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Revue Scientifique Et Technique... Aug 2008The invasion of multiple strains of the midge-borne bluetongue virus into southern Europe since the late 1990s provides a rare example of a clear impact of climate... (Review)
Review
The invasion of multiple strains of the midge-borne bluetongue virus into southern Europe since the late 1990s provides a rare example of a clear impact of climate change on a vector-borne disease. However, the subsequent dramatic continent-wide spread and burden of this disease has depended largely on altered biotic interactions with vector and host communities in newly invaded areas. Transmission by Palearctic vectors has facilitated the establishment of the disease in cooler and wetter areas of both northern and southern Europe. This paper discusses the important biological and climatic processes involved in these invasions, and the lessons that must be drawn for effective risk management of bluetongue and other midge-borne viruses in Europe.
Topics: Animals; Bluetongue; Bluetongue virus; Ceratopogonidae; Climate; Demography; Europe; Greenhouse Effect; Host-Pathogen Interactions; Insect Vectors; Molecular Epidemiology; Orbivirus; Reoviridae Infections
PubMed: 18819670
DOI: No ID Found -
PloS One 2012Eubenangee virus has previously been identified as the cause of Tammar sudden death syndrome (TSDS). Eubenangee virus (EUBV), Tilligery virus (TILV), Pata virus (PATAV)...
Eubenangee virus has previously been identified as the cause of Tammar sudden death syndrome (TSDS). Eubenangee virus (EUBV), Tilligery virus (TILV), Pata virus (PATAV) and Ngoupe virus (NGOV) are currently all classified within the Eubenangee virus species of the genus Orbivirus, family Reoviridae. Full genome sequencing confirmed that EUBV and TILV (both of which are from Australia) show high levels of aa sequence identity (>92%) in the conserved polymerase VP1(Pol), sub-core VP3(T2) and outer core VP7(T13) proteins, and are therefore appropriately classified within the same virus species. However, they show much lower amino acid (aa) identity levels in their larger outer-capsid protein VP2 (<53%), consistent with membership of two different serotypes - EUBV-1 and EUBV-2 (respectively). In contrast PATAV showed significantly lower levels of aa sequence identity with either EUBV or TILV (with <71% in VP1(Pol) and VP3(T2), and <57% aa identity in VP7(T13)) consistent with membership of a distinct virus species. A proposal has therefore been sent to the Reoviridae Study Group of ICTV to recognise 'Pata virus' as a new Orbivirus species, with the PATAV isolate as serotype 1 (PATAV-1). Amongst the other orbiviruses, PATAV shows closest relationships to Epizootic Haemorrhagic Disease virus (EHDV), with 80.7%, 72.4% and 66.9% aa identity in VP3(T2), VP1(Pol), and VP7(T13) respectively. Although Ngoupe virus was not available for these studies, like PATAV it was isolated in Central Africa, and therefore seems likely to also belong to the new species, possibly as a distinct 'type'. The data presented will facilitate diagnostic assay design and the identification of additional isolates of these viruses.
Topics: Africa, Central; Animals; Australia; Base Sequence; Conserved Sequence; Genome, Viral; Hemorrhagic Disease Virus, Epizootic; Macropodidae; Orbivirus; Phylogeography; RNA, Viral; Reoviridae Infections; Species Specificity; Viral Core Proteins; Viral Structural Proteins
PubMed: 22438872
DOI: 10.1371/journal.pone.0031911 -
Viruses Aug 2023Midges are widely distributed globally and can transmit various human and animal diseases through blood-sucking. As part of this study, 259,300 midges were collected...
Midges are widely distributed globally and can transmit various human and animal diseases through blood-sucking. As part of this study, 259,300 midges were collected from four districts in Yunnan province, China, to detect the viral richness and diversity using metavirome analysis techniques. As many as 26 virus families were detected, and the partial sequences of bluetongue virus (BTV), dengue virus (DENV), and Getah virus (GETV) were identified by phylogenetic analysis and PCR amplification. Two BTV gene fragments, 866 bps for the VP2 gene of BTV type 16 and 655 bps for the VP5 gene of BTV type 21, were amplified. The nucleotide sequence identities of the two amplified BTV fragments were 94.46% and 98.81%, respectively, with two classical BTV-16 (GenBank: JN671907) and BTV-21 strains (GenBank: MK250961) isolated in Yunnan province. Furthermore, the BTV-16 DH2021 strain was successfully isolated in C6/36 cells, and the peak value of the copy number reached 3.13 × 10 copies/μL after five consecutive BHK-21 cell passages. Moreover, two 2054 bps fragments including the E gene of DENV genotype Asia II were amplified and shared the highest identity with the DENV strain isolated in New Guinea in 1944. A length of 656 bps GETV gene sequence encoded the partial capsid protein, and it shared the highest identity of 99.68% with the GETV isolated from Shandong province, China, in 2017. Overall, this study emphasizes the importance of implementing prevention and control strategies for viral diseases transmitted by midges in China.
Topics: Animals; Humans; China; Phylogeny; Alphavirus; Asia; Capsid Proteins; Bluetongue virus
PubMed: 37766224
DOI: 10.3390/v15091817 -
Viruses Jul 2021Statin derivatives can inhibit the replication of a range of viruses, including hepatitis C virus (HCV, ), dengue virus (), African swine fever virus () and poliovirus...
Statin derivatives can inhibit the replication of a range of viruses, including hepatitis C virus (HCV, ), dengue virus (), African swine fever virus () and poliovirus (). We assess the antiviral effect of fluvastatin in cells infected with orbiviruses (bluetongue virus (BTV) and Great Island virus (GIV)). The synthesis of orbivirus outer-capsid protein VP2 (detected by confocal immunofluorescence imaging) was used to assess levels of virus replication, showing a reduction in fluvastatin-treated cells. A reduction in virus titres of ~1.7 log (98%) in fluvastatin-treated cells was detected by a plaque assay. We have previously identified a fourth non-structural protein (NS4) of BTV and GIV, showing that it interacts with lipid droplets in infected cells. Fluvastatin, which inhibits 3-hydroxy 3-methyl glutaryl CoA reductase in the mevalonic acid pathway, disrupts these NS4 interactions. These findings highlight the role of the lipid pathways in orbivirus replication and suggest a greater role for the membrane-enveloped orbivirus particles than previously recognised. Chemical intermediates of the mevalonic acid pathway were used to assess their potential to rescue orbivirus replication. Pre-treatment of IFNAR mice with fluvastatin promoted their survival upon challenge with live BTV, although only limited protection was observed.
Topics: Animals; Antiviral Agents; Bluetongue; Bluetongue virus; Cell Line; Ceratopogonidae; Fluvastatin; Humans; Hydroxymethylglutaryl CoA Reductases; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Metabolic Networks and Pathways; Mevalonic Acid; Mice; Orbivirus; Receptor, Interferon alpha-beta; Viral Load; Virus Replication; Yellow fever virus
PubMed: 34452303
DOI: 10.3390/v13081437 -
Viruses Sep 2019African horse sickness is a devastating disease that causes great suffering and many fatalities amongst horses in sub-Saharan Africa. It is caused by nine different... (Review)
Review
African horse sickness is a devastating disease that causes great suffering and many fatalities amongst horses in sub-Saharan Africa. It is caused by nine different serotypes of the orbivirus African horse sickness virus (AHSV) and it is spread by Culicoid midges. The disease has significant economic consequences for the equine industry both in southern Africa and increasingly further afield as the geographic distribution of the midge vector broadens with global warming and climate change. Live attenuated vaccines (LAV) have been used with relative success for many decades but carry the risk of reversion to virulence and/or genetic re-assortment between outbreak and vaccine strains. Furthermore, the vaccines lack DIVA capacity, the ability to distinguish between vaccine-induced immunity and that induced by natural infection. These concerns have motivated interest in the development of new, more favourable recombinant vaccines that utilize viral vectors or are based on reverse genetics or virus-like particle technologies. This review summarizes the current understanding of AHSV structure and the viral replication cycle and also evaluates existing and potential vaccine strategies that may be applied to prevent or control the disease.
