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Revue Scientifique Et Technique... Aug 2015Summary Bluetongue (BT) is an arthropod-transmitted viral disease of non-African ungulates, principally sheep. The disease results from vascular injury analogous to that...
Summary Bluetongue (BT) is an arthropod-transmitted viral disease of non-African ungulates, principally sheep. The disease results from vascular injury analogous to that of human haemorrhagic viral fevers, with characteristic tissue infarction, haemorrhage, vascular leakage, oedema, and hypovolaemic shock. Importantly, BT is not zoonotic. Bluetongue virus (BTV) infection of ruminants and vector Culicoides midges is endemic throughout many tropical and temperate regions of the world; however, within this global range the virus exists within relatively discrete ecosystems (syn. episystems) where specific constellations of BTV serotypes are spread by different species of biting Culicoides midges. Recently discovered goat-associated BTVs, notably BTV serotype 25 (BTV-25) in central Europe, appear to have distinctive biological properties and an epidemiology that is not reliant on Culicoides midges as vectors for virus transmission. Bluetongue virus infection of ruminants is often subclinical, but outbreaks of severe disease occur regularly at the upper and lower limits of the virus's global range, where infection is distinctly seasonal. There have been recent regional alterations in the global distribution of BTV infection, particularly in Europe. It is proposed that climate change is responsible for these events through its impact on vector midges. However, the role of anthropogenic factors in mediating emergence of BTV into new areas remains poorly defined; for example, it is not clear to what extent anthropogenic factors were responsible for the recent translocation to northern and eastern Europe of live attenuated vaccine viruses and an especially virulent strain of BTV-8 with distinctive properties. Without thorough characterisation of all environmental and anthropogenic drivers of the recent emergence of BT in northern Europe and elsewhere, it is difficult to predict what the future holds in terms of global emergence of BTV infection. Accurate and convenient laboratory tests are available for the sensitive and specific serological and virological diagnosis of BTV infection and confirmation of BT in animals. Prevention and control strategies for BT are largely reactive in nature, and typically are reliant on vaccination of susceptible livestock and restrictions on animal trade and movement.
Topics: Animals; Bluetongue; Bluetongue virus; Ceratopogonidae; Communicable Diseases, Emerging; Insect Vectors; Sheep
PubMed: 26601438
DOI: 10.20506/rst.34.2.2360 -
Revue Scientifique Et Technique... Aug 2015African horse sickness (AHS) is a devastating disease of equids caused by an arthropod-borne virus belonging to the Reoviridae family, genus Orbivirus. It is considered... (Review)
Review
African horse sickness (AHS) is a devastating disease of equids caused by an arthropod-borne virus belonging to the Reoviridae family, genus Orbivirus. It is considered a major health threat for horses in endemic areas in sub-Saharan Africa. African horse sickness virus (AHSV) repeatedly caused large epizootics in the Mediterranean region (North Africa and southern Europe in particular) as a result of trade in infected equids. The unexpected emergence of a closely related virus, the bluetongue virus, in northern Europe in 2006 has raised fears about AHSV introduction into Europe, and more specifically into AHSV-free regions that have reported the presence of AHSV vectors, e.g. Culicoides midges. North African and European countries should be prepared to face AHSV incursions in the future, especially since two AHSV serotypes (serotypes 2 and 7) have recently spread northwards to western (e.g. Senegal, Nigeria, Gambia) and eastern Africa (Ethiopia), where historically only serotype 9 had been isolated. The authors review key elements of AHS epidemiology, surveillance and prophylaxis.
