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.
Sharp EL, Farrell HE, Borchers K, Holmes EC, Davis-Poynter NJ.Equid herpesvirus 2 (EHV-2), in common with other members of the subfamily Gammaherpesvirinae, encodes homologues of cellular seven-transmembrane receptors (7TMR), namely open reading frames (ORFs) E1, 74 and E6, which each show some similarity to cellular chemokine receptors. Whereas ORF74 and E6 are members of gammaherpesvirus-conserved 7TMR gene families, E1 is currently unique to EHV-2. To investigate their genetic variability, EHV-2 7TMRs from a panel of equine gammaherpesvirus isolates were sequenced. A region of gB was sequenced to provide comparative sequence data. Phylogenetic analysi...
Brown JA, Mapes S, Ball BA, Hodder AD, Liu IK, Pusterla N.To determine the incidence of equine herpesvirus-1 (EHV-1) infection among Thoroughbreds residing on a farm on which the virus was known to be endemic. Methods: Prospective cohort study. Methods: 10 nonpregnant mares, 8 stallions, 16 weanlings, 11 racehorses, and 30 pregnant mares and their foals born during the 2006 foaling season. Methods: Blood and nasopharygeal swab samples were collected every 3 to 5 weeks for 9 months, and placenta and colostrum samples were collected at foaling. All samples were submitted for testing for EHV-1 DNA with a PCR assay. A type-specific EHV-1 ELISA was used t...
Léon A, Fortier G, Fortier C, Freymuth F, Tapprest J, Leclercq R, Pronost S.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...
Ghanem YM, Ibrahim el-SM, Yamada S, Matsumura T, Osterrieder N, Yamaguchi T, Fukushi H.The pathogenicities of RacL11 and Kentucky D strains of equine herpesvirus 1 in the hamster infection model are different from those of Ab4p and the Japanese isolates. Virus genome restriction fragment length polymorphism analysis and sequence comparison of an intergenic region, glycoproteins and tegument genes showed higher conservation but with some strain-specific differences. These results indicate that point nucleotide differences in RacL11 and Kentucky D might be responsible for their pathogenicity in rodent models.
Luce R, Shepherd M, Paillot R, Blacklawst B, Wood JL, Kydd JH.An assay has been developed that measures EHV-1 specific interferon gamma synthesis (IFNgamma), a cytokine produced following the activation of memory T lymphocytes and therefore a measure of cell mediated immunity. The method requires validation in the field. Objective: To measure the frequency of EHV-1 specific, IFNgamma synthesising peripheral blood mononuclear cells (PBMC) in a population of Thoroughbred horses, and examine its relationship with age, gender, premises and history of vaccination or field infection with EHV-1. Methods: Lymphocytes from 200 Thoroughbred horses were stimulated ...
Pusterla N, Chaney KP, Maes R, Wise AG, Holland R, Schott HC.The objective of this study was to investigate whether intramuscular vaccination of healthy adult horses with a killed or a modified live equine herpesvirus type 1 (EHV-1) vaccine could induce transient positive PCR results in either blood or secretions collected on a nasopharyngeal swab. Four horses in each group received either a single killed or a modified-live vaccine intramuscularly. Two local commingled and 2 distant nonvaccinated controls were included for each group. All horses were observed daily for evidence of clinical abnormalities throughout the study periods. Blood and nasopharyn...
Hebia I, Fiéni F, Duchamp G, Destrumelle S, Pellerin JL, Zientara S, Vautherot JF, Bruyas JF.The objective of this study was to determine whether the 10 wash cycles proposed by the International Embryo Transfer Society (IETS) for bovine embryos efficiently decontaminated equine embryos exposed to equine herpes virus 1 (EHV-1) in vitro. Donor mares and stallions were individually screened and shown to be negative for the virus by PCR detection of EHV-1 DNA in blood leukocytes, semen, and uterine lavages in which embryos were recovered. Twenty embryos were recovered and randomly assigned to one of two groups: 10 embryos were exposed for 24h to infectious EHV-1 at 10(6)TCID(50)/ml, and 1...
