Table 1.

Identified risk factors and motivation for inclusion.

Risk Factor	Reason for Inclusion	References
Number of ASF outbreaks reported in that province from Jan 2000 to Oct 2020	Previous outbreaks in the area may indicate that a source of ASFV could still be present in the area.	[10,11,14,23]
Number of pigs in the province	In order for ASF outbreaks to occur, it stands to reason that domestic pigs should be present, and that the more pigs, the higher the risk of an outbreak there is.	[19,24,25]
Whether warthogs are present in the province	Although very simplified, if wildlife reservoirs of ASF are present in the province, they could serve as a potential source/maintainer of virus.	[12,24,26,27]
Responsiveness to ASF questionnaire request per province	This can give a crude indication of the current priority of ASF prevention (as this was combined with an ASF awareness campaign) in the particular province.	[1,28]
Pigs not kept confined	This was found to have played a significant role in previous ASF outbreaks in both South Africa and other countries due to owners having no control over what the pigs come into contact with.	[19,29,30,31,32,33]
Feeding of uncooked swill potentially containing meat products	This was found to have played a role in previous ASF outbreaks in both South Africa and other countries due to the ASF virus being able to survive well in a proteinaceous environment.	[2,14,19,32,34,35,36,37,38,39,40,41]
Buying and/or selling at auctions	This was found to have played a role in previous ASF outbreaks in both South Africa and other countries due to the mixing of pigs of various origins, including some which may be at auction due to panic selling that occurs once pigs start dying.	[1,14,34,42]
Practising home slaughter	When pigs are informally slaughtered, there is no meat inspection performed to detect signs of ASF. Furthermore, households slaughtering pigs often provide meat to neighbours or sell the meat in the local community, which may contribute to the spread of disease. Disposal of the remains also presents problems, especially in areas with free-roaming pigs.	[1,24,33,36,37,40,42,43,44]
Poor knowledge of ASF	Where a pig keeper’s knowledge of ASF is poor to none, no measures are implemented to prevent the entry of ASF into the pig herd.	[34,44].