Topics: Africa; African Horse Sickness; Animals; Horses; Orbivirus
PubMed: 26601437
DOI: 10.20506/rst.34.2.2359 -
Revue Scientifique Et Technique... Aug 2015Summary Epizootic haemorrhagic disease (EHD) is an arthropod-transmitted viral disease of certain wild ungulates, notably North American white-tailed deer and, more... (Review)
Review
Summary Epizootic haemorrhagic disease (EHD) is an arthropod-transmitted viral disease of certain wild ungulates, notably North American white-tailed deer and, more rarely, cattle. The disease in white-tailed deer results from vascular injury analogous to that caused by bluetongue virus (BTV), to which EHD virus (EHDV) is closely related. There are seven serotypes of EHDV recognised, and Ibaraki virus, which is the cause of sporadic disease outbreaks in cattle in Asia, is included in EHDV serotype 2. The global distribution and epidemiology of BTV and EHDV infections are also similar, as both viruses occur throughout temperate and tropical regions of the world where they are transmitted by biting Culicoides midges and infect a wide variety of domestic and wild ungulates. However, the global distribution and epidemiology of EHDV infection are less well characterised than they are for BTV. Whereas most natural and experimental EHDV infections (other than Ibaraki virus infection) of livestock are subclinical or asymptomatic, outbreaks of EHD have recently been reported among cattle in the Mediterranean Basin, Reunion Island, South Africa, and the United States. Accurate and convenient laboratory tests are increasingly available for the sensitive and specific serological and virological diagnosis of EHDV infection and confirmation of EHD in animals, but commercial vaccines are available only for prevention of Ibaraki disease and not for protection against other strains and serotypes of EHDV.
Topics: Animals; Cattle; Disease Outbreaks; Hemorrhagic Disease Virus, Epizootic; Reoviridae Infections
PubMed: 26601439
DOI: 10.20506/rst.34.2.2361 -
Microorganisms Dec 2020Bluetongue virus (BTV), the prototype member of the genus (family ), is the causative agent of an important livestock disease, bluetongue (BT), which is transmitted via... (Review)
Review
Bluetongue virus (BTV), the prototype member of the genus (family ), is the causative agent of an important livestock disease, bluetongue (BT), which is transmitted via biting midges of the genus To date, up to 29 serotypes of BTV have been described, which are classified as classical (BTV 1-24) or atypical (serotypes 25-27), and its distribution has been expanding since 1998, with important outbreaks in the Mediterranean Basin and devastating incursions in Northern and Western Europe. Classical vaccine approaches, such as live-attenuated and inactivated vaccines, have been used as prophylactic measures to control BT through the years. However, these vaccine approaches fail to address important matters like vaccine safety profile, effectiveness, induction of a cross-protective immune response among serotypes, and implementation of a DIVA (differentiation of infected from vaccinated animals) strategy. In this context, a wide range of recombinant vaccine prototypes against BTV, ranging from subunit vaccines to recombinant viral vector vaccines, have been investigated. This article offers a comprehensive outline of the live viral vectors used against BTV.
PubMed: 33375723
DOI: 10.3390/microorganisms9010042 -
Advances in Virus Research 2020Bluetongue virus (BTV) is an insect-vectored emerging pathogen of wild ruminants and livestock in many parts of the world. The virion particle is a complex structure of... (Review)
Review
Bluetongue virus (BTV) is an insect-vectored emerging pathogen of wild ruminants and livestock in many parts of the world. The virion particle is a complex structure of consecutive layers of protein surrounding a genome of 10 double-stranded (ds) RNA segments. BTV has been studied extensively as a model system for large, nonenveloped dsRNA viruses. A combination of recombinant proteins and particles together with reverse genetics, high-resolution structural analysis by X-ray crystallography and cryo-electron microscopy techniques have been utilized to provide an order for the assembly of the capsid shell and the protein sequestration required for it. Further, a reconstituted in vitro assembly system and RNA-RNA interaction assay, have defined the individual steps required for the assembly and packaging of the 10-segmented RNA genome. In addition, various microscopic techniques have been utilized to illuminate the stages of virus maturation and its egress via multiple pathways. These findings have not only given an overall understanding of BTV assembly and morphogenesis but also indicated that similar assembly and egress pathways are likely to be used by related viruses and provided an informed starting point for intervention or prevention.
