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Fürer F, Fraefel C, Lechmann J. Multiplex real-time PCR for the detection and differentiation of equid gammaherpesvirus 2 and 5. J Virol Methods 2022; 310:114615. [PMID: 36087793 DOI: 10.1016/j.jviromet.2022.114615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 12/24/2022]
Abstract
Equid gammaherpesvirus 2 (EHV-2) and 5 (EHV-5) are widely distributed in the equines. Although their pathogenic potential is not yet fully understood, they appear to play a role in disease patterns like equine multinodular pulmonary fibrosis. In this study, a multiplex real-time PCR (rtPCR) was designed to detect DNA of the glycoprotein H (EHV-2) and E11 gene (EHV-5). Analytical specificity was determined by testing DNA of other herpesviruses by SYBR Green rtPCR and melting curve analysis, as well as Sanger sequencing of positive field samples. Analytical sensitivity was assessed by standard curve generation of serial plasmid dilutions containing the respective target gene. Melting curves and BLAST analysis of the sequences indicated specific detection of the viruses. The lower limit of detection of the singleplex rtPCR was 40 and 29 DNA copies per reaction for EHV-2 and EHV-5, respectively. Comparison of the Ct values of a selection of positive field samples showed only minimal differences between the singleplex and the multiplex assay. The here described multiplex rtPCR protocol allows sensitive and specific detection of EHV-2 and EHV-5. It represents a convenient and rapid tool for future studies to investigate the clinical relevance of EHV-2 and EHV-5 in more detail.
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Affiliation(s)
- Flavia Fürer
- Institute of Virology, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland
| | - Cornel Fraefel
- Institute of Virology, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland
| | - Julia Lechmann
- Institute of Virology, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland.
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2
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Stasiak K, Dunowska M, Rola J. Kinetics of the Equid Herpesvirus 2 and 5 Infections among Mares and Foals from Three Polish National Studs. Viruses 2022; 14:v14040713. [PMID: 35458443 PMCID: PMC9031536 DOI: 10.3390/v14040713] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/18/2022] [Accepted: 03/28/2022] [Indexed: 02/01/2023] Open
Abstract
Equid herpesvirus 2 (EHV-2) and 5 (EHV-5) are two γ-herpesviruses that are commonly detected from horses worldwide, based on several cross-sectional molecular surveys. Comparatively few studies examined the dynamics of γ-herpesvirus infection over time in a group of horses. The aim of the current study was to investigate the dynamics of EHV-2/5 infections among mares and their foals at three Polish national studs with different breeds of horses: Arabians, Thoroughbreds and Polish Konik horses. Nasal swabs were collected from each of 38 mare-foal pairs monthly for a period of 6 to 8 months. Virus-specific quantitative PCR assays were used to determine the viral load of EHV-2 and EHV-5 in each sample. All 76 horses sampled were positive for EHV-2 or EHV-5 on at least one sampling occasion. The majority (73/76, 96%) were infected with both EHV-2 and EHV-5. In general, the mean load of viral DNA was higher in samples from foals than from mares, but similar for EHV-2 and EHV-5 at most sampling occasions. There was, however, a considerable variability in the viral DNA load between samples collected at different times from the same foal, as well as between samples from different foals. The latter was more apparent for EHV-2 than for EHV-5. All foals became infected with both viruses early in life, before weaning, and remained positive on all, or most, subsequent samplings. The virus shedding by mares was more intermittent, indicating the existence of age-related differences. Overall, the data presented extend our knowledge of EHV-2/5 epidemiology among mares and foals.
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Affiliation(s)
- Karol Stasiak
- Department of Virology, National Veterinary Research Institute, 24-100 Pulawy, Poland;
| | - Magdalena Dunowska
- School of Veterinary Science, Massey University, Palmerston North 4442, New Zealand;
| | - Jerzy Rola
- Department of Virology, National Veterinary Research Institute, 24-100 Pulawy, Poland;
- Correspondence: ; Tel.: +48-818-893-069
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Thorsteinsdóttir L, Jónsdóttir S, Stefánsdóttir SB, Andrésdóttir V, Wagner B, Marti E, Torsteinsdóttir S, Svansson V. The effect of maternal immunity on the equine gammaherpesvirus type 2 and 5 viral load and antibody response. PLoS One 2019; 14:e0218576. [PMID: 31226153 PMCID: PMC6588279 DOI: 10.1371/journal.pone.0218576] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 06/04/2019] [Indexed: 12/27/2022] Open
Abstract
Two types of gammaherpesviruses (γEHV) are known to infect horses, EHV-2 and EHV-5. Foals become infected early in life, probably via the upper respiratory tract, despite maternal antibodies. In this study, we analyzed samples from a herd of mares and their foals. The foals were followed from birth to 22 months of age and the dams during the first 6 months postpartum. Blood and nasal swab samples were taken regularly for evaluation of antibody responses, virus isolation and viral load by qPCR. EHV-2 was isolated on day 5, and EHV-5 on day 12, earlier than previously reported. γEHV specific antibodies were not detectable in serum of foals before colostrum intake but peaked a few days after colostrum. Overall, EHV-2 viral load peaked in nasal swab at three to four months of age, paralleled with decline in maternal antibodies, but EHV-5 viral load did not peak until month 12. Maternal antibodies had a notable effect on the viral load and induction of endogenous antibody production. Foals were grouped in two groups depending on the mare’s γEHV specific total IgG levels in serum at birth, group-high and group-low. Group-high had higher levels of maternal γEHV specific total IgG and IgG4/7 for the first 3 months, but when the endogenous production had superseded maternal antibodies, group-low was higher. The maternal antibodies had an effect on the γEHV viral load. Group-low peaked in EHV-2 viral load one month earlier than group-high. These effects were more evident for EHV-5, as there were seven months between the viral load peaks for the groups. The study provides information on how maternal antibody transfer affects γEHV shedding and antibody production in offspring. It also extends our knowledge on the occurrence of EHV-2 and EHV-5 infection in foals during the first two years of life.
