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Bernard M, Donnelly CG, Miller A, Diel de Amorim M. Diagnosis and management of placentitis with severe funisitis in a multiparous Warmblood mare. J Equine Vet Sci 2024; 137:105075. [PMID: 38697371 DOI: 10.1016/j.jevs.2024.105075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 04/21/2024] [Accepted: 04/28/2024] [Indexed: 05/05/2024]
Abstract
Placentitis is an important cause of reproductive losses in the equine industry. Many cases of clinical placentitis are not diagnosed until late in the course of the disease, and for this reason there is variability in the timing of intervention, diagnostic measurements, and treatment protocols. An 8-year-old multiparous Dutch Warmblood mare that was recently exposed to EHV-1 in the herd of origin presented for routine foaling management. Placentitis was diagnosed upon intake, and medical treatment was initiated. The mare delivered a term foal, and diagnostics for infectious etiology were unrewarding. While there were obvious clinical signs supporting a diagnosis of placentitis, histopathologic examination did not reveal active inflammatory lesions in the chorioallantois; however, severe funisitis was present. This report reviews early diagnosis and management of placentitis, demonstrates an array of classic and subtle pathologic lesions seen on microscopic examination, and discusses pathophysiology of placentitis.
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Affiliation(s)
- M Bernard
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - C G Donnelly
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - A Miller
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - M Diel de Amorim
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
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2
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Murase H, El-Sheikh Ali H, Ruby RE, Scoggin KE, Ball BA. Transcriptomic analysis of the chorioallantois in equine premature placental separation. Equine Vet J 2022; 55:405-418. [PMID: 35622344 DOI: 10.1111/evj.13602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 05/12/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND Equine premature placental separation (PPS) is poorly understood and represents an important risk factor for fetal/neonatal hypoxia. OBJECTIVES To examine transcriptomic changes in the chorioallantois (CA) from mares with clinical PPS compared to the CA from normal foaling mares. Differential gene expression was determined and gene ontology as well as molecular pathways related to PPS were characterised. STUDY DESIGN Retrospective case: control study. METHODS CA were collected from Thoroughbred mares with a clinical history of PPS (n=33) and from control Thoroughbred mares (n=4) with normal parturition for examination of transcriptional changes in the placenta associated with PPS. Transcriptomic changes in the villous CA near the cervical star were determined by Illumina® sequencing and subsequent bioinformatic analysis. PPS samples were divided by k-means clustering, and differentially expressed genes (DEGs) in each PPS cluster were identified by comparing to controls. Shared DEGs between PPS clusters were used for gene ontology analysis and pathway analysis. RESULTS A total of 1204 DEGs were identified between PPS and control. Gene ontology revealed extracellular matrix (ECM) and cell adhesion, and pathway analysis revealed fatty acid, p-53, hypoxia, and inflammation. Eleven key regulator genes of PPS including growth factors (IGF1, TGFB2, TGFB3), transcription factors (HIF1A, JUNB, SMAD3), and transmembrane receptors (FGFR1, TNFRSF1A, TYROBP) were also identified. MAIN LIMITATIONS The use of clinical history of PPS, in the absence of other criteria, may have led to misidentification of some cases as PPS. CONCLUSIONS Transcriptomic analysis indicated that changes in ECM and cell adhesion were important factors in equine PPS. Key predicted upstream events include genes associated with hypoxia, inflammation and growth factors related to the pathogenesis of equine PPS.
