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.

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.

African swine fever (ASF) has been reported in South Africa since the early 20th century. The disease has been controlled and confined to northern South Africa over the past 80 years by means of a well-defined boundary line, with strict control measures and movement restrictions north of this line. In 2012, the first outbreak of ASF outside the ASF control zone since 1996 occurred. The objective of this study was to evaluate the current relevance of the ASF control line as a demarcation line between endemic ASF (north) areas and ASF-free (south) area and to determine whether there was a need to realign its trajectory, given the recent outbreaks of ASF, global climate changes and urban development since the line’s inception. A study of ASF determinants was conducted in an area 20 km north and 20 km south of the ASF control line, in Limpopo, Mpumalanga, North West and Gauteng provinces between May 2008 and September 2012. The study confirmed that warthogs, warthog burrows and the soft tick reservoir, Ornithodoros moubata, are present south of the ASF control line, but no virus or viral DNA was detected in these ticks. There appears to be an increasing trend in the diurnal maximum temperature and a decrease in humidity along the line, but the impact of these changes is uncertain. No discernible changes in minimum temperatures and average rainfall along the disease control line were observed between 1992 and 2014. Even though the reservoirs were found south of the ASF boundary line, the study concluded that there was no need to realign the trajectory of the ASF disease control line, with the exception of Limpopo Province. However, the provincial surveillance programmes for the reservoir, vector and ASF virus south of this line needs to be maintained and intensified as changing farming practices may favour the spread of ASF virus beyond the control line. Keywords: African swine fever; warthog burrow; Ornithodoros moubata;control line

African swine fever (ASF) has been reported in South Africa since the early 20th century. The disease has been controlled and confined to northern South Africa over the past 80 years by means of a well-defined boundary line, with strict control measures and movement restrictions north of this line. In 2012, the first outbreak of ASF outside the ASF control zone since 1996 occurred. The objective of this study was to evaluate the current relevance of the ASF control line as a demarcation line between endemic ASF (north) areas and ASF-free (south) area and to determine whether there was a need to realign its trajectory, given the recent outbreaks of ASF, global climate changes and urban development since the line's inception. A study of ASF determinants was conducted in an area 20 km north and 20 km south of the ASF control line, in Limpopo, Mpumalanga, North West and Gauteng provinces between May 2008 and September 2012. The study confirmed that warthogs, warthog burrows and the soft tick reservoir, Ornithodoros moubata, are present south of the ASF control line, but no virus or viral DNA was detected in these ticks. There appears to be an increasing trend in the diurnal maximum temperature and a decrease in humidity along the line, but the impact of these changes is uncertain. No discernible changes in minimum temperatures and average rainfall along the disease control line were observed between 1992 and 2014. Even though the reservoirs were found south of the ASF boundary line, the study concluded that there was no need to realign the trajectory of the ASF disease control line, with the exception of Limpopo Province. However, the provincial surveillance programmes for the reservoir, vector and ASF virus south of this line needs to be maintained and intensified as changing farming practices may favour the spread of ASF virus beyond the control line.