Equine Herpesvirus (EHV) is a contagious virus that affects horses, causing a range of clinical conditions. It primarily impacts the respiratory system but can also lead to neurological disorders, abortion in pregnant mares, and neonatal foal death. The virus is transmitted through direct contact with infected horses or through contaminated surfaces and equipment. There are several strains of EHV, with Equine Herpesvirus-1 (EHV-1) and Equine Herpesvirus-4 (EHV-4) being the most commonly studied due to their prevalence and impact on equine health. EHV-1 is associated with more severe outcomes, including equine herpesvirus myeloencephalopathy (EHM). This page aggregates peer-reviewed research studies and scholarly articles that explore the epidemiology, pathogenesis, clinical manifestations, and management strategies related to Equine Herpesvirus in horses.
Ata EB, Zaghawa A, Ghazy AA, Elsify A, Abdelrahman K, Kasem S, Nayel M.Equine herpesvirus-1 (EHV-1) is an important pathogen, which infects horses worldwide with high morbidity but low mortality rates. The respiratory disorders and abortions are the most common indicators. Ab4p (an abortigenic and paralytic virus) is one of the most important and virulent strains. The development and functional characterization of the open reading frame-68 (ORF68) negative EHV-1 Ab4p mutants and an assessment of their roles in the infection at the cellular level were the main targets of the current study. Escherichia coli DH10β containing the Ab4p bacterial artificial chromosome...
Seeber PA, Quintard B, Sicks F, Dehnhard M, Greenwood AD, Franz M.Equine Herpesviruses (EHV) are common and often latent pathogens of equids which can cause fatalities when transmitted to non-equids. Stress and elevated glucocorticoids have been associated with EHV reactivation in domestic horses, but little is known about the correlation between stress and viral reactivation in wild equids. We investigated the effect of an environmental stressor (social group restructuring following a translocation event) on EHV reactivation in captive Grévy's zebras (). A mare was translocated by road transport from Zoo Mulhouse, France, to join a resident group of three ...
Schnabel CL, Wimer CL, Perkins G, Babasyan S, Freer H, Watts C, Rollins A, Osterrieder N, Wagner B.Equine herpesvirus type 1 (EHV-1) induces respiratory infection, abortion, and neurologic disease with significant impact. Virulence factors contributing to infection and immune evasion are of particular interest. A potential virulence factor of the neuropathogenic EHV-1 strain Ab4 is ORF2. This study on 24 Icelandic horses, 2 to 4 years of age, describes the infection with EHV-1 Ab4, or its deletion mutant devoid of ORF2 (Ab4ΔORF2) compared to non-infected controls (each group n = 8). The horses' clinical presentation, virus shedding, viremia, antibody and cellular immune responses were...
Bedenice D, Johnson AL.EPM, CVSM, and EDM are currently recognized as the 3 most common neurologic diseases in US horses, with the latter 2 conditions being most prevalent in young animals. Moreover, horses competing at shows and performance events are at greater risk for exposure to highly contagious, neurologic EHV-1 outbreaks. A clinical diagnosis of any neurologic disease should be based on a careful history, complete neurologic examination, and appropriate diagnostic testing and interpretation. However, mild or early neurologic signs can often mimic or be mistaken for an orthopedic condition when horses present...
Stasiak K, Dunowska M, Rola J.Equid herpesviruses (EHVs) are widespread in equine populations worldwide. While the infection with equine α-herpesviruses (EHV-1 and EHV-4) has been linked to several clinical outcomes, the pathogenic potential for equine γ-herpesviruses (EHV-2 and EHV-5) is still unclear. The objective of the current study was to determine the prevalence of infection with EHVs among Polish horses, to investigate factors associated with EHV infections among horses sampled, and to determine genetic variability within Polish EHV-2 isolates. Virus-specific real-time PCR assays were used for detection of EHV-1,...
Bannai H, Nemoto M, Tsujimura K, Yamanaka T, Kokado H, Kondo T, Matsumura T.Immune responses were compared after intranasal (IN) and intramuscular (IM) vaccination of horses with a modified live equine herpesvirus type-1 (EHV-1) vaccine, and the protective effect after EHV-1 challenge was evaluated. IN- and IM-vaccinated groups (n = 5 each) showed significant rises in serum virus-neutralizing titers with increased levels of IgGa and IgGb antibodies after the first vaccination (P < 0.05). In nasal secretions, the IN group had significantly increased levels of IgA antibodies after vaccination (P < 0.05), whereas the response of the IM group was dominat...
