The study of viral infections that affect equine species assesses the relationship between viruses and horses. Infections can lead to a range of clinical symptoms and may impact the health and performance of horses. Common equine viruses include Equine Influenza Virus, Equine Herpesvirus, and West Nile Virus, among others. Understanding the mechanisms of viral transmission, pathogenesis, and host immune responses is essential for developing effective prevention and treatment strategies. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, molecular biology, and clinical management of viral infections in horses.
Stasiak K, Rola J, Zmudzinski JF.A highly sensitive and specific real-time PCR assay was used for detection and quantitation of equine herpesvirus type 1 (EHV-1) in the different internal organs of aborted fetuses. Tissue samples from 23 aborted fetuses submitted to the Department of Virology of the National Veterinary Research Institute in Pulawy between 2012 and 2013 were used for testing. Total DNA was extracted using a phenol-chloroform-isoamyl alcohol standard protocol. A real-time PCR with forward and reverse primers encompassing a highly conserved region encoding viral glycoprotein B was adapted for diagnosis of EHV-1 ...
Kang BK, Hwang JM, Moon H, Han SY, Kim JM, Yang DK, Park BK, Song D.The Japanese encephalitis virus (JEV) genotype circulating in Korea has changed from G3 to G1. Therefore, the purpose of this study was to compare the antigenic relationship between the two genotypes by using antibody tests. Methods: Blood samples from 42 sows and 216 horses were collected, and their seroprevalence was monitored using the hemagglutination inhibition and virus neutralization tests. Antisera against JEV G1 and G3 were isolated and prepared from guinea pigs. The cross-reactivity of these two viruses was then compared using the neutralizing antibody test. Results: We found that th...
Kim H, Lee YK, Kang SC, Han BK, Choi KM.Various new technologies have been applied for developing vaccines against various animal diseases. Virus-like particle (VLP) vaccine technology was used for manufacturing the porcine circovirus type 2 and RNA particle vaccines based on an alphavirus vector for porcine epidemic diarrhea (PED). Although VLP is classified as a killed-virus vaccine, because its structure is similar to the original virus, it can induce long-term and cell-mediated immunity. The RNA particle vaccine used a Venezuela equine encephalitis (VEE) virus gene as a vector. The VEE virus partial gene can be substituted with ...
West Nile virus in Europe and the USA. Evidence that the spread of vesicular stomatitis in the USA is beginning to slow. Summary of UK surveillance testing, July to September 2015 These are among matters discussed in the most recent quarterly equine disease surveillance report, prepared by Defra, the Animal Health Trust and the British Equine Veterinary Association.
West Nile virus in Europe and the USA. Evidence that the spread of vesicular stomatitis in the USA is beginning to slow. Summary of UK surveillance testing, July to September 2015 These are among matters discussed in the most recent quarterly equine disease surveillance report, prepared by Defra, the Animal Health Trust and the British Equine Veterinary Association.
Liu Q, Ma J, Wang XF, Xiao F, Li LJ, Zhang JE, Lin YZ, Du C, He XJ, Wang X, Zhou JH.The live equine infectious anemia virus (EIAV) vaccine strain EIAVDLV121 was developed by in vitro attenuation of a virulent strain, EIAVLN40, in the 1970s, and it has been demonstrated to induce protective immunity under laboratory and natural EIAV infection conditions. The detailed biological features of this attenuated virus remain to be further investigated. Experimental inoculation with EIAVDLV121 did not result in clinical symptoms even with immunosuppressive treatment in our previous studies. Here, we further investigated whether the replication of the vaccine strain EIAVDLV121 in exper...
Baer A, Lundberg L, Swales D, Waybright N, Pinkham C, Dinman JD, Jacobs JL, Kehn-Hall K.Venezuelan equine encephalitis virus (VEEV) is a previously weaponized arthropod-borne virus responsible for causing acute and fatal encephalitis in animal and human hosts. The increased circulation and spread in the Americas of VEEV and other encephalitic arboviruses, such as eastern equine encephalitis virus and West Nile virus, underscore the need for research aimed at characterizing the pathogenesis of viral encephalomyelitis for the development of novel medical countermeasures. The host-pathogen dynamics of VEEV Trinidad donkey-infected human astrocytoma U87MG cells were determined by car...
Pusterla N, Magdesian KG, Mapes SM, Zavodovskaya R, Kass PH.The ante mortem diagnosis of equine multinodular pulmonary fibrosis (EMPF) relies on histopathological results and polymerase chain reaction (PCR)-positive equine herpesvirus (EHV)-5 testing of lung tissue. Polymerase chain reaction detection of EHV-5 in bronchoalveolar lavage fluid (BALF) is commonly used to support a diagnosis of EMPF. However, the diagnostic power of EHV-5 testing on BALF and other biological samples such as blood and nasal secretions has yet to be shown to support a diagnosis of EMPF. Objective: To determine the frequency of detection and the viral loads of EHV-5 by quanti...
