructive measures.