Craig MI, Barrandeguy ME, Fernández FM.Equine herpesvirus 2 (EHV-2) was isolated from healthy animals; therefore, the association between EHV-2 infection and respiratory disease raises the question of the role of this agent in this pathology. To date, there are no reports that relate viral excretion to health, this study then analysed 153 nasal swabs from horses in different age groups (older and younger than 1 year old) and state of health (clinically healthy and with respiratory symptoms). Results showed that the percentage of horses with viral excretion was higher within the clinically healthy group, being significative (p < 0.0...
Henninger RW, Reed SM, Saville WJ, Allen GP, Hass GF, Kohn CW, Sofaly C.Equine herpesvirus type 1 (EHV-1) infection causes neurologic disease in horses. However, risk factors for the disease and long-term prognosis are poorly characterized. Objective: There are identifiable risk factors for equine herpes-1 myeloencephalopathy. Methods: The entire population of 135 horses housed within the equestrian facility. Methods: A descriptive study investigated the clinical, serologic, virologic, and management aspects of an outbreak of EHV-1 myeloencephalopathy. Results: Out of 135 horses at the facility, 117 displayed signs of EHV-1 infection. Forty-six horses developed ne...
Dynon K, Black WD, Ficorilli N, Hartley CA, Studdert MJ.To examine the association of viruses with acute febrile respiratory disease in horses. Design Nasal swab and serum samples were collected from 20 horses with acute febrile upper respiratory disease that was clinically assessed to have a viral origin. Methods: Each of the samples was inoculated onto equine fetal kidney, RK13 and Vero cell cultures, and viral nucleic acid was extracted for polymerase chain reaction (PCR) or reverse transcription PCR. PCR primers were designed to amplify nucleic acid from viruses known to cause or be associated with acute febrile respiratory disease in horses in...
Diallo IS, Hewitson G, Wright LL, Kelly MA, Rodwell BJ, Corney BG.A multiplex real-time PCR was designed to detect and differentiate equid herpesvirus 1 (EHV-1) and equid herpesvirus 4 (EHV-4). The PCR targets the glycoprotein B gene of EHV-1 and EHV-4. Primers and probes were specific to each equine herpesvirus type and can be used in monoplex or multiplex PCRs, allowing the differentiation of these two closely related members of the Alphaherpesvirinae. The two probes were minor-groove binding probes (MGB) labelled with 6-carboxy-fluorescein (FAM) and VIC for detection of EHV-1 and EHV-4, respectively. Ten EHV-1 isolates, six EHV-1 positive clinical samples...
Rosas CT, Tischer BK, Perkins GA, Wagner B, Goodman LB, Osterrieder N.The immunogenicity in horses of a recombinant equine herpesvirus type 1 (EHV-1) vaccine expressing West Nile virus (WNV) prM and E proteins was studied. To construct the recombinant EHV-1, two-step en passant mutagenesis was employed for manipulation of a bacterial artificial chromosome (BAC) of vaccine strain RacH. Recombinant EHV-1 stably expressed the WNV prM and E proteins as demonstrated by indirect immunofluorescence and Western blotting. In addition, growth properties in vitro of the EHV-1/WNV recombinant were found to not be significantly different from those of the parental virus. To ...
Garré B, van der Meulen K, Nugent J, Neyts J, Croubels S, De Backer P, Nauwynck H.Equine herpesvirus 1 (EHV-1) is an important equine pathogen that causes respiratory disease, abortion, neonatal death and paralysis. Although vaccines are available, they are not fully protective and outbreaks of disease may occur in vaccinated herds. Therefore, there is an urgent need for effective antiviral treatment. For three abortigenic (94P247, 97P70 and 99P96) and three neuropathogenic isolates (97P82, 99P136 and 03P37), the effect of acyclovir, ganciclovir, cidofovir, adefovir, 9-(2-phosphonylmethoxyethyl)-2,6-diaminopurine (PMEDAP) and foscarnet on plaque number was studied. Addition...