Stokol T, Serpa PBS, Brooks MB, Divers T, Ness S.Equine herpesvirus type 1 (EHV-1) is a major cause of infectious respiratory disease, abortion and neurologic disease. Thrombosis in placental and spinal vessels and subsequent ischemic injury in EHV-1-infected horses manifests clinically as abortion and myeloencephalopathy. We have previously shown that addition of heparin anticoagulants to equine platelet-rich plasma (PRP) can abolish ex vivo EHV-1-induced platelet activation. The goal of this study was to test whether platelets isolated from horses treated with unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) were resista...
Guevara L, Abdelgawad A, Onzere C, Greenwood AD, Davidson Z, Bishop R, Mutinda M.Equid herpesviruses types 1 (EHV-1) and 9 (EHV-9) are unusual among herpesviruses in that they lack strong host specificity, and the full extent of their host range remains unclear. The virus establishes latency for long periods and can be reactivated and shed, resulting in clinical disease in susceptible species. A sensitive and specific peptide-based enzyme-linked immunosorbent assay was developed to study the seroprevalence of both viruses in a broad range of species among both wild and captive populations. We used this assay to study the seroprevalences of EHV-1 and EHV-9 in a natural popu...
Vissani MA, Zabal O, Tordoya MS, Parreño V, Thiry E, Barrandeguy M.Equid alphaherpesvirus 3 (EHV3) is the etiological agent of equine coital exanthema (ECE), which is a venereal, highly contagious disease, characterized by the formation of papules, vesicles, pustules and ulcers on the external genitalia of mares and stallions. EHV3 remains in a latent state after a successful infection and there are latently infected animals in which the virus is reactivated and generally re-excreted subclinically. There are no available vaccines for this condition and prevention is based on the clinical examination of mares prior to mating, which allows to segregate those sh...
Laing G, Christley R, Stringer A, Aklilu N, Ashine T, Newton R, Radford A, Pinchbeck G.Pathogens are frequently implicated in equine respiratory disease. In Ethiopia, respiratory disease is a frequent cause for presentation at veterinary clinics and a priority concern for users of working horses. However, there is little existing literature on possible aetiologies. Objective: Determine prevalence of respiratory signs and exposure to major respiratory pathogens through a serological survey. Methods: Cross-sectional. Methods: Systematically selected horses from 19 sites in central Ethiopia were examined clinically and sampled once (August-December 2013). A face-to-face interview c...
Wilson ME, Holz CL, Kopec AK, Dau JJ, Luyendyk JP, Soboll Hussey G.Equine herpesvirus type 1 (EHV-1) is the cause of respiratory disease, abortion storms, and outbreaks of herpesvirus myeloencephalopathy (EHM). Infection of the spinal cord is characterised by multifocal regions of virally infected vascular endothelium, associated with vasculitis, thrombosis and haemorrhage that result in ischaemia and organ dysfunction. However, the mechanism of thrombosis in affected horses is unknown. Objective: To evaluate tissue factor (TF) procoagulant activity and thrombin-antithrombin complex (TAT) levels in horses following infection with EHV-1. Methods: In vitro and ...
Smith FL, Watson JL, Spier SJ, Kilcoyne I, Mapes S, Sonder C, Pusterla N.Imported horses that have undergone recent long distance transport might represent a serious risk for spreading infectious respiratory pathogens into populations of horses. Objective: To investigate the frequency of shedding of respiratory pathogens in recently imported horses. Methods: All imported horses with signed owner consent (n = 167) entering a USDA quarantine for contagious equine metritis from October 2014 to June 2016 were enrolled in the study. Methods: Prospective observational study. Enrolled horses had a physical examination performed and nasal secretions collected at the ti...
Moeller RB, Crossley B, Pipkin A, Li Y, Balasuriya UBR.A 2-y-old female Grant's zebra ( Equus quagga [ burchellii] boehmi) was presented with a clinical history of depression, anorexia, and weakness of 1-wk duration. Postmortem examination identified ulcers on the tongue and palate; a large abscess adjacent to the larynx; left lung consolidation; mild swelling, darkening, and congestion of the liver with accentuation of the lobular pattern; and edema and congestion of the distal small and large intestines. Histologic examination identified necrotizing bronchopneumonia, necrotizing hepatitis, nephritis, and enterocolitis. Eosinophilic intranuclear ...
Vissani MA, Tordoya MS, Tsai YL, Lee PA, Shen YH, Lee FC, Wang HT, Parreño V, Barrandeguy M.Equine coital exanthema (ECE) is an infectious, venereally transmitted muco-cutaneous disease affecting mares and stallions, caused by equid alphaherpesvirus 3 (EHV3). Diagnostic tools for rapid identification of EHV3 are of primary importance to diminish the risk of EHV3 dissemination at the time of breeding. In the last years, it has been shown that the performance of the insulated-isothermal polymerase chain reaction (iiPCR) is comparable to virus isolation, nested PCR and real-time PCR (qPCR) in detecting pathogens of various animal species. Analytical sensitivity and specificity of the ii...
