Quantitative risk assessment of African swine fever introduction into Spain by legal import of swine products.

African swine fever (ASF) is currently threatening the global swine industry. Its unstoppable global spread poses a serious risk to Spain, one of the world's leading producers. Over the past years, there has been an increased global burden of ASF not only in swine but also swine products. Unfortunately, many pigs are not diagnosed before slaughter and their products are used for human consumption. These ASF-contaminated products are only a source for new ASF outbreaks when they are consumed by domestic pigs or wild boar, which may happen either by swill feeding or landfill access. This study presents a quantitative stochastic risk assessment model for the introduction of ASF into Spain via the legal import of swine products, specifically pork and pork products. Entry assessment, exposure assessment, consequence assessment and risk estimation were carried out. The results suggest an annual probability of ASF introduction into Spain of 1.74 × 10-4, the highest risk being represented by Hungary, Portugal, and Poland. Monthly risk distribution is homogeneously distributed throughout the year. Illegal trade and pork product movement for own consumption (e.g., air and ship passenger luggage) have not been taken into account due to the lack of available, accredited data sources. This limitation may have influenced the model's outcomes and, the risk of introduction might be higher than that estimated. Nevertheless, the results presented herein would contribute to allocating resources to areas at higher risk, improving prevention and control strategies and, ultimately, would help reduce the risk of ASF introduction into Spain.

Quantitative Risk Assessment of African Swine Fever Introduction into Spain by Legal Import of Live Pigs.

African swine fever (ASF) is a devastating infectious disease of pigs that is threatening the global swine industry at present. The current spread of ASF in Europe and its recent incursion into Germany pose a serious risk to Spain, one of the world's leading pig producers. A quantitative stochastic risk assessment model was developed to estimate the probability of ASF introduction into Spain via the legal import of live pigs. The results suggest a low annual probability of ASF introduction into Spain (1.07 × 10-4), the highest risk being concentrated in Central European countries (Germany, the Netherlands, Belgium, and Luxembourg) during the months of April and February. The methods and results presented herein could contribute to improving prevention and control strategies and, ultimately, would help reduce the risk of ASF introduction into Spain.

African swine fever vaccine: Turning a dream into reality.

African swine fever (ASF) is currently threatening the swine industry at a global level. The disease originated in Africa has spread to Europe, Asia and Oceania, since 2007, reaching a pandemic dimension. Currently, the spread of ASF is unstoppable and that the development of a safe and effective vaccine is urgently required. The objective of this paper is to review the vaccine candidates tested during the 20th and 21st centuries, to identify the strengths and weaknesses of these studies and to highlight what we should learn. Several strategies have been explored to date, some of which have shown positive and negative results. Inactivated preparations and subunit vaccines are not a viable option. The most promising strategy would appear to be live attenuated vaccines, because these vaccine candidates are able to induce variable percentages of protection against certain homologous and heterologous virus isolates. The number of studies on live attenuated vaccine candidates has steadily increased in the 21st century thanks to advances in molecular biology and an in-depth knowledge of ASF virus, which have allowed the development of vaccines based on deletion mutants. The deletion of virulence-related genes has proved to be a useful tool for attenuation, although attenuation does not always mean protection and even less, cross protection. Therefore, ASF vaccine development has proved to be one of the top priorities in ASF research. Efforts are still being made to fill the gaps in the knowledge regarding immune response, safety and cross protection, and these efforts will hopefully help to find a safe and effective vaccine that could be commercialised soon, thus making it possible to turn a dream into reality.