Mason JB, Gurda BL, Van Wettere A, Engiles JB, Wilson JM, Richardson DW.Our long-term aim is to develop a gene therapy approach for the prevention of laminitis in the contralateral foot of horses with major musculoskeletal injuries and non-weightbearing lameness. Objective: The goal of this study was to develop a practical method to efficiently deliver therapeutic proteins deep within the equine foot. Methods: Randomised in vivo experiment. Methods: We used recombinant adeno-associated viral vectors (rAAVs) to deliver marker genes using regional limb perfusion through the palmar digital artery of the horse. Results: Vector serotypes rAAV2/1, 2/8 and 2/9 all succes...
Aeschbacher S, Santschi E, Gerber V, Stalder HP, Zanoni RG.Equine influenza is a highly contagious respiratory disease in horses caused by influenza A viruses. In this work a real-time RT-PCR for fast and sensitive diagnosis of equine influenza viruses (EIV) targeting a highly conserved region of the matrix gene was developed. In addition two RT-PCR methods for the amplification of large parts of the matrix- and HA gene were adapted for molecular-epidemiological characterization of viruses. The primers of the real-time RT-PCR had homologies of 99.4% to EIV- and 97.7% to all influenza A viral sequences, whereas the minor groove binder (MGB) probe showe...
Sarkar S, Chelvarajan L, Go YY, Cook F, Artiushin S, Mondal S, Anderson K, Eberth J, Timoney PJ, Kalbfleisch TS, Bailey E, Balasuriya UB.Previous studies in our laboratory have identified equine CXCL16 (EqCXCL16) to be a candidate molecule and possible cell entry receptor for equine arteritis virus (EAV). In horses, the CXCL16 gene is located on equine chromosome 11 (ECA11) and encodes a glycosylated, type I transmembrane protein with 247 amino acids. Stable transfection of HEK-293T cells with plasmid DNA carrying EqCXCL16 (HEK-EqCXCL16 cells) increased the proportion of the cell population permissive to EAV infection from <3% to almost 100%. The increase in permissiveness was blocked either by transfection of HEK-EqCXCL16 cell...
Anand T, Vaid RK, Bera BCh, Singh J, Barua S, Virmani N, Rajukumar K, Yadav NK, Nagar D, Singh RK, Tripathi BN.A bacteriophage (VTCCBPA6) against a pathogenic strain of Aeromonas hydrophila was isolated from the sewage of an organized equine breeding farm. On the basis of TEM analysis, phage belonged to family Myoviridae. PCR amplification and sequence analysis of gp23 gene (encoding for major capsid protein) revealed phylogenetic resemblance to T4 like virus genus. Protein profiling by SDS-PAGE also indicated its resemblance to T4 like phage group. However, the comparison of its gp23 gene sequence with previously reported phages showed similarity with T4-like phages infecting Enterobacteriaceae instea...
Ahmadnejad F, Otarod V, Fathnia A, Ahmadabadi A, Fallah MH, Zavareh A, Miandehi N, Durand B, Sabatier P.Geographic distribution of West Nile virus (WNV) is heterogeneous in Iran by a high circulation in the southern-western areas. The objective of our study was to determine environmental and climatic factors associated with the risk of WNV equine seropositivity in Iran. Methods: Serological data were obtained from a serosurvey conducted in equine population in 260 districts in Iran. The climate and environmental parameters included in the models were distance to the nearest wetland area, type of stable, Normalized Difference Vegetation Index (NDVI), annual mean temperature, humidity and precipit...
Lu Z, Sarkar S, Zhang J, Balasuriya UB.Equine arteritis virus (EAV), the causative agent of equine viral arteritis, has relatively broad cell tropism in vitro. In horses, EAV primarily replicates in macrophages and endothelial cells of small blood vessels. Until now, neither the cellular receptor(s) nor the mechanism(s) of virus attachment and entry have been determined for this virus. In this study, we investigated the effect of heparin on EAV infection in equine endothelial cells (EECs). Heparin, but not other glycosaminoglycans, could reduce EAV infection up to 93 %. Sequence analysis of the EAV E minor envelope protein reveale...