Tallmadge RL, Žygelytė E, Van de Walle GR, Kristie TM, Felippe MJB.Equine herpesvirus type 1 (EHV-1) is a ubiquitous and highly contagious pathogen that causes a range of disease severities with outbreaks of notable economic impact. Given the limitations in immune protection of current vaccines and the limited effectiveness of antiviral drugs on EHV-1 infections , improved treatment measures are needed to control disease. The use of drugs that alter the epigenetic state of herpes simplex virus genome has been shown to limit viral primary infection and reactivation both and . Therefore, we tested the hypothesis that maintaining a repressive epigenetic state o...
Oladunni FS, Sarkar S, Reedy S, Balasuriya UBR, Horohov DW, Chambers TM.Equine herpesvirus-1 (EHV-1) infection is an important and highly prevalent disease in equine populations worldwide. Previously we have demonstrated that a neuropathogenic strain of EHV-1, T953, suppresses the host cell's antiviral type-I interferon (IFN) response in vitro. Whether or not this is unique to EHV-1 strains possessing the neuropathogenic genotype has been undetermined. Here, we examined whether there is any direct relationship between neuropathogenic genotype and the induced IFN-β response in equine endothelial cells (EECs) infected with 10 different strains of EHV-1. The extent ...
Bryant NA, Wilkie GS, Russell CA, Compston L, Grafham D, Clissold L, McLay K, Medcalf L, Newton R, Davison AJ, Elton DM.Equine herpesvirus 1 (EHV-1) causes respiratory disease, abortion, neonatal death and neurological disease in equines and is endemic in most countries. The viral factors that influence EHV-1 disease severity are poorly understood, and this has hampered vaccine development. However, the N752D substitution in the viral DNA polymerase catalytic subunit has been shown statistically to be associated with neurological disease. This has given rise to the term "neuropathic strain," even though strains lacking the polymorphism have been recovered from cases of neurological disease. To broaden understan...
Garvey M, Suárez NM, Kerr K, Hector R, Moloney-Quinn L, Arkins S, Davison AJ, Cullinane A.Equid herpesvirus 8 (EHV-8), formerly known as asinine herpesvirus 3, is an alphaherpesvirus that is closely related to equid herpesviruses 1 and 9 (EHV-1 and EHV-9). The pathogenesis of EHV-8 is relatively little studied and to date has only been associated with respiratory disease in donkeys in Australia and horses in China. A single EHV-8 genome sequence has been generated for strain Wh in China, but is apparently incomplete and contains frameshifts in two genes. In this study, the complete genome sequences of four EHV-8 strains isolated in Ireland between 2003 and 2015 were determined by I...
Okada A, Suganuma S, Badr Y, Omatsu T, Mizutani T, Ohya K, Fukushi H.VP22 is a major tegument protein of equine herpesvirus type 1 (EHV-1). In the present study, we examined functions of VP22 in EHV-1 replication by viral protein expression analyses in cells infected with the VP22-deficient virus. The expressions of several viral proteins in the cells infected with the VP22-deficient virus were lower than those in the cells infected with the parent virus. One of the weakly expressed proteins was identified as ICP4, which is a major regulatory protein encoded by an immediate early gene of EHV-1. A real-time PCR analysis showed that the mRNA expression of ICP4 wa...
Shakya AK, O'Callaghan DJ, Kim SK.Equine herpesvirus 1 (EHV-1) is a major pathogen affecting equines worldwide. The virus causes respiratory disease, abortion, and, in some cases, neurological disease. EHV-1 Kentucky A (KyA) is attenuated in the mouse and equine, whereas wild-type pathogenic strain RacL11 induces severe inflammatory infiltration of the lung, causing infected mice to succumb. The complete DNA sequencing of the KyA genome revealed that genes UL17 (ORF17), US6 (ORF73; gI), US7 (ORF74; gE), and US8 (ORF75; 10 K) are deleted as compared to the RacL11 and Ab4 genomes. In-frame deletions in the US1 (ORF68), US4 (OR...
Van Cleemput J, Poelaert KCK, Laval K, Maes R, Hussey GS, Van den Broeck W, Nauwynck HJ.The respiratory epithelium of humans and animals is frequently exposed to alphaherpesviruses, originating from either external exposure or reactivation from latency. To date, the polarity of alphaherpesvirus infection in the respiratory epithelium and the role of respiratory epithelial integrity herein has not been studied. Equine herpesvirus type 1 (EHV1), a well-known member of the alphaherpesvirus family, was used to infect equine respiratory mucosal explants and primary equine respiratory epithelial cells (EREC), grown at the air-liquid interface. EHV1 binding to and infection of mucosal e...
Badr Y, Okada A, Abo-Sakaya R, Beshir E, Ohya K, Fukushi H.Equine herpesvirus type 1 (EHV-1) UL11 is a 74-amino-acid tegument protein encoded by ORF51 of the EHV-1 genome. EHV-1 UL11 was previously reported by other researchers using the RacL22 and RacH strains to be nonessential for viral replication in cultured cells. Here, we constructed UL11 mutant viruses including a UL11 null mutant and three C-terminal truncated mutants, for further characterization of EHV-1 UL11 using bacterial artificial chromosome (BAC) technology based on the neuropathogenic strain Ab4p. EHV-1 Ab4p UL11 was localized to juxtanuclear and Golgi regions as reported by other re...
Wellcome open researchOctober 17, 2017
Volume 2 60 doi: 10.12688/wellcomeopenres.12176.2
Wardle R, Pullman JA, Haldenby S, Ressel L, Pope M, Clegg PD, Radford A, Stewart JP, Al-Saadi M, Dyer P, Peffers MJ. Incidental findings of virus-like particles were identified following electron microscopy of tissue-engineered tendon constructs (TETC) derived from equine tenocytes. We set out to determine the nature of these particles, as there are few studies which identify virus in tendons , and their presence could have implications for tissue-engineering using allogenic grafts. Virus particles were identified in electron microscopy of TETCs. Virion morphology was used to initially hypothesise the virus identity. Next generation sequencing was implemented to identify the virus. A pan herpesvirus PCR ...
Maxwell LK, Bentz BG, Gilliam LL, Ritchey JW, Pusterla N, Eberle R, Holbrook TC, McFarlane D, Rezabek GB, Meinkoth J, Whitfield C, Goad CL, Allen GP.OBJECTIVE To determine whether prophylactic administration of valacyclovir hydrochloride versus initiation of treatment at the onset of fever would differentially protect horses from viral replication and clinical disease attributable to equine herpesvirus type-1 (EHV-1) infection. ANIMALS 18 aged mares. PROCEDURES Horses were randomly assigned to receive an oral placebo (control), treatment at detection of fever, or prophylactic treatment (initiated 1 day prior to viral challenge) and then inoculated intranasally with a neuropathogenic strain of EHV-1. Placebo or valacyclovir was administered...
Hue ES, Richard EA, Fortier CI, Fortier GD, Paillot R, Raue R, Pronost SL.Equine herpesviruses (EHV) infect horses early during life and the persistence of these viruses through establishment of latency represents a real risk. A better understanding of the immune response to EHV infection is necessary to improve our methods of prevention and decrease the risk of transmission. The objectives of this study were to characterise the cytokine gene expression profile of peripheral blood mononuclear cells (PBMC) after in vitro EHV-1, EHV-4, and EHV-2 infection and to determine the efficacy of inactivated (iPPVO) against these 3 viruses. PBMC were isolated from 3 horses an...
Pennington MR, Cossic BGA, Perkins GA, Duffy C, Duhamel GE, Van de Walle GR.Horses commonly develop gastric mucosal ulcers, similar to humans, a condition known as equine gastric ulcer syndrome (EGUS) that can lead to poor performance and lost training time and care expenses. Unlike humans, however, an infectious bacterial cause of ulcers has not been conclusively identified. Herpesviruses, while well-established causative agents of diseases such as cold sores, genital lesions, and certain types of cancer, have also been implicated in the development of a subset of gastric ulcers in humans. The presence of equid herpesviruses in the gastrointestinal tract and their po...
Seeber PA, Soilemetzidou SE, East ML, Walzer C, Greenwood AD.Direct collection of samples from wildlife can be difficult and sometimes impossible. Non-invasive remote sampling for the purpose of DNA extraction is a potential tool for monitoring the presence of wildlife at the individual level, and for identifying the pathogens shed by wildlife. Equine herpesviruses (EHV) are common pathogens of equids that can be fatal if transmitted to other mammals. Transmission usually occurs by nasal aerosol discharge from virus-shedding individuals. The aim of this study was to validate a simple, non-invasive method to track EHV shedding in zebras and to establish ...
