Review of African swine fever outbreaks history in South Africa: From 1926 to 2018

Abstract

The article reviews the outbreaks and distribution of African swine fever (ASF) in South Africa since the first probable outbreak that occurred in the Koedoesrand Ward in 1926. Retrospective data on the ASF outbreaks in South Africa were obtained from the World Organisation for Animal Health (OIE) disease database and the South African veterinary services annual reports in addition to published articles and online sources. South Africa has experienced many outbreaks that can be divided into 2 time periods: the period before the development of the OIE diseases database (1993) and the period after. More than 141 outbreaks of ASF were reported during the first period. Since the development of OIE disease database, 72 outbreaks directly involving 2968 cases, 2187 dead and 2358 killed pigs mainly in smallholder pig farms were reported. The median number of cases for a given ASF outbreak is 17, but in 50% of outbreaks no pigs were killed for prevention. The most important ASF outbreak was reported in April 2014 in the Greater Zeerust district (North West province) involving 326 cases and 1462 killed pigs. However, the outbreak with highest mortality involving 250 pigs was reported in 2016 (Free State province). According to phylogenetic analysis, nine p72 genotypes (I, III, IV, VII, VIII, XIX, XX, XXI and XXII) have been identified in South Africa. Season-wise, more outbreaks were recorded during summer. It was also observed that the OIE disease database could contain errors that would have been introduced through compiled forms at country level. Spatiotemporal studies on ASF outbreaks in South Africa are therefore required in order to assess statistically and quantitatively the clustering of outbreaks over space and time.

Development and application of a duplex real‐time PCR assay for differentiation of genotypes I and II African swine fever viruses

“…ASFV can infect domestic pigs, wild boars, and warthogs which caused high fever, lethargy, digestive dysfunctions, and abortion with mortality close to 100%. ASFVs could be divided into 24 genotypes based on viral B646L gene and most genotypes have been confined to Africa (Mushagalusa et al., 2021). As a notifiable disease to the World Organization for Animal Health (OIE), ASF has been circulating in Africa for a century since its first report in Kenya in 1921 (Montgomery, 1921).…”

“…TA B L E 1 Primers and Taqman probes used for differentiating between genotypes I and II African swine fever virus (ASFV). F, P, and R indicate forward primer, probe, and reverse primer, respectively Africa (Mushagalusa et al, 2021). As a notifiable disease to the World Organization for Animal Health (OIE), ASF has been circulating in Africa for a century since its first report in Kenya in 1921 (Montgomery, 1921).…”

Interaction network of African swine fever virus structural protein p30 with host proteins

“…It is the only member of the Asfarviridae family, with a mortality rate of 100% ( Penrith et al, 2019 ; Blome et al, 2020 ). ASF was first identified in Kenya and eastern Africa in the early twentieth century, and the first outbreak of ASF was reported in China in 2018 ( Zhou et al, 2018 ; Mushagalusa et al, 2021 ). Presently, ASFV has no effective commercial vaccine or antiviral drug and can only be strictly prevented and controlled.…”

Detection of African Swine Fever Virus in Ornithodoros Tick Species Associated with Indigenous and Extralimital Warthog Populations in South Africa

“…Appropriately-sized bands (~478 bp) of amplification product were excised from agarose electrophoresis gels, purified, and subjected to Sanger nucleotide sequencing. The sequences were viewed, 399 base fragments of DNA were aligned using MEGA X software [ 28 ] and neighbour-joining phylogenetic analysis was performed with representative sequences of the 10 ASFV p72 genotypes confirmed to occur in South Africa plus one unassigned virus (L. Heath, unpublished) using MEGA X software [ 28 , 29 ].…”