Infectious diseases of swine, particularly zoonoses, have had a significant influence on nutritional safety and availability of pig meat as high-energy protein product since the time that pigs were domesticated back in the 7th century BC. The main sources of swine infectious diseases include the so-called primary sources (direct infection, i.e. through contact with infected and sick animals) and secondary sources (contaminated meat products, slaughter products, and vectors, including ticks). At present, the most serious epidemiological and economic threat to swine breeding in Europe is African swine fever (ASF). This disease, originally coming from Africa, is incurable and causes death of infected pigs and wild boars during 7−10 days after infection. Among the various factors that influence the spread of ASF, important role is played by ticks from the genus Ornithodoros, mainly from the species Ornithodoros moubata. Research on the ASF indicates that other species of ticks can also transmit the virus to healthy pigs in laboratory conditions. Sylvatic and domestic cycles of ASF virus transmission, which have been described so far, require further studies and updating in order to point the potential new vectors in the Caucasus and Eastern Europe affected by the ASF. Effective methods of control and biosecurity may significantly slow down the spread of ASF, which undoubtedly is a major threat to world pig production and international swine trade.