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10 Jan 2019 - Identification of T-cell epitopes in African swine fever virus CD2v and C-type lectin proteins
African swine fever (ASF) is an emerging disease threat for the swine industry worldwide. No ASF vaccine is available, and progress is hindered by lack of knowledge concerning the extent of ASF virus (ASFV) strain diversity and the viral antigens conferring type-specific protective immunity in pigs. Previously, we demonstrated that ASFV serotype-specific proteins CD2v (EP402R) and/or C-type lectin (EP153R) are important for protection against homologous ASF infection. Here, we identified six discrete T-cell epitope regions present on CD2v and C-type lectin using IFN-γ ELISpot assay and PBMCs from ASF immune animals, indicating cellular reactivity to these proteins in the context of ASFV infection and protective immunity. Notably, three of the epitope regions map to previously described serotype-specific signature regions of these proteins. Improved understanding of ASFV protective antigens, relevant epitopes and their diversity in nature will facilitate ASFV subunit vaccine design and development.
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17Jun2019 - Comparative Analysis of Whole-Genome Sequence of African Swine Fever Virus Belgium 2018/1
We analyzed the whole-genome sequence of African swine fever virus Belgium 2018/1. The strain fits into the European genotype II (>99.98% identity). The high-coverage sequence revealed 15 differences compared with an improved virus African swine fever virus Georgia 2007/1 sequence. However, in the absence of genetic markers, no spatial or temporal correlations could be defined.
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2019 Jan - Phylogeographic Analysis of African Swine Fever Virus, Western Europe, 2018
In September 2018, African swine fever in wild boars was detected in Belgium. We used African swine fever–infected spleen samples to perform a phylogenetic analysis of the virus. The causative strain belongs to genotype II, and its closest relatives are viruses previously isolated in Ukraine, Belarus, Estonia, and European Russia.
African swine fever (ASF) is a devastating disease of domestic pigs and wild boars caused by a DNA arbovirus, African swine fever virus (ASFV), belonging to the family Asfarviridae. ASF is endemic in sub-Saharan Africa countries and has become more prevalent in the Caucasus region since its spread from eastern Africa to Georgia in 2007. The epizootic then spread to the surrounding countries, including the Russian Federation, and further to Belarus and Ukraine. In 2014, ASFV reached the European Union member states of Estonia, Latvia, Lithuania, and Poland; in 2016, Moldova; and, in 2017, the Czech Republic and Romania (1).
On September 13, 2018, authorities in Belgium reported that ASF had been confirmed in 2 wild boars near the village of Étalle (49.6833° N, 5.6° E), in the province of Luxembourg, which is located 12 km from the border with France and 17 km from the country of Luxembourg. ASFV appears to have jumped a considerable distance from previously affected countries: ≈500 km from the border with the Czech Republic, 800 km from Hungary, and 1,200 km from the border with Romania. Since then, ≈75% of the wild boars found dead near the primordial spot have been found to be ASFV positive; a total of 96 positive results had been recorded as of October 16, 2018.
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28Mar2019 - African swine fever: update on Eastern, Central and Southern Africa
Control of African swine fever (ASF) in countries in Eastern, Central and Southern Africa (ECSA) is particularly complex owing to the presence of all three known epidemiological cycles of maintenance of the virus, namely an ancient sylvatic cycle involving the natural hosts and vectors of the disease as well as domestic cycles with and without involvement of natural vectors. While the situation is well documented in some of the countries, for others very little information is available. In spite of the unfavourable ASF situation, the pig population in the sub‐region has grown exponentially in recent decades and is likely to continue to grow in response to rapid urban growth resulting in increasing demand for animal protein by populations that are no longer engaged in livestock production. Better management of ASF will be essential to permit the pig sector to reach its full potential as a supplier of high quality protein and a source of income to improve livelihoods and create wealth. No vaccine is currently available and it is likely that, for the near future, the sub‐region will continue to rely on the implementation of preventive measures, based on the epidemiology of the disease, to avoid both the devastating losses that outbreaks can cause and the risk the sub‐region poses to other parts of Africa and the world. The current situation in the ECSA sub‐region is reviewed and gaps in knowledge are identified in order to support ongoing strategy development for managing ASF in endemic areas.
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11 Jan 2019 - Epidemiology of African swine fever in Africa today: Sylvatic cycle versus socio‐economic imperatives
African swine fever (ASF) is believed to have evolved in eastern and southern Africa in a sylvatic cycle between common warthogs (Phacochoerus africanus) and argasid ticks of the Ornithodoros moubata complex that live in their burrows. The involvement of warthogs and possibly other wild suids in the maintenance of ASF virus means that the infection cannot be eradicated from Africa, but only prevented and controlled in domestic pig populations. Historically, outbreaks of ASF in domestic pigs in Africa were almost invariably linked to the presence of warthogs, but subsequent investigations of the disease in pigs revealed the presence of another cycle involving domestic pigs and ticks, with a third cycle becoming apparent when the disease expanded into West Africa where the sylvatic cycle is not present. The increase in ASF outbreaks that has accompanied the exponential growth of the African pig population over the last three decades has heralded a shift in the epidemiology of ASF in Africa, and the growing importance of the pig husbandry and trade in the maintenance and spread of ASF. This review, which focuses on the ASF situation between 1989 and 2017, suggests a minor role for wild suids compared with the domestic cycle, driven by socio‐economic factors that determine the ability of producers to implement the control measures needed for better management of ASF in Africa.
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29 March 2019 - African Swine Fever Virus
African swine fever is a large, icosahedral, linear double‐stranded DNA virus and the only member of the family Asfarviridae, genus Asfivirus. African swine fever virus (ASFV) is maintained in Africa via a complex transmission cycle involving African wild suid species, soft ticks, and domestic pigs. ASFV is transmitted within Europe most often directly via contact between sick and healthy animals, including domestic pigs and wild boar. The sites of primary ASFV replication are the monocytes and macrophages of the lymph nodes nearest the point of virus entry. The most convenient, safe, and frequently used techniques to detect and identify ASFV are the polymerase chain reaction. The serological diagnosis of ASF plays an important role in the surveillance program due to the fact that no vaccine is currently available against ASFV and, therefore, the presence of anti‐ASFV antibodies in an animal indicates infection.
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