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Affiliation(s)
- Harutaka Murase
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.,Equine Science Division, Hidaka Training and Research Center, Japan Racing Association, Urakawa, Hokkaido, Japan
| | - Hossam El-Sheikh Ali
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.,Faculty of Veterinary Medicine, Mansoura University, Egypt
| | - Rebecca E Ruby
- Veterinary Diagnostic Laboratory, University of Kentucky, Lexington, KY, USA
| | - Kirsten E Scoggin
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA
| | - Barry A Ball
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA
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3
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Agerholm JS, Klas EM, Damborg P, Borel N, Pedersen HG, Christoffersen M. A Diagnostic Survey of Aborted Equine Fetuses and Stillborn Premature Foals in Denmark. Front Vet Sci 2021; 8:740621. [PMID: 34859085 PMCID: PMC8631530 DOI: 10.3389/fvets.2021.740621] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 10/14/2021] [Indexed: 12/03/2022] Open
Abstract
Background: Loss of pregnancy in mares can have many different causes, including both infectious and non-infectious conditions. Extrapolation of findings from other studies is often uncertain as the significance of each cause varies across regions. Causes of pregnancy loss in mares have never been thoroughly studied in Denmark, so a prospective cross-sectional cohort study targeting the entire Danish population of pregnant mares was performed over a period of 13 months to obtain knowledge of the significance of individual causes. Fifty aborted or prematurely delivered stillborn fetuses were submitted for necropsy and examined by a panel of diagnostic laboratory methods. Results: Overall, a cause of fetal loss was established for 72% of the examined cases. Most cases (62%) were lost due to a non-infectious cause, of which obstruction of the feto-placental blood circulation due to severe torsion of the umbilical cord was most prevalent. Pregnancy loss due to a variety of opportunistic bacteria, including bacteria not previously associated with abortion in mares, accounted for 12%, while equid alphaherpesvirus (EHV) type 1 was the cause of pregnancy loss in 8% of the cases. EHV type 4 and Chlamydiaceae species were identified in some cases, but not regarded as the cause of fetal loss. Conclusion: Umbilical cord torsion was found to be the most prevalent cause of fetal loss in Danish mares, while infectious causes such as EHV type 1 and streptococci only accounted for a minor proportion of the losses. The study highlights the need for defined criteria for establishing an abortion diagnosis in mares, particularly in relation to EHV types 1 and 4.
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Affiliation(s)
- Jørgen Steen Agerholm
- Department of Veterinary Clinical Sciences, University of Copenhagen, Høje Taastrup, Denmark
| | - Eva-Maria Klas
- Department of Molecular Biology, LABOKLIN GmbH & Co. KG, Bad Kissingen, Germany
| | - Peter Damborg
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Nicole Borel
- Institute of Veterinary Pathology, Vetsuisse Faculty University Zurich, Zurich, Switzerland
| | - Hanne Gervi Pedersen
- Department of Veterinary Clinical Sciences, University of Copenhagen, Høje Taastrup, Denmark
| | - Mette Christoffersen
- Department of Veterinary Clinical Sciences, University of Copenhagen, Høje Taastrup, Denmark
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4
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Causes of equine perinatal mortality. Vet J 2021; 273:105675. [PMID: 34148598 DOI: 10.1016/j.tvjl.2021.105675] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 03/24/2021] [Accepted: 04/06/2021] [Indexed: 12/15/2022]
Abstract
The peripartum period is critical in equine medicine for maintaining healthy mares, and ensuring the delivery of healthy neonatal foals. The field of perinatal mortality in horses is continuously evolving, with several advances being recently made in causes of perinatal fetal and foal loss. This review details the main causes of perinatal loss in horses, through late pregnancy, parturition and the neonatal period. Recent advances in identification of infectious organisms and indicators of survival in neonatal foals will be discussed. Continued advances in reproductive and neonatal medicine will aid improved survival of foals through fewer pregnancy losses, and improved management of high-risk pregnancies and critically ill neonatal foals.