Laabassi F, Hue E, Fortier C, Morilland E, Legrand L, Hans A, Pronost S.An episode of acute equine respiratory infection was reported in western Algeria (Tiaret province) between February and March 2011, affecting a large population of horses. Nasal swabs (n=100) were taken from horses aged between 1 and 27 years, presenting with cough and mucopurulent nasal discharge. The prevalence of equine respiratory virus infections was examined using quantitative polymerase chain reaction (qPCR). One, or more, of four equine respiratory viruses were detected in the nasal swabs of 90 of 100 horses (90%) and the detection rate of equine herpesvirus type 1 (EHV-1), equine herp...
Bolfa P, Jeon I, Loftis A, Leslie T, Marchi S, Sithole F, Beck C, Lecollinet S, Zientara S, Hans A, Issel CJ.Equines in the West Indies are used for recreational purposes, tourism industry, racing and agriculture or can be found in feral populations. Little is known in the Caribbean basin about the prevalence of some major equine infectious diseases, some with zoonotic potential, listed as reportable by the OIE. Our objective was to study the prevalence of antibodies for West Nile Virus (WNV), Equine Herpes Virus-1 and 4 (EHV-1 and EHV-4), Equine Influenza (EI), Equine Viral Arteritis (EVA) and Equine Infectious Anemia Virus (EIAV) using a retrospective serological convenience study. We used 180 equi...
Balasuriya UB, Crossley BM, Timoney PJ.Equid herpesvirus 1 (EHV-1) is one of the most economically important equine viral pathogens. Its clinical manifestations in horses vary from acute upper respiratory tract disease, abortion, or neonatal death, to neurological disease termed equine herpesviral myeloencephalopathy, which may lead to paralysis and a fatal outcome. Successful identification of EHV-1 infection in horses depends on a variety of factors such as suitable case selection with emphasis on timing of sample collection, selection of appropriate sample(s) based on the clinical manifestations, application of relevant diagnost...
Whitwell KE, Blunden AS.In 1988 an outbreak of the paralytic form of Equid herpesvirus type 1 (EHV-1) infection occurred on a stud farm and several animals died. This provided an opportunity to perform detailed pathological investigations to gain insights into the pathogenesis of this spontaneous disease. Two paretic mares, three foals, an aborted foetus and its non-paretic dam were examined. The endotheliotropism of the virus was clearly demonstrated by the use of an indirect immunoperoxidase (IP) stain. At autopsy, evidence of viral infection was widespread in the foetus and foals, but limited or absent in the mare...
Houtsma A, Bedenice D, Pusterla N, Pugliese B, Mapes S, Hoffman AM, Paxson J, Rozanski E, Mukherjee J, Wigley M, Mazan MR.Inflammatory airway disease (IAD) in horses, similar to asthma in humans, is a common cause of chronic poor respiratory health and exercise intolerance due to airway inflammation and exaggerated airway constrictive responses. Human rhinovirus is an important trigger for the development of asthma; a similar role for viral respiratory disease in equine IAD has not been established yet. Methods: In a case-control study, horses with IAD (n = 24) were compared to control animals from comparable stabling environments (n = 14). Horses were classified using pulmonary function testing and bronc...
Matsumura T, O'Callaghan DJ, Kondo T, Kamada M.The virulence of the cell culture adapted KyA strain of equine herpesvirus type 1 (EHV-1), which lacks at least six genes by deletions in its genome, was assessed by intranasal inoculation of six young horses that were serologically negative for EHV-1. No horses showed clinical signs, and a neutralizing antibody response against EHV-1 was detected in two horses which had antibodies against EHV-4 prior to the inoculation. A challenge experiment using a highly virulent strain of EHV-1 conducted 4 weeks later against 4 of the 6 horses inoculated intranasally with the KyA strain and 2 control hors...
Barbić L, Lojkić I, Stevanović V, Bedeković T, Starešina V, Lemo N, Lojkić M, Madić J.Equine herpesvirus type 1 (EHV-1) is a worldwide spread pathogen of horses. It can cause abortion, respiratory and neurological disease and consequentially significant economic losses in equine industries. During 2009, two outbreaks of EHV-1 were confirmed in two stud farms in Eastern Croatia. The first outbreak occurred in February following the import of 12 horses from USA, serologically negative to EHV-1 before transport. Four mares aborted in the late stage of pregnancy and one perinatal death was recorded. Other six mares showed clinical signs of myeloencephalopathy with fatal end in four...
Rappocciolo G, Birch J, Ellis SA.There is good evidence that cytotoxic T lymphocytes play an important role in the clearance of equine herpesvirus-1 (EHV1) in horses. We have demonstrated that, in common with other alphaherpesviruses, EHV1 infection can lead to dramatic down-regulation of MHC class I expression at the cell surface, a common strategy for pathogen evasion of the host immune response. This down-regulation is specific for MHC class I and does not reflect a general shut-off of host-cell protein synthesis. The use of monoclonal antibodies that recognize different MHC class I epitopes has demonstrated that the effec...