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Affiliation(s)
- Lilja Thorsteinsdóttir
- Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavík, Iceland
- * E-mail:
| | - Sigríður Jónsdóttir
- Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavík, Iceland
- Department of Clinical Research and Veterinary Public Health, Vetsuisse Faculty, University of Berne, Berne, Switzerland
| | - Sara Björk Stefánsdóttir
- Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavík, Iceland
| | - Valgerður Andrésdóttir
- Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavík, Iceland
| | - Bettina Wagner
- Department of Population Medicine & Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States of America
| | - Eliane Marti
- Department of Clinical Research and Veterinary Public Health, Vetsuisse Faculty, University of Berne, Berne, Switzerland
| | - Sigurbjörg Torsteinsdóttir
- Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavík, Iceland
| | - Vilhjálmur Svansson
- Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavík, Iceland
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Van Cleemput J, Poelaert KCK, Laval K, Nauwynck HJ. Unravelling the first key steps in equine herpesvirus type 5 (EHV5) pathogenesis using ex vivo and in vitro equine models. Vet Res 2019; 50:13. [PMID: 30777128 PMCID: PMC6380010 DOI: 10.1186/s13567-019-0630-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 01/24/2019] [Indexed: 12/21/2022] Open
Abstract
Equine herpesvirus type 5 (EHV5) is a ubiquitous, yet obscure pathogen in the horse population and is commonly associated with fatal equine multinodular pulmonary fibrosis (EMPF). To date, little is known about the precise pathogenesis of EHV5. Here, we evaluated the dynamics of EHV5 infection in representative ex vivo and in vitro equine models, using immunofluorescence staining and virus titration. EHV5 was unable to infect epithelial cells lining the mucosa of nasal and tracheal explants. Similarly, primary equine respiratory epithelial cells (EREC) were not susceptible to EHV5 following inoculation at the apical or basolateral surfaces. Upon direct delivery of EHV5 particles to lung explants, few EHV5-positive cell clusters were observed at 72 hours post-inoculation (hpi). These EHV5-positive cells were identified as cytokeratin-positive alveolar cells. Next, we examined the potential of EHV5 to infect three distinct equine PBMC populations (CD172a+ monocytes, CD3+ T lymphocytes and Ig light chain+ B lymphocytes). Monocytes did not support EHV5 replication. In contrast, up to 10% of inoculated equine T and B lymphocytes synthetized intracellular viral antigens 24 hpi and 72 hpi, respectively. Still, the production of mature virus particles was hampered, as we did not observe an increase in extracellular virus titer. After reaching a peak, the percentage of infected T and B lymphocytes decayed, which was partly due to the onset of apoptosis, but not necrosis. Based on these findings, we propose a model for EHV5 pathogenesis in the horse. Uncovering EHV5 pathogenesis is the corner step to finally contain or even eradicate the virus.
