Equine Viral Arteritis (EVA) is a contagious viral disease affecting horses, caused by the equine arteritis virus (EAV). The virus primarily spreads through respiratory secretions and venereal transmission, impacting both the respiratory and reproductive systems of horses. Clinical signs of EVA can vary widely, from subclinical infections to more severe symptoms such as fever, nasal discharge, conjunctivitis, and swelling of limbs and genitalia. In pregnant mares, the virus can lead to abortion. EVA can be diagnosed through serological tests, virus isolation, and molecular techniques such as PCR. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, pathogenesis, diagnosis, and control measures of Equine Viral Arteritis in equine populations.
Heinrich A, Riethmüller D, Gloger M, Schusser GF, Giese M, Ulbert S.Equine Arteritis Virus (EAV) belongs to the Arteriviridae and causes viral arteritis in horses. In an attempt to develop novel and save therapies against the infection it was tested whether EAV is susceptible to RNA interference (RNAi) in an equine in vitro system. Horse cells were transfected with chemically synthesized small interfering RNA oligonucleotides (siRNAs) and challenged with EAV. Application of these siRNAs led to a significant protection of the cells, and virus titers decreased drastically. siRNAs derived from DNA plasmids expressing small hairpin RNAs (shRNAs) were also effectiv...
Metz GE, Serena MS, Ocampos GM, Panei CJ, Fernandez VL, Echeverría MG.Equine arteritis virus (EAV) was isolated from a testicle of the presumable first stallion infected with EAV in Argentina. This virus isolate (named LT-LP-ARG) was confirmed by GP5-specific PCR and indirect immunofluorescence assays. The PCR product was sequenced, and the phylogenetic analysis revealed that the LT-LP-ARG strain of EAV forms a monophyletic group, together with other strains previously isolated in our laboratory (LP02 group). However, all Argentinean EAV strains belong to a polyphyletic group. We believe that the virus isolate presented in this report could be the origin of EAV ...
Zhang J, Go YY, MacLachlan NJ, Meade BJ, Timoney PJ, Balasuriya UB.Comparative sequence analysis of a series of strains of equine arteritis virus (EAV) of defined virulence for horses, ranging from the horse-adapted virulent Bucyrus (VB) strain to a fully attenuated vaccine strain derived from it, identified 13 amino acid substitutions associated with attenuation. These include 4 substitutions in the replicase proteins and 9 in the structural proteins. Using reverse genetic techniques, these amino acid substitutions were introduced into a virulent infectious cDNA clone pEAVrVBS derived from the VB strain of EAV. Inoculation of horses with the recombinant viru...
Nitschke M, Korte T, Tielesch C, Ter-Avetisyan G, Tünnemann G, Cardoso MC, Veit M, Herrmann A.Equine arteritis virus (EAV) is an enveloped, positive-stranded RNA virus belonging to the family Arteriviridae. Infection by EAV requires the release of the viral genome by fusion with the respective target membrane of the host cell. We have investigated the entry pathway of EAV into Baby Hamster Kidney cells (BHK). Infection of cells assessed by the plaque reduction assay was strongly inhibited by substances which interfere with clathrin-dependent endocytosis and by lysosomotropic compounds. Furthermore, infection of BHK cells was suppressed when clathrin-dependent endocytosis was inhibited ...
Holyoak GR, Balasuriya UB, Broaddus CC, Timoney PJ.Recently, there has been increased interest in equine viral arteritis (EVA) among veterinarians and horse owners. Outbreaks of the disease were identified initially in New Mexico, USA in 2006, and in the Normandy region of France in the summer of 2007. Both occurrences were associated with AI of cool-shipped semen. Each was linked to respiratory illness, neonatal death, abortion, development of carrier stallions, and cancellation of equestrian events. In light of the increased interest, this paper will present a brief case history, followed by a review addressing common concerns regarding EVA,...