Azab W, Lehmann MJ, Osterrieder N.Herpesviruses enter cells either by direct fusion at the plasma membrane or from within endosomes, depending on the cell type and receptor(s). We investigated two closely related herpesviruses of horses, equine herpesvirus type 1 (EHV-1) and EHV-4, for which the cellular and viral determinants routing virus entry are unknown. We show that EHV-1 enters equine epithelial cells via direct fusion at the plasma membrane, while EHV-4 does so via an endocytic pathway, which is dependent on dynamin II, cholesterol, caveolin 1, and tyrosine kinase activity. Exchange of glycoprotein H (gH) between EHV-1...
Pronost S, Legrand L, Pitel PH, Wegge B, Lissens J, Freymuth F, Richard E, Fortier G.Equid herpesvirus 1 (EHV-1)-associated myeloencephalopathy (EHM) is a disease affecting the central nervous system of horses. Despite the constantly increasing interest about this syndrome, epidemiological data are limited especially when related to the description of large outbreaks. The aim of this article is to describe clinical, virological and molecular data obtained throughout a severe outbreak of EHM, with emphasis on laboratory diagnostic methods. The epidemic disease concerned a riding school in France where 7/66 horses aged 12-22 years developed signs of neurological disease in July ...
Robertson AT, Caughman GB, Gray WL, Baumann RP, Staczek J, O'Callaghan DJ.Equine herpesvirus type 1 (EHV-1) gene expression is coordinately regulated in an alpha, beta, gamma fashion. Viral alpha gene products include a 6.0-kb immediate early (IE) mRNA species (W. L. Gray et al., 1987, Virology 158, 79-87) and at least four closely related IE polypeptides (IEPs) (G.B. Caughman et al., 1985, Virology 145, 49-61). In this report, we describe results obtained from a series of in vitro translation experiments which were performed in an effort to characterize the IEPs and identify the mechanism by which individual IE protein species are generated. Our data indicate that ...
Although equine herpesvirus myeloencephalopathy (EHM) is a relatively uncommon manifestation of equine herpesvirus-1 (EHV-1) infection, it can cause devastating losses during outbreaks. Antemortem diagnosis of EHM relies mainly on the molecular detection of EHV-1 in nasal secretions and blood. Management of horses affected by EHM is aimed at supportive nursing and nutritional care, at reducing central nervous system inflammation and preventing thromboembolic sequelae. Horses exhibiting sudden and severe neurologic signs consistent with a diagnosis of EHM pose a definite risk to the surrounding...
Pusterla N, Sandler-Burtness E, Barnum S, Hill LA, Mendonsa E, Khan R, Portener D, Ridland H, Schumacher S.The objective of this study was to determine detection frequency of respiratory viruses (equine influenza virus [EIV], equine herpesvirus-1 [EHV-1], EHV-2, EHV-4, EHV-5, equine rhinitis A virus [ERAV], ERBV) and bacteria (Streptococcus equi ss. equi[S. equi], S. equi ss. zooepidemicus[S. zooepidemicus]) in 162 nasal secretions and 149 stall swabs from healthy sport horses attending a spring show in California. Nasal and stall swabs were collected at a single time point and analyzed using qPCR. The detection frequency of respiratory pathogens in nasal secretions was 38.9% for EHV-2, 36.4% for E...
Sherman J, Thorsen J, Barnum DA, Mitchell WR, Ingram DG.Upper respiratory disease has been a serious problem in Standardbred horses on racetracks in Ontario, with outbreaks occurring once or twice annually in late winter and early spring seasons. To determine the causes of these epidemics, a 3-year investigation was carried out in which nasal swabs and serum samples were obtained at intervals from apparently healthy horses and from horses suffering from upper respiratory disease. The nasal swabs were used to isolate bacteria and viruses. The serum samples were examined for the presence and level of antibodies to equine influenza viruses and equine ...
Marenzoni ML, Coppola G, Maranesi M, Passamonti F, Cappelli K, Capomaccio S, Verini Supplizi A, Thiry E, Coletti M.Equid herpesvirus 5 (EHV-5) infection was detected in a farm in Italy by the use of a semi-nested polymerase chain reaction (PCR) targeting glycoprotein B of EHV-5 on nasal swabs and blood samples of clinically healthy and randomly selected Lipizzaner horses (n = 55). Twenty-five horses at the age of 4-17 years and 30 at an age of 1-3 years were sampled once. The association of the infection with these age-groups and the gender of the horses was investigated. The apparent prevalence of EHV-5 infection was significantly different between age-cohorts: it was higher in the younger group of ...
