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Emerging Infectious Diseases Apr 2019Epizootic hemorrhagic disease affects wild and domestic ruminants and has recently spread northward within the United States. In September 2017, we detected epizootic...
Epizootic hemorrhagic disease affects wild and domestic ruminants and has recently spread northward within the United States. In September 2017, we detected epizootic hemorrhagic disease virus in wild white-tailed deer, Odocoileus virginianus, in east-central Canada. Culicoides spp. midges of the subgenus Avaritia were the most common potential vectors identified on site.
Topics: Animal Diseases; Animals; Canada; Deer; Hemorrhagic Disease Virus, Epizootic; Reoviridae Infections; Seroepidemiologic Studies; Vector Borne Diseases
PubMed: 30882321
DOI: 10.3201/eid2504.180743 -
Open Veterinary Journal 2022Bluetongue (BT) is an important infectious, non-contagious, OIE-listed viral disease of domestic and wild ruminants. The disease is transmitted among susceptible animals...
BACKGROUND
Bluetongue (BT) is an important infectious, non-contagious, OIE-listed viral disease of domestic and wild ruminants. The disease is transmitted among susceptible animals by a few species of an insect vector in the genus . Recently, during the fall of 2020 (September and October), a Bluetongue virus-4 epizootic marked the epidemiological situation in several delegations of Tunisia with clinical cases recorded in sheep and cattle.
AIM
Determine the eco-climatic variables most likely associated with delegations reporting BT cases.
METHODS
A logistic regression model (LRM) was used to examine which eco-climatic variables were most likely associated with delegations reporting BT cases.
RESULTS
Based on the LRM, our findings demonstrated that the key factors contributing significantly to BT cases' distribution among delegations in Tunisia included day land surface temperatures (DLST), night land surface temperatures (NLST) and normalized difference vegetation index (NDVI). A positive correlation between sheep distribution and rainfall amounts was demonstrated. Statistical analysis focusing on the most affected delegations during the BT epidemic (the Sahel and the Centre of Tunisia) demonstrated that the epidemic situation seems to be a consequence of the combination of the following environmental parameters: NDVI with values ranging between 0.16 and 0.2, moderate rainfall 2-4-fold above the normal (10-50 mm) and DLST values between 32°C and 34°C in September.
CONCLUSION
These findings suggest and develop a robust and efficient early warning surveillance program in risk areas based on eco-climatic risk factors.
Topics: Animals; Bluetongue; Bluetongue virus; Cattle; Cattle Diseases; Ceratopogonidae; Insect Vectors; Sheep; Sheep Diseases; Tunisia
PubMed: 35342732
DOI: 10.5455/OVJ.2022.v12.i1.14 -
Transactions of the Royal Society of... Sep 2021Phlebotomine sand flies are vectors for several pathogenic bacteria, parasites and viruses that have significant impacts on public health. Sand fly-associated viruses...
BACKGROUND
Phlebotomine sand flies are vectors for several pathogenic bacteria, parasites and viruses that have significant impacts on public health. Sand fly-associated viruses that cause diseases in humans and animals have recently received more attention. This study aimed to detect pathogenic viruses belonging to the Orbivirus genus, Phlebovirus genus, Flavivirus genus and family Rhabdoviridae in several field-caught sand fly species in southern Thailand.
METHODS
Sand flies were collected in southern Thailand using CDC light traps. Each sample was processed individually for virus screening using RT-PCR and sequencing.
RESULTS
Seven out of 60 sand fly samples (two samples of Idiophlebotomus spp., three of Phlebotomus papatasi and two of Sergentomyia khawi) were positive for the Orbivirus genus, which is closely related to Changuinola virus (CGLV). Phlebovirus genus, Flavivirus genus and family Rhabdoviridae were negative in all samples.
CONCLUSIONS
CGLV causes Changuinola virus disease or Changuinola fever, a febrile illness in Central and South America. The virus has never been reported in Thailand. This study is the first report of the detection of CGLV in sand flies from Thailand. An extensive study of sand flies from other regions of the country and the associations between sand flies, viruses and vertebrate hosts in Thailand should be undertaken.
Topics: Animals; Humans; Orbivirus; Phlebotomus; Psychodidae; Reoviridae; Thailand
PubMed: 33515044
DOI: 10.1093/trstmh/traa203 -
Viruses Dec 2022Epizootic haemorrhagic disease (EHD) is a -borne viral disease caused by the epizootic haemorrhagic disease virus (EHDV) associated with clinical manifestations in...
Epizootic haemorrhagic disease (EHD) is a -borne viral disease caused by the epizootic haemorrhagic disease virus (EHDV) associated with clinical manifestations in domestic and wild ruminants, primarily white-tailed deer () and cattle (). In late September 2021, EHDV was reported in cattle farms in central/western Tunisia. It rapidly spread throughout the country with more than 200 confirmed outbreaks. We applied a combination of classical and molecular techniques to characterize the causative virus as a member of the serotype EHDV-8. This is the first evidence of EHDV- 8 circulation since 1982 when the prototype EHDV-8 strain was isolated in Australia. This work highlights the urgent need for vaccines for a range of EHDV serotypes.
