Wednesday morning 23 October 2020 marks the first of a hopeful relationship between pork producers, farmers and government along with university academics. The location is not that of a new outbreak, rather joined efforts between farmers and researchers the Gauteng province.
An initiative was born out of the current local and international situation of African Swine Fever (ASF). Countries like the United States of America have never reported the disease while China was hit hard with ASF since August 2018. South Africa also reacted heavily with strict quarantine in affected provinces and banning movement and sales of pigs following reported ASF cases. The outbreaks that are under close watch are those outside of the control zone.
ASF is endemic to South Africa, and poses challenging conditions with its free and control zones. The control zone is demarcated by the 'redline' separating the controlled areas where occurrence of the sylvatic cycle between African Warthog and the Ornithodoris soft tick occurs. The soft tick is the vector for the ASF virus in this cycle. Contact between domestic pigs and Warthogs in these situations, result in virus transmission and the manner in which outbreaks in the past occured. The changing conditions of Warthog movements and possible tick spreading further outside of the control zone, creates a unique learning situation for the strain of viruses that cause the disease in domestic pigs.
Researcher Anthony Graig, currently a PhD student along with Professor Robert Swanepoel, from the University of Pretoria, sampled for the soft tick on this occasion. Burrows were investigated for Warthog activity as burrows are sometimes shared with other animals. Sand scrapings were collected from the internal burrow walls and floor area, as the tick lives here, awaiting a blood feeding from the burrow inhabitants. All forms of pig farming or pig keeping in South Africa is at risk.
It has to be emphasized that proper pig production facilities with strict bio-security measures will maintain a good contact buffer between warthogs and a possible ASF disease. However, low-level disease prevention in pig farming such as fencing that only keep pigs in, but not preventing direct contact with Warthogs. Not showering in or changing of clothes and shoes, faces the greatest risk of a possible outbreak of the disease in a herd. This in return poses a risk to the national swine herd, highlighting the need for strict bio-security and appropriate facilities at all levels.
ASF does not seem to affect the African Warthog even though it is classed as Suidae.
Another increasing risk, which may pose a serious future problem is the intentional crossbreeding of European Wild Boar with domestic pigs, and the release of European Wild Boar onto farming areas. These animals not only devastate crops and natural vegetation but could share burrows with Warthogs and its ticks, becoming infected with the virus and develop ASF.
A long hot day of travelling and checking sand siftings in the sun was valuable. Connections between farmers, State Veterinary Services and pork producers were established and goals aligned in the effort against local outbreaks of ASF.
By Marc R. Raath
Animal Health Technician
Taaibosch Piggery