Topics: Africa, Southern; African Horse Sickness; African Horse Sickness Virus; Animals; Antibodies, Neutralizing; Antibodies, Viral; Ceratopogonidae; Horses; Reverse Genetics; Vaccines, Attenuated; Vaccines, Synthetic; Viral Vaccines
PubMed: 31514299
DOI: 10.3390/v11090844 -
Revue Scientifique Et Technique... Jun 2021The availability of rapid, highly sensitive and specific molecular and serologic diagnostic assays, such as competitive enzyme-linked immunosorbent assay (cELISA), has... (Review)
Review
The availability of rapid, highly sensitive and specific molecular and serologic diagnostic assays, such as competitive enzyme-linked immunosorbent assay (cELISA), has expedited the diagnosis of emerging transboundary animal diseases, including bluetongue (BT) and African horse sickness (AHS), and facilitated more thorough characterisation of their epidemiology. The development of assays based on real-time, reverse-transcription polymerase chain reaction (RT-PCR) to detect and identify the numerous serotypes of BT virus (BTV) and AHS virus (AHSV) has aided in-depth studies of the epidemiology of BTV infection in California and AHSV infection in South Africa. The subsequent evaluation of pan-serotype, real-time, RT-PCR-positive samples through the use of serotype-specific RT-PCR assays allows the rapid identification of virus serotypes, reducing the need for expensive and time-consuming conventional methods, such as virus isolation and serotype-specific virus neutralisation assays. These molecular assays and cELISA platforms provide tools that have enhanced epidemiologic surveillance strategies and improved our understanding of potentially altered Culicoides midge behaviour when infected with BTV. They have also supported the detection of subclinical AHSV infection of vaccinated horses in South Africa. Moreover, in conjunction with whole genome sequence analysis, these tests have clarified that the mechanism behind recent outbreaks of AHS in the AHS-controlled area of South Africa was the result of the reversion to virulence and/or genome reassortment of live attenuated vaccine viruses. This review focuses on the use of contemporary molecular diagnostic assays in the context of recent epidemiologic studies and explores their advantages over historic virus isolation and serologic techniques.
Topics: African Horse Sickness; African Horse Sickness Virus; Animals; Bluetongue; Bluetongue virus; Horse Diseases; Horses; Sheep; Sheep Diseases; South Africa
PubMed: 34140738
DOI: 10.20506/rst.40.1.3210 -
EcoHealth Dec 2022Orbiviruses are arthropod borne viruses of vertebrates, with some of them being important pathogens of veterinary, conservation and economic importance, while others are...
Orbiviruses are arthropod borne viruses of vertebrates, with some of them being important pathogens of veterinary, conservation and economic importance, while others are occasionally associated with human disease. Some apparently bat specific orbiviruses have been detected, but little is known about their distribution and diversity. We thus sampled and screened 52 bats living in the Congo Basin, and detected RNA indicative of a novel orbivirus in a single banana serotine (Afronycteris nanus) by PCR. The detected RNA clusters with epizootic haemorrhagic disease virus, bluetongue virus, and others. The findings highlight the need for more studies into arbovirus presence and diversity in bat species.
Topics: Animals; Humans; Orbivirus; Chiroptera; Congo; Musa; RNA; Arboviruses
PubMed: 36629956
DOI: 10.1007/s10393-022-01619-2 -
Current Opinion in Virology Oct 2020Bluetongue virus (BTV) reverse genetics (RG), available since 2007, has allowed the dissection of the virus replication cycle, including discovery of a primary... (Review)
Review
Bluetongue virus (BTV) reverse genetics (RG), available since 2007, has allowed the dissection of the virus replication cycle, including discovery of a primary replication stage. This information has allowed the generation of Entry-Competent-Replication-Abortive (ECRA) vaccines, which enter cells and complete primary replication but fail to complete the later stage. A series of vaccine trials in sheep and cattle either with a single ECRA serotype or a cocktail of multiple ECRA serotypes have demonstrated that these vaccines provide complete protection against virulent virus challenge without cross-serotype interference. Similarly, an RG system developed for the related African Horse Sickness virus, which causes high mortality in equids has provided AHSV ECRA vaccines that are protective in horses. ECRA vaccines were incapable of productive replication in animals despite being competent for cell entry. This technology allows rapid generation of emerging Orbivirus vaccines and offers immunogenicity and safety levels that surpass attenuated or recombinant routes.