Allen GP, Yeargan MR, Bryans JT.The effect of in vitro and in vivo serial virus passage on the genetic stability of equine herpesvirus 1 (EHV-1) was investigated by restriction endonuclease analysis of the viral DNA. DNAs of EHV-1 isolates at different passage levels in cultured cells or in Syrian hamsters were compared by electrophoresis of the DNA cleavage fragments produced by restriction endonuclease digestion. No changes were observed in the restriction profile of the DNAs of EHV-1 strains after 100 sequential passages in cultured equine cells. However, serial passage of the virus in hamsters or in cells of non-equine o...
Harty RN, Caughman GB, Holden VR, O'Callaghan DJ.Equine herpesvirus 1 (EHV-1, Kentucky A strain) preparations enriched for defective interfering particles (DIPs) can readily establish persistent infection. The UL1 gene, which is conserved in the genome of DIPs that mediate persistent infection, maps between nucleotides 1418 and 2192 (258 amino acids) from the L (long) terminus. UL1 has no homology with any known gene encoded by herpes simplex virus type 1 but has limited homology to open reading frame 2 of varicella-zoster virus and the "circ" gene of bovine herpesvirus type 1. Previous work showed that the EHV-1 UL1 gene belongs to the earl...
Fortier G, Richard E, Hue E, Fortier C, Pronost S, Pottier D, Lemaitre L, Lekeux P, Borchers K, Thiry E.The aim of this trial was to investigate the putative involvement of equid herpesvirus 2 (EHV-2) in airway inflammation of adult horses. Six horses received corticosteroid treatment, before either mock infection (n=2) or EHV-2 strain LK4 inoculation (n=4). These four horses were also submitted to immunosuppression 84 days post inoculation. EHV-2 was detected by quantitative PCR in respiratory samples up to respectively 21 days and 14 days. Nested PCR, cloning and sequencing allowed the detection of five different 'field' strains throughout the trial. Neutrophils proportions were transiently in...
Perkins GA, Goodman LB, Dubovi EJ, Kim SG, Osterrieder N.Early identification of inhalation-transmitted equine herpesvirus type 1 (EHV-1) infections has been facilitated by the availability of a number of real-time quantitative PCR (qPCR) tests. A direct comparison between nasal swab qPCR and traditional virus isolation (VI) requires a method for normalizing the qPCR samples and controlling for PCR inhibitors present in some clinical samples. Objective: To quantify EHV-1 shedding in viral swabs using an internal control and to compare fast qPCR to VI for the detection of EHV-1 in nasal swabs from horses. Methods: Fifteen horses experimentally infect...
Kershaw O, von Oppen T, Glitz F, Deegen E, Ludwig H, Borchers K.The prevalence of EHV-2 in 27 horses with keratoconjunctivitis and 21 clinically healthy horses of different ages and stocks were analyzed. We demonstrated that EHV-2 was present in 12 keratoconjunctivitis cases as shown by nested PCR on ocular swabs. This is statistically more often than in the control group, where only two ocular swabs were EHV-2 positive. Cocultivation was successful on peripheral blood leukocytes of healthy and diseased horses but not on swabs. We isolated ten EHV-2 strains from diseased and nine from control horses, whereas 16 isolates showed different restriction enzyme ...
Yildirim Y, Yilmaz V, Kirmizigul AH.The herpesviruses infections in equides are caused by five different serotypes of viruses, belonging to family Herpesviridae. The goal of this study was to conduct a seroepidemiological investigation of equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4) in horses and donkeys raised in two provinces and their villages in northeastern Turkey. A total of 666 samples from 423 horses and 243 donkeys that were not immunized against these infections were tested with ELISA. While 52.48% of tested horse sera was found to carry specific antibodies to EHV-1, 83.69% of these serums were found to carry s...
Goehring LS, Landolt GA, Morley PS.Because of the serious disease sequelae associated with equine herpesvirus type 1 (EHV-1) infections, awareness and control measures used to control outbreaks are important issues for all horse populations. Objective: Describe the occurrence and management of an outbreak of EHV-1 infection at a veterinary hospital. Methods: Horses hospitalized at a referral veterinary hospital. Methods: A horse with myeloencephalopathy associated with EHV-1 infection (EHM) was admitted for diagnostic evaluation and treatment under strict infection control procedures. We describe the occurrence and management o...
