scholarly journals Extension of Sylvatic Circulation of African Swine Fever Virus in Extralimital Warthogs in South Africa

2021 ◽  
Vol 8 ◽  
Author(s):  
Anthony F. Craig ◽  
Mathilde L. Schade-Weskott ◽  
Henry J. Harris ◽  
Livio Heath ◽  
Gideon J. P. Kriel ◽  
...  
Keyword(s):  
South Africa ◽  
Invasive Species ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Serological Evidence ◽  
The South ◽  
Domestic Pigs ◽  
The Past ◽  
The North

Sylvatic circulation of African swine fever virus (ASFV) in warthogs and Ornithodoros ticks that live in warthog burrows historically occurred in northern South Africa. Outbreaks of the disease in domestic pigs originated in this region. A controlled area was declared in the north in 1935 and regulations were implemented to prevent transfer of potentially infected suids or products to the rest of the country. However, over the past six decades, warthogs have been widely translocated to the south where the extralimital animals have flourished to become an invasive species. Since 2016, there have been outbreaks of ASF in pigs outside the controlled area that cannot be linked to transfer of infected animals or products from the north. An investigation in 2008–2012 revealed that the presence of Ornithodoros ticks and ASFV in warthog burrows extended marginally across the boundary of the controlled area. We found serological evidence of ASFV circulation in extralimital warthogs further south in the central part of the country.

scholarly journals Updated distribution and host records for the argasid tick Ornithodoros (Pavlovskyella) zumpti: A potential vector of African swine fever virus in South Africa

2021 ◽  
Vol 88 (1) ◽  
Author(s):  
Anthony F. Craig ◽  
Livio Heath ◽  
Jan E. Crafford ◽  
Juergen A. Richt ◽  
Robert Swanepoel
Keyword(s):  
South Africa ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Eastern Cape ◽  
The South ◽  
Domestic Pigs ◽  
The North ◽  
Argasid Tick ◽  
First Time

African swine fever virus (ASFV) causes a lethal and contagious disease of domestic pigs. In South Africa, the virus historically circulated in warthogs and ornithodorid ticks that were only found in warthog burrows in the north of the country. Regulations implemented in 1935 to prevent transfer of infected animals or products to the south initially proved effective but from 2016 there have been outbreaks of disease in the south that cannot be traced to transfer of infection from the north. From 1963 there were widespread translocations of warthogs to the south, initially from a source considered to be free of ornithodorid ticks. We undertook to determine whether sylvatic circulation of ASFV occurs in the south, including identification of potential new vectors, through testing extralimital warthogs for antibody and ticks for virus. Results of testing warthogs for antibody and other species of ticks for virus will be presented separately. Here we report finding Ornithodoros (Pavlovskyella) zumpti ticks in warthog burrows for the first time. This occurred in the Eastern Cape Province (ECP) in 2019. Since African swine fever was recognised in the ECP for the first time in 2020 and outbreaks of the disease in domestic pigs continue to occur there, priority should be given to determining the distribution range and vector potential of O. (P.) zumpti for ASFV.

scholarly journals Substitution of warthog NF-κB motifs into RELA of domestic pigs is not sufficient to confer resilience to African swine fever virus

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Stephen McCleary ◽  
Rebecca Strong ◽  
Ronan R. McCarthy ◽  
Jane C. Edwards ◽  
Emma L. Howes ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Domestic Pigs

scholarly journals Identification of a Continuously Stable and Commercially Available Cell Line for the Identification of Infectious African Swine Fever Virus in Clinical Samples

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 820 ◽  
Author(s):  
Ayushi Rai ◽  
Sarah Pruitt ◽  
Elizabeth Ramirez-Medina ◽  
Elizabeth A. Vuono ◽  
Ediane Silva ◽  
...  
Keyword(s):  
Cell Line ◽  
Virus Isolation ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Clinical Samples ◽  
Outbreak Strain ◽  
Domestic Pigs ◽  
Current Outbreak ◽  
High Degree

African swine fever virus (ASFV) is causing outbreaks both in domestic pigs and wild boar in Europe and Asia. In 2018, the largest pig producing country, China, reported its first outbreak of African swine fever (ASF). Since then, the disease has quickly spread to all provinces in China and to other countries in southeast Asia, and most recently to India. Outbreaks of the disease occur in Europe as far west as Poland, and one isolated outbreak has been reported in Belgium. The current outbreak strain is highly contagious and can cause a high degree of lethality in domestic pigs, leading to widespread and costly losses to the industry. Currently, detection of infectious ASFV in field clinical samples requires accessibility to primary swine macrophage cultures, which are infrequently available in most regional veterinary diagnostic laboratories. Here, we report the identification of a commercially available cell line, MA-104, as a suitable substrate for virus isolation of African swine fever virus.