Topics: Animals; Antibodies, Neutralizing; Antibodies, Viral; Bluetongue; Bluetongue virus; Cattle; Orbivirus; Reoviridae Infections; Reverse Genetics; Sheep; Vaccines, Attenuated; Viral Vaccines; Virus Replication
PubMed: 32610251
DOI: 10.1016/j.coviro.2020.05.003 -
BMC Veterinary Research Jun 2016Within the last few decades Culicoides spp. (Diptera: Ceratopogonidae) emerged Europe-wide as a major vector for epizootic viral diseases e.g. caused by Bluetongue (BT)...
BACKGROUND
Within the last few decades Culicoides spp. (Diptera: Ceratopogonidae) emerged Europe-wide as a major vector for epizootic viral diseases e.g. caused by Bluetongue (BT) or Schmallenberg virus. In accordance with the EU regulation 1266/2007, veterinary authorities are requested to determine vector-free periods for loosing trade and movement restrictions of susceptible livestock. Additionally, the widely used basic reproduction number [Formula: see text] is optionally applied for risk assessment of vector-borne diseases. Values of R0 < 1 indicate periods with no disease transmission risk. For the determination of vector-free period and R0 a continuously operating daily Culicoides spp. monitoring in Vienna (Austria) was established. It covered the period 2009-2013 and depicts the seasonal vector abundance indoor and outdoor. Future BT and African horse sickness (AHS) outbreak risks were estimated by projecting R0 to climate change scenarios. Therefore, temperature-dependent vector parameters were applied.
RESULTS
The vector-free period lasted about 100 days inside stables, while less than five Culicoides were trapped outdoors on 150 days per season, i.e. winter half year. Additionally, the potential outbreak risk was assessed for BT and AHS. For BT, a basic reproduction number of R0 > 1 was found each year between June and August. The periods without transmission risk, i.e. R0 < 1, were notably higher (200 days). Contrary, values of R0 < 1 were estimated for AHS during the whole period. Finally, the basic reproduction numbers were projected to the future by using temperature forecasts for the period 2014-2100. While the mean summer peak values for BT increase from of R0 = 2.3 to R0 = 3.4 until 2100 (1.1/100 years), no risk for AHS was estimated even under climate warming assumptions.
CONCLUSIONS
Restrictions to trade and movement are always associated with an economic impact during epidemic diseases. To minimize these impacts, risk assessments based on the vector-free period or the basic reproduction number R0 can essentially support veterinary authorities to improve protection and control measurements.
Topics: African Horse Sickness; Animals; Austria; Bluetongue; Bluetongue virus; Ceratopogonidae; Climate; Disease Outbreaks; Entomology; Epidemiological Monitoring; Female; Horses; Insect Vectors; Male; Orbivirus; Orthobunyavirus; Population Dynamics; Risk Assessment; Seasons
PubMed: 27259473
DOI: 10.1186/s12917-016-0710-z -
Veterinary Research 2010Arthropod-transmitted viruses (Arboviruses) are important causes of disease in humans and animals, and it is proposed that climate change will increase the distribution... (Review)
Review
Arthropod-transmitted viruses (Arboviruses) are important causes of disease in humans and animals, and it is proposed that climate change will increase the distribution and severity of arboviral diseases. Orbiviruses are the cause of important and apparently emerging arboviral diseases of livestock, including bluetongue virus (BTV), African horse sickness virus (AHSV), equine encephalosis virus (EEV), and epizootic hemorrhagic disease virus (EHDV) that are all transmitted by haematophagous Culicoides insects. Recent changes in the global distribution and nature of BTV infection have been especially dramatic, with spread of multiple serotypes of the virus throughout extensive portions of Europe and invasion of the south-eastern USA with previously exotic virus serotypes. Although climate change has been incriminated in the emergence of BTV infection of ungulates, the precise role of anthropogenic factors and the like is less certain. Similarly, although there have been somewhat less dramatic recent alterations in the distribution of EHDV, AHSV, and EEV, it is not yet clear what the future holds in terms of these diseases, nor of other potentially important but poorly characterized Orbiviruses such as Peruvian horse sickness virus.
Topics: African Horse Sickness; Animals; Bluetongue; Communicable Diseases, Emerging; Horses; Orbivirus; Sheep
PubMed: 20167199
DOI: 10.1051/vetres/2010007