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Affiliation(s)
- Jolien Van Cleemput
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Katrien C K Poelaert
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Kathlyn Laval
- Department of Molecular Biology, Princeton University, 119 Lewis Thomas Laboratory, Washington Road, Princeton, NJ, 08544, USA
| | - Hans J Nauwynck
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
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Stasiak K, Dunowska M, Rola J. Prevalence and sequence analysis of equid herpesviruses from the respiratory tract of Polish horses. Virol J 2018; 15:106. [PMID: 29996858 PMCID: PMC6042439 DOI: 10.1186/s12985-018-1018-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 07/04/2018] [Indexed: 12/24/2022] Open
Abstract
Background Equid herpesviruses (EHVs) are widespread in equine populations worldwide. While the infection with equine α-herpesviruses (EHV-1 and EHV-4) has been linked to several clinical outcomes, the pathogenic potential for equine γ-herpesviruses (EHV-2 and EHV-5) is still unclear. The objective of the current study was to determine the prevalence of infection with EHVs among Polish horses, to investigate factors associated with EHV infections among horses sampled, and to determine genetic variability within Polish EHV-2 isolates. Methods Virus-specific real-time PCR assays were used for detection of EHV-1, EHV-2, EHV-4 and EHV-5 in nasal swabs collected from 540 horses from 13 national horse studs located throughout Poland. A proportion of EHV-2/5 positive samples were subjected to virus isolation followed by amplification and analysis of partial glycoprotein B sequence. Results Overall, 448/540 (83.0%) horses sampled were positive for at least one virus. The most prevalent was infection with EHV-2 (77.2%), followed by EHV-5 (47.0%), and EHV-4 (0.4%). None of the horses was positive for EHV-1. Approximately half of the virus-infected horses were positive for both EHV-2 and EHV-5. The proportion of EHV-2/5 positive horses varied by age, breed, and season. Only 8.0% of horses sampled, mostly Arabians, showed clinical signs of respiratory disease at the time of sampling. The viral load of both EHV-2 and EHV-5 DNA was highest in swabs from young horses, which was particularly evident for EHV-2 infected foals. Mean viral loads in nasal swabs collected from diseased horses were higher than in swabs from healthy horses. That was also true for EHV-2 when only diseased Arabian foals were considered, but the levels of EHV-5 DNA were lower in swabs from diseased than from healthy foals. In agreement with other studies, there was a considerable variability between Polish EHV-2 sequences, with no clustering of sequences from horses with different health status. The level of EHV-2 variability seemed to differ between different studs/breeds. Conclusions The presence of foals and yearlings on a property is likely to increase the risk of active EHV-2/5 infection among in-contact horses. The existence of breed-specific differences in susceptibility to EHV-2/5 infections should be further investigated, as it may provide one variable that needs to be considered in attempts to associate EHV-2/5 infections with disease. Overall, the data presented add to the existing knowledge of the epidemiology and biology of equine γ-herpesviruses, with the long-term goal of better understanding of the pathogenesis and the impact of infections with these viruses on the well-being of the horse.
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Affiliation(s)
- Karol Stasiak
- Department of Virology, National Veterinary Research Institute, Al. Partyzantow 57, 24-100, Pulawy, Poland
| | - Magdalena Dunowska
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
| | - Jerzy Rola
- Department of Virology, National Veterinary Research Institute, Al. Partyzantow 57, 24-100, Pulawy, Poland.
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6
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Bell SA, Balasuriya UBR, Nordhausen RW, MacLachlan NJ. Isolation of Equine Herpesvirus-5 from Blood Mononuclear Cells of a Gelding. J Vet Diagn Invest 2016; 18:472-5. [PMID: 17037617 DOI: 10.1177/104063870601800509] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
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 portion of the glycoprotein B gene of this strain of EHV-5 had 99% identity to the published EHV-5 sequence, and it was clearly distinguishable from other EHV (1–4) by virus-specific PCR assays. Prevalence of EHV-5 infection in a group of young racehorses was estimated at 64% using the EHV-5 specific PCR on nasopharyngeal secretions.
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Affiliation(s)
- Stephanie A Bell
- Equine Viral Disease Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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7
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Thorsteinsdóttir L, Torsteinsdóttir S, Svansson V. Establishment and characterization of fetal equine kidney and lung cells with extended lifespan. Susceptibility to equine gammaherpesvirus infection and transfection efficiency. In Vitro Cell Dev Biol Anim 2016; 52:872-7. [PMID: 27173610 DOI: 10.1007/s11626-016-0046-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 04/14/2016] [Indexed: 11/28/2022]
Abstract
Due to the slow growth of equine gammaherpesviruses, isolation of these viruses requires cells that can be propagated long term and show clear cytopathy following infection. Equine cell lines with extended lifespan were established from primary cells originating from equine fetal kidney and lung by transfecting the cells with the retroviral vector LXSN116E6E7 containing the human papilloma virus oncogenes 16 E6 and E7. The transfected equine kidney cell line and equine lung cell line can be propagated for more than 40 passages, whereas the corresponding primary cells only for 10-12 passages. The primary cells and the derived cell lines can be infected with equine gammaherpesvirus 2 (EHV-2) with similar efficiency. However EHV-5 can be grown to a substantially higher titer in the kidney cell line than their primary counterpart, with cytopathic effect visible three days earlier than in the primary cells. Due to rapid cell growth the lung cell line is difficult to use for virus production. The kidney cell line was four times more susceptible to transfection as compared to the primary kidney cells. On the other hand no difference was between the lung cell line and the primary lung cells in transfection efficiency. The cell lines can be a valuable tool for investigating gammaherpesviruses, and possibly other viruses infecting horses.
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Affiliation(s)
- Lilja Thorsteinsdóttir
- Institute for Experimental Pathology, University of Iceland, Keldur, Keldnavegur 3, 112, Reykjavík, Iceland.
| | - Sigurbjörg Torsteinsdóttir
- Institute for Experimental Pathology, University of Iceland, Keldur, Keldnavegur 3, 112, Reykjavík, Iceland
| | - Vilhjálmur Svansson
- Institute for Experimental Pathology, University of Iceland, Keldur, Keldnavegur 3, 112, Reykjavík, Iceland
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8
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Marenzoni ML, Stefanetti V, Danzetta ML, Timoney PJ. Gammaherpesvirus infections in equids: a review. VETERINARY MEDICINE-RESEARCH AND REPORTS 2015; 6:91-101. [PMID: 30155436 PMCID: PMC6065615 DOI: 10.2147/vmrr.s39473] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Although the first equine gammaherpesvirus was identified over 50 years ago, the isolation and characterization of other members of this virus group has been relatively recent. Even so, numerous clinical syndromes have been identified in equid species in association with these viruses. Equid gammaherpesviruses are a genetically heterogeneous viral subfamily, the function of which in host immune modulation and disease pathogenesis has not yet been elucidated. While they share similarities with gammaherpesviruses in humans, the role they play in their relationship with the host is the subject of continued interest and research. Their widespread presence in horses and other equid species provides a considerable challenge in linking them with particular clinical and pathological conditions and in defining their significance from a diagnostic and therapeutic viewpoint. The present review provides an update on the taxonomy, epidemiology, and clinical syndromes, especially respiratory, reported in association with gammaherpesvirus infection in horses, donkeys, and other equid species.
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Affiliation(s)
| | | | | | - Peter Joseph Timoney
- Department of Veterinary Science, Maxwell H Gluck Equine Research Center, Lexington, KY, USA
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Akkutay AZ, Osterrieder N, Damiani A, Tischer BK, Borchers K, Alkan F. Prevalence of equine gammaherpesviruses on breeding farms in Turkey and development of a TaqMan MGB real-time PCR to detect equine herpesvirus 5 (EHV-5). Arch Virol 2014; 159:2989-95. [DOI: 10.1007/s00705-014-2165-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 06/27/2014] [Indexed: 10/25/2022]
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10
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Dunowska M, Hardcastle MR, Tonkin FB. Identification of the first New Zealand case of equine multinodular pulmonary fibrosis. N Z Vet J 2014; 62:226-31. [DOI: 10.1080/00480169.2014.899933] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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11
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Kessell AE, Wilkes E, Raidal S, Browne EA, Hughes K. Diagnostic challenge: mare with clinical history of chronic respiratory disease. Severe interstitial pneumonia. Aust Vet J 2014; 92:46-8. [PMID: 24471883 DOI: 10.1111/avj.12134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2013] [Indexed: 11/27/2022]
Affiliation(s)
- A E Kessell
- School of Animal and Veterinary Science, Charles Sturt University, Wagga Wagga, New South Wales 2650, Australia.
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Hue ES, Fortier GD, Fortier CI, Leon AM, Richard EA, Legrand LJ, Pronost SL. Detection and quantitation of equid gammaherpesviruses (EHV-2, EHV-5) in nasal swabs using an accredited standardised quantitative PCR method. J Virol Methods 2013; 198:18-25. [PMID: 24370678 DOI: 10.1016/j.jviromet.2013.12.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 11/21/2013] [Accepted: 12/14/2013] [Indexed: 10/25/2022]
Abstract
Equid gammaherpesviruses-2 and -5 are involved in respiratory problems, with potential clinical manifestations such as nasal discharge, pharyngitis and swollen lymph nodes. These viruses are sometimes associated with a poor-performance syndrome, which may result in a significant and negative economic impact for the horse industry. The aim of the present study was to develop and validate quantitative PCR methods for the detection and quantitation of EHV-2 and EHV-5 in equine respiratory fluids. Two distinct tests were characterised: (a) for the qPCR alone and (b) for the whole method (extraction and qPCR) according to the standard model AFNOR XP U47-600-2 (viz., specificity, quantifiable sensibility, linearity, accuracy, range of application, trueness, precision, repeatability and precision of reproducibility). EHV-2 and EHV-5 detection were performed on nasal swabs collected from 172 horses, all of which exhibited clinical signs of respiratory disease. The data revealed a high rate of EHV-2/EHV-5 co-detection that was correlated significantly with age. Viral load of EHV-2 was significantly higher in young horses whereas viral load of EHV-5 was not significantly different with age.
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Affiliation(s)
- Erika S Hue
- Frank Duncombe Laboratory-LABÉO, 1 route de Rosel, 14053 Caen Cedex 4, France; Normandie Universite, 14000 Caen, France; Unite Risques Microbiens (U2RM), EA 4655, 14032 Caen, France; Hippolia Foundation, La Maison du cheval, 6 avenue du Maréchal Montgomery, 14000 Caen, France.
| | - Guillaume D Fortier
- Frank Duncombe Laboratory-LABÉO, 1 route de Rosel, 14053 Caen Cedex 4, France; Normandie Universite, 14000 Caen, France; Unite Risques Microbiens (U2RM), EA 4655, 14032 Caen, France; Hippolia Foundation, La Maison du cheval, 6 avenue du Maréchal Montgomery, 14000 Caen, France.
| | - Christine I Fortier
- Frank Duncombe Laboratory-LABÉO, 1 route de Rosel, 14053 Caen Cedex 4, France; Hippolia Foundation, La Maison du cheval, 6 avenue du Maréchal Montgomery, 14000 Caen, France.