scholarly journals African Swine Fever spread across Asia, 2018---2019

2020 ◽  
Author(s):  
Michael Ward ◽  
Ellen Mighell
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Temporal Analysis ◽  
The Philippines ◽  
Control Measures ◽  
The South ◽  
Start Date ◽  
North East ◽  
The North ◽  
Spatio Temporal

African Swine Fever Virus (ASFV) is a highly contagious pathogen causing disease in pigs, commonly characterised by acute haemorrhagic fever. Prior to August 2018, African Swine Fever (ASF) had not been reported in Asia, but has since spread throughout China, Mongolia, Korea, Vietnam, Laos, Cambodia, Myanmar, the Philippines, Hong Kong, Indonesia, Timor-Leste and Papua New Guinea. Using data collated from reports of confirmed cases, we applied spatio-temporal analysis to describe ASFV spread throughout Asia, from 1 August 2018 (reported start date) to 31 December 2019. Analysis revealed a propagating epidemic of ASFV throughout Asia, with peaks corresponding to increased reports from China, Vietnam and Laos. Two clusters of reported outbreaks were found. During the epidemic, ASFV primarily spread from the North-East to the South-East: a larger, secondary cluster in the North-East represented earlier reports, whilst the smaller, primary cluster in the South-East was characterised by later reports. Significant differences in country-specific epidemics, morbidity, mortality and unit types were discovered, likely attributable to differences in prevention, surveillance and control measures. The initial number of outbreaks and enterprise size are likely predictors of the speed of spread and the effectiveness of ASFV stamping out procedures. Biosecurity methods, wild boar populations and the transportation of pigs and movement of infected fomites are discussed as likely risk factors for facilitating ASFV spread across Asia.

scholarly journals Impaired T‐cell responses in domestic pigs and wild boar upon infection with a highly virulent African swine fever virus strain

2020 ◽  
Vol 67 (6) ◽  
pp. 3016-3032 ◽  
Author(s):  
Jane Hühr ◽  
Alexander Schäfer ◽  
Theresa Schwaiger ◽  
Laura Zani ◽  
Julia Sehl ◽  
...  
Keyword(s):  
T Cell ◽  
Wild Boar ◽  
Virus Strain ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
T Cell Responses ◽  
Fever Virus ◽  
Domestic Pigs ◽  
Cell Responses ◽  
Highly Virulent

scholarly journals Comparative Pathology of Domestic Pigs and Wild Boar Infected with the Moderately Virulent African Swine Fever Virus Strain “Estonia 2014”

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 662
Author(s):  
Julia Sehl ◽  
Jutta Pikalo ◽  
Alexander Schäfer ◽  
Kati Franzke ◽  
Katrin Pannhorst ◽  
...  
Keyword(s):  
Wild Boar ◽  
Viral Antigen ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Kinetic Experiment ◽  
Domestic Pigs ◽  
Hunting Bag ◽  
North Eastern ◽  
The Baltic

Endemically infected European wild boar are considered a major reservoir of African swine fever virus in Europe. While high lethality was observed in the majority of field cases, strains of moderate virulence occurred in the Baltic States. One of these, “Estonia 2014”, led to a higher number of clinically healthy, antibody-positive animals in the hunting bag of North-Eastern Estonia. Experimental characterization showed high virulence in wild boar but moderate virulence in domestic pigs. Putative pathogenic differences between wild boar and domestic pigs are unresolved and comparative pathological studies are limited. We here report on a kinetic experiment in both subspecies. Three animals each were euthanized at 4, 7, and 10 days post infection (dpi). Clinical data confirmed higher virulence in wild boar although macroscopy and viral genome load in blood and tissues were comparable in both subspecies. The percentage of viral antigen positive myeloid cells tested by flow cytometry did not differ significantly in most tissues. Only immunohistochemistry revealed consistently higher viral antigen loads in wild boar tissues in particular 7 dpi, whereas domestic pigs already eliminated the virus. The moderate virulence in domestic pigs could be explained by a more effective viral clearance.

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