African swine fever virus (ASFV) is a double-stranded DNA virus that replicates predominantly in the cytoplasm of macrophages and is the only member of the Asfarviridae family, genus Asfivirus. ASFV is the causitive agent of African swine fever (ASF) a highly contagious hemorrhagic disease of pigs which causes high mortality, approaching 100%, in domestic pigs. Clinical signs and lesions closely resemble those of classical swine fever (see Classical Swine Fever). It is an economically important disease that is enzootic in many African countries and the Mediterranean island, Sardinia. In June 2007, ASF was confirmed for the first time in Georgia in the Caucasus region. Since its introduction into Georgia, ASFV has spread rapidly into vast areas of western and southern Russia, circulating out of control in domestic and wild pig populations. The virus has spread to the edges of Europe, putting at risk the very large pig populations present in Eastern Europe. At present, ASF does not occur in the western hemisphere.