| | - Albertine M Leon
- Frank Duncombe Laboratory-LABÉO, 1 route de Rosel, 14053 Caen Cedex 4, France; Normandie Universite, 14000 Caen, France; Unite Risques Microbiens (U2RM), EA 4655, 14032 Caen, France; Hippolia Foundation, La Maison du cheval, 6 avenue du Maréchal Montgomery, 14000 Caen, France.
| | - Eric A Richard
- Frank Duncombe Laboratory-LABÉO, 1 route de Rosel, 14053 Caen Cedex 4, France; Hippolia Foundation, La Maison du cheval, 6 avenue du Maréchal Montgomery, 14000 Caen, France.
| | - Loïc J Legrand
- Frank Duncombe Laboratory-LABÉO, 1 route de Rosel, 14053 Caen Cedex 4, France; Normandie Universite, 14000 Caen, France; Unite Risques Microbiens (U2RM), EA 4655, 14032 Caen, France; Hippolia Foundation, La Maison du cheval, 6 avenue du Maréchal Montgomery, 14000 Caen, France.
| | - Stéphane L Pronost
- Frank Duncombe Laboratory-LABÉO, 1 route de Rosel, 14053 Caen Cedex 4, France; Normandie Universite, 14000 Caen, France; Unite Risques Microbiens (U2RM), EA 4655, 14032 Caen, France; Hippolia Foundation, La Maison du cheval, 6 avenue du Maréchal Montgomery, 14000 Caen, France.
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13
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Equine gammaherpesviruses: perfect parasites? Vet Microbiol 2013; 167:86-92. [PMID: 23845734 DOI: 10.1016/j.vetmic.2013.05.031] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2012] [Revised: 05/29/2013] [Accepted: 05/31/2013] [Indexed: 12/29/2022]
Abstract
The evolutionary success of the equine gammaherpesviruses (GHVs) is demonstrated by their consistent and widespread presence in horse populations worldwide. Equine GHVs establish infection in young foals and can be continually detected over the lifetime of the host either by recrudescence of latent infections or by re-infection. A definitive diagnosis of clinical disease in horses due to GHV infection remains challenging given the ubiquitous nature of the GHVs in horses without clinical signs, as well as in horses with clinical signs ranging from mild respiratory disease to severe equine multinodular pulmonary fibrosis. This review aims to examine what is known about equine GHV and explore the balance of the relationship that has evolved over millions of years between these viruses and their host.
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14
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Abstract
AIMS To determine which viruses circulate among selected populations of New Zealand horses and whether or not viral infections were associated with development of respiratory disease. METHODS Nasal swabs were collected from 33 healthy horses and 52 horses with respiratory disease and tested by virus isolation and/or PCR for the presence of equine herpesviruses (EHV) and equine rhinitis viruses. RESULTS Herpesviruses were the only viruses detected in nasal swab samples. When both the results of nasal swab PCR and virus isolation were considered together, a total of 41/52 (79%) horses with respiratory disease and 2/32 (6%) healthy horses were positive for at least one virus. As such, rates of virus detection were significantly higher (p<0.001) in samples from horses with respiratory disease than from healthy horses. More than half of the virus-positive horses were infected with multiple viruses. Infection with EHV-5 was most common (28 horses), followed by EHV-2 (27 horses), EHV-4 (21 horses) and EHV-1 (3 horses). CONCLUSIONS Herpesviruses were more commonly detected in nasal swabs from horses with respiratory disease than from healthy horses suggesting their aetiological involvement in the development of clinical signs among sampled horses. Further investigation to elucidate the exact relationships between these viruses and respiratory disease in horses is warranted. CLINICAL RELEVANCE Equine respiratory disease has been recognised as an important cause of wastage for the equine industry worldwide. It is likely multifactorial, involving complex interactions between different microorganisms, the environment and the host. Ability to control, or minimise, the adverse effects of equine respiratory disease is critically dependent on our understanding of microbial agents involved in these interactions. The results of the present study update our knowledge on the equine respiratory viruses currently circulating among selected populations of horses in New Zealand.