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5
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Moore SE, Strang CL, Marr CM, Newton R, Cameron IJ. Management of an outbreak of multiple equine herpesvirus type 1 abortions among vaccinated mares on a large UK Thoroughbred stud farm. VETERINARY RECORD CASE REPORTS 2019. [DOI: 10.1136/vetreccr-2018-000799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | - Camilla L Strang
- Epidemiology UnitAnimal Health TrustNewmarketUK
- Pathobiology and Population SciencesRoyal Veterinary CollegeLondonUK
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6
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Poelaert KCK, Van Cleemput J, Laval K, Favoreel HW, Soboll Hussey G, Maes RK, Nauwynck HJ. Abortigenic but Not Neurotropic Equine Herpes Virus 1 Modulates the Interferon Antiviral Defense. Front Cell Infect Microbiol 2018; 8:312. [PMID: 30258819 PMCID: PMC6144955 DOI: 10.3389/fcimb.2018.00312] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 08/15/2018] [Indexed: 12/20/2022] Open
Abstract
Equine herpesvirus 1 (EHV1) is considered as a major pathogen of Equidae, causing symptoms from mild respiratory disease to late-term abortion and neurological disorders. Different EHV1 strains circulating in the field have been characterized to be of abortigenic or neurovirulent phenotype. Both variants replicate in a plaque-wise manner in the epithelium of the upper respiratory tract (URT), where the abortigenic strains induce more prominent viral plaques, compared to the neurovirulent strains. Considering the differences in replication at the URT, we hypothesized that abortigenic strains may show an increased ability to modulate the type I IFN secretion/signaling pathway, compared to strains that display the neurovirulent phenotype. Here, we analyze IFN levels induced by abortigenic and neurovirulent EHV1 using primary respiratory epithelial cells (EREC) and respiratory mucosa ex vivo explants. Similar levels of IFNα (~70 U/ml) were detected in explants inoculated with both types of EHV1 strains from 48 to 72 hpi. Second, EREC and mucosa explants were treated with recombinant equine IFNα (rEqIFNα) or Ruxolitinib (Rux), an IFN signaling inhibitor, prior to and during inoculation with abortigenic or neurovirulent EHV1. Replication of both EHV1 variants was suppressed by rEqIFNα. Further, addition of Rux increased replication in a concentration-dependent manner, indicating an IFN-susceptibility for both variants. However, in two out of three horses, at a physiological concentration of 100 U/ml of rEqIFNα, an increase in abortigenic EHV1 replication was observed compared to 10 U/ml of rEqIFNα, which was not observed for the neurovirulent strains. Moreover, in the presence of Rux, the plaque size of the abortigenic variants remained unaltered, whereas the typically smaller viral plaques induced by the neurovirulent variants became larger. Overall, our results demonstrate the importance of IFNα in the control of EHV1 replication in the URT for both abortigenic and neurovirulent variants. In addition, our findings support the speculation that abortigenic variants of EHV1 may have developed anti-IFN mechanisms that appear to be absent or less pronounced in neurovirulent EHV1 strains.
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Affiliation(s)
- Katrien C K Poelaert
- Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Jolien Van Cleemput
- Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Kathlyn Laval
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton Neuroscience Institute, Princeton University, Princeton, NJ, United States
| | - Herman W Favoreel
- Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Gisela Soboll Hussey
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI, United States
| | - Roger K Maes
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI, United States
| | - Hans J Nauwynck
- Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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7
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Strang C. Equine herpesvirus - a constant threat. Vet Rec 2016; 178:499-500. [PMID: 27179088 DOI: 10.1136/vr.i2318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Camilla Strang of the Animal Health Trust provides an overview of the diagnosis and control of conditions associated with infection by equine herpesvirus.
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Affiliation(s)
- Camilla Strang
- Animal Health Trust, Lanwades Park, Newmarket, Suffolk CB8 7UU
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8
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Spiesschaert B, Stephanowitz H, Krause E, Osterrieder N, Azab W. Glycoprotein B of equine herpesvirus type 1 has two recognition sites for subtilisin-like proteases that are cleaved by furin. J Gen Virol 2016; 97:1218-1228. [PMID: 26843465 DOI: 10.1099/jgv.0.000418] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Glycoprotein B (gB) of equine herpesvirus type 1 (EHV-1) is predicted to be cleaved by furin in a fashion similar to that of related herpesviruses. To investigate the contribution of furin-mediated gB cleavage to EHV-1 growth, canonical furin cleavage sites were mutated. Western blot analysis of mutated EHV-1 gB showed that it was cleaved at two positions, 518RRRR521 and 544RLHK547, and that the 28 aa between the two sites were removed after cleavage. Treating infected cells with either convertase or furin inhibitors reduced gB cleavage efficiency. Further, removal of the first furin recognition motif did not affect in vitro growth of EHV-1, while mutation of the second motif greatly affected virus growth. In addition, a second possible signal peptide cleavage site was identified for EHV-1 gB between residues 98 and 99, which was 13 aa downstream of that previously identified.