Topics: Animals; Cattle; Deer; Serogroup; Hemorrhagic Disease Virus, Epizootic; Reoviridae Infections; Tunisia; Ruminants
PubMed: 36680057
DOI: 10.3390/v15010016 -
Emerging Infectious Diseases May 2023We describe the detection of epizootic hemorrhagic disease virus (EHDV) serotype 8 in cattle farms in Sardinia and Sicily in October-November 2022. The virus has a...
We describe the detection of epizootic hemorrhagic disease virus (EHDV) serotype 8 in cattle farms in Sardinia and Sicily in October-November 2022. The virus has a direct origin in North Africa; its genome is identical (>99.9% nucleotide sequence identity) to EHDV serotype 8 strains detected in Tunisia in 2021.
Topics: Animals; Cattle; Reoviridae Infections; Serogroup; Hemorrhagic Disease Virus, Epizootic; Base Sequence; Italy; Cattle Diseases
PubMed: 37081599
DOI: 10.3201/eid2905.221773 -
Veterinary World May 2020African horse sickness (AHS) is a non-contagious viral disease of horses and other equids caused by an arbovirus belonging to the family and genus . AHS is an endemic...
BACKGROUND AND AIM
African horse sickness (AHS) is a non-contagious viral disease of horses and other equids caused by an arbovirus belonging to the family and genus . AHS is an endemic disease that is responsible for the death of a high number of horses every year in Namibia. At present, there is no information on the prevalence and distribution of AHS virus (AHSV) serotypes in the different regions of Namibia. Therefore, this survey aimed to fill this knowledge gap by investigating the AHSV seroprevalence in Namibian donkeys.
MATERIALS AND METHODS
A total of 260 blood samples (20 samples for each region) were randomly collected from donkeys aged between 3 and 5 years. Sera were screened for AHSV-specific immunoglobulin G antibodies using acommercial competitive enzyme-linked immunosorbent assay kit and samples positive to AHSV antibodies were further tested by serum neutralization (SN) assay to evaluate the AHSV serotype-specific immune response.
RESULTS
Seroprevalence of antibodies against AHSV in Namibian donkeys was 63.5%. The AHSV prevalence was significantly higher in the northern region (64%) than in the southern region (36%). A significantly (p<0.05) higher number of donkeys had antibodies against AHSV-6 (37.8%) and AHSV-9 (37.8%). The AHSV-2, AHSV-6, and AHSV-9 prevalence were higher (p<0.05) in the northern regions compared to the southern regions. None of the donkeys in this study, however, tested positive for AHSV-8.
CONCLUSION
Results of the current study indicate that all AHSV serotypes have either circulated previously or are circulating in Namibia except for AHSV-8. In particular, AHSV-1, -2, -3, -4, -5, -6, and -9 serotypes have circulated or are circulating in the northern region of Namibia, while AHSV-1, -4, -5, -6, -7, and -9 have infected donkeys in the south. AHSV-9 and AHSV-6 were the most prevalent serotypes detected in donkeys in this study. SN results showed that several donkeys from Kavango East, Kavango West, and Ohangwena regions had been exposed to multiple serotypes, indicating the possibility of cocirculation of several strains in Namibia.
PubMed: 32636601
DOI: 10.14202/vetworld.2020.1005-1009 -
Journal of Virology Feb 2018Among the family of double-stranded RNA viruses, only members of the genus possess a unique structural protein, termed VP6, within their particles. Bluetongue virus...
Among the family of double-stranded RNA viruses, only members of the genus possess a unique structural protein, termed VP6, within their particles. Bluetongue virus (BTV), an important livestock pathogen, is the prototype BTV VP6 is an ATP-dependent RNA helicase, and it is indispensable for virus replication. In the study described in this report, we investigated how VP6 might be recruited to the virus capsid and whether the BTV structural protein VP3, which forms the internal layer of the virus capsid core, is involved in VP6 recruitment. We first demonstrated that VP6 interacts with VP3 and colocalizes with VP3 during capsid assembly. A series of VP6 mutants was then generated, and in combination with immunoprecipitation and size exclusion chromatographic analyses, we demonstrated that VP6 directly interacts with VP3 via a specific region of the C-terminal portion of VP6. Finally, using our reverse genetics system, mutant VP6 proteins were introduced into the BTV genome and interactions between VP6 and VP3 were shown in a live cell system. We demonstrate that BTV strains possessing a mutant VP6 are replication deficient in wild-type BSR cells and fail to recruit the viral replicase complex into the virus particle core. Taken together, these data suggest that the interaction between VP3 and VP6 could be important in the packaging of the viral genome and early stages of particle formation. The orbivirus bluetongue virus (BTV) is the causative agent of bluetongue disease of livestock, often causing significant economic and agricultural impacts in the livestock industry. In the study described in this report, we identified the essential region and residues of the unique orbivirus capsid protein VP6 which are responsible for its interaction with other BTV proteins and its subsequent recruitment into the virus particle. The nature and mechanism of these interactions suggest that VP6 has a key role in packaging of the BTV genome into the virus particle. As such, this is a highly significant finding, as this new understanding of BTV assembly could be exploited to design novel vaccines and antivirals against bluetongue disease.