Dayaram A, Seeber PA, Greenwood AD.Equine herpesviruses (EHV) are a major health concern for domestic and wild equids and represent one of the most economically important disease agents of horses. Most known EHVs are transmitted directly between individuals as a result of direct exposure to exudates and aerosols. However, accumulating evidence suggests that environmental transmission may play a role including air, water, and fomites. Here, we reviewed studies on environmental stability and transmission of EHVs, which may influence viral dynamics and the use of environmental samples for monitoring EHV shedding.
Ataseven VS, Dağalp SB, Güzel M, Başaran Z, Tan MT, Geraghty B.In this report we examined the presence of specific antibodies against equine herpesvirus type 1 (EHV-1), and equine herpesvirus type 4 (EHV-4) in several equidae, including mules, donkeys, horses. The presence of EHV-1 and EHV-4 in respiratory diseases of equids, and ability of multiplex nested polymerase chain reaction (PCR) screening in simultaneous diagnosis of horses acutely infected by EHV-1 and EHV-4 were also investigated. Sera from 504 horses, mules and donkeys sampled were tested for the presence of EHV-1 and EHV-4 specific antibodies. Blood samples taken from 21 symptomatic horses a...
Bolfa P, Jeon I, Loftis A, Leslie T, Marchi S, Sithole F, Beck C, Lecollinet S, Zientara S, Hans A, Issel CJ.Equines in the West Indies are used for recreational purposes, tourism industry, racing and agriculture or can be found in feral populations. Little is known in the Caribbean basin about the prevalence of some major equine infectious diseases, some with zoonotic potential, listed as reportable by the OIE. Our objective was to study the prevalence of antibodies for West Nile Virus (WNV), Equine Herpes Virus-1 and 4 (EHV-1 and EHV-4), Equine Influenza (EI), Equine Viral Arteritis (EVA) and Equine Infectious Anemia Virus (EIAV) using a retrospective serological convenience study. We used 180 equi...
Crabb BS, MacPherson CM, Reubel GH, Browning GF, Studdert MJ, Drummer HE.We describe a type-specific ELISA, which distinguishes antibody to equine herpesvirus 4 (EHV4; equine rhinopneumonitis) and EHV1 (equine abortion virus) thereby identifying horses that have been infected with either or both of these antigenically related viruses. The antigens used are parts of the EHV4 and EHV1 glycoprotein G (gG) homologues expressed in E. coli as fusion proteins [Crabb and Studdert, 1993: J Virol 67: 6332-6338). The expressed proteins comprise corresponding regions of the gG molecules that are highly divergent and encompass strong, typespecific epitopes. Plasma samples from ...
Trapp S, von Einem J, Hofmann H, Köstler J, Wild J, Wagner R, Beer M, Osterrieder N.Key problems using viral vectors for vaccination and gene therapy are antivector immunity, low transduction efficiencies, acute toxicity, and limited capacity to package foreign genetic information. It could be demonstrated that animal and human cells were efficiently transduced with equine herpesvirus 1 (EHV-1) reconstituted from viral DNA maintained and manipulated in Escherichia coli. Between 13 and 23% of primary human CD3+, CD4+, CD8+, CD11b+, and CD19+ cells and more than 70% of CD4+ MT4 cells or various human tumor cell lines (MeWo, Huh7, HeLa, 293T, or H1299) could be transduced with o...
Bond SL, Workentine M, Hundt J, Gilkerson JR, Léguillette R.Prolonged exposure to environmental antigens or allergens elicits an immune response in both healthy horses and those with mild asthma. Corticosteroids often are used to treat lower airway inflammation. Objective: To investigate the changes in equine herpesvirus (EHV)-1,2,4,5 glycoprotein B gene expression and changes in respiratory bacterial and fungal communities after nebulized dexamethasone treatment of horses with asthma. Methods: Horses with naturally occurring mild asthma (n = 16) and healthy control horses (n = 4). Methods: Prospective, randomized, controlled, blinded clinical trial. P...
Carroll CL, Westbury HA.This research paper discusses the isolation of equine herpesvirus 1 (EHV1) from the brain of a horse experiencing paresis, demonstrating the connection between EHV1 infections and neurological disorders like ataxia, […]
DARLINGTON RW, RANDALL CC.Equine abortion virus was purified from the plasma of infected golden Syrian hamsters by differential centrifugation and nuclease treatment. The preparations were essentially free of nonviral elements on electron microscopic examination, and sedimentation in sucrose and potassium tartrate density gradients resulted in a single visible band. Electron microscopy of this band showed it to be composed of viral particles, and injection into hamsters resulted in infection and death of the animals. The viral particles had a sedimentation coefficient of approximately 2200 S and a hydrated density of 1...