Lu Z, Branscum AJ, Shuck KM, Zhang J, Dubovi EJ, Timoney PJ, Balasuriya UB.Two previously developed TaqMan fluorogenic probe-based 1-tube real-time reverse transcription polymerase chain reaction (real-time RT-PCR) assays (T1 and T2) were compared and validated for the detection of Equine arteritis virus (EAV) nucleic acid in equine semen and tissue culture fluid (TCF). The specificity and sensitivity of these 2 molecular-based assays were compared to traditional virus isolation (VI) in cell culture. The T1 real-time RT-PCR had a higher sensitivity (93.4%) than the T2 real-time RT-PCR (42.6%) for detection of EAV RNA in semen. However, the T1 real-time RT-PCR was les...
Posthuma CC, Pedersen KW, Lu Z, Joosten RG, Roos N, Zevenhoven-Dobbe JC, Snijder EJ.The replication/transcription complex of the arterivirus equine arteritis virus (EAV) is associated with paired membranes and/or double-membrane vesicles (DMVs) that are thought to originate from the endoplasmic reticulum. Previously, coexpression of two putative transmembrane nonstructural proteins (nsp2 and nsp3) was found to suffice to induce these remarkable membrane structures, which are typical of arterivirus infection. Here, site-directed mutagenesis was used to investigate the role of nsp3 in more detail. Liberation of the hydrophobic N terminus of nsp3, which is normally achieved by c...
Duthie S, Mills H, Burr P.Infection with equine arteritis virus is a notifiable disease with sporadic occurrence in the UK. As stallions may harbour the virus after infection, horses are screened for exposure by serological testing prior to breeding. The virus neutralisation test is considered the 'gold standard' serological screening test, but it is time-consuming and labour intensive; consequently there is a move towards more rapid screening methodology. In this study, a commercially available EVA antibody ELISA is assessed. The ELISA performed poorly with a specificity [corrected] of 26% and a sensitivity [corrected...
Veit M, Kabatek A, Tielesch C, Hermann A.Equine arteritis virus (EAV), a member of the newly established family Arteriviridae, is a small, positive-stranded RNA virus. It carries two protein complexes in its envelope, gp5/M and the recently described gp2b/gp3/gp4 complex. We report here on several basic features of EAV replication in cell culture and on the protein composition of virus particles. We have also characterized gp2b, gp3, and gp4 expressed using a baculovirus system in insect cells. Finally, we provide evidence that EAV possess hemagglutinating and hemolytic activity. The hemolysis assay might be useful for determining wh...
Liu L, Castillo-Olivares J, Davis-Poynter NJ, Baule C, Xia H, Belák S.Samples from horses experimentally infected with the "large plaque variant (LP3A+)" of equine arteritis virus were analysed. These included 182 nasal swabs collected from day 1 to 14 post-infection (p.i.), and 21 virus isolates obtained from white blood cells of animals that showed a prolonged viraemia between days 30 to 72 p.i. In order to determine the genetic stability of the virus and particularly to characterise the genetic variants found during the prolonged viraemia, partial sequences of open reading frame 5 (ORF5) encoding glycoprotein 5 (GP5) were generated. Viruses with amino acid su...
Go YY, Wong SJ, Branscum AJ, Demarest VL, Shuck KM, Vickers ML, Zhang J, McCollum WH, Timoney PJ, Balasuriya UB.The development and validation of a microsphere immunoassay (MIA) to detect equine antibodies to the major structural proteins of equine arteritis virus (EAV) are described. The assay development process was based on the cloning and expression of genes for full-length individual major structural proteins (GP5 amino acids 1 to 255 [GP5(1-255)], M(1-162), and N(1-110)), as well as partial sequences of these structural proteins (GP5(1-116), GP5(75-112), GP5(55-98), M(88-162), and N(1-69)) that constituted putative antigenic regions. Purified recombinant viral proteins expressed in Escherichia col...
Mankoc S, Hostnik P, Grom J, Toplak I, Klobucar I, Kosec M, Barlic-Maganja D.In the present study, a new one-step real-time reverse transcription-polymerase chain reaction (RT-PCR) strategy with minor-groove-binder (MGB) technology for the detection of EAV from 40 semen samples of Slovenian carrier stallions was tested. A novel MGB probe (EAVMGBpr) and a reverse primer (EAV-R) based on the multiple sequence alignment of 49 different EAV strain sequences of the highly conserved ORF7 (nucleocapsid gene) were designed. The performance of the assay was compared with different molecular detection methods. Three different primer pairs targeting the ORF1b and ORF7 were used, ...
Zhang J, Miszczak F, Pronost S, Fortier C, Balasuriya UB, Zientara S, Fortier G, Timoney PJ.Genetic variation and phylogenetic relationships among 22 French isolates of equine arteritis virus (EAV) obtained over four breeding seasons (2001-2004) were determined by sequencing open reading frames (ORFs) 2a-7. The ORFs 2a-7 of 22 isolates differed from the prototype virulent Bucyrus strain of EAV by between 14 (99.5% identity) and 328 (88.7% identity) nucleotides, and differed from each other by between 0 (100% identity) and 346 (88.1% identity) nucleotides, confirming genetic diversity among EAV strains circulating in France. Phylogenetic analysis based on the partial ORF5 sequences (n...
Balasuriya UBR, Snijder EJ, Heidner HW, Zhang J, Zevenhoven-Dobbe JC, Boone JD, McCollum WH, Timoney PJ, MacLachlan NJ.Strains of Equine arteritis virus (EAV) differ in the severity of the disease that they induce in horses. Infectious cDNA clones are potentially useful for identification of genetic determinants of EAV virulence; to date, two clones have been derived from a cell culture-adapted variant of the original (Bucyrus) isolate of EAV, and it has previously been shown that recombinant virus derived from one of these (rEAV030) is attenuated in horses. A complete cDNA copy of the genome of the virulent Bucyrus strain of EAV has now been assembled into a plasmid vector. In contrast to rEAV030, recombinant...
Echeverría MG, Díaz S, Metz GE, Serena MS, Panei CJ, Nosetto E.We report the nucleotide sequence and genetic diversity of four Equine Arteritis Virus (EAV) ORF 5 and 6 from Argentina isolates, obtained from asymptomatic virus-shedding stallions. Nucleic acid recovered from the isolates were amplified by RT-PCR and sequenced. Nucleotide and deduced amino acid sequences from the Argentine isolates were compared with 17 sequences available from the GenBank. Phylogenetic analysis revealed that the Argentine isolates grouped together in a definite cluster near European strains. Despite the greater genetic variability among ORF 5 from different isolates and str...
MacLachlan NJ, Balasuriya UB, Davis NL, Collier M, Johnston RE, Ferraro GL, Guthrie AJ.Viral diseases constitute an ever growing threat to the horse industry worldwide because of the rapid movement of large numbers of horses for competition and breeding. A number of different types of vaccines are available for protective immunization of horses against viral diseases. Traditional inactivated and live-attenuated (modified live virus, MLV) virus vaccines remain popular and efficacious but recombinant vaccines are increasingly being developed and used, in part because of the perceived deficiencies of some existing products. New generation vaccines include MLVs with deletions and/or...
van Aken D, Zevenhoven-Dobbe J, Gorbalenya AE, Snijder EJ.The positive-stranded RNA genome of the arterivirus Equine arteritis virus (order Nidovirales) encodes the partially overlapping replicase polyproteins pp1a (1727 aa) and pp1ab (3175 aa). Previously, three viral proteinases were reported to cleave these large polyproteins into 12 non-structural proteins (nsps). The chymotrypsin-like viral main proteinase residing in nsp4 is responsible for eight of these cleavages. Processing of the C-terminal half of pp1a (the nsp3-8 region) was postulated to occur following either of two alternative proteolytic pathways (the 'major' and 'minor' pathways). He...
Liang CZ, Cao RB, Wei JC, Zhu LH, Chen PY.According to the antigenic analysis of equine arteritis virus (EAV) GL protein, one pair of primers were designed, with which the gene fragment coding the high antigenic domain of EAV GL protein was amplified from the EAV genome. The cloned gene was digested with BamH I and Xho I and then inserted into pET-32a and resulted pET-GL1. The pET-GL1 was transformed into the host cell BL21(DE3) and the expression was optimized including cultivation temperature and concentration of IPTG. The aim protein was highly expressed and the obtained recombinant protein manifested well reactiongenicity as was c...
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...
Samper JC, Tibary A.Bacterial, viral and protozoal infections may cause severe reproductive losses. The present paper reviews the risk factors, clinical signs and preventive measures for the most important venereal or potential sexually transmitted diseases in horses. The stallion and use of semen for artificial insemination represent major risk factors for the transmission of bacterial contaminants of the penis, including Streptococcus equi subspecies zooepidemicus, Pseudomonas aeruginosa and Klebsiella pneumoniae, known to cause endometritis and infertility in the mare. The role of the stallion in disease trans...
Morrell JM, Geraghty RM.A method of removing equine arteritis virus (EAV) from equine semen used for artificial insemination is urgently needed. Recent medical studies suggest that a double semen processing technique of density gradient centrifugation followed by a 'swim-up' can provide virus-free sperm preparations for assisted reproduction. Objective: To investigate the use of the double semen processing technique to obtain virus-free sperm preparations from stallion semen containing EAV. Methods: Aliquots of an ejaculate from an uninfected stallion were spiked with virus and processed by the double processing tech...
Mittelholzer C, Stadejek T, Johansson I, Baule C, Ciabatti I, Hannant D, Paton D, Autorino GL, Nowotny N, Belák S.To determine a conclusive phylogeny, equine arteritis viruses from Italy, Austria, Hungary, Sweden, South Africa and other parts of the world were analysed by reverse-transcription polymerase chain reaction amplification and direct sequencing. The nucleotide sequences corresponding to the variable part of the large glycoprotein GP5, specified by open reading frame 5, were compared and added to a previously published phylogenetic tree in which a clear division between 'European' and 'American' type viruses had been established. Adding the sequences determined in this study and new sequences ret...
Zhang XY, Li HM, Liang H, Shen T, Ma Y, Xiang WH, Shen RX, Shao YM.To elucidate cellular immune protective mechanism of EIAV. Methods: Four horses were immunized with (DLV) by subcutaneous injection and 2 horses with 0.85% sodium chloride as the negative control. Rectal temperatures and clinical features were recorded daily. Whole blood samples were collected, from which PBMC were separated and used for CTL assay and lymphocyte proliferation assay. Results: The target cells were activated by PWM and treated with DLV or recombinant vaccinia vectors expressing DLV and LN Gag or Env separately. The percentage of EIAV-specific CTL lysis was under 5% in the negati...
Mittelholzer C, Johansson I, Olsson AK, Ronéus M, Klingeborn B, Belák S.Recovery of infectious Equine arteritis virus (EAV) from the semen of persistently infected Swedish stallions was attempted by classical cell culture isolation and by transfection of extracted total RNA. Whereas virus from semen samples stored for several months at -20 degrees C or from extended semen could only be recovered by transfection of extracted RNA, isolation in cell culture was achieved readily with fresh, unextended semen stored at -70 degrees C or directly used after sampling. In parallel, the viruses were examined in the variable region of the large glycoprotein GP5 by nested RT-P...
Dunowska M, Wilks CR, Studdert MJ, Meers J.To identify viruses associated with respiratory disease in young horses in New Zealand. Methods: Nasal swabs and blood samples were collected from 45 foals or horses from five separate outbreaks of respiratory disease that occurred in New Zealand in 1996, and from 37 yearlings at the time of the annual yearling sales in January that same year. Virus isolation from nasal swabs and peripheral blood leukocytes (PBL) was undertaken and serum samples were tested for antibodies against equine herpesviruses (EHV-1, EHV-2, EHV-4 and EHV-5), equine rhinitis-A virus (ERAV), equine rhinitis-B virus (ERBV...