Topics: Animals; Bluetongue virus; Books; Capsid; Capsid Proteins; Cryoelectron Microscopy; Genome, Viral; Insect Vectors; Livestock; Viral Proteins; Virion; Virus Assembly; Virus Release; Virus Replication
PubMed: 33837718
DOI: 10.1016/bs.aivir.2020.08.002 -
Equine Veterinary Journal Jul 2018Equine populations worldwide are at increasing risk of infection by viruses transmitted by biting arthropods, including mosquitoes, biting midges (Culicoides), sandflies... (Review)
Review
Equine populations worldwide are at increasing risk of infection by viruses transmitted by biting arthropods, including mosquitoes, biting midges (Culicoides), sandflies and ticks. These include the flaviviruses (Japanese encephalitis, West Nile and Murray Valley encephalitis), alphaviruses (eastern, western and Venezuelan encephalitis) and the orbiviruses (African horse sickness and equine encephalosis). This review provides an overview of the challenges faced in the surveillance, prevention and control of the major equine arboviruses, particularly in the context of these viruses emerging in new regions of the world.
Topics: Animals; Global Health; Horse Diseases; Horses; RNA Virus Infections; RNA Viruses
PubMed: 29517814
DOI: 10.1111/evj.12829 -
Viruses Mar 2019While serological and virological evidence documents the exposure of bats to medically-important arboviruses, their role as reservoirs or amplifying hosts is less...
While serological and virological evidence documents the exposure of bats to medically-important arboviruses, their role as reservoirs or amplifying hosts is less well-characterized. We describe a novel orbivirus () isolated from an Egyptian fruit bat () trapped in 2013 in Uganda and named Bukakata orbivirus. This is the fifth orbivirus isolated from a bat, however genetic information had previously only been available for one bat-associated orbivirus. We performed whole-genome sequencing on Bukakata orbivirus and three other bat-associated orbiviruses (Fomede, Ife, and Japanaut) to assess their phylogenetic relationship within the genus and develop hypotheses regarding potential arthropod vectors. Replication kinetics were assessed for Bukakata orbivirus in three different vertebrate cell lines. Lastly, qRT-PCR and nested PCR were used to determine the prevalence of Bukakata orbivirus RNA in archived samples from three populations of Egyptian fruit bats and one population of cave-associated soft ticks in Uganda. Complete coding sequences were obtained for all ten segments of Fomede, Ife, and Japanaut orbiviruses and for nine of the ten segments for Bukakata orbivirus. Phylogenetic analysis placed Bukakata and Fomede in the tick-borne orbivirus clade and Ife and Japanaut within the /phlebotomine sandfly orbivirus clade. Further, Bukakata and Fomede appear to be serotypes of the species. Bukakata orbivirus replicated to high titers (10⁶⁻10⁷ PFU/mL) in Vero, BHK-21 [C-13], and R06E (Egyptian fruit bat) cells. Preliminary screening of archived bat and tick samples do not support Bukakata orbivirus presence in these collections, however additional testing is warranted given the phylogenetic associations observed. This study provided complete coding sequence for several bat-associated orbiviruses and in vitro characterization of a bat-associated orbivirus. Our results indicate that bats may play an important role in the epidemiology of viruses in the genus and further investigation is warranted into vector-host associations and ongoing surveillance efforts.
Topics: Animals; Cell Line; Chiroptera; Chlorocebus aethiops; Disease Reservoirs; Genome, Viral; Open Reading Frames; Orbivirus; Phylogeny; RNA, Viral; Real-Time Polymerase Chain Reaction; Sequence Analysis, DNA; Vero Cells; Viral Proteins; Virus Replication; Whole Genome Sequencing
PubMed: 30832334
DOI: 10.3390/v11030209 -
Journal of Infection in Developing... Feb 2023Bluetongue (BT), once considered a disease of sheep confined to the southern African region, has spread all over the world. BT is a viral disease caused by the... (Review)
Review
Bluetongue (BT), once considered a disease of sheep confined to the southern African region, has spread all over the world. BT is a viral disease caused by the bluetongue virus (BTV). BT is regarded as an economically important disease in ruminants of compulsory notification to OIE. BTV is transmitted by the bite of Culicoides species. Research over the years has led to a better understanding of the disease, the nature of the virus life cycle between ruminants and Culicoides species, and its distribution in different geographical regions. Advances have also been made in understanding the molecular structure and function of the virus, the biology of the Culicoides species, its ability to transmit the disease, and the persistence of the virus inside the Culicoides and the mammalian hosts. Global climate change has enabled the colonization of new habitats and the spread of the virus into additional species of the Culicoides vector. This review highlights some of the current findings on the status of BT in the world based on the latest research on disease aspects, virus-host-vector interactions, and the different diagnostic approaches and control strategies available for BTV.
