African swine fever in wild boar ecology and biosecurity

Introduction In 2007, African swine fever (ASF) was introduced in the Caucasus and has now spread to several countries in eastern and northern Europe. In 2018 the ASF crisis expanded to Asia. The large-scale epidemic travelled thousands of kilometres away from its original incursion point in Georgia and, in addition to endemic establishment in domestic pigs, the disease eventually invaded populations of wild boar. In Europe, from 2014 to 2015 the circulation of this virus in the natural ecosystems developed into a self-sustained epidemiological cycle. Currently, the disease is endemic in wild boar populations in several countries and continues to expand its range in Europe, causing very serious concern. Controlling this sylvatic epidemic of ASF is a very challenging task for the veterinary authorities, given the complexity of the disease epidemiology, the lack of previous experience, the unprecedented geographical scope of the problem, and its transboundary and multi-sectorial nature. This document was prepared following recommendations of the Standing Group of Experts on African swine fever (hereafter referred to as SGE ASF) in the Baltic and eastern Europe region. The group was set up under the umbrella of the Global Framework for the Progressive Control of Transboundary Animal Diseases (GF-TADs) to build closer cooperation between countries affected by ASF fostering a more collaborative and harmonized approach to the disease across the Baltic and eastern Europe subregion. At the eighth meeting of SGE ASF (SGE ASF8) in Chisinau, Moldova, on 20–21 September 2017, the World Organisation for Animal Health (OIE), the Food and Agriculture Organization of the United Nations (FAO) and the European Union (EU) decided to cooperate in the preparation of a technical, but at the same time, practically usable, document containing a compendium of essential information about hunting management, biosecurity and wild boar carcass disposal. The purpose of this document is to provide an evidence-based overview of ASF ecology in the northern and eastern European populations of wild boar. It should briefly describe a range of practical management and biosecurity measures or interventions, which can help stockholders in the countries experiencing large-scale epidemics of this exotic disease to address the problem in a more coherent, collaborative and comprehensive way. The publication should not be viewed as an authoritative manual providing ready-made solutions on how to eradicate ASF from wild boars. The facts, observations and approaches described in the document are presented with the intention to broadly inform veterinary authorities, wildlife conservation bodies, hunting communities, farmers and the general public about the complexity of this novel disease and the need to plan wisely and coordinate carefully any efforts aimed at its prevention and control. In order to reduce risks and prevent the negative implications of the now widespread presence of ASF in the ecosystems of northern and eastern Europe, close and continuous cross-sectorial collaboration is essential. Veterinary authorities, forestry and wildlife management agencies, nature conservation and hunting bodies, organizations, communities and clubs should be mutually informed on different aspects of the problem, which sometimes go well beyond their immediate competencies and conventional responsibilities. Therefore, the focal target audience of the publication includes a rather broad range of potential readers, whose decisions or actions on national or local scales are concerned with controlling ASF in wild boars and mitigating the negative implications of this devastating disease for agriculture, as well as for the forestry and game management sectors. The geographical scope and most of the information or examples provided are intentionally limited to the countries of northern and eastern Europe. These countries share similar environments, agroecological and wildlife management systems, and experience the same sylvatic transmission cycle of ASF, which emerged a few years ago. As the epidemiological situation in Europe remains dynamic and the knowledge about ASF epidemiology in wild boars is far from complete, the document will require future revision and updates in order to reflect new findings, experiences and lessons to learn. The publication consists of seven chapters. The first chapter describes the epidemiological cycle of ASF in wild boars as it is currently perceived by expert and research communities. It details the main risk factors related to the circulation of the virus in the ecosystems of northern and eastern Europe. Chapters 2 and 3 briefly reflect on some questions and issues (some of which are controversial) that are typically raised and debated in relation to wild boar biology and population management in the context of ASF control. Chapters 4 and 5 are dedicated to a detailed description of the practical implementation of the key elements of biosecurity strategy recommended at the level of hunting grounds. Those elements are based on the experiences of countries in northern and eastern Europe affected by the ongoing sylvatic epidemic of ASF. There is a chapter on data collection, stressing the need for continuous systematic efforts to better document field observations in order to improve our understanding of disease epidemiology as it evolves and expands its geographical range. Finally, the document addresses risk communication strategies and approaches, which are crucial for effective cross-sectorial collaboration among stakeholders dealing with such a complex problem as the spread of ASF in wild boars. Each chapter opens with a short paragraph briefly introducing its contents and concludes with a summary of the take-away points of each discussion. A list of references is provided for those who want to familiarize themselves with more in-depth information and peer-reviewed publications on the matters reviewed.