Szeredi L, Hornyák A, Pálfi V, Molnár T, Glávits R, Dénes B.The occurrence of equine arteritis virus (EAV) induced equine abortions was studied with different laboratory methods during a 3-year period. Tissue samples from 96 aborted equine foetuses or newborn foals were collected from 57 farms located in different parts of Hungary. Virus isolation, polymerase chain reaction (PCR), immunohistochemistry and serology were used for the detection of EAV infection. The overall seroprevalence of EAV infection in mares was 65%. EAV induced abortion was diagnosed in eight (8.3%) cases from six (10.5%) herds. Abortion was sporadic in all herds except for one, wh...
Mangana-Vougiouka O, Boutsini S, Ntousi D, Patakakis M, Orfanou E, Zafiropoulou K, Dilaveris D, Panagiotatos D, Nomikou K.During the period 2001 to 2008, a total of 7,872 equine sera were tested at the Centre of Veterinary Institutes of Athens. Antibodies against seven infectious diseases of equids were determined: equine infectious anaemia (EIA), African horse sickness (AHS), equine viral arteritis (EVA), West Nile encephalitis (WNE), glanders, piroplasmosis and dourine. Tests for the four viral diseases found 4.5% seropositivity for EIA, 0% for AHS, 3.3% for EVA and 4% for WNE. All sera tested for glanders antibodies were negative. Tests for piroplasmosis detected antibodies against T. equi and B. caballi in 12...
Chirnside ED.The causative agent of the respiratory disease equine viral arteritis is a small, single-stranded RNA virus with a genome organization and replication strategy related to that of coronaviruses and toroviruses. Clinical signs of infection in horses vary widely and severe infection can lead to pregnant mares aborting. Infected horses generally make good recoveries but stallions may become semen shedders of equine arteritis virus (EAV). These carrier stallions play an important role in the dissemination and perpetuation of EAV. Laboratory tests exist to detect virus and the equine immune response...
Huntington PJ, Forman AJ, Ellis PM.This paper reports the first isolation of equine arteritis virus (EAV) in Australia and serological evidence of exposure to EAV in Australian horses. Twelve Standardbred stallions imported from North America were found to shed EAV in semen. One hundred and seven stallions were tested for serum antibodies to EAV and 73% of Standardbred stallions tested were seropositive as compared to 8% of Thoroughbred stallions. Serum antibody was detected in 71% of Standardbred mares, 6% of Standardbred racehorses and 1% of Thoroughbred mares and racehorses. Examination of stored serums demonstrated that EAV...
Hullinger PJ, Gardner IA, Hietala SK, Ferraro GL, MacLachlan NJ.To compare seroprevalence of antibodies against equine arteritis virus (EAV) in horses residing in the United States with that of imported horses. Methods: Serologic survey. Methods: Serum samples from 364 horses on 44 equine operations in California and 226 horses imported from various countries. Methods: Serum samples were collected from each imported horse and from up to 20 horses on each operation. For resident horses, the number of sampled horses on each operation was determined on the basis of the number of horses on the operation. Samples were tested for antibodies against EAV by use of...
Wood JL, Chirnside ED, Mumford JA, Higgins AJ.Equine viral arteritis was diagnosed for the first time in the United Kingdom in 1993. The outbreak began on a non-thoroughbred stud in south Nottinghamshire and spread to five other premises through chilled semen used for artificial insemination and from acutely and subclinically infected mares returning home. The outbreak was contained on these six premises by means of voluntary movement restrictions. The most commonly observed clinical signs were typical: pyrexia with depression, and conjunctivitis with periorbital oedema; nasal discharge, and oedema of the distal limbs, prepuce and mammary...