Topics: Animals; Sheep; Bluetongue virus; Insect Vectors; Ruminants; Bluetongue; Ceratopogonidae
PubMed: 36897898
DOI: 10.3855/jidc.16947 -
Viruses Nov 2021The aim of this review is to follow the history of studies on endemiv arboviruses and the diseases they cause which were detected in the Czech lands (Bohemia, Moravia... (Review)
Review
The aim of this review is to follow the history of studies on endemiv arboviruses and the diseases they cause which were detected in the Czech lands (Bohemia, Moravia and Silesia (i.e., the Czech Republic)). The viruses involve tick-borne encephalitis, West Nile and Usutu flaviviruses; the Sindbis alphavirus; Ťahyňa, Batai, Lednice and Sedlec bunyaviruses; the Uukuniemi phlebovirus; and the Tribeč orbivirus. Arboviruses temporarily imported from abroad to the Czech Republic have been omitted. This brief historical review includes a bibliography of all relevant papers.
Topics: Animals; Arbovirus Infections; Arboviruses; Czech Republic; History, 20th Century; History, 21st Century; Humans
PubMed: 34835140
DOI: 10.3390/v13112334 -
MSphere Apr 2023Arboviruses are among emerging pathogens of public and veterinary health significance. However, in most of sub-Saharan Africa, their role in the aetiologies of diseases...
Arboviruses are among emerging pathogens of public and veterinary health significance. However, in most of sub-Saharan Africa, their role in the aetiologies of diseases in farm animals is poorly described due to paucity of active surveillance and appropriate diagnosis. Here, we report the discovery of a previously unknown orbivirus in cattle collected in the Kenyan Rift Valley in 2020 and 2021. We isolated the virus in cell culture from the serum of a clinically sick cow aged 2 to 3 years, presenting signs of lethargy. High-throughput sequencing revealed an orbivirus genome architecture with 10 double-stranded RNA segments and a total size of 18,731 bp. The VP1 (Pol) and VP3 (T2) nucleotide sequences of the detected virus, tentatively named Kaptombes virus (KPTV), shared maximum similarities of 77.5% and 80.7% to the mosquito-borne Sathuvachari virus (SVIV) found in some Asian countries, respectively. Screening of 2,039 sera from cattle, goats, and sheep by specific RT-PCR identified KPTV in three additional samples originating from different herds collected in 2020 and 2021. Neutralizing antibodies against KPTV were found in 6% of sera from ruminants (12/200) collected in the region. experiments with new-born and adult mice induced body tremors, hind limb paralysis, weakness, lethargy, and mortality. Taken together, the data suggest the detection of a potentially disease-causing orbivirus in cattle in Kenya. Its impact on livestock, as well as its potential economic damage, needs to be addressed in future studies using targeted surveillance and diagnostics. The genus contains several viruses that cause large outbreaks in wild and domestic animals. However, there is little knowledge on the contribution of orbiviruses to diseases in livestock in Africa. Here, we report the identification of a novel presumably disease-causing orbivirus in cattle, Kenya. The virus, designated Kaptombes virus (KPTV), was initially isolated from a clinically sick cow aged 2 to 3 years, presenting signs of lethargy. The virus was subsequently detected in three additional cows sampled in neighboring locations in the subsequent year. Neutralizing antibodies against KPTV were found in 10% of cattle sera. Infection of new-born and adult mice with KPTV caused severe symptoms and lead to death. Together, these findings indicate the presence of a previously unknown orbivirus in ruminants in Kenya. These data are of relevance as cattle represents an important livestock species in farming industry and often is the main source of livelihoods in rural areas of Africa.
Topics: Female; Animals; Cattle; Sheep; Mice; Orbivirus; Kenya; Lethargy; Ruminants; Animals, Domestic; Goats; Livestock; Antibodies, Neutralizing
PubMed: 36794933
DOI: 10.1128/msphere.00488-22