Biosecurity risks for African swine fever occurrence in smallholder systems in Gauteng, South Africa

African swine fever (ASF) outbreaks in Gauteng province (2012, 2019–2022) occurred outside South Africa’s (SA’s) traditional control zones and highlighted biosecurity deficiencies among smallholder producers. This study aimed to assess biosecurity practices and knowledge gaps among smallholder pig farmers in Gauteng by comparing ASF-free areas with high-risk areas (HRA) that had or had not experienced ASF outbreaks. Between 2020 and 2021, structured interviews were conducted with 137 pig farmers across four municipalities: Ekurhuleni, Lesedi, Tshwane and West Rand. The questionnaire captured data on farm and household characteristics, herd size and ownership, animal health management, biosecurity practices, pig movement and trade, ASF awareness, and potential routes of virus introduction. Farmers in HRA should implement additional biosecurity measures. Key risk factors included the absence of quarantine facilities (p < 0.05), improper carcass disposal and limited knowledge of ASF transmission. Contribution The findings provide baseline data crucial for developing evidence-based ASF control strategies targeting SA’s peri-urban smallholder pig production systems.