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Affiliation(s)
- Bart Spiesschaert
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin,Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163 Berlin,Germany
| | - Heike Stephanowitz
- Leibniz-Institut für Molekulare Pharmakologie,Robert-Rössle-Strasse 10, D-13125 Berlin,Germany
| | - Eberhard Krause
- Leibniz-Institut für Molekulare Pharmakologie,Robert-Rössle-Strasse 10, D-13125 Berlin,Germany
| | - Nikolaus Osterrieder
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin,Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163 Berlin,Germany
| | - Walid Azab
- Department of Virology, Faculty of Veterinary Medicine,Zagazig University,Egypt.,Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin,Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163 Berlin,Germany
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9
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Comparative analysis of glycoprotein B (gB) of equine herpesvirus type 1 and type 4 (EHV-1 and EHV-4) in cellular tropism and cell-to-cell transmission. Viruses 2015; 7:522-42. [PMID: 25654240 PMCID: PMC4353902 DOI: 10.3390/v7020522] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 01/04/2015] [Accepted: 01/27/2015] [Indexed: 12/05/2022] Open
Abstract
Glycoprotein B (gB) plays an important role in alphaherpesvirus cellular entry and acts in concert with gD and the gH/gL complex. To evaluate whether functional differences exist between gB1 and gB4, the corresponding genes were exchanged between the two viruses. The gB4-containing-EHV-1 (EHV-1_gB4) recombinant virus was analyzed for growth in culture, cell tropism, and cell entry rivaling no significant differences when compared to parental virus. We also disrupted a potential integrin-binding motif, which did not affect the function of gB in culture. In contrast, a significant reduction of plaque sizes and growth kinetics of gB1-containing-EHV-4 (EHV-4_gB1) was evident when compared to parental EHV-4 and revertant viruses. The reduction in virus growth may be attributable to the loss of functional interaction between gB and the other envelope proteins involved in virus entry, including gD and gH/gL. Alternatively, gB4 might have an additional function, required for EHV-4 replication, which is not fulfilled by gB1. In conclusion, our results show that the exchange of gB between EHV-1 and EHV-4 is possible, but results in a significant attenuation of virus growth in the case of EHV-4_gB1. The generation of stable recombinant viruses is a valuable tool to address viral entry in a comparative fashion and investigate this aspect of virus replication further.
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10
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Schulman ML, Becker A, van der Merwe BD, Guthrie AJ, Stout TAE. Epidemiology and reproductive outcomes of EHV-1 abortion epizootics in unvaccinated Thoroughbred mares in South Africa. Equine Vet J 2014; 47:155-9. [PMID: 24617603 DOI: 10.1111/evj.12264] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 03/03/2014] [Indexed: 12/01/2022]
Abstract
REASONS FOR PERFORMING STUDY Equine herpesvirus 1 (EHV-1) is one of the most common causes of infectious abortion in mares. Analysing the demography of outbreaks and detailing subsequent reproductive performance of affected mares will assist in the management of future (threatened) epizootics. OBJECTIVES To examine the epidemiology and reproductive outcomes of 2 EHV-1 abortion epizootics with very different patterns of morbidity. STUDY DESIGN Epidemiological and reproductive data were analysed retrospectively following abortion epizootics associated with EHV-1, but initiated via different routes, among unvaccinated mares on 2 Thoroughbred farms in South Africa. METHODS Aborting mares were assigned to either the EHV-1 abortion cohort via positive immunostaining (Farms 1 and 2) or quantitative PCR (Farm 2) on tissue samples, or to the non-EHV abortion cohort. RESULTS During their respective epizootics, EHV-1 abortions affected 9/30 (30.0%) and 18/316 (5.7%) of the pregnant mares on Farms 1 and 2, respectively; there were also 25 (7.9%) non-EHV abortions on Farm 2. Epizootic differences included: durations (Farm 1 = 135 days; Farm 2 = 34 days), intervals between first and subsequent abortions (Farm 1 = 39 days; Farm 2 = 2 days) and intervals to confirmation of EHV-1 (Farm 1 = 40 days; Farm 2 = 2 days). The median (range) age of EHV-1 abortion mares (8.0; 5-18 years) in both epizootics was similar but significantly younger (P = 0.004) than the 25 non-EHV-1 abortion mares (11.0; 4-24 years) on Farm 2. Gestation stage (median; range) of EHV-1 (291.5; 277-313) and non-EHV-1 (211.9; 61-339 days) abortions were significantly different (P = 0.001). The post abortion complications and subsequent reproductive outcomes had no significant association with EHV-1 abortion. CONCLUSIONS The marked difference in morbidity between the 2 epizootics may be associated with routes of introduction or intervention strategy dictated by availability of molecular diagnostic techniques. Unexpectedly, EHV-1 was not more commonly associated with post abortion complications.
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Affiliation(s)
- M L Schulman
- Section of Reproduction, Faculty of Veterinary Science, University of Pretoria, South Africa
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11
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Rusli ND, Mat KB, Harun HC. A Review: Interactions of Equine Herpesvirus-1 with Immune System and Equine Lymphocyte. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/ojvm.2014.412036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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12
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Role of equine herpesviruses as co-infecting agents in cases of abortion, placental disease and neonatal foal mortality. Vet Res Commun 2013; 37:311-7. [DOI: 10.1007/s11259-013-9578-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2013] [Indexed: 10/26/2022]
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13
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Crook T, Benavides J, Russell G, Gilray J, Maley M, Willoughby K. Bovine herpesvirus 1 abortion: current prevalence in the United Kingdom and evidence of hematogenous spread within the fetus in natural cases. J Vet Diagn Invest 2012; 24:662-70. [PMID: 22649159 DOI: 10.1177/1040638712448187] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
While Bovine herpesvirus 1 (BoHV-1) has been known as a cause of bovine abortion for nearly 50 years, information is limited on the current prevalence of BoHV-1 abortion in the United Kingdom, or about the mode of virus dissemination to cause infection of the fetus. The present study aimed to investigate these issues by surveying the prevalence of BoHV-1 in abortion cases in the United Kingdom, and comparing diagnostic methods to determine which are most efficient in BoHV-1-induced abortion. Where BoHV-1 DNA was detected, viral load was compared in fetal tissues, using real-time polymerase chain reaction (PCR), supported by histopathology and immunohistochemistry (IHC) to investigate virus dissemination in bovine abortions. A total of 400 U.K. bovine abortion cases were studied; PCR detected BoHV-1 nucleic acids in 10 cases, suggestive histopathological lesions were observed in 8, and positive IHC staining was observed in 9. In routine diagnosis, BoHV-1 was identified in 2 of these cases, highlighting the utility of using molecular diagnostic tests such as real-time PCR to achieve high sensitivity in potentially autolyzed tissues. The study of different fetal samples showed the highest viral load in the liver, along with severe multifocal necrotic hepatitis, suggesting either a clear tropism of the virus for this organ or that it is the first location to be reached in the fetus. Presence of viral antigen in endothelial cells of the placenta, brain, or heart suggest a hematogenous spread of virus from placenta to the liver, through the umbilical vein, and then to the rest of the organs via fetal blood vessels.
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Affiliation(s)
- Tara Crook
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, EH26 0PZ, Scotland
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14
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Pronost S, Léon A, Legrand L, Fortier C, Miszczak F, Freymuth F, Fortier G. Neuropathogenic and non-neuropathogenic variants of equine herpesvirus 1 in France. Vet Microbiol 2010; 145:329-33. [PMID: 20427133 DOI: 10.1016/j.vetmic.2010.03.031] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 03/29/2010] [Accepted: 03/31/2010] [Indexed: 10/19/2022]
Abstract
Equine herpesvirus 1 (EHV-1) is a common pathogen of the horse which may induce mild respiratory distress, abortion, neonatal death and neurological disease. A single nucleotide polymorphism in the EHV-1 DNA polymerase (ORF30 A(2254) to G(2254)) has been associated with clinical signs of Equine herpes myeloencephalopathy (EHM). The aim of this work was to analyze the ORF30 genomic region among a panel of EHV-1 DNA extract in order to estimate the prevalence of the EHV-1 neuropathogenic genotype in France. Samples coming from cases associated with EHM, horses with respiratory symptoms and aborted mares, each obtained between 2002 and 2009, were investigated. DNA was directly extracted from biological samples and allelic discrimination was performed using real-time PCR. Thirty of the 125 analysed horses (24%) presented the G(2254) genotype of ORF 30. Among them, 7/16 were provided by EHM cases, 1/24 by respiratory cases and 22/85 by abortion cases. Concerning EHM, the 7 G(2254) genotype of ORF30 were all isolated in 2009 during two outbreaks where mortality was observed. Regarding the 22 G(2254) genotype of ORF 30, 17 were identified in foetuses on which EHV-1 was detected by PCR, without any certainty of viral implication in the abortion. These findings clearly suggest that other factors need to be considered for a better understanding of the impact of DNA polymerase genotype upon EHV-1 neuropathogenic phenotype.
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Affiliation(s)
- Stéphane Pronost
- Animal Health Department, Research andDevelopment Service, Frank Duncombe Laboratory, 1 route de Rosel, Caen cedex 4, France.
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15
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Lunn DP, Davis-Poynter N, Flaminio MJBF, Horohov DW, Osterrieder K, Pusterla N, Townsend HGG. Equine herpesvirus-1 consensus statement. J Vet Intern Med 2009; 23:450-61. [PMID: 19645832 DOI: 10.1111/j.1939-1676.2009.0304.x] [Citation(s) in RCA: 207] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Equine herpesvirus-1 is a highly prevalent and frequently pathogenic infection of equids. The most serious clinical consequences of infection are abortion and equine herpesvirus myeloencephalopathy (EHM). In recent years, there has been an apparent increase in the incidence of EHM in North America, with serious consequences for horses and the horse industry. This consensus statement draws together current knowledge in the areas of pathogenesis, strain variation, epidemiology, diagnostic testing, vaccination, outbreak prevention and control, and treatment.
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Affiliation(s)
- D P Lunn
- Department of Clinical Sciences, James L Voss Veterinary Teaching Hospital, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1620, USA.
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16
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Léon A, Fortier G, Fortier C, Freymuth F, Tapprest J, Leclercq R, Pronost S. Detection of equine herpesviruses in aborted foetuses by consensus PCR. Vet Microbiol 2008; 126:20-9. [PMID: 17686590 DOI: 10.1016/j.vetmic.2007.06.019] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Revised: 06/14/2007] [Accepted: 06/17/2007] [Indexed: 11/26/2022]
Abstract
The major role of EHV-1 in equine abortion is widely reported in the literature but the contribution of EHV-2, EHV-3, EHV-4 or EHV-5 remains less well documented. The objective of this study is to evaluate the contribution of these five different EHVs to equine abortion in a variety of biological tissues using a consensus polymerase chain reaction (PCR). The test was validated for specificity and sensitivity in horses before screening specimens from 407 foetuses, stillbirths and premature foals collected over a 2.5-year interval. Positive results obtained with this assay were compared to other EHV type-specific PCR or by sequencing. EHV-1 was identified as the major cause of abortion in French mares (59/407 cases). However, there was evidence to suggest some variation in the potential of EHV-1 strains to induce abortion. Indeed, DNA samples from EHV-2 (in three cases) and EHV-5 (in one case) inferred a role of these viruses in abortion. The presence of viral DNA from EHV-3 or EHV-4 strains was not detected in the specimens studied. The data obtained suggest that the consensus herpesvirus PCR is an efficient screening tool. In association with a specific PCR, the test provides a rapid identification of the type of herpesvirus involved in abortion and is useful for routine diagnostic tests as it allows the identification of herpesviruses other than the EHV-1 strain.