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Affiliation(s)
- K A McBrearty
- Institute of Veterinary Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
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16
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Soare T, Leeming G, Morgan R, Papoula-Pereira R, Kipar A, Stewart JP, Hetzel U. Equine multinodular pulmonary fibrosis in horses in the UK. Vet Rec 2011; 169:313. [DOI: 10.1136/vr.d4348] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- T. Soare
- Veterinary Pathology; University of Liverpool; School of Veterinary Science; Crown Street Liverpool L69 7ZJ UK
| | - G. Leeming
- Veterinary Pathology; University of Liverpool; School of Veterinary Science; Crown Street Liverpool L69 7ZJ UK
| | - R. Morgan
- Philip Leverhulme Equine Hospital; University of Liverpool, Leahurst; Chester High Road Neston Cheshire CH64 7TE UK
| | - R. Papoula-Pereira
- Veterinary Pathology; University of Liverpool; School of Veterinary Science; Crown Street Liverpool L69 7ZJ UK
| | - A. Kipar
- Veterinary Pathology; University of Liverpool; School of Veterinary Science; Crown Street Liverpool L69 7ZJ UK
| | - J. P. Stewart
- National Centre for Zoonosis Research; University of Liverpool, Leahurst; Chester High Road Neston Cheshire CH64 7TE UK
| | - U. Hetzel
- Veterinary Pathology; University of Liverpool; School of Veterinary Science; Crown Street Liverpool L69 7ZJ UK
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17
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Age-dependent prevalence of equid herpesvirus 5 infection. Vet Res Commun 2010; 34:703-8. [DOI: 10.1007/s11259-010-9443-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2010] [Indexed: 10/19/2022]
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18
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Ataseven VS, Bilge-Dagalp S, Oguzoglu TC, Karapinar Z, Güzel M, Tan MT. Detection and sequence analysis of equine gammaherpesviruses from horses with respiratory tract disease in Turkey. Transbound Emerg Dis 2010; 57:271-6. [PMID: 20553426 DOI: 10.1111/j.1865-1682.2010.01146.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The equid herpesvirus 2 (EHV-2) and 5 (EHV-5), identified agents of respiratory infections and keratoconjunctivitis cases in some equids, comprise a high degree of antigenic heterogeneity. Prevalence and genetic characterization of EHV-2 and EHV-5 strains from Turkey were investigated in this study. A total of 73 nasal swabs and 54 blood specimens were sampled from horses with respiratory tract diseases characterized by mucopurulent nasal discharge and occasional coughing. Overall, EHV-2- and EHV-5-specific DNA amplicons were obtained from 19.2% (14/73) and 21.9% (16/73) of horses tested by multiplex nested PCR. Sequences of EHV-2 and EHV-5 glycoprotein B (gB) gene were used in a phylogenetic analysis that included six EHV-2 and three EHV-5 isolates, which showed that the Turkish EHV-2 and EHV-5 strains have marked sequence divergence from European strains and from each other. Turkish EHV-2 isolates were divided into two distinct subdivisions, and a few isolates were located on a separate branch. This study provides the first epidemiological and phylogenetical report about EHV-2 and EHV-5 infections in Turkey.
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Affiliation(s)
- V S Ataseven
- Department of Virology, Mustafa Kemal University Hatay, Turkey
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19
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Niedermaier G, Poth T, Gehlen H. Clinical aspects of multinodular pulmonary fibrosis in two warmblood horses. Vet Rec 2010; 166:426-30. [DOI: 10.1136/vr.b4811] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | - T. Poth
- Institute of Veterinary Pathology; Veterinary Faculty; Ludwig-Maximilians University of Munich; Veterinärstrasse 13 80539 Munich Germany
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20
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Equine gammaherpesviruses: pathogenesis, epidemiology and diagnosis. Vet J 2009; 186:148-56. [PMID: 19766026 DOI: 10.1016/j.tvjl.2009.08.017] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 08/11/2009] [Accepted: 08/15/2009] [Indexed: 01/03/2023]
Abstract
Equine gammaherpesviruses (γEHV) have been widely studied over the past 45 years and many isolates have been characterised. Despite this, the diagnosis of γEHV infection remains difficult to establish as its clinical manifestations lack specificity, ranging from mild respiratory signs in a small number of animals to outbreaks in large groups of young horses. This review focuses on the epidemiology, pathogenesis, clinical manifestations and diagnosis of equine herpesvirus (EHV)-2 and -5 infections, as well as on the genetic variation of these viruses. Study of these variations has resulted in hypotheses relating to viral re-infection and re-activation. Interestingly, the viruses were found to contain genetic sequences identical to those of eukaryotic cells which are considered central to the development of viral latency through interfering with host immune and inflammatory responses. Future molecular biological studies will further elucidate the virulence mechanisms of these equine pathogens.
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21
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Diallo IS, Hewitson GR, de Jong A, Kelly MA, Wright DJ, Corney BG, Rodwell BJ. Equine herpesvirus infections in yearlings in South-East Queensland. Arch Virol 2008; 153:1643-9. [DOI: 10.1007/s00705-008-0158-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Accepted: 06/09/2008] [Indexed: 11/24/2022]
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22
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Wong DM, Belgrave RL, Williams KJ, Del Piero F, Alcott CJ, Bolin SR, Marr CM, Nolen-Walston R, Myers RK, Wilkins PA. Multinodular pulmonary fibrosis in five horses. J Am Vet Med Assoc 2008; 232:898-905. [DOI: 10.2460/javma.232.6.898] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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23
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Torfason EG, Thorsteinsdóttir L, Torsteinsdóttir S, Svansson V. Study of equid herpesviruses 2 and 5 in Iceland with a type-specific polymerase chain reaction. Res Vet Sci 2008; 85:605-11. [PMID: 18336849 DOI: 10.1016/j.rvsc.2008.01.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Revised: 12/21/2007] [Accepted: 01/11/2008] [Indexed: 11/29/2022]
Abstract
The horse population in Iceland is a special breed, isolated from other horses for at least 1000 years. This provides an exceptional opportunity to investigate old and new pathogens in an inbred herd with few infectious diseases. We have developed a high sensitivity semi-nested PCR to study equid gammaherpesviruses 2 and 5 (EHV-2 and 5) in Iceland. The first PCR is group specific, the second type-specific, targeting a 113bp sequence in the glyB gene. DNA isolated from white blood cells and 18 different organs was tested for the presence of EHV-2 and 5. This was done in adult horses and foals, healthy and with various enteric infections. Both virus types were easily detected in all types of organs tested or EHV-2 in 79% cases and EHV-5 in 63%. In DNA from PBMC or buffy-coat EHV-2 was found in 20% cases and EHV-5 in 10%, all except one positive were foals. Co-culture of PBMC on fetal horse kidney cells was efficient for detecting EHV-2 but not for EHV-5. We verify here for the first time infections with EHV-2 and 5 in horses in Iceland and show that both viruses are common.
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Affiliation(s)
- Einar G Torfason
- Department of Medical Virology, Landspitali - University Hospital, Reykjavík, Iceland
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24
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Wang L, Raidal SL, Pizzirani A, Wilcox GE. Detection of respiratory herpesviruses in foals and adult horses determined by nested multiplex PCR. Vet Microbiol 2007; 121:18-28. [PMID: 17208393 DOI: 10.1016/j.vetmic.2006.11.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Revised: 11/08/2006] [Accepted: 11/13/2006] [Indexed: 10/23/2022]
Abstract
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 specific technique for the detection of EHV in cell culture and clinical samples. The technique described appeared equally sensitive as one using a single set of primers for individual EHV but reduced labour and reagent costs. Cell cultures showing cytopathic effect (CPE) were always positive for EHV on PCR. EHV were also detected by multiplex PCR in 11 samples which failed to show CPE. By a combination of multiplex PCR and cell culture or direct multiplex PCR, the presence of up to three EHV in the same sample was detected. Overall, EHV5 was detected by direct multiplex PCR of peripheral blood mononuclear cells (PBMC) and/or NS samples from 78% of foals and 47% of adult horses. Repeated sampling or cell culture in combination with multiplex PCR and with the incorporation of IL-2 in culture medium increased the sensitivity for detection of EHV in PBMC and demonstrated that EHV5 DNA could be identified in PBMC from 89% of foals and 100% of adult horses. EHV2 was identified from approximately 30% of foals, but was more frequently identified in samples from 17 foals with mild respiratory disease and was isolated infrequently from adult horses. EHV1 and EHV4 were identified uncommonly in any population in the current study.
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Affiliation(s)
- L Wang
- Division of Veterinary and Biomedical Sciences, Murdoch University, Murdoch, WA 6150, Australia
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25
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Bell SA, Balasuriya UBR, Gardner IA, Barry PA, Wilson WD, Ferraro GL, MacLachlan NJ. Temporal detection of equine herpesvirus infections of a cohort of mares and their foals. Vet Microbiol 2006; 116:249-57. [PMID: 16774810 DOI: 10.1016/j.vetmic.2006.05.002] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 04/28/2006] [Accepted: 05/04/2006] [Indexed: 11/26/2022]
Abstract
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 all detected in NS from the horses, but only EHV-4 was associated with respiratory disease (P=0.005). EHV-2 and 5 infections were both common, but foals shed EHV-2 in their NS earlier in life than EHV-5 (P=0.01). Latent EHV-2 and 5 infections were detected in the PBMC of 75 and 88%, respectively, of the foals at approximately 6 months of age. The strains of EHV-2 shed in the NS of individual horses were more genetically heterogeneous than the strains of EHV-5 (95.5-99.3% versus 98.8-99.3% nucleotide identity, respectively). One-month-old foals typically shed strains of EHV-2 that were identical to those infecting their dams whereas older foals often shed virus strains that were different from those of their dams. Although herpesvirus infections were ubiquitous in this cohort of horses, there were distinct clinical consequences and clear epidemiological differences between infections with the different viruses.
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MESH Headings
- Aging/immunology
- Animals
- Animals, Newborn
- Base Sequence
- Cohort Studies
- DNA, Viral/chemistry
- DNA, Viral/isolation & purification
- Female
- Herpesviridae Infections/epidemiology
- Herpesviridae Infections/veterinary
- Herpesviridae Infections/virology
- Herpesvirus 1, Equid/classification
- Herpesvirus 1, Equid/genetics
- Herpesvirus 1, Equid/isolation & purification
- Herpesvirus 3, Equid/classification
- Herpesvirus 3, Equid/genetics
- Herpesvirus 3, Equid/isolation & purification
- Herpesvirus 4, Equid/classification
- Herpesvirus 4, Equid/genetics
- Herpesvirus 4, Equid/isolation & purification
- Horse Diseases/epidemiology
- Horse Diseases/virology
- Horses
- Leukocytes, Mononuclear/virology
- Molecular Sequence Data
- Nasal Mucosa/virology
- Phylogeny
- Polymerase Chain Reaction/methods
- Polymerase Chain Reaction/veterinary
- Prevalence
- Rhadinovirus/classification
- Rhadinovirus/genetics
- Rhadinovirus/isolation & purification
- Species Specificity
- Varicellovirus/classification
- Varicellovirus/genetics
- Varicellovirus/isolation & purification
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Affiliation(s)
- Stephanie A Bell
- Equine Viral Disease Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, One Shields Avenue, University of California, Davis, CA 95616, USA
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26
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Dunowska M, Wilks CR, Studdert MJ, Meers J. Viruses associated with outbreaks of equine respiratory disease in New Zealand. N Z Vet J 2005; 50:132-9. [PMID: 16032259 DOI: 10.1080/00480169.2002.36299] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AIM 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), equine adenovirus 1 (EAdV-1), equine arteritis virus (EAV), reovirus 3 and parainfluenza virus type 3 (PIV3). RESULTS Viruses were isolated from 24/94 (26%) nasal swab samples and from 77/80 (96%) PBL samples collected from both healthy horses and horses showing clinical signs of respiratory disease. All isolates were identified as EHV-2, EHV-4, EHV-5 or untyped EHV. Of the horses and foals tested, 59/82 (72%) were positive for EHV-1 and/or EHV-4 serum neutralising (SN) antibody on at least one sampling occasion, 52/82 (63%) for EHV-1-specific antibody tested by enzyme-linked immunosorbent assay (ELISA), 10/80 (13%) for ERAV SN antibody, 60/80 (75%) for ERBV SN antibody, and 42/80 (53%) for haemagglutination inhibition (HI) antibody to EAdV-1. None of the 64 serum samples tested were positive for antibodies to EAV, reovirus 3 or PIV3. Evidence of infection with all viruses tested was detected in both healthy horses and in horses showing clinical signs of respiratory disease. Recent EHV-2 infection was associated with the development of signs of respiratory disease among yearlings [relative risk (RR)=2.67, 95% CI=1.59-4.47, p=0.017]. CONCLUSIONS Of the equine respiratory viruses detected in horses in New Zealand during this study, EHV-2 was most likely to be associated with respiratory disease. However, factors other than viral infection are probably important in the development of clinical signs of disease.
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Affiliation(s)
- M Dunowska
- Institute of Veterinary Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.
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27
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Dunowska M, Wilks CR, Studdert MJ, Meers J. Equine respiratory viruses in foals in New Zealand. N Z Vet J 2002; 50:140-7. [PMID: 16032260 DOI: 10.1080/00480169.2002.36300] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AIMS To identify the respiratory viruses that are present among foals in New Zealand and to establish the age at which foals first become infected with these viruses. METHODS Foals were recruited to the study in October/ November 1995 at the age of 1 month (Group A) or in March/ April 1996 at the age of 4-6 months (Groups B and C). Nasal swabs and blood samples were collected at monthly intervals. Nasal swabs and peripheral blood leucocytes (PBL) harvested from heparinised blood samples were used for virus isolation; serum harvested from whole-blood samples was used for serological testing for the presence of antibodies against equine herpesvirus (EHV)-1 or -4, equine rhinitis-A virus (ERAV), equine rhinitis-B virus (ERBV), equine adenovirus 1 (EAdV-1), equine arteritis virus (EAV), reovirus 3 and parainfluenza virus type 3 (PIV3). Twelve foals were sampled until December 1996; the remaining 19 foals were lost from the study at various times prior to this date. RESULTS The only viruses isolated were EHV-2 and EHV-5. EHV-2 was isolated from 155/157 PBL samples collected during the period of study and from 40/172 nasal swabs collected from 18 foals. All isolations from nasal swabs, except one, were made over a period of 2-4 months from January to April (Group A), March to April (Group B) or May to July (Group C). EHV-5 was isolated from either PBL, nasal swabs, or both, from 15 foals on 32 occasions. All foals were positive for antibodies to EHV-1 or EHV-4, as tested by serum neutralisation (SN), on at least one sampling occasion and all but one were positive for EHV-1 antibodies measured by enzyme-linked immunosorbent assay (ELISA) on at least one sampling occasion. Recent EHV-1 infection was evident at least once during the period of study in 18/23 (78%) foals for which at least two samples were collected. SN antibodies to ERBV were evident in 19/23 (83%) foals on at least one sampling occasion and 15/23 foals showed evidence of seroconversion to ERBV. Antibodies to ERAV were only detected in serum samples collected from foals in Group A and probably represented maternally-derived antibodies. Haemagglutination inhibition (HI) antibody titres 1:10 to EAdV-1were evident in 21/23 (91%) foals on at least one sampling occasion and 16/23 foals showed serological evidence of recent EAdV-1 infection. None of the 67 serum samples tested were positive for antibodies to EAV, reovirus 3 or PIV3. There was no clear association between infection with any of the viruses isolated or tested for and the presence of overt clinical signs of respiratory disease. CONCLUSIONS There was serological and/or virological evidence that EHV-1, EHV-2, EHV-5, EAdV-1 and ERBV infections were present among foals in New Zealand. EHV-2 infection was first detected in foals as young as 3 months of age. The isolation of EHV-2 from nasal swabs preceded serological evidence of infection with other respiratory viruses, suggesting that EHV-2 may predispose foals to other viral infections.
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Affiliation(s)
- M Dunowska
- Institute of Veterinary Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.
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