The larger the impact of animal diseases on agricultural production, the more evident the need to prevent the entry of pathogens into a country, and to ensure the preparedness of veterinary services and other stakeholders for timely detection and control. An example of the impact on livelihoods is exemplified by the 1978 African swine fever (ASF) epidemic in the Caribbean island of Hispaniola, controlled by the swine depopulation on the entire island, which had a particularly dramatic effect in the already precarious livelihood of the rural population of Haiti. An even bigger economic impact was seen in the 2001 outbreak of foot and mouth disease virus (FMD) in the United Kingdom, which led to costs exceeding £3.1 billion ($4.4 billion) to the agriculture and food chain sectors alone. The same year, foot and mouth disease (FMD) led to the destruction of Taiwan’s pig industry. Moreover, zoonotic pig diseases must be judged by their impact on public health.Īs examples of economic impact, the 1997 classical swine fever (CSF) epidemic in the Netherlands led to the destruction of 10 million pigs and an estimated cost of $2.3 billion US dollars.

Control measures, such as massive depopulations, will also add to the cost, both from the economic and the social points of view. Additionally, the trade restrictions that often accompany the reporting of livestock diseases, may add a considerable economic burden, particularly to exporting countries.

Doing so, they do not only challenge the livelihoods of the producers, but can have major socio-economic consequences for the wider population. Livestock diseases adversely impact the productivity of livestock production systems by reducing the quantity and quality of livestock-derived products. Nevertheless, this knowledge is deemed essential to set up risk based awareness, prevention and surveillance programs that correspond to reality. However, quantitative information on informal disease introduction pathways remains very scarce and often incomplete, making it difficult to estimate the actual magnitudes of risks. Risk assessments can aid in the identification of pathways of pathogen introduction and exposure. The main exposure pathways are also described with the oral route playing a prominent role. Meat products are most commonly mentioned, although fomites have also played a role in some cases, with live pigs, being more difficult to smuggle playing a role less frequently. Much more difficult to control is the transboundary swine disease transmission originating through informal trade, which entails illegal smuggling, but also the informal cross-border transfer of animals and products for personal use or within informal market chains. Formal trade of pigs and pork products is regulated by legislation and measures protecting animal populations from exotic diseases. Introduction pathways are classified as formal international trade (by product), informal international trade (by product), and spread through fomites. Inspired in the risk assessment methodology, this paper classifies and provides an overview of the different pig disease introduction and exposure pathways, illustrated with abundant examples. All of the above pose a constant threat to swine health, mainly as a result of both formal and informal international trade. The global pig sector, with its size and dichotomy between production type and biosecurity level, is particularly vulnerable to the transmission of transboundary animal diseases such as African and classical swine fever, foot and mouth disease, or porcine reproductive and respiratory syndrome. As globalization increases the interconnectedness between nations, economies, and industries, the introduction of diseases will continue to remain a prominent threat to the livestock sector and the trade of animals and animal products, as well as the livelihoods of farmers, food security and public health.

Keil veterinary