Topics: Animals; Bluetongue; Bluetongue virus; Capsid Proteins; Genome, Viral; RNA, Double-Stranded; Sf9 Cells; Spodoptera; Viral Core Proteins; Virion; Virus Assembly
PubMed: 29142128
DOI: 10.1128/JVI.01784-17 -
Journal of Vector Ecology : Journal of... Dec 2014Culicoides biting midges play an important role in the epidemiology of many vector-borne infections, including bluetongue virus, an internationally important virus of... (Review)
Review
Culicoides biting midges play an important role in the epidemiology of many vector-borne infections, including bluetongue virus, an internationally important virus of ruminants. The territory of the Russian Federation includes regions with diverse climatic conditions and a wide range of habitats suitable for Culicoides. This review summarizes available data on Culicoides studied in the Russian Federation covering geographically different regions, as well as findings from adjacent countries. Previous literature on species composition, ranges of dominant species, breeding sites, and host preferences is reviewed and suggestions made for future studies to elucidate vector-virus relationships.
Topics: Animals; Bluetongue virus; Diptera; Insect Vectors; Russia; Seasons
PubMed: 25424259
DOI: 10.1111/jvec.12105 -
Infection, Genetics and Evolution :... Oct 2023Biting midges are vectors of arboviruses such as bluetongue virus, bovine ephemeral fever virus, Akabane virus, African horse sickness virus, epizootic haemorrhagic...
Biting midges are vectors of arboviruses such as bluetongue virus, bovine ephemeral fever virus, Akabane virus, African horse sickness virus, epizootic haemorrhagic disease virus and Schmallenberg virus. Fast and accurate identification of biting midges is crucial in the study of Culicoides-borne diseases. Morphological identification of biting midges has revealed the presence of cryptic species. A total of 20 species are reported in Madagascar. In this study, we assessed wing morphometric analysis for identification of seven species namely C. dubitatus Kremer, Rebholtz-Hirtzel and Delécolle, C. enderleini Cornet and Brunhes, C. kibatiensis Goetghebuer, C. miombo Meiswinkel, C. moreli Clastrier, C. nevilli Cornet and Brunhes, and C. zuluensis de Meillon. Culicoides enderleini, C. miombo, C. moreli, C. nevilli and C. zuluensis are vectors diseases. A molecular approach, based on the cytochrome oxidase I gene (Cox1), was used for species delimitation. The molecular analysis presented seven different clades grouped two-by-two according to morphological characters. A total of 179 wing images were digitised. We found morphometric variation among seven species based on 11 landmarks and two outlines. Wing shape variation plots showed that species overlapped with species belonging to the same group. The cross-validation revealed a relatively high percentage of correct classification in most species, ranging from 91.3% to 100% for landmarks; 60% to 82.6% for outlines-1 and 77.1% to 91.3% for outlines-2. Our study suggests that wing geometric morphometric analysis is a robust tool for reliable "Moka Fohy" identification in Madagascar. This inexpensive and simple method is a precise supplement to morphological identification, with reaches the accuracy of Cox1 barcoding.
Topics: Animals; Cattle; Ceratopogonidae; Madagascar; Arboviruses; African Horse Sickness Virus; Orthobunyavirus
PubMed: 37640128
DOI: 10.1016/j.meegid.2023.105494 -
Viruses Feb 2020The discovery and characterization of novel arthropod-borne viruses provide valuable information on their genetic diversity, ecology, evolution and potential to threaten...
The discovery and characterization of novel arthropod-borne viruses provide valuable information on their genetic diversity, ecology, evolution and potential to threaten animal or public health. Arbovirus surveillance is not conducted regularly in Romania, being particularly very scarce in the remote and diverse areas like the Danube Delta. Here we describe the detection and genetic characterization of a novel orbivirus (: ) designated as Letea virus, which was found in grass snakes () during a metagenomic and metatranscriptomic survey conducted between 2014 and 2017. This virus is the first orbivirus discovered in reptiles. Phylogenetic analyses placed Letea virus as a highly divergent species in the -/sand fly-borne orbivirus clade. Gene reassortment and intragenic recombination were detected in the majority of the nine Letea virus strains obtained, implying that these mechanisms play important roles in the evolution and diversification of the virus. However, the screening of arthropods, including biting midges collected within the same surveillance program, tested negative for Letea virus infection and could not confirm the arthropod vector of the virus. The study provided complete genome sequences for nine Letea virus strains and new information about orbivirus diversity, host range, ecology and evolution. The phylogenetic associations warrant further screening of arthropods, as well as sustained surveillance efforts for elucidation of Letea virus natural cycle and possible implications for animal and human health.
Topics: Animals; Arboviruses; Colubridae; Genetic Variation; Genome, Viral; Genomics; Host Specificity; Orbivirus; Phylogeny; Psychodidae; Reassortant Viruses; Recombination, Genetic; Romania; Sequence Analysis, DNA; Whole Genome Sequencing
PubMed: 32098186
DOI: 10.3390/v12020243