Cole JR, Hall RF, Gosser HS, Hendricks JB, Pursell AR, Senne DA, Pearson JE, Gipson CA.A group of 14 pregnant mares was exposed via contact to 4 mares bred to stallions infected with equine viral arteritis virus. There was a demonstrable febrile response in each donor mare and in 12 of the pregnant mares. All 18 mares became seropositive after exposure. Equine viral arteritis virus was isolated from the nasopharynx of 5 pregnant mares, but not from the donor mares. Ten of the pregnant mares aborted, and virus was isolated from fetal specimens or placenta of 8.
Glaser AL, Chirnside ED, Horzinek MC, de Vries AA.Equine arteritis virus (EAV) is a small, enveloped, positive-stranded RNA virus, in the family Arteriviridae , W.H.ich can infect both horses and donkeys. While the majority of EAV infections are asymptomatic, acutely infected animals may develop a wide range of clinical signs, including pyrexia, limb and ventral edema, depression, rhinitis, and conjunctivitis. The virus may cause abortion and has caused mortality in neonates. After natural EAV infection, most horses develop a solid, long-term immunity to the disease. Marzz and geldings eliminate the virus within 60 days, but 30 to 60% of acut...
Campos JR, Breheny P, Araujo RR, Troedsson MH, Squires EL, Timoney PJ, Balasuriya UB.Equine arteritis virus (EAV) is the causal agent of equine viral arteritis (EVA), a respiratory and reproductive disease of equids. Some strains of EAV can cause fever, leukopenia, and dependent edema of the limbs, scrotum, and preputium in the acutely infected stallion. We hypothesized that fever and scrotal edema observed during the acute phase of the infection, but not the presence of EAV, have an adverse effect on semen quality. A group of seven stallions were intranasally inoculated with the Kentucky 84 (KY84) strain of EAV. Stallions were monitored for clinical signs of EVA until 42 days...
Metcalf ES.Despite the numerous benefits of having the capability to transport semen internationally, there are serious potential ramifications if that semen is contaminated with a communicable disease. Bacteria: Many commensal bacteria colonize the exterior of the stallion penis and are not regarded as pathogenic. They may be cultured from an ejaculate. Alterations of the normal bacterial flora on the exterior genitalia may cause the growth of opportunistic bacteria such as Klebsiella pneumonia, Pseudomonas aeruginosa, Streptococcus zooepidemicus, which, if inseminated, may cause infertility in suscepti...
Go YY, Snijder EJ, Timoney PJ, Balasuriya UB.Equine arteritis virus (EAV) replicase consists of two polyproteins (pp1a and pp1ab) that are encoded by open reading frames (ORFs) 1a and 1b of the viral genome. These two replicase polyproteins are posttranslationally processed by three ORF 1a-encoded proteinases to yield at least 13 nonstructural proteins (nsp1 to nsp12, including nsp7α and 7β). These nsps are expressed in EAV-infected cells, but the equine immune response they induce has not been studied. Therefore, the primary purpose of this study was to evaluate the humoral immune response of horses to each of the nsps following EAV i...
Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory and reproductive disease of equids. There has been significant recent progress in understanding the molecular biology of EAV and the pathogenesis of its infection in horses. In particular, the use of contemporary genomic techniques, along with the development and reverse genetic manipulation of infectious cDNA clones of several strains of EAV, has generated significant novel information regarding the basic molecular biology of the virus. Therefore, the objective of this review is to summarize cur...
Harry TO, McCollum WH.The Bucyrus strain of equine arteritis virus, previously modified to avirulence and vaccinal virus by 131 serial passages in primary cell cultures of horse kidney followed by 111 passages in primary cell cultures of rabbit kidney, was further passaged in cultures of the E. Derm (NBL-6) cell line, a continuous diploid cell line. Pools of the 16th and 25th passages of the virus in this last equine dermal cell line were lyophilized and stored in lots at 37 C, 23 to 28 C, 4C, and -20 C. The viability of the vaccinal virus deteriorated rapidly during storage at 37 C and at 23 to 28 C, but was relat...