Cervantes DT, Ball JM, Edwards J, Payne S.Equine infectious anemia virus (EIAV) causes lifelong infections ranging from acutely fatal, to chronic, to asymptomatic. Within infected animals, EIAV is found as a quasispecies. Many experimental studies on EIAV, carried out in the U.S. over the past 70 years, have used either the highly virulent Wyoming (EIAVWYO) field strain or various derivatives of that strain. These infections have provided insights into the variety of genetic changes that accumulate in the env gene and LTR in experimentally infected horses. In the current study, we obtained EIAV sequences from blood samples collected f...
Pfahl K, Chung C, Singleton MD, Shuck KM, Go YY, Zhang J, Campos J, Adams E, Adams DS, Timoney PJ, Balasuriya UB.The purpose of this study was to further evaluate and validate two commercially available equine arteritis virus (EAV) competitive ELISAs (original and enhanced cELISAs) using archived equine sera from experimentally inoculated animals and field sera submitted for laboratory diagnosis. First, the original and subsequently enhanced cELISAs were compared with the virus neutralisation test (VNT) using a panel of archived serum samples from experimentally inoculated animals. Then, the enhanced cELISA was compared with the VNT using a large panel of archived serum samples. The total number of equin...
Claessen C, De Lange V, Huang T, Ma G, Osterrieder N, Favoreel H, Van de Walle GR.Equine herpesvirus 1 (EHV1) is an α-herpesvirus that can infect a variety of different cells in vitro and in vivo, including dendritic cells (DC) which are essential in the immune response against EHV1. Infection of equine monocyte-derived DC (MDDC) with EHV1 induced down-regulation of major histocompatibility complex I (MHCI), CD83, CD86, CD206, CD29 and CD172a, but not of CD11a/CD18 and MHCII. This down-regulation was not mediated by the virion host-shutoff (VHS) protein or pUL49.5. Interestingly, down-regulation of CD83 and CD86 was in part mediated by pUL56. Taken together, these data ind...
Mondal SP, Cook RF, Chelvarajan RL, Henney PJ, Timoney PJ, Balasuriya UB.Strains of equine arteritis virus (EAV) differ in their virulence phenotypes, causing anywhere from subclinical infections to severe disease in horses. Here, we describe the in silico design and de novo synthesis of a full-length infectious cDNA clone of the horse-adapted virulent Bucyrus strain (VBS) of EAV encoding mCherry along with in vitro characterization of the progeny virions (EAV sVBSmCherry) in terms of host-cell tropism, replicative capacity and stability of the mCherry coding sequences following sequential passage in cell culture. The relative stability of the mCherry sequence duri...
Saqib M, Hussain MH, Sajid MS, Mansoor MK, Asi MN, Fadya AA, Zohaib A, Sial AU, Muhammad G, Ullah I.Toxoplasmosis is a serious threat for livestock in addition to being of zoonotic significance. In this study, serodiagnosis of equine toxoplasmosis was conducted in a randomly selected population from the 3 metropolises of Punjab, Pakistan. To this end, 272 draught equines were screened using a commercial latex agglutination assay kit. Association of probable risk factors of equine toxoplasmosis was also documented. A total of 91 (33.5%) equines were found sero-positive for Toxoplama (T.) gondii having antibody titers ranging between 1:32 to 1:612. The highest rates of seropositive cases were ...
Back H, Berndtsson LT, Gröndahl G, Ståhl K, Pringle J, Zohari S.Equine Influenza Virus (EIV) is a major cause of respiratory disease in horses and the virus constantly undergoes antigenic drift. Here we characterize and describe the HA1 and the NA genes of H3N8 within samples obtained from outbreaks in Sweden during November-December 2011. Both clade 1 and clade 2 viruses of the Florida sublineage were identified. The index case of clade 2 was transported to Sweden from Spain through the Netherlands, whereas the clade 1 had its origin from a Swedish stud farm. The clade 1 virus was efficiently spread between training yards by unvaccinated young horses, but...
Vaz PK, Horsington J, Hartley CA, Browning GF, Ficorilli NP, Studdert MJ, Gilkerson JR, Devlin JM.Recombination in alphaherpesviruses allows evolution to occur in viruses that have an otherwise stable DNA genome with a low rate of nucleotide substitution. High-throughput sequencing of complete viral genomes has recently allowed natural (field) recombination to be studied in a number of different alphaherpesviruses, however, such studies have not been applied to equine herpesvirus 1 (EHV-1) or equine herpesvirus 4 (EHV-4). These two equine alphaherpesviruses are genetically similar, but differ in their pathogenesis and epidemiology. Both cause economically significant disease in horse popul...
