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.
Kamran K, Ali A, Villagra C, Siddiqui S, Alouffi AS, Iqbal A.Zoonotic diseases are significant public health issues. There is an urgent need to focus our efforts on the development of strategies that prevent and control potential arthropod vector-borne pathogens. Hard ticks transmit a variety of viral, bacterial and protozoan pathogens to their vertebrate hosts. This is becoming of more concern, as anthropogenic alterations of the environment may unleash the spread of tick-borne diseases throughout the world. Developing countries that are highly dependent on the livestock economy are a hot spot for tick-borne infectious diseases. In this work, through a...
Leonel JAF, Tannihão B, Arantes JA, Vioti G, Benassi JC, Brandi RA, Ferreira HL, Keid LB, Soares RM, Oliveira TMFS.Visceral leishmaniasis (VL) is a neglected tropical disease caused by the Leishmania infantum parasite. The protozoan is able to infect several domestic and wild mammals. Since the first report on Leishmania spp. infection in horses in South America, leishmaniasis in equids has been highlighted in Brazil. A molecular epidemiological survey was carried out to verify the occurrence of Leishmania spp. DNA in horses and donkeys, in leishmaniases endemic areas in Sao Paulo State, Brazil. To this end, blood samples were obtained from 107 horses and 36 donkeys and subjected to DNA extraction followed...
Álvarez-Narváez S, Giguère S, Cohen N, Slovis N, Vázquez-Boland JA.Multidrug resistance has been detected in the animal and zoonotic human pathogen Rhodococcus equi after mass macrolide/rifampin antibioprophylaxis in endemically affected equine farms in the United States. Multidrug-resistant (MDR) R. equi emerged upon acquisition of pRERm46, a conjugative plasmid conferring resistance to macrolides, lincosamides, streptogramins, and, as we describe, tetracycline. Phylogenomic analyses indicate that the increasing prevalence of MDR R. equi since it was first documented in 2002 is caused by a clone, R. equi 2287, attributable to coselection of pRErm46 with a ch...
Romero-Salas D, Solis-Cortés M, Zazueta-Islas HM, Flores-Vásquez F, Cruz-Romero A, Aguilar-Domínguez M, Salguero-Romero JL, de León AP....Equine piroplasmosis is a tropical parasitic disease caused by several intraerythrocytic members of the genera Babesia and Theileria. These pathogens are transmitted by multiple tick species and are considered as important exotic microorganisms in several countries. Equine piroplasmosis causes significant economic losses due to abortions, decreased activity and even death of equines, making surveillance of these infectious disease essential. In the northern and eastern parts of Mexico, few molecular and serological reports have been made on the presence and exposure of horse to these agents. F...
Fetene E, Leta S, Regassa F, Büscher P.Trypanosomosis caused by Trypanosