Infectious diseases in horses encompass a range of illnesses caused by bacteria, viruses, fungi, or parasites. These diseases can affect various systems within the equine body, leading to symptoms that range from mild discomfort to severe systemic illness. Common infectious diseases in horses include equine influenza, strangles, equine herpesvirus, and West Nile virus. These diseases can be transmitted through direct contact with infected animals, contaminated surfaces, or vectors such as insects. Understanding the mechanisms of transmission, pathogenesis, and immune response is essential for effective prevention and control. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, diagnosis, treatment, and management of infectious diseases in horses.
Buergelt CD, Cooley AJ, Hines SA, Pipers FS.Six horses (five males) aged three months to fourteen years had endocarditis at necropsy. Two of the horses had a clinical diagnosis of valvular endocarditis with negative blood cultures. Single or complex valvular involvement was present in five horses. One horse had non-infectious thrombi associated only with the chordae tendineae. Mitral valves were affected in four horses, and aortic semilunar valves were affected in two. Infarcts had occurred in the kidneys and the myocardium of four horses. Bacteria were isolated postmortem from the valvular vegetations of two horses; Candida parapsilosi...
Blythe LL, Mattson DE, Lassen ED, Craig AM.Neutralizing antibodies against equine herpesvirus 1 were measured in serum and cerebrospinal fluid of 16 horses and ponies from a closed herd both before and after vaccination with modified live equine herpesvirus 1. These titers were also measured in 22 neurologically normal and 15 neurologically abnormal horses at a teaching hospital. Animals from the closed herd had prevaccination serum titers up to 1:8 and postvaccination serum titers up to 1:128. Horses from the teaching hospital had serum titers up to 1:64. Cerebrospinal fluid titers were not detected in the vaccinated horses or the neu...
Gabal MA, Mohammed KA.An enzyme-linked immunosorbent assay was evaluated for the detection of antibody in sera of equine naturally infected with Histoplasma farciminosum 'epizootic lymphangitis'. Ten sera from naturally infected horses were tested. A hydrogen peroxide ABTS mixture constituted the substrate. The reactions were read as the absorbance values measured at 405 nm using a spectrophotometer. The standard deviation and the average percentage of the absorbance values of the different serum samples were considered in the interpretation of the results. All sera were proved positive with variations in the diffe...
Chhabra MB, Gupta SL, Gautam OP.In a serological survey of latent Toxoplasma prevalence on 3761 animals in northern India by the microtitre indirect haemagglutination test, 23.7 per cent were found to have antibody titres ranging from 1:4 to 1:1024. Seropositivity was recorded in 25.3 per cent of 1227 sheep, 30.3 per cent of 961 goats, 11.8 per cent of 603 horses, 19.3 per cent of 243 cattle, 15.7 per cent of 108 water buffaloes, 31.5 per cent of 178 pigs, 30.9 per cent of 175 dogs, 33.7 per cent of 80 cats and in 9.7 per cent of 186 bandicoot rats. Relevant epidemiological data has been furnished. High seropositivity in foo...
Sims LD, Tzipori S, Hazard GH, Carroll CL.Two foals aged 35 and 48 h from 2 Thoroughbred studs died several hours after developing clinical signs of depression, severe haemorrhagic diarrhoea and dehydration. Both foals had an acute haemorrhagic enteritis extending from the anterior jejunum to the terminal ileum which was characterised histologically by villus necrosis. Necrotic villi were surrounded by large numbers of rod-shaped Gram positive bacteria. Clostridium perfringens was recovered from the intestines of both foals and the isolates were considered to be C. perfringens type C. Other cases of diarrhoea were also observed in foa...
Selim SA, Soliman R, Osman K, Padhye AA, Ajello L.Isolation of Histoplasma farciminosum from five horses, showing typical signs of histoplasmosis farciminosi (epizootic lymphangitis) was successfully attempted. The mycelial form of H. farciminosum was isolated on Sabouraud dextrose agar enriched with 2.5% glycerol, brain heart infusion (BHI) agar enriched with 10% horse blood and PPLO dextrose glycerol agar. The last medium proved to be the most effective, both for primary isolation and subculturing of the fungus. It was found that on primary isolation, the lag phase of the mycelial form of the fungus was relatively long, involving 4-8 weeks ...
Foil L, Stage D, Adams WV, Issel CJ.The occurrence of tabanid feeding between mares and foals was observed. When mares and foals were observed freely moving within a pasture situation, foals had 2.43% (4 flies in 77 observations vs 297 flies in 139 observations) of the tabanid feeding occurrences of the mares. This difference in tabanid burden varied due to herd size, herd location, and tabanid species. Lower tabanid burden of foals was indicated as a practical protective mechanism against pathogenic agents mechanically transmitted by tabanids, such as equine infectious anemia virus.
Widders PR, Stokes CR, Newby TJ, Bourne FJ.This study identifies nonimmune binding of equine immunoglobulin by the causative organism of contagious equine metritis. Immunoglobulin binding to the bacterium was strongest for immunoglobulin G (IgG) and less for IgM; IgA was not bound. Binding of equine IgG was inhibited by human IgG, but not by IgG of domestic animals. Immunoglobulin binding by the bacterium appeared to be directed towards an epitope in the hinge region of the immunoglobulin molecule.
Skalka B, Svastová A.Two techniques were developed to detect antibodies against the exosubstance of C. equi called equi-factor. In the first technique serum samples are tested against native equi-factor produced by the growth of C. equi on agar medium. A positive result is manifested by the development of precipitation lines. The second test is based on neutralization of prepurified equi-factor by antibody, resulting in the inhibition of its hemolytic synergism with staphylococcal beta toxin. Sera (125 samples) from horses of different ages, kept in localities with a history of C. equi infections, were examined. T...
Ikeda JS, Hirsh DC.An outbreak of equine salmonellosis occurred at the Veterinary Medical Teaching Hospital, University of California, Davis, between June 1981 and March 1982. Forty-four horses were infected with Salmonella saint-paul, a serotype rarely isolated from animals at the university before the outbreak. Unlike the isolates of S saint-paul obtained at the beginning of the outbreak, almost all strains isolated near the end were resistant to ampicillin, cephalothin, chloramphenicol, gentamicin, kanamycin, sulfadiazine, trimethoprim, and trimethoprim-sulfadiazine. A conjugal-resistance plasmid (R-plasmid) ...
Kemen MJ, Frank RA, Babish JB.An outbreak of an influenza-like illness affected approximately 1/3 of the 1050 race horses stabled at a standardbred racetrack and resulted in a 3-day suspension of racing. A/Equi-2 influenza virus was isolated from 1 affected horse and 8 of 10 horses sampled seroconverted. Threshold protective levels of HI antibody against A/Equi-2 influenza virus were not demonstrated in unaffected horses. Resistance in unaffected horses was assumed to result from other factors following previous exposure. Few of the horses had been vaccinated against equine influenza. It was felt that an outbreak of this m...
Owens WR, Miller RI, Haynes PF, Snider TG.Basidiobolus haptosporus was isolated from a horse with a rapidly progressive ulcerative lesion of the ventral midline. The pathologic findings of an irregular line of yellow material composed of hyphae, eosinophils, and granulomatous inflammation between the superficial edematous tissue and the underlying muscle, and hyphae in tissue sections intimately surrounded by granular eosinophilic cuffs were considered diagnostic for this and one other case diagnosed retrospectively. Both horses were successfully treated by surgery and potassium iodide.
Fletcher WO, Stallknecht DE, Jenney EW.Seventeen species of mammals and seven species of birds from Ossabaw Island, Georgia, were tested for vesicular stomatitis (VS) neutralizing antibodies. Seropositive results were restricted to mammals with six of 17 species testing seropositive for VS (New Jersey type) neutralizing antibodies. Seropositive species included: raccoons (Procyon lotor), white-tailed deer (Odocoileus virginianus), feral swine (Sus scrofa), cattle (Bos taurus), horses (Equus caballus), and donkeys (Equus asinus). All tests for VS (Indiana type) were negative.
Devriese LA, Nzuambe D, Godard C.One hundred and twenty eight strains of Staphylococcus from lesions, mostly of the skin, in horses were identified and compared with 29 strains isolated from the healthy skin. The pathogenic species Staphylococcus aureus, S. intermedius and S. hyicus were found almost exclusively in lesions. Other species such as S. xylosus and S. sciuri were more frequently found on the healthy skin than in lesions. The S. aureus strains formed a very heterogeneous collection. Many of these strains were staphylokinase positive and rapidly coagulated bovine plasma. Such strains are rarely found in other animal...
Benson CE, Palmer JE, Bannister MF.The antibiograms of 408 Salmonella species isolated from large animals were collected during a three year study from 1981 through 1983. The predominant Salmonella serogroup among these isolates was group B. A consistently high percentage of all isolates were resistant to ampicillin and tetracycline. A pattern of increasing resistance to chloramphenicol and gentamicin was documented for serogroup B isolates while the susceptibility of the isolates to neomycin increased. There was a decrease in the incidence of susceptibility to sulfamethoxazole-trimethoprim among the group E isolates. These cha...
Palmer JE.Few foals escape gastrointestinal disease during the first weeks of life. Diarrhea is an extremely common problem; fortunately, however, it is usually mild and self-limiting. When it is not, the underlying cause is often an infectious agent, such as rotavirus or Salmonella spp. Our understanding of many of the infectious agents causing neonatal diarrhea is far from complete. Gastric and duodenal ulcers are a less common disease of neonatal foals. There has been an apparent increase in the incidence of ulcer disease in foals during the past few years. The most effective way of decreasing seriou...
Balke E, Weiss R, Seipp A.A total of 110 strains of beta-hemolytic streptococci, belonging to serogroup C (Lancefield), isolated from horses (71 S. zooepidemicus, 27 S. equisimilis and 12 S. equi) as well as 5 reference strains were tested for their ability to produce hyaluronidase. The determinations were carried out in a culture test on agarose gel and in a liquid test system (turbidity test according to DiFerrante). The results of both methods used showed that the three Streptococcus species could be differentiated by the relative quantitative determination of hyaluronidase activity. S. equisimilis strains produce 5...
Hitchcock PJ, Brown TM, Corwin D, Hayes SF, Olszewski A, Todd WJ.Examination of recently isolated cultures of three strains of Contagious Equine Metritis Organism grown on specially formulated, serum-free, clear typing medium revealed the presence of numerous colonial opacity variants. These colonies were prepared by a number of fixation and staining techniques and examined by scanning and transmission electron microscopy. Opaque and transparent phenotypes produced copious amounts of extracellular material compared with intermediate-opacity phenotypes which produced little or none. Also unique to intermediate colonies were numerous thin intercellular strand...
Coad CT, Robinson NM, Wilhelmus KR.We evaluated 31 fungal specimens obtained from equine corneas over a 10-year period, 1973 to 1983. More than half were received in late summer and early autumn, and the number tended to increase in frequency during the 1980s. These isolates included 13 different genera and 20 different species. The prevalent genus was Aspergillus (35%). On the basis of examinations for tube-dilution minimal inhibitory concentrations and minimal fungicidal concentrations of 16 fungal isolates, the imidazole antibiotics such as miconazole and ketoconazole consistently showed the lowest geometric mean titers for ...
Gould JC, Rossano MG, Lawrence LM, Burk SV, Ennis RB, Lyons ET.Parascaris equorum generally infects horses less than 18 months old and its pathological effects can be severe. Infection occurs when larvated eggs, present in pastures, paddocks, stalls, and on feeding and watering equipment are ingested. The purpose of this study was to examine the effects of windrow composting on the viability of P. equorum eggs at a cooperating central Kentucky horse farm. Three grams of feces containing 2216 P. equorum eggs per gram were sealed in filter bag sentinel chambers. Chambers were exposed to 1 of 3 treatments: constant exposure or intermittent exposure to the in...
Mayhew IG.Parameters for the accuracy of clinical diagnosis of neurologic diseases in the horse were determined from 210 horses in which a definitive pathologic diagnosis was confirmed. The overall efficiency of diagnosis for all diseases was 0.95 although the validity varied from 0.79 to 1.00, the sensitivity varied from 0.73 to 0.95, and the specificity varied from 0.88 to 1.00 for individual disease categories. Equine protozoal myeloencephalitis was overdiagnosed, whereas Eastern equine encephalomyelitis, equine degenerative myeloencephalopathy, and traumatic neurologic disease were underdiagnosed. T...
Cook AG, Maxwell VB, Donaldson LL, Parker NA, Ward DL, Morrow JK.To determine whether antibodies against Sarcocystis neurona could be detected in CSF from clinically normal neonatal (2 to 7 days old) and young (2 to 3 months old) foals. Methods: Prospective study. Methods: 15 clinically normal neonatal Thoroughbred foals. Methods: Serum and CSF samples were obtained from foals at 2 to 7 days of age and tested for antibodies against S. neurona by means of western blotting. Serum samples from the mares were also tested for antibodies against S. neurona. Additional CSF and blood samples were obtained from 5 foals between 13 and 41 days after birth and between ...
Sheoran AS, Nally JE, Donahue JM, Smith BJ, Timoney JF.Leptospira-specific antibody isotypes in sera of late term equine fetuses aborted due to Leptospira interrogans serovar pomona-type kennewicki infection were characterized and compared with those of their dams. IgM was the dominant Leptospira-Specific isotype in both fetuses and mares. However, IgGa was the isotype in highest concentration in petal sera and strong Leptospira-specific IgGa but no IgGb and little or no IgG(T) were detected. In contrast, although IgGb was quantitatively the dominant isotype in mares serum, Leptospira-specific serum IgG in aborting mares was dominated by IgG(T) bu...
Williams NJ, Slovis NM, Browne NS, Troedsson MHT, Giguėre S, Hernandez JA.Diarrhea remains an important cause of morbidity and mortality in neonatal foals, and correct identification of etiologic agents is essential for effective disease management. Objective: To examine the association between diarrhea and detection of Enterococcus durans or other enteropathogens in neonatal foals on 1 breeding farm in Kentucky, USA. Methods: Fifty-nine Thoroughbred foals and their broodmares. Methods: Prospective observational study. Study foals and broodmares were sampled and tested for E. durans and other enteropathogens during the first 10 days after foaling. The frequency of...
Chapuis RJJ, Ragno VM, Ariza CA, Movasseghi AR, Sayi S, Uehlinger FD, Montgomery JB.In the summer of 2017, 4 horses were diagnosed with septic fibrinous pericarditis at the Western College of Veterinary Medicine, Saskatoon. This case series occurred after a significant outbreak of forest tent caterpillars in the province during that spring. Three horses were immediately euthanized, and treatment was attempted in 1 mare. This is the first case series of pericarditis possibly associated with the ingestion of forest tent caterpillars to be reported in western Canada. Although cause-effect is not proven, it is prudent to prevent the ingestion of caterpillars by horses. Key clini...
Mazzei M, Savini G, Di Gennaro A, Macchioni F, Prati MC, Guzmàn LR, Tolari F.West Nile virus (WNV) is a mosquito-borne virus belonging to the family Flaviviridae included in the Japanese encephalitis antigenic complex (JEAC). A seroepidemiological study was carried out in 2011 using 160 horse sera collected from different areas of Bolivia to investigate the presence of WNV antibody. A high proportion (59.4%) of the tested sera were positive to a commercially available WNV competitive enzyme-linked immunosorbent assay (C-ELISA). Sixty-six randomly selected C-ELISA-positive sera were further tested by WNV plaque reduction neutralization test (PRNT), virus neutralization ...
Bartosik J, Łojek J, Długosz E, Górski P, Zygner W.Tapeworm infections in Konik Polski horses from Biebrza National Park were investigated in this study. Faecal samples were collected 10 times: in 2012 - 1 time, in 2013 - 4 times, in 2014 - 4 times and in 2015 - 1 time. In total, 162 faecal samples were collected and tested. Faecal egg counts (FECs) method was used in the study. Positive samples with cestode eggs were noted only twice - in October 2012 and December 2013 in two adult mares (9 and 11 years old). The determined prevalence was surprisingly low comparing to other studies, 4.3% in October 2013 and 28.5% in December 2013. Parasite ge...
Downs JA, Hyzer G, Marion E, Smith ZJ, Kelen PV, Unnasch TR.Eastern equine encephalitis (EEE) is a mosquito-borne viral disease that is often fatal to humans and horses. Some species including white-tailed deer and passerine birds can survive infection with the EEE virus (EEEV) and develop antibodies that can be detected using laboratory techniques. In this way, collected serum samples from free ranging white-tailed deer can be used to monitor the presence of the virus in ecosystems. This study developed and tested a risk index model designed to predict EEEV activity in white-tailed deer in a three-county area of Michigan. The model evaluates EEEV risk...
Montes-Cortés MG, Fernández-García JL, Martínez-Estéllez MÁH.Equine piroplasmosis is caused by two haemoprotozoan parasites: and . Negative economic impact on international trade has been associated to endemic sites. This is the reason why carrier detection requires reliable diagnostic methods. Various diagnostic modalities can be used alone or in combination including PCR. However, genetic variation of commonly used genes is still of debate. The aim of this research was to sequence the β-tubulin gene of a strain from Spain and to compare it with known β-tubulin sequences. Methods: DNA was isolated from a cryopreserved strain from Spain and acute an...
The Journal of parasitologyNovember 26, 2004
Volume 90, Issue 5 1027-1033 doi: 10.1645/0022-3395(2004)090[1027:AEOARB]2.0.CO;2
Gupta GD, Lakritz J, Saville WJ, Livingston RS, Dubey JP, Middleton JR, Marsh AE.Sarcocystis neurona is the primary parasite associated with equine protozoal myeloencephalitis (EPM). This is a commonly diagnosed neurological disorder in the Americas that infects the central nervous system of horses. Current serologic assays utilize culture-derived parasites as antigen. This method requires large numbers of parasites to be grown in culture, which is labor intensive and time consuming. Also, a culture-derived whole-parasite preparation contains conserved antigens that could cross-react with antibodies against other Sarcocystis species and members of Sarcocystidae such as Neo...
Surma-Kurusiewicz K, Winiarczyk S, Adaszek Ł.The purpose of this study was to conduct a comparative analysis of the ORF5 gene fragment nucleotide sequences and the GP5 protein amino acid sequences formed on this matrix, for the equine arteritis virus (EAV) strains isolated from the semen of infected stallions from Eastern Poland. The study covered 41 stallions whose blood serum tested positive for antigens specific to the EAV. The presence of EAV genetic material was shown in material from 5 horses, in one of which permanent presence of viral RNA was detected over the entire 4-year study period (the material was sampled four times at yea...
de Vos CJ, Petie R, van Klink EGM, Swanenburg M.Increasing globalization and international trade contribute to rapid expansion of animal and human diseases. Hence, preparedness is warranted to prevent outbreaks of emerging and re-emerging diseases or detect outbreaks in an early stage. We developed a rapid risk assessment tool (RRAT) to inform risk managers on the incursion risk of multiple livestock diseases, about the main sources for incursion and the change of risk over time. RRAT was built as a relational database to link data on disease outbreaks worldwide, on introduction routes and on disease-specific parameters. The tool was parame...
Smith IM, Girard A, Corner AH, Mitchell D.Using two known positive equine viral rhinopneumonitis (EVR) sera, conjugates were prepared with fluorescein isothiocyanate and tested for specificity using EVR infected tissue culture cells. The conjugate was then applied to selected tissues from 32 aborted fetuses and foals submitted during a natural outbreak of EVR. Antigen was detected in various tissues by immunofluorescence in 20 cases (62.5%). In 24 cases bovine fetal kidney cell monolayers were inoculated with a pool of lung and liver and EVR virus was isolated from 15 (62.5%). Histological examination of various tissues from 29 cases ...
Satou K, Nishiura H.To evaluate the partial effects of vaccination against equine Japanese encephalitis (JE) and characterize other prognostic factors based on previous outbreak records in Japan from 1953 to 1960. Methods: Individual case records, which included demographic information, vaccination history, and clinical information (dates of onset, recovery and death, and symptoms), were investigated. The relations between two outcomes, JE death and symptomatic period, and other variables were examined. Results: Of a total reported 803 cases during the observation period, 453 (56.5%) were diagnosed with either se...
McCluskey BJ, Mumford EL, Salman MD, Traub-Dargatz JJ.Approximately 20 sentinel premises in Colorado were visited quarterly during a 3-year prospective study to investigate the persistence of VS viruses in horses. A survey to assess management practices, health events, animal movements and environmental data was completed at each visit. Collection of serum samples and oral swabs along with a clinical examination of sentinel horses were performed at each visit. Serum samples were tested by 2 or more of 4 available serological tests. The data collected for two years (August 1998 to August 2000) are reported here. During this period there was seroco...
Mori S, Horita A, Ginnaga A, Miyatsu Y, Sawabe K, Matsumura T, Ato M, Yamamoto A, Shibayama K, Arai S, Yamagishi T, Takahashi M, Taki H, Hifumi T.This is the first report on large-scale experimental production of an equine antivenom against the redback spider (Latrodectus hasseltii) lived in Japan. We captured 10,000 redback spiders in Japan and prepared the toxoids of crude venom extract, mixed the toxoids with a mineral oil adjuvant, and immunized healthy horses repeatedly over a period of several weeks. Thereafter, we separated the horse plasma, purified the γ-globulin fraction, and stocked it as a purified antivenom concentrate. Consequently, we manufactured approximately 6,500 vials of a single-dose freeze-dried test lot from a po...
Reck C, Menin Á, Batista F, Meira Santos PO, Miletti LC.Surra is an infectious disease caused by , which affects a large number of domestic and wild animal species. Infection control is based on rapid diagnosis followed by treatment of sick animals. This study aimed to evaluate a buffered antigen and rapid serum agglutination test (BA/Te) for the detection of anti- antibodies in serum samples of horses. For this purpose, 445 serum samples from horses were evaluated and the results compared with the diagnosis by CATT/. Our data show a sensitivity of 92%, specificity of 91% and a degree of agreement kappa () of 0.82 (95% CI: 0.771-0.877, < 0...
Pastoret PP.Veterinary vaccinology is a very interesting and rapidly developing field. In fact veterinary vaccines are not only used for the prevention of infectious diseases in the animal health sector, but also help to solve problems of public health, to reduce detrimental environmental impact of the use of some veterinary drugs and prevent the emergence of resistance of micro-organisms or parasites. After a short introduction, this paper will deal with the use of vaccines for animal health and welfare, including new developments in the veterinary field such as marker vaccines and vectored vaccines, the...
Dauphin G, Zientara S.West Nile virus, a flavivirus transmitted by mosquitoes, has been intensively studied since a few years because of epidemics/epizootics it has caused the last ten years, in particular around the Mediterranean basin and on the North-American continent. This virus mainly circulates in birds ; migrating bird species disseminate the virus while resident species could play a role in viral cycle amplification. A large number of mammal, amphibian and reptile species can also be infected. This virus can cause a lethal disease in humans and horses. For this reason, an active and/or passive surveillance...
Ma J, Zhang Z, Yao Q, Su C, Yin X, Wang X.Rev, an important accessory protein of equine infectious anaemia virus (EIAV), induces the nuclear export of incompletely spliced viral mRNAs. Rev is translated from the tat-rev mRNA through leaky scanning of the tat CUG. In this study, the function of the Kozak sequence at the beginning of the rev ORF was investigated. Deletion or attenuation of the Kozak sequence resulted in expression of an N-terminal 11 aa-truncated Rev in addition to WT Rev. Truncated Rev displayed weaker promotion of Gag expression and processing than WT Rev. Furthermore, EIAV rescued from an infectious molecular clon...
Naranjo Cerrillo G, Soler Rodríguez F, Gómez Gordo L, Hermoso de Mendoza Salcedo M, Roncero Cordero V.In 1988 an outbreak of leukoencephalomalacia was diagnosed in equids that had eaten corn with a pinkish fungal growth. The fungus was then identified as Fusarium moniliforme. The main symptoms observed appeared acutely and were overexcitement, blindness, incoordination, facial paralysis and death within 24 h. The main pathological changes were restricted to the central nervous system. Macroscopically they consisted of hyperemia and haemorrhages, the consistency was friable and the gyri were somewhat flattened. Microscopically, the lesions were profuse and had extensive haemorrhages, and numero...
Kinoshita Y, Kakoi H, Ishige T, Yamanaka T, Niwa H, Uchida-Fujii E, Nukada T, Ueno T.Taylorella equigenitalis causes contagious equine metritis. Here we compared seven nucleic acid amplification tests for T. equigenitalis to select a rapid and reliable diagnostic method. The 95% detection limits of each assay varied greatly: real-time PCR had the lowest detection limit (0.77 fg/reaction); those of some of the conventional PCRs (cPCRs) were >100 fg/reaction. In experimentally infected samples, real-time PCR and semi-nested PCR showed the highest positive numbers (33 out of 42 samples), but two of the cPCRs detected only 2 and 7 positive results. Our results indicate that the us...