Sarkar S, Balasuriya UB, Horohov DW, Chambers TM.Equine herpesvirus-1 (EHV-1) infects equine endothelial cells (EECs) lining the small blood vessels in the central nervous system. However, the effect of type I IFN on EHV-1 replication in the EECs is not well studied. Thus, the primary objective of this study was to investigate the effect of type-I IFN on the replication of the neuropathogenic T953 strain of EHV-1 in vitro in EECs. The initial data showed that the EHV-1 was partly resistant to the biological effect of exogenously supplied recombinant equine IFN-α. Subsequent investigation into the mechanism of resistance showed that EHV-1 in...
Zhang Z, Ma J, Zhang X, Su C, Yao QC, Wang X.Gag intracellular assembly and export are very important processes for lentiviruses replication. Previous studies have demonstrated that equine infectious anemia virus (EIAV) matrix (MA) possesses distinct phosphoinositide affinity compared with HIV-1 MA and that phosphoinositide-mediated targeting to peripheral and internal membranes is a critical factor in EIAV assembly and release. In this study, we compared the cellular assembly sites of EIAV and HIV-1. We observed that the assembly of EIAV particles occurred on interior cellular membranes, while HIV-1 was targeted to the plasma membrane (...
Lee E, Kim EJ, Shin YK, Song JY.The avian influenza A virus causes respiratory infections in animal species. It can undergo genomic recombination with newly obtained genetic material through an interspecies transmission. However, the process is an unpredictable event, making it difficult to predict the emergence of a new pandemic virus and distinguish its origin, especially when the virus is the result of multiple infections. Therefore, identifying a novel influenza is entirely dependent on sequencing its whole genome. Occasionally, however, it can be time-consuming, costly, and labor-intensive when sequencing many influenza...
Méndez-López MR, Attoui H, Florin D, Calisher CH, Florian-Carrillo JC, Montero S.Since 1983, cases of diseased donkeys and horses with symptoms similar to those produced by alphaviruses were identified in two departments in northern Peru; however serological testing ruled out the presence of those viruses and attempts to isolate an agent were also unproductive. In 1997, also in northern Peru, two new orbiviruses were discovered, each recognized as a causative agent of neurological diseases in livestock and domestic animals and, at the same time, mosquitoes were found to be infected with these viruses. Peruvian horse sickness virus (PHSV) was isolated from pools of culicid ...
Attoui H, Mohd Jaafar F.Many novel emerging orbiviruses have been isolated in the past 15 years. Important viruses include Peruvian horse sickness virus (PHSV) and Yunnan orbivirus (YUOV), pathogens of equids which were originally isolated almost simultaneously from 1997 to 1999 in the People's Republic of China, Australia and Peru. YUOV has also been isolated from cattle, sheep and a dog. The isolation of YUOVfrom a dog is not the first case of an orbivirus being isolated from a carnivore. Bluetongue virus and African horse sickness virus were earlier detected in carnivores which fed on contaminated meat. PHSV and Y...
Aréchiga-Ceballos N, Aguilar-Setién A.Summary Alphaviral equine encephalomyelitis is a mosquito-borne infection that causes severe neurological disease and fatalities in horses and humans in the Americas. Consequently, the equine alphaviruses (Eastern, Western and Venezuelan) are of considerable concern worldwide and are notifiable to the World Organisation for Animal Health. In addition, these diseases are considered a potent potential biological weapon, emphasising the need to develop an effective vaccine. Alphaviral equine encephalomyelitis is caused by Eastern equine encephalomyelitis virus (EEEV), Western equine encephalomyel...
Issel CJ, Foil LD.There is no credible evidence that the lentivirus that causes equine infectious anaemia (EIA) replicates in invertebrates. The virus persistently infects its equid hosts and is often present in blood in significant quantities. Blood-feeding arthropods thus have the potential to transfer the virus between hosts, especially if their feeding on the first host is interrupted and immediately continued on a second host. The general details and dynamics of mechanical transmission are included in this paper, as this agent presents an excellent model. Mechanical transmission can be effectively controll...
Morita K, Nabeshima T, Buerano CC.Japanese encephalitis (JE) is an inflammation of the central nervous system in humans and animals, specifically horses and cattle. The disease, which can sometimes be fatal, is caused by the flavivirus Japanese encephalitis virus (JEV), of which there are five genotypes (genotypes 1, 2, 3, 4 and 5). The transmission cycle of the virus involves pigs and wild birds as virus amplifiers and mosquitoes as vectors for transferring the virus between amplifying hosts and to dead- end hosts, i.e. humans, horses and cattle. In horses and cattle the disease is usually asymptomatic, but when clinical sign...
Calisher CH, Sasso DR, Sather GE.During 1971, an epizootic of Venezuelan equine encephalitis (VEE) reached the United States. Laboratory tests were performed on a large number of sick, healthy, unvaccinated, and vaccinated horses. Neutralization (N) tests in cell cultures revealed that 153 of 193 (79.3%) equines outside the state of Texas and 175 of 204 (85.8%) within Texas (82.6% overall) had detectable N antibody to VEE virus a week or more after vaccination. Twenty-six of 40 (65%) non-Texas equines and 18 of 29 (62%) Texas equines which had no detectable antibody against VEE virus a week or more after vaccination had N ant...
Isa P, Snodgrass DR.A series of viral reassortants was prepared between equine rotaviruses H1 (G5), H2 (G3), and L338 (G13) and human rotavirus ST3 (G4). All contained the VP4 cognate gene segment 4 from the equine parental virus and the VP7 cognate gene segment 9 from ST3. Using these viruses and antisera prepared to them, it was shown that each of the three equine viruses possessed a serologically distinct VP4 or P serotype with a > or = 16-fold difference in reciprocal cross-neutralization titers. H1 VP4 was closely related to that of porcine virus OSU, i.e., P7. L338 gene 4 was sequenced, and the sequence and...
Yeo WM, Osterrieder N, Stokol T.The alphaherpesvirus, equine herpesvirus type 1 (EHV-1), is a highly prevalent cause of equine infectious abortion and encephalomyelopathy. These syndromes have been attributed to ischemic necrosis from thrombosis in placental and neural vessels, although the mechanisms underlying thrombosis are unknown. After inhalation, EHV-1 establishes a peripheral blood mononuclear cell-associated viremia, with monocytes being a target of infection. Monocytes are also the main source of tissue factor (TF) in diseased states. Since TF is the primary activator of coagulation, increased monocyte TF expressio...
McFadden AM, Hanlon D, McKenzie RK, Gibson I, Bueno IM, Pulford DJ, Orr D, Dunowska M, Stanislawek WL, Spence RP, McDonald WL, Munro G, Mayhew IG.On 9 January 2014 (Day 0) a mare from a stud farm in the Waikato region presented with urinary incontinence without pyrexia. Over the following 33 days 15 mares were clinically affected with neurological signs. All but one mare had a foal at foot. The most commonly observed clinical signs were hind limb paresis and ataxia. In some cases recumbency occurred very early in the course of disease and seven mares were subject to euthanasia for humane reasons. Results: Equid herpesvirus (EHV) type 1 was detected using PCR in various tissues collected post mortem from two mares with neurological signs...
Saegerman C, Alba-Casals A, García-Bocanegra I, Dal Pozzo F, van Galen G.West Nile fever (WNF) is a viral zoonotic infection caused by a mosquito-borne flavivirus of the Flaviviridae family. According to a comparative study, the passive surveillance of horses by equine veterinarians appeared to be the most cost-effective system in the European context of WNF. Clinical data issued from a passive epidemiosurveillance network from September 2010 to December 2011 on horses in Spain were statistically compared and used to develop a predictive diagnostic decision tree, both with the aim to improve the early clinical detection of WNF in horses. Although clinical signs wer...
Toh X, Wang Y, Rajapakse MP, Lee B, Songkasupa T, Suwankitwat N, Kamlangdee A, Judith Fernandez C, Huangfu T.African horse sickness (AHS) is a highly infectious and deadly disease despite availability of vaccines. Molecular characterization of African horse sickness virus (AHSV) detected from the March 2020 Thailand outbreak was carried out by whole-genome sequencing using Nanopore with a Sequence-Independent Single Primer Amplification (SISPA) approach. Nucleotide sequence of the whole genome was compared with closest matching AHSV strains using phylogenetic analyses and the AHSV-1 virus shared high sequence identity with isolates from the same outbreak. Substitution analysis revealed non-synonymous...
Beutelspacher SC, Ardjomand N, Tan PH, Patton GS, Larkin DF, George AJ, McClure MO.In this study we compare the ability of self-inactivating Human Immunodeficiency Virus 1 (HIV-1) and Equine Infectious Anaemia Virus (EIAV)-based vectors to mediate gene transfer to rabbit and human corneas and to a murine corneal endothelial cell line. Both vectors were pseudotyped with vesicular stomatitis virus-G (VSV-G) envelope and contained marker transgenes under the control of an internal CMV promoter. For specificity of action, the heterologous promoter in the EIAV-vector was exchanged for an inducible E-Selectin promoter, previously shown to regulate gene-expression in a plasmid syst...
Robinson RA, Tucker PW, Dauenhauer SA, O'Callaghan DJ.Genomic DNA sequences of equine herpesvirus type 1 (EHV-1) have been cloned as BamHI and EcoRI restriction fragments into the plasmid pBR322 and propagated in Escherichia coli. With the exception of two EcoRI restriction fragments that reside in the S region of the viral genome, all of the cloned fragments demonstrated the same electrophoretic mobilities, restriction cleavage sites, and blot-hybridization patterns as did the parent fragments produced by BamHI or EcoRI digestion of virion DNA. The EcoRI J fragment and the BamHI E fragment of the L-region terminus were cloned after the addition ...
Pan X, Wu Y, Wang W, Zhang L, Xiao G.Argentine haemorrhagic fever (AHF) is a rodent-borne disease with a lethality as high as ~30%, which is caused by the New World arenavirus, Junín virus (JUNV). It was once a major epidemic in South America and puts millions of people in Argentina at risk. Here, we aimed to develop horse antibodies or antibody fragments against JUNV. Before preparing the horse antibodies, a strategy to efficiently generate horse antisera was established based on comparisons among immunogens and immunization methods in both mice and horses. Antisera against JUNV were finally obtained by vaccinating horses with ...
Gruwell JA, Fogarty CL, Bennett SG, Challet GL, Vanderpool KS, Jozan M, Webb JP.In response to the 1984 St. Louis encephalitis (SLE) epidemic in the Los Angeles Basin of southern California (USA), an investigative program was initiated to evaluate the interactive components of the SLE virus transmission cycle. From 1987 through 1996 (10 yr), 52,589 birds were bled and their sera tested for SLE and western equine encephalomyelitis (WEE) virus antibodies by the hemagglutination inhibition (HAI) test. Eighty-three percent of the birds tested were house finches (Carpodacus mexicanus) (48.7%) and house sparrows (Passer domesticus) (34.6%); 1.1% of these birds were positive for...
Ward MP, Scheurmann JA.Cases of human and equine West Nile virus (WNV) disease reported in Texas in 2002 were analyzed to assess their temporal relationship. For each human case with a known residential location, the closest equine case (within a 5 km radius) was selected. A total of 80 human-equine case pairs were identified, 51 (64%) of which were located in urban areas. Dates-of-onset of human and equine cases were positively correlated (r(SP)=0.494, P<0.001). Although overall there was no significant (P=0.207) difference between the dates-of-onset of human and equine cases, in urban areas of Texas equine case...
Ghim SJ, Rector A, Delius H, Sundberg JP, Jenson AB, Van Ranst M.Equus caballus papillomavirus type 1 (EcPV-1) was isolated from a cutaneous papilloma, the most common neoplasm in horses. The complete EcPV-1 nucleotide sequence and genomic organization were determined. Phylogenetic analysis showed that EcPV-1 is a close-to-root papillomavirus, with only distant relationships to the fibropapillomaviruses and the benign cutaneous papillomaviruses. To produce EcPV-1 virus-like particles (VLPs), the EcPV-1 L1 major capsid protein was expressed in insect cells using a recombinant baculovirus vector. The self-assembled EcPV-1 VLPs were morphologically indistingui...
Cook RF, Cook SJ, Berger SL, Leroux C, Ghabrial NN, Gantz M, Bolin PS, Mousel MR, Montelaro RC, Issel CJ.Pathogenicity was reportedly restored to an avirulent molecular clone of equine infectious anemia virus (EIAV) by substitution of 3' sequences from the pathogenic variant strain (EIAV(PV)). However, the incidence of disease in horses/ponies was found to be significantly lower (P = 0.016) with the chimeric clone (EIAV(UK)) than with EIAV(PV). This was attributable to 3' rather than 5' regions of the proviral genome, where EIAV(UK) differs from the consensus EIAV(PV) sequence by having a 68-bp duplication in the 3' LTR and arginine (R(103)) rather than tryptophan (W(103)) at position 103 in the ...
van Berlo MF, Rottier PJ, Spaan WJ, Horzinek MC.Intracellular virus-specific proteins induced by equine arteritis virus (EAV) have been compared with in vitro translation products of virion and intracellular EAV RNAs. In infected BHK-21 cells, the two major virion proteins (C and E1) and polypeptides with mol. wt. of 60,000 (p60), 42,000 (p42) and 30,000 (p30) were found. There were no indications that the viral proteins were processed from a larger precursor as shown by pulse-chase, amino acid analogue and protease inhibitor experiments. The six polyadenylated RNAs that occur in EAV-infected cells were isolated and translated in an mRNA-de...
Sudia WD, McLean RG, Newhouse VF, Johnston JG, Miller DL, Trevino H, Bowen GS, Sather G.Epidemic Venezuelan equine encephalitis in North America in 1971: vertebrate field studies. Am J Epidemiol 101:36-50, 1975.-In June 1971, epidemic Venezuelan equine encephalitis (VEE) invaded the lower Rio Grande Valley in south Texas. The Boca Chica area of Cameron County was selected as a study site to investigate vertebrate involvement in the natural cycle of epidemic VEE on the basis of considerable evidence of VEE virus activity there in equines, humans, and mosquito vectors. Only one VEE virus isolation was made from 4739 wild and domestic non-equine vertebrates, although numerous equine...
Lupala CS, Kumar V, Su XD, Wu C, Liu H.The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the COVID-19 pandemic. Angiotensin-converting enzyme 2 (ACE2) has been identified as the host cell receptor that binds to the receptor-binding domain (RBD) of the SARS-COV-2 spike protein and mediates cell entry. Because the ACE2 proteins are widely available in mammals, it is important to investigate the interactions between the RBD and the ACE2 of other mammals. Here we analyzed the sequences of ACE2 proteins from 16 mammals, predicted the structures of ACE2-RBD complexes by homology modeling, and refi...
Hinton TM, Li F, Crabb BS.Equine rhinitis A virus (ERAV) has recently been classified as an aphthovirus, a genus otherwise comprised of the different serotypes of Foot-and-mouth disease virus (FMDV). FMDV initiates translation via a type II internal ribosomal entry site (IRES) and utilizes two in-frame AUG codons to produce the leader proteinases Lab and Lb. Here we show that the ERAV 5' nontranslated region also possesses the core structures of a type II IRES. The functional activity of this region was characterized by transfection of bicistronic plasmids into BHK-21 cells. In this system the core type II structures, ...
Schiltz RL, Shih DS, Rasty S, Montelaro RC, Rushlow KE.The utilization of predicted splice donor and acceptor sites in generating equine infectious anemia virus (EIAV) transcripts in fetal donkey dermal cells (FDD) was examined. A single splice donor site identified immediately upstream of the gag coding region joins the viral leader sequence to all downstream exons of spliced EIAV transcripts. The predominant 3.5-kb transcript synthesized in EIAV-infected FDD cells appears to be generated by a single splicing event which links the leader sequence to the first of two functional splice acceptor sites near the 5' end of the S1 open reading frame (OR...
Go YY, Li Y, Chen Z, Han M, Yoo D, Fang Y, Balasuriya UB.The objective of this study was to investigate the effect of equine arteritis virus (EAV) on type I interferon (IFN) production. Equine endothelial cells (EECs) were infected with the virulent Bucyrus strain (VBS) of EAV and expression of IFN-β was measured at mRNA and protein levels by quantitative real-time RT-PCR and IFN bioassay using vesicular stomatitis virus expressing the green fluorescence protein (VSV-GFP), respectively. Quantitative RT-PCR results showed that IFN-β mRNA levels in EECs infected with EAV VBS were not increased compared to those in mock-infected cells. Consistent wit...
Noiman S, Yaniv A, Sherman L, Tronick SR, Gazit A.The pattern of expression of the equine infectious anemia virus (EIAV) genome in a persistently infected canine cell line was determined. Five EIAV-specific transcripts (8.2, 5.0, 4.0, 2, and 1.8 kilobases [kb]) were detected by using subgenomic restriction enzyme fragments of EIAV DNA and EIAV-specific oligonucleotides as probes. The 8.2-kb mRNA could be shown to represent viral genomic RNA, whereas the smaller transcripts were generated by splicing events. Evidence was obtained that indicated that each subgenomic RNA species shared a common 5'-splice donor. The 5.0-kb mRNA was found to be ex...
Bannai H, Nemoto M, Niwa H, Murakami S, Tsujimura K, Yamanaka T, Kondo T.We studied a recent epizootic of Getah virus infection among pigs in the southern part of Ibaraki Prefecture and the northern part of Chiba Prefecture, Japan, focusing on its possible association with outbreaks in racehorses in 2014 and 2015. The genomic sequence of a Getah virus strain from an infected pig was analyzed to evaluate the degree of identity with the strains from horses. Results: Sera were collected from pigs from September to December 2012 to 2015 in south Ibaraki (380 pigs in 29 batches), and from September to December 2010 to 2015 in north Chiba (538 pigs in 104 batches). They ...