Zhang J, Go YY, MacLachlan NJ, Meade BJ, Timoney PJ, Balasuriya UB.Comparative sequence analysis of a series of strains of equine arteritis virus (EAV) of defined virulence for horses, ranging from the horse-adapted virulent Bucyrus (VB) strain to a fully attenuated vaccine strain derived from it, identified 13 amino acid substitutions associated with attenuation. These include 4 substitutions in the replicase proteins and 9 in the structural proteins. Using reverse genetic techniques, these amino acid substitutions were introduced into a virulent infectious cDNA clone pEAVrVBS derived from the VB strain of EAV. Inoculation of horses with the recombinant viru...
Lazić S, Lupulović D, Gaudaire D, Petrovic T, Lazić G, Hans A.Equine arteritis virus (EAV) is responsible for infections in equids. It can spread easily within the horse population and has a major impact on the horse breeding industry. No EAV outbreak has ever been reported in Serbia. To determine whether EAV is nonetheless circulating there, especially in the Vojvodina region, 340 horse serum samples were subjected to serology testing to detect EAV antibodies. In parallel, semen samples from three seropositive stallions were collected to evaluate their EAV status, using RT-qPCR and virus isolation on cell culture. Results: Horse sera with EAV antibodies...
MacLachlan NJ, Balasuriya UB, Davis NL, Collier M, Johnston RE, Ferraro GL, Guthrie AJ.Viral diseases constitute an ever growing threat to the horse industry worldwide because of the rapid movement of large numbers of horses for competition and breeding. A number of different types of vaccines are available for protective immunization of horses against viral diseases. Traditional inactivated and live-attenuated (modified live virus, MLV) virus vaccines remain popular and efficacious but recombinant vaccines are increasingly being developed and used, in part because of the perceived deficiencies of some existing products. New generation vaccines include MLVs with deletions and/or...
Timoney PJ, McCollum WH.Further characterization of the carrier state in stallions infected with equine arteritis virus revealed that there is considerable variation in the frequency of its occurrence among breeds. The frequency ranged from 12.5% (Holsteiner stallions) to 72.7% (Dutch Warmblood stallions), with a mean occurrence of 40.8% in the seropositive stallions (n=561) examined. More than 70% of the virus shedders were Standardbred stallions. The carrier state was not confirmed in any of the stallions that had been vaccinated against equine viral arteritis nor was there any evidence of intermittent virus sheddi...
Carossino M, Wagner B, Loynachan AT, Cook RF, Canisso IF, Chelvarajan L, Edwards CL, Nam B, Timoney JF, Timoney PJ, Balasuriya UBR.Equine arteritis virus (EAV) has the ability to establish persistent infection in the reproductive tract of the stallion (carrier) and is continuously shed in its semen. We have recently demonstrated that EAV persists within stromal cells and a subset of lymphocytes in the stallion accessory sex glands in the presence of a significant local inflammatory response. In the present study, we demonstrated that EAV elicits a mucosal antibody response in the reproductive tract during persistent infection with homing of plasma cells into accessory sex glands. The EAV-specific immunoglobulin isotypes i...
Giese M, Bahr U, Jakob NJ, Kehm R, Handermann M, Müller H, Vahlenkamp TH, Spiess C, Schneider TH, Schusse G, Darai G.Equine arteritis virus (EAV) is the causative agent of the equine viral arteritis. It is a small RNA virus with a linear, non-segmented plus RNA genome. EAV is a member of the Arteriviridae family that includes porcine reproductive and respiratory syndrome virus (PRSSV), simian haemorrhagic fever virus (SHFV) and lactate dehydrogenase virus (LDV). The viral transmission is via respiratory and reproductive routes. Clinical signs in horses vary, and severe infection can lead to abortions in pregnant mares or neonatal foal death. The aim of this study was to investigate the development of the imm...
