The African Swine Fever epizootic: virology, epidemiology and perspective for control

Abstract

African Swine Fever (ASF) is an emerging infectious disease of domestic and wild swine. A contagious disease among swine, but not transmissible to humans, it causes an often fatal haemorrhagic syndrome in domestic pigs and wild boars. The outbreak currently affecting Europe and Asia began in Georgia in 2007. The highly virulent strain involved, belonging to genotype II, is extremely resistant in meat and the environment. All strains isolated in Europe and Asia are derived from the same introduction, although the virus has evolved into less virulent forms in some very localized wild boar populations. From Georgia, the virus spread throughout the Caucasus and the Russian Federation, then to Ukraine and Belarus in 2013. In January 2014, ASF has reached the Eastern borders of the European Union and spread to the three Baltic States and Poland widely in wild boar populations, while sporadic outbreaks in domestic pigs were effectively controlled. Recent countries affected in Europe are the Czech Republic, Hungary, Moldova, Romania, Bulgaria and most recently Belgium (13 Sep 2018), Serbia, Slovakia, and Greece in 2020. In China, the virus introduced on 3 Aug 2018, probably from Russia, gave rise to a major epidemic, mainly in the domestic reservoir, that is now completely out of control and has spread to Mongolia and several countries in South-East Asia, and recently to India. Human activities play a central role as a propagation factor, thus promoting progression by jumps, sometimes over long distances. No vaccine nor treatment are currently available, the only remaining control method is sanitary prophylaxis and prevention of introduction into free territories such as France.