Martinez-Torrecuadrada JL, Iwata H, Venteo A, Casal I, Roy P.African horsesickness virus (AHSV) is a gnat-transmitted member of the Orbivirus genus of the Reoviridae family. The virus has a genome of 10 double-stranded RNA species (L1-L3, M4-M6, S7-S10). The L2 and M6 genes of AHSV serotype 4 (AHSV-4) which encode the outer capsid proteins VP2 and VP5, respectively, were inserted into recombinant baculoviruses downstream of the baculovirus polyhedrin, or p10 promoters. Recombinant baculoviruses expressing VP2, VP5, or VP2 and VP5 proteins of AHSV-4 were isolated. The expressed AHSV proteins were similar in size and antigenic properties to those of viral...
Howard JJ, Grayson MA, White DJ, Oliver J.A regional surveillance system for eastern equine encephalitis (EEE) virus was established in central New York in 1984 after the 2nd human EEE fatality occurred in 1983. Extensive mosquito surveillance activities were coordinated with the rapid laboratory processing of mosquito specimens for EEE virus. Active surveillance for EEE infections in humans and equines also was initiated. Results of long-term surveillance detected the presence of multiple Culiseta breeding swamps. A 6-yr interepizootic period (1984-1989) was followed by 2 yr of equine EEE. In 1990, there were 7 equine cases and a rec...
Stitz L, Bilzer T, Richt JA, Rott R.Borna disease represents a unique model of a virus-induced immunological disease of the brain. Naturally occurring in horses and sheep, the mechanisms of pathogenesis have been studied in experimental animals, namely in the rat. Many investigations have revealed that the infection of the natural hosts principally follows the same pathogenic pathways as observed in rats, leading to a severe encephalomyelitis. This affliction of the central nervous system results in severe neurological disorders that again, are fully comparable in laboratory animals to those in the natural and the different expe...
Drummer HE, Reubel GH, Studdert MJ.Peripheral blood leukocytes were collected from 5 Thoroughbred horses and examined for the presence of EHV2 in sub-populations of mononuclear cells. Peripheral blood mononuclear cells were separated on Percoll gradients and then enriched for plastic adherent cells (predominantly monocytes), surface immunoglobulin positive (sIg+) B lymphocytes and T lymphocytes, using panning techniques. The purity of each cell population was assessed by fluorescence activated cell scanning. In an infectious centre assay, each cell population was inoculated onto equine foetal kidney monolayer cell cultures whic...
García-Carrasco JM, Muñoz AR, Olivero J, Segura M, García-Bocanegra I, Real R.BackgroundWest Nile virus (WNV) is a flavivirus with an enzootic cycle between birds and mosquitoes; humans and horses are incidental dead-end hosts. In 2020, the largest outbreak of West Nile virus infection in the Iberian Peninsula occurred, with 141 clusters in horses and 77 human cases.AimWe analysed which drivers influence spillover from the cycle to humans and equines and identified areas at risk for WNV transmission.MethodsBased on data on WNV cases in horses and humans in 2020 in Portugal and Spain, we developed logistic regression models using environmental and anthropic variables to ...
Barros SC, Ramos F, Fagulha T, Duarte M, Henriques M, Luís T, Fevereiro M.The circulation of West Nile virus in Portugal was assessed by serological surveys conducted during 2004-2010 in horses and birds. The detection of WNV antibodies in both species in all the years covered by the study as well as the presence of anti-WNV IgM in symptomatic horses that had not traveled outside the country, support the notion that WNV circulates in Portugal.
Motoshima M, Okamatsu M, Asakura S, Kuribayashi S, Sengee S, Batchuluun D, Ito M, Maeda Y, Eto M, Sakoda Y, Sodnomdarjaa R, Kida H.A/equine/Kanazawa/1/2007 (H3N8), A/equine/Hokkaido/I828/2008 (H3N8) and A/equine/Mongolia/1/2008 (H3N8) were isolated from infected horses. A/equine/Yokohama/aq19/2009 (H3N8) and A/equine/Yokohama/aq13/2010 (H3N8) were isolated from horses imported from Canada and Belgium examined at the Animal Quarantine Service in Yokohama, Japan. In the present study, these five isolates were genetically and antigenically analyzed. Phylogenetic analysis of hemagglutinin (HA) and neuraminidase (NA) genes showed that three isolates from horses in Japan and imported from Canada belonged to the same branch, cla...
Dunowska M.Equid herpesvirus (EHV) type 1 is a common pathogen of horses with worldwide distribution. Infection with EHV-1 can be subclinical, or can result in sociologically and economically important outcomes such as abortion, neonatal death or neurological disease. The perceived recent increase in the reported cases of EHV-1 neurological disease in the United States of America and Europe over the past decade has caused concerns amongst veterinarians and horse owners worldwide. This review provides an update on the recent developments in our understanding of the pathogenesis and epidemiology of EHV-1 a...