Mittelholzer C, Stadejek T, Johansson I, Baule C, Ciabatti I, Hannant D, Paton D, Autorino GL, Nowotny N, Belák S.To determine a conclusive phylogeny, equine arteritis viruses from Italy, Austria, Hungary, Sweden, South Africa and other parts of the world were analysed by reverse-transcription polymerase chain reaction amplification and direct sequencing. The nucleotide sequences corresponding to the variable part of the large glycoprotein GP5, specified by open reading frame 5, were compared and added to a previously published phylogenetic tree in which a clear division between 'European' and 'American' type viruses had been established. Adding the sequences determined in this study and new sequences ret...
Steinbach F, Westcott DG, McGowan SL, Grierson SS, Frossard JP, Choudhury B.Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory and reproductive disease of equids, which is notifiable in some countries including the Great Britain (GB) and to the OIE. Herein, we present the case of a persistently infected stallion and the phylogenetic tracing of the virus strain isolated. Discussing EAV occurrence and phylogenetic analysis we review features, which may aid to harmonise and enhance the classification of EAV.
Back H, Weld J, Walsh C, Cullinane A.The aim of this study was to identify respiratory viruses circulating amongst elite racehorses in a training yard by serological testing of serial samples and to determine their impact on health status and ability to race. A six-month longitudinal study was conducted in 30 Thoroughbred racehorses (21 two-year-olds, five three-year-olds and four four-year-olds) during the Flat racing season. Sera were tested for the presence of antibodies against equine herpesvirus 1 and 4 (EHV-1 and EHV-4) and equine rhinitis viruses A and B (ERAV and ERBV) by complement fixation (CF) and equine arteritis viru...
Del Piero F, Wilkins PA, Lopez JW, Glaser AL, Dubovi EJ, Schlafer DH, Lein DH.Clinical, pathological, immunohistochemical, serological and microbiological findings are described for 2 geographically and temporally distinct equine arteritis virus (EAV) epidemics in newborn foals. Outbreak A occurred at a commercial Standardbred breeding facility; Outbreak B began in a group of research animals. Clinical signs were severe and primarily referable to the respiratory tract. Fever and leucopenia and/or thrombocytopenia were observed in foals surviving for more than 24 h. The most common gross pathological findings were limited to the respiratory tract. Common histopathologica...
Echeverría MG, Pecoraro MR, Galosi CM, Etcheverrigaray ME, Nosetto EO.This paper describes the first isolation of equine arteritis virus (EAV) in Argentina. The virus was isolated from the semen of an imported seropositive stallion held in isolation at a breeding farm in Tandil in the Buenos Aires Province. In addition, viral nucleic acid was detected in seminal plasma using the reverse-transcription polymerase chain reaction. The isolated virus was propagated in cell cultures and confirmed as EAV by indirect immunofluorescence and virus neutralisation, using a serum specific for the reference Bucyrus strain of EAV. As far as the authors are aware, this is the f...
Metz GE, Abeyá MM, Serena MS, Panei CJ, Echeverría MG.Equine arteritis virus (EAV) induces apoptosis in infected cells. Cell death caused by EAV has been studied mainly using three cell lines, BHK-21, RK-13 and Vero cells. The mechanism of apoptosis varies among cell lines and results cannot be correlated owing to differences in EAV strains used. We evaluated different markers for apoptosis in BHK-21, RK-13 and Vero cell lines using the Bucyrus EAV reference strain. Acridine orange/ethidium bromide staining revealed morphological changes in infected cells, while flow cytometry indicated the extent of apoptosis. We also observed DNA fragmentation,...
Valle-Casuso JC, Gaudaire D, Martin-Faivre L, Madeline A, Dallemagne P, Pronost S, Munier-Lehmann H, Zientara S, Vidalain PO, Hans A.RNA viruses are responsible for a large variety of animal infections. Equine Arteritis Virus (EAV) is a positive single-stranded RNA virus member of the family Arteriviridae from the order Nidovirales like the Coronaviridae. EAV causes respiratory and reproductive diseases in equids. Although two vaccines are available, the vaccination coverage of the equine population is largely insufficient to prevent new EAV outbreaks around the world. In this study, we present a high-throughput in vitro assay suitable for testing candidate antiviral molecules on equine dermal cells infected by EAV. Using t...