Whalley JM, Ruitenberg KM, Sullivan K, Seshadri L, Hansen K, Birch D, Gilkerson JR, Wellington JE.Equine herpesviruses 1 and 4 (EHV-1 and EHV-4) cause equine respiratory disease worldwide. However, only EHV-1 is a cause of abortion and neurological disease, despite the two viruses having all 76 genes in common. In addition EHV-1 has a broader host range in cell culture than EHV-4, as exemplified by the rabbit kidney (RK) cell line that is permissive for EHV-1, but not for EHV-4. Here we describe that when EHV-4 produced in equine cells was inoculated onto RK cells expressing glycoprotein D of EHV-1 (RKgD1), infection developed as clusters of rounded cells, and this infectivity could be pas...
Wang L, Raidal SL, Pizzirani A, Wilcox GE.A nested multiplex PCR was developed as a rapid (<12h), sensitive test for the simultaneous identification of equine herpesviruses (EHV1, EHV4, EHV2 and EHV5) in clinical samples from horses. Peripheral blood and nasal swab (NS) samples from 205 weanling Thoroughbred foals on 6 different studs over 3 consecutive seasons and from 92 adult horses without clinical signs of respiratory disease were examined using direct multiplex PCR of clinical samples (direct PCR) and conventional cell culture with differentiation of EHV in cell cultures by multiplex PCR. Multiplex PCR proved a sensitive and ...
Tsujimura K, Yamanaka T, Kondo T, Fukushi H, Matsumura T.To develop a live vaccine for equine herpesvirus type 1 (EHV-1), two EHV-1 mutants containing no heterogeneous DNA, DeltagI and DeltagE, were constructed with deletions in the open reading frame of either glycoprotein I (gI) or E (gE), respectively. In equine cell culture, deletion mutants formed smaller plaques than the parental and revertant viruses, but the one-step growth patterns of the deletion mutants and the parental strain were approximately the same. These results suggest that both gI and gE contribute to the ability of EHV-1 to spread directly from cell-to-cell, but that these glyco...
Ibrahim ES, Kinoh M, Matsumura T, Kennedy M, Allen GP, Yamaguchi T, Fukushi H.Equine herpesvirus 1 was isolated from an onager in 1985, a zebra in 1986 and a Thomson's gazelle in 1996 in USA. The genetic relatedness and pathogenicity of these three viruses were investigated based on the nucleotide sequences of the glycoprotein G (gG) gene, experimental infection in hamsters, and comparison with horse isolates. The gG gene sequences of EHV-1 from onager and zebra were identical. The gG gene sequences of the gazelle isolate showed 99.5% identity to those of onager and zebra isolates. The gG gene sequences of EHV-1 isolated from horses were 99.9-100% identical and 98, 98 a...
Bell SA, Balasuriya UB, Nordhausen RW, MacLachlan NJ.Horses are commonly infected by herpesviruses, but isolation of equine herpesvirus-5 (EHV-5) has only infrequently been reported. We describe the isolation and characterization of a strain of EHV-5 from the blood mononuclear cells of a healthy adult horse in California. The virus was initially identified by EHV-5 specific polymerase chain reaction (PCR), and it caused lytic infection of cultured rabbit kidney cells only after repeated serial passage. Virions with characteristic herpesvirus morphology were readily demonstrated in cell culture lysate by transmission electron microscopy. A portio...
Pusterla N, Wilson WD, Conrad PA, Barr BC, Ferraro GL, Daft BM, Leutenegger CM.This study was designed to determine the relative levels of gene transcription of selected pathogens and cytokines in the brain and spinal cord of 12 horses with equine protozoal myeloencephalitis (EPM), 11 with equine herpesvirus type 1 (EHV-1) myeloencephalopathy, and 12 healthy control horses by applying a real time pcr to the formalin-fixed and paraffin-embedded tissues. Total rna was extracted from each tissue, transcribed to complementary dna (cDNA) and assayed for Sarcocystis neurona, Neospora hughesi, EHV-1, equine GAPDH (housekeeping gene), tumour necrosis factor (TNF)-alpha, interfer...
Hussey SB, Clark R, Lunn KF, Breathnach C, Soboll G, Whalley JM, Lunn DP.Equine herpesvirus-1 (EHV-1) infection is common in young horses throughout the world, resulting in respiratory disease, epidemic abortion, sporadic myelitis, or latent infections. To improve on conventional diagnostic tests for EHV-1, a real-time polymerase chain reaction (PCR) technique was developed, using primers and probes specific for the EHV-1 gB gene. Amplification efficiencies of 100% +/- 5% were obtained for DNA isolated from a plasmid, infected peripheral blood mononuclear cells (PBMCs), and nasal secretions from infected ponies. The dynamic range of the assay was 8 log10 dilutions,...
Borchers K, Ebert M, Fetsch A, Hammond T, Sterner-Kock A.Equine herpes virus 2 (EHV-2), a gamma(2)-herpesvirus, is common in horses of all ages. Its role as a primary pathogen is unclear but there is an association between EHV-2, respiratory disease and keratoconjunctivitis. The purpose of this study was to gain more information on the prevalence of EHV-2 DNA in conjunctival swabs from horses with and without ocular disease and to define the anatomical site and cell type harbouring viral genome or antigen. By polymerase chain reaction (PCR) 22 out of 77 (28.6%) ocular swabs of clinically healthy and only 4 out of 48 (8.3%) samples from diseased hors...
Kydd JH, Davis-Poynter NJ, Birch J, Hannant D, Minke J, Audonnet JC, Antczak DF, Ellis SA.Equine herpesvirus 1 (EHV-1) causes respiratory and neurological disease and abortion in horses. Animals with high frequencies of cytotoxic T lymphocytes (CTL) show reduced severity of respiratory disease and frequency of abortion, probably by CTL-mediated control of cell-associated viraemia. This study aimed to identify CTL epitopes restricted by selected major histocompatibility complex (MHC) class I alleles expressed in the equine leukocyte antigen (ELA) A3 haplotype. Effector CTL were induced from EHV-1-primed ponies and thoroughbreds with characterized MHC class I haplotypes and screened ...
Allen GP.To evaluate a technique for identifying horses latently infected with neuropathogenic strains of equine herpesvirus-1 (EHV-1). Methods: 36 adult mares, 24 of which were experimentally infected as weanlings with neuropathogenic or nonneuropathogenic EHV-1. Methods: Mandibular lymph node (MLN) tissue was obtained from each horse via biopsy during general anesthesia. Purified DNA from MLNs was tested for EHV-1 DNA by use of a magnetic bead, sequencecapture, nested PCR assay. For MLNs that contained EHV-1 DNA, the 256-bp DNA fragments amplified via sequence-capture nested PCR were sequenced to det...
Sledge DG, Miller DL, Styer EL, Hydrick HA, Baldwin CA.Granulomatous dermatitis in horses has been linked to many etiologies, including various parasites, fungi, and bacteria. Idiopathic forms of granulomatous inflammation-producing diseases, some of which are localized to the skin, also have been reported in horses. Herein we describe a case of recurrent equine granulomatous skin disease characterized by intranuclear viral inclusions within macrophages and giant cells. The histologic changes were primarily noted in the deep dermis and included multifocal to coalescing areas of necrosis marked by histiocytic cell infiltration and presence of giant...
Hornyák A, Bakonyi T, Kulik M, Kecskeméti S, Rusvai M.The occurrence of two important pathogens, equine herpesvirus 1 (EHV1) and equine arteritis virus (EAV) causing abortions, perinatal foal mortality and respiratory disease, was investigated by polymerase chain reaction (PCR) and virus isolation to demonstrate the presence of abortigenic viruses in samples from 248 horse fetuses in Hungary. We found 26 EHV1- and 4 EAV-positive aborted or prematurely born foals from 16 and 4 outbreaks, respectively, proving that despite the widely applied vaccination, EHV1 is a far more important cause of abortions in the studs than EAV. We compared the virus co...
Bell SA, Balasuriya UB, Gardner IA, Barry PA, Wilson WD, Ferraro GL, MacLachlan NJ.The objectives of this study were to estimate the prevalence of equine herpesviruses (EHV) 1-5 in the nasal secretions (NS) of a cohort of 12 mares and their foals from birth to 6 months of age, estimate the prevalence of EHV-1-5 infection of peripheral blood mononuclear cells (PBMC) of selected foals, and investigate phylogenetic relationships amongst the various strains of EHV-2 and 5. Virus-specific PCR assays were used to detect EHV-1-5 in NS and PBMC. A homologous portion of the glycoprotein B (gB) gene of the various strains of EHV-2 and 5 was sequenced and compared. EHV-2, 4, and 5 were...
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...
Vissani MA, Perglione CO, Zabal O, Alvarez G, Thiry E, Barrandeguy M, Parreño V.Equid alphaherpesvirus 3 (EHV-3) is the etiological agent of equine coital exanthema (ECE). Because no vaccines or antiviral therapies are available, prevention consists of clinical examination of mares and stallions before mating or semen collection and resting from breeding activities when lesions are present. However, this methodology does not identify subclinically infected animals. Ganciclovir is the most potent compound known to reduce EHV-3 replication. This study aimed to evaluate the efficacy of topical ganciclovir application to reduce EHV-3 replication in experimentally infected mar...
Spelta CW, Axon JE, Begg A, Diallo IS, Carrick JB, Russell CM, Collins NM.Equine multinodular pulmonary fibrosis (EMPF) is a recently described form of interstitial pneumonia associated with the presence of equine herpesvirus type 5 (EHV-5). Since 2007, several case reports from America, Europe and the United Kingdom have further characterised the clinical presentation and laboratory findings of this disease. Methods: Three Thoroughbred broodmares were diagnosed with EMPF. Diagnosis was based on lung histopathology and positive identification of EHV-5 using PCR DNA amplification. There was multiple organ involvement in all three cases, including identification of EH...
Niedermaier G, Poth T, Gehlen H.Two warmblood horses with a history of chronic weight loss and inappetence were referred to the Faculty of Veterinary Medicine, Ludwig-Maximilians University of Munich, Germany, for further examination. The clinical signs in horse 1 were fever, tachycardia and tachypnoea, and chronic ulcerative keratopathy of both eyes. Horse 2 had severe oral ulcerations and was coughing during feeding. In both horses, increased bronchovesicular sounds were heard during auscultation of the lungs. Laboratory findings included mild anaemia, lymphopenia and hypoalbuminaemia. Radiographic examination of the thora...
Drebert Z, Golke A, Cymerys J, Słońska A, Chmielewska A, Tucholska A, Bańbura MW.Equid herpesvirus type 1 (EHV-1) is a prevalent causative agent of equine diseases worldwide. After primary replication in the respiratory epithelium the virus disseminates systemically through a peripheral blood mononuclear cell (PBMC)-associated viraemia. EHV-1 is the only alphaherpes- virus known so far which is capable of establishing latent infection not only in neurons but also in immune system cells (mainly in lymphocytes and macrophages). Since leukocytes are not the target cells for viral replication but are used to transport EHV-1 to the internal organs, the questionremains how the v...
Carvalho R, Passos LM, Martins AS.In this study, a multiplex polymerase chain reaction (PCR) procedure was developed for differentiation of strains and field isolates of equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4). Specific oli-gonucleotide primers were combined to amplify the thymidine kinase (TK) gene region of EHV-1 and EHV-4, which would yield fragments of different lengths for each virus in the same amplification reaction. The specificity of the largest PCR amplicon for EHV-4 was confirmed by restriction digestion with HindIII. The multiplex PCR proved to be a fast and sensitive method for typing EHV-1 and EHV-4 ...
Dutta SK, Campbell DL.Blastic transformation of peripheral blood mononuclear cells and serum neutralization antibody levels for equine herpesivurs type 1 were measured in 19 mares from three farms at the time of termination of their pregnancy by normal foaling or viral abortion. The stimulation indexes of lymphocytes obtained from the mares from two farms (Farm 1 and 2) which had virus abortions, ranged from 2.1 to 10.8. But there was no significant difference in stimulation index levels between the aborting and normal foaling mares on these two farms. Equine herpesvirus type 1 was isolated from the mononuclear cel...
Xie J, Tong P, Zhang L, Ren M, Song X, Jia C, Palidan N, Zhang L, Kuang L.In November 2018, an outbreak of respiratory disease occurred in foals at an equestrian club in Changji, northern Xinjiang, China. We applied viral metagenomics to investigate this outbreak and identify potential pathogens involved in this equine respiratory syndrome. The metagenomics data revealed the presence of sequences matching those of equid herpesvirus (EHV) 2, 4, and 5. PCR with specific primers targeting ORF33 of EHV-4 and ORF8 of EHV-2 and EHV-5 revealed coinfection with these viruses in this respiratory syndrome. To investigate the prevalence of these viruses in China, 453 nasal swa...
Smith KC, Borchers K.The polymerase chain reaction and DNA in-situ hybridization were used to study sections of uterine tissue collected from mares near the time of abortion due to equid herpesvirus-1 (EHV-1) infection. These techniques revealed viral nucleic acids in endothelial cells of endometrial arterioles, in accordance with previously published immunohistological data. In addition, however, they revealed nucleic acids in cellular debris within endometrial glands and diffusing across the placenta at sites of microcotyledonary infarction. Perivascular leucocytes were generally negative for viral DNA, despite ...
Studdert MJ, Crabb BS, Ficorilli N.The restriction endonuclease DNA fingerprints of 57 isolates of equine herpesvirus 1 (EHV1; equine abortion virus) from abortion, perinatal foal mortalities and encephalitis from 15 epidemics that occurred in Australasia between 1975 and 1989 were examined using the enzymes Bam HI, EcoRI and Bgl II. There was a remarkable degree of uniformity in the restriction patterns; mobility differences were observed in only 14 of 52 (27%) of the fragments. Twelve of these 14 fragments were located within the repeat structures that bracket the unique short region of the genome or were located at the left ...
Borchers K, Frölich K, Ludwig H.In blood samples of seven captive equid species from four German zoos EHV-1 specific antibodies were detected in 76% and EHV-4 specific antibodies in 73% of the 55 animals, whereas 93% were tested positive for EHV-2 and EHV-5, respectively. In only one blood sample from a Przewalski's wild horse EHV-4 DNA was amplified by PCR. From seven Przewalski's wild horses EHV-2, and from another one EHV-5 was isolated by cocultivation. The identity of the virus isolates was verified by PCR and restriction enzyme digestion.
Lawton K, Runk D, Hankin S, Mendonsa E, Hull D, Barnum S, Pusterla N.The aim of this study was to use environmental sampling to determine the frequency of detection of selected equine respiratory viruses and bacteria in horses attending a multi-week equestrian show during the winter months. At four time points during showing, environmental sponge samples were collected from all stalls on the property and tested for the presence of equine herpesvirus-1 (EHV-1), EHV-2, EHV-4, equine influenza virus (EIV), equine rhinitis B virus (ERBV), Streptococcus equi ss. equi (S. equi), and S. equi ss. zooepidemicus (S. zooepidemicus) using real-time PCR (PCR). Environmental...
Kasem S, Yu MHH, Alkhalefa N, Ata EB, Nayel M, Abdo W, Abdel-Moneim AS, Fukushi H.Equine herpesvirus 1 (EHV-1) causes respiratory illness, fetal loss, perinatal mortality, and myeloencephalopathy. This study investigated ORF15's impact on virus infectivity and neurovirulence. The Ab4p neurovirulent strain of EHV1 was used as a backbone to create Ab4p attB, Ab4p∆ORF15, and Ab4p∆ORF15R chimeras via BAC DNA transfection into RK-13 cells. Viral growth kinetics, plaque size, transcription, and growth were assessed in MDBK cells, mouse neurons, and fetal equine brain cells. Neurovirulence was evaluated post-intranasal inoculation into male CBA/N1 SPF mice, measuring signs, vi...
Wang T, Li S, Hu X, Geng Y, Chen L, Liu W, Zhao J, Tian W, Wang C, Li Y, Li L.Equid alphaherpesvirus 8 (EqHV-8) is one of the most economically important viruses that is known to cause severe respiratory disease, abortion, and neurological syndromes in equines. However, no effective vaccines or therapeutic agents are available to control EqHV-8 infection. Heme oxygenase-1 (HO-1) is an antioxidant defense enzyme that displays significant cytoprotective effects against different viral infections. However, the literature on the function of HO-1 during EqHV-8 infection is little. We explored the effects of HO-1 on EqHV-8 infection and revealed its potential mechanisms. Our ...
Li L, Cui X, Yu Y, Sun Q, Li W, Li Y, Li S, Chen L, Khan MZ, Wang C, Wang T.Equid herpesvirus type 8 (EqHV-8) poses a significant threat to equine health, leading to miscarriages and respiratory diseases in horses and donkeys, and results in substantial economic losses in the donkey industry. Currently, there are no effective drugs or vaccines available for EqHV-8 infection control. Unassigned: In this study, we investigated the and antiviral efficacy of Blebbistatin, a myosin II ATPase inhibitor, against EqHV-8. Unassigned: Our results demonstrated that Blebbistatin significantly inhibited EqHV-8 infection in Rabbit kidney (RK-13) and Madin-Darby Bovine Kidney (MDB...
Tong P, Pan J, Dang Y, Yang E, Jia C, Duan R, Tian S, Palidan N, Kuang L, Wang C, Lu G, Xie J.Equine herpesvirus type 1 (EHV-1) is commonly associated with horse abortion. Currently, there are no reported cases of abortion resulting from EHV-1 infection in donkeys. This was the first survey-based study of Chinese donkeys. The presence of EHV-1 was identified by PCR. This survey was conducted in Chabuchar County, North Xinjiang, China, in 2020. A donkey EHV-1 strain (Chabuchar/2020) was successfully isolated in MDBK cells. Seventy-two of 100 donkey sera were able to neutralize the isolated EHV-1. Moreover, the ORF33 sequence of the donkey-origin EHV-1 Chabuchar/2020 strain showed high l...
Lebrasseur O, More KD, Orlando L.Equine viral outbreaks have disrupted the socio-economic life of past human societies up until the late 19th century and continue to be of major concern to the horse industry today. With a seroprevalence of 60-80 per cent, equine herpesvirus 4 (EHV-4) is the most common horse pathogen on the planet. Yet, its evolutionary history remains understudied. Here, we screen the sequenced data of 264 archaeological horse remains to detect the presence of EHV-4. We recover the first ancient EHV-4 genome with 4.2× average depth-of-coverage from a specimen excavated in the Southeastern Urals and dated ...
Ferreira CGT, Campos MG, Felix DM, Santos MR, Carvalho OV, Diaz MAN, Fietto JLR, Bressan GC, Silva-Júnior A, Almeida MR.Equid herpesvirus 1 (EHV-1) is a pathogen of high economic importance in equine breeding operations around the world. EHV-1 infection causes respiratory, neurologic and reproductive disease. The absence of an efficient therapy has caught the attention of the scientific community and the therapeutic activities of natural products with its antivirals effects might be effective for the disease's treatment. Herein it was evaluated the prophylactic and therapeutic potential of quercetin and ethanolic extracts of Bacharis dracunculifolia formulations compared to Penciclovir® in an in vivo EHV-1 inf...
Perkins GA, Van de Walle GR, Pusterla N, Erb HN, Osterrieder N.To evaluate metaphylactic RNA interference to prevent equine herpesvirus type 1 (EHV-1) infection in experimental herpesvirus myeloencephalopathy in horses and to determine whether horses infected with a neuropathogenic strain of the virus that develop equine herpesvirus myeloencephalopathy (EHM) have differences in viremia. Methods: 13 seronegative horses. Methods: EHV-1 strain Ab4 was administered intranasally on day 0, and small interfering RNAs (siRNAs [EHV-1 specific siRNAs {n = 7} or an irrelevant siRNA {6}]) were administered intranasally 24 hours before and 12, 24, 36, and 48 hours aft...
Glorieux S, Vandekerckhove AP, Goris N, Yang XY, Steukers L, Van de Walle GR, Croubels S, Neyts J, Nauwynck HJ.Equine herpesvirus 1 (EHV1) is a ubiquitous equine alphaherpesvirus that causes respiratory disease, neurological symptoms and abortions. Current vaccines are not fully protective and effective therapeutics are lacking. A-5021 [(1'S,2'R)-9-[[1',2'-bis(hydroxymethyl)cycloprop-1'-yl]methyl]guanine], previously shown to possess potent anti-herpetic activity against most human herpesviruses, was evaluated for its potential to inhibit EHV1 replication. In equine embryonic lung (EEL) cells, infected with either a non-neurovirulent (97P70) or a neurovirulent (03P37) EHV1 isolate, A-5021 proved to be ...
O'Niell FD, Issel CJ, Henk WG.Organ cultures of equine fetal tracheal and nasal turbinate epithelium were inoculated with equine influenza virus-A1 (EIV-A1), equine herpesvirus-1 (EHV-1), or equine rhinovirus-1 (ERV-1). Infected organ cultures were processed for scanning and transmission electron microscopy at various intervals and were compared with noninfected controls. Organ cultures inoculated with ERV-1 appeared normal with the exception of rare island-like lesions in infected nasal turbinate. Virus particles were not seen in thin sections of organ cultures infected with ERV-1. The EHV-1 caused extensive loss of the e...
Jiménez D, Romero-Zuñiga JJ, Dolz G.Blood samples from 181 equines from the Central Valley of Costa Rica were collected in the year 2012 to determine the presence of antibodies against selected infectious agents in horses and to determine the risk factors associated with these agents. The presence of antibodies against Equine Infectious Anemia Virus (EIAV), Equine Herpes Virus 1 and 4 (EHV-1 and EHV-4), West Nile Virus (WNV), Influenza A Virus (IAV), Equine Viral Arteritis Virus (EVAV), Babesia caballi, Theileria equi, Neospora caninum and Chlamydia abortus was determined using commercial assays, and risk factors associated with...
Crandell RA, Davis ER.The virus causing equine coital exanthema (equine herpesvirus 3) was isolated from a lesion on the nostril of a 2-month-old foal. One week after the mare had returned from a stallion station, vesicular lesions developed on her vulva. They were diagnosed clinically as coital exanthema, and 5 days later a lesion developed on the nostril of her foal. This case is an example of horse-to-horse transmission of coital exanthema virus without coitus. A laboratory diagnosis is necessary to differentiate viruses that cause vesicular lesions about the oral and nasal cavities of horses.
Thomson GW, McCready R, Sanford E, Gagnon A.In the foaling season of 1977, five vaccinated horses in a Standardbred breeding stable were affected with herpesvirus myeloencephalitis. Respiratory and abortigenic forms also occurred in other individuals on the premises. Equine herpesvirus type 1 was isolated from the brain of one case of myeloencephalitis and from lungs of two aborted fetuses. Twelve of 16 horses demonstrated fourfold or greater increases in titres to equine herpesvirus type 1.