Hedell R, Andersson MG, Faverjon C, Marcillaud-Pitel C, Leblond A, Mostad P.A potentially sensitive way to detect disease outbreaks is syndromic surveillance, i.e. monitoring the number of syndromes reported in the population of interest, comparing it to the baseline rate, and drawing conclusions about outbreaks using statistical methods. A decision maker may use the results to take disease control actions or to initiate enhanced epidemiological investigations. In addition to the total count of syndromes there are often additional pieces of information to consider when assessing the probability of an outbreak. This includes clustering of syndromes in space and time as...
Wiebe ME, Scherer WF, Peick WJ.Ninety-four strains of Venezuelan encephalitis (VE) virus isolated from sentinel hamsters exposed in the Middle American countries of Mexico, Guatemala, Belize, and Honduras were examined for the presence of virions with marker characteristics of strains that cause large epidemics and equine epizootics. Thirty-four strains came from before and 60 strains came from after the Middle American epidemics and equine epizootics of 1966 and 1969-1972. Twenty-three virion clones that resembled epizootic strains by hydroxylapatite chromatography and Vero monkey kidney cell plaque size determinations wer...
Inzana TJ, Iritani B.A group C latex agglutination reagent, included as the negative control in the PathoDx Strep A latex agglutination test (Diagnostic Products Corp., Los Angeles, Calif), was compared with culture for rapid detection of group C streptococci (Streptococcus equi, S. equisimilis, S. zooepidemicus, and S. dysgalactiae) from swabs of veterinary specimens. The overall sensitivity of the latex test was 78%, and specificity was 97.6%. Only 25% of S. dysgalactiae isolates were detected, thereby accounting for the relatively low sensitivity. Ninety-three percent of the group C streptococci other than S. d...
Chung C, Wilson C, Timoney P, Adams E, Adams DS, Chung JS, Evermann JF, Shuck K, Lee SS, McGuire TC.Equine arteritis virus (EAV) causes contagious equine viral arteritis, characterized by fever, anorexia, conjunctivitis, nasal discharge, dependent edema, abortion, infrequent death in foals, and establishment of the carrier state in stallions. The World Organization for Animal Health (OIE) defines a horse as seropositive if the serum neutralization (SN) antibody titer is ≥1:4 to EAV. However, determining the SN titer is time-consuming and requires specific laboratory facilities, equipment, and technical expertise to perform. Furthermore, interpretation of the SN titer of some sera can be di...
Ahn B, Zhang Y, Osterrieder N, O'Callaghan DJ.The 150 kbp genome of equine herpesvirus-1 (EHV-1) is composed of a unique long (UL) region and a unique short (Us) segment, which is flanked by identical internal and terminal repeat (IR and TR) sequences of 12.7 kbp. We constructed an EHV-1 lacking the entire IR (vL11ΔIR) and showed that the IR is dispensable for EHV-1 replication but that the vL11ΔIR exhibits a smaller plaque size and delayed growth kinetics. Western blot analyses of cells infected with vL11ΔIR showed that the synthesis of viral proteins encoded by the immediate-early, early, and late genes was reduced at immediate-early...
Tantawichien T, Benjavongkulchai M, Wilde H, Jaijaroensup W, Siakasem A, Chareonwai S, Yountong C, Sitprija V.The high cost of postexposure prophylaxis for rabies is one reason that treatment is inadequate in developing countries. This problem has kindled interest in the use of equine rabies immune globulin, which is a less expensive, yet effective, substitute for human rabies immune globulin. Fatal anaphylaxis is a feared complication of the administration of heterologous serum; therefore, authoritative sources recommend prior skin testing. However, recommendations for methods of administering such a skin test and for its interpretation vary greatly. We embarked on a long-term study to develop guidel...
Allen GP, Cohen JC, Randall CC, O'Callaghan DJ.The replication of equine herpesvirus type 1 (EHV-1) and type 3 (EHV-3) was unimpeded in three different cell types-equine epithelial cells, equine fibroblasts, and mouse fibroblasts-which had been blocked in their capacity to synthesize host DNA by 2.5 mM hydroxyurea (HU) or 2 mM thymidine (TdR). The rate of DNA synthesis in uninfected or equine herpesvirus-infected cells in the presence of HU or TdR was measured by pulse-labeling cell samples with a labeled DNA precursor at different times after infection. DNA synthesis in uninfected cultures was completely inhibited by both compounds. Howev...