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Affiliation(s)
- A Léon
- Frank Duncombe Laboratory, 1 route de Rosel, 14053 Caen Cedex 4, France; Microbiology Service and EA 2128 Host Relations and Micro-organisms of the Epithelium, University Hospital of Caen, France
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Kydd JH, Townsend HGG, Hannant D. The equine immune response to equine herpesvirus-1: The virus and its vaccines. Vet Immunol Immunopathol 2006; 111:15-30. [PMID: 16476492 DOI: 10.1016/j.vetimm.2006.01.005] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Equine herpesvirus-1 (EHV-1) is an alphaherpesvirus which infects horses, causing respiratory and neurological disease and abortion in pregnant mares. Latency is established in trigeminal ganglia and lymphocytes. Immunity to EHV-1 lasts between 3 and 6 months. Current vaccines, many of which contain inactivated virus, have reduced the incidence of abortion storms in pregnant mares but individual animals, which may be of high commercial value, remain susceptible to infection. The development of effective vaccines which stimulate both humoral and cellular immune responses remains a priority. Utilising data generated following experimental and field infections of the target species, this review describes the immunopathogenesis of EHV-1 and the interaction between the horse's immune system and this virus, both in vivo and in vitro, and identifies immune responses, highlighting those which have been associated with protective immunity. It then goes on to recount a brief history of vaccination, outlines factors likely to influence the outcome of vaccine administration and describes the immune response stimulated by a selection of commercial and experimental vaccines. Finally, based on the available data, a rational strategy designed to stimulate protective immune responses by vaccination is outlined.
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Affiliation(s)
- Julia H Kydd
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, United Kingdom.
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Patel JR, Heldens J. Equine herpesviruses 1 (EHV-1) and 4 (EHV-4) – epidemiology, disease and immunoprophylaxis: A brief review. Vet J 2005; 170:14-23. [PMID: 15993786 DOI: 10.1016/j.tvjl.2004.04.018] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2004] [Indexed: 11/24/2022]
Abstract
This review concentrates on the epidemiology, latency and pathogenesis of, and the approaches taken to control infection of horses by equine herpesvirus types 1 (EHV-1) and 4 (EHV-4). Although both viruses may cause febrile rhinopneumonitis, EHV-1 is the main cause of abortions, paresis and neonatal foal deaths. The lesion central to these three conditions is necrotising vasculitis and thrombosis resulting from lytic infection of endothelial cells lining blood capillaries. The initiation of infection in these lesions is likely to be by reactivated EHV-1 from latently infected leukocytes. However, host factors responsible for reactivation remain poorly understood. While vaccine development against these important viruses of equines involving classical and modern approaches has been ongoing for over five decades, progress, compared to other alpha herpesviruses of veterinary importance affecting cattle and pigs, has been slow. However recent data with a live temperature sensitive EHV-1 vaccine show promise.
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Affiliation(s)
- J R Patel
- Intervet UK Ltd., The Elms, Thicket Road, Houghton, Huntingdon, Cambridgeshire, PE28 2BQ, UK.
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Abstract
Equine herpesvirus infections in horses remain a significant cause of abortion and neurologic disease. These viruses are also responsible for mild signs of respiratory disease. The ability to establish latent infections with periodic reactivation or transmission to other horses is an important feature of these herpesviruses. One of the most unique aspects of this report is the description of horses demonstrating neurologic signs serving as the source of infection for other horses. Accurate diagnosis and better means of protection for horses remain problems facing veterinarians and horse owners.
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Affiliation(s)
- Stephen M Reed
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, 601 Vernon Tharp Street, Columbus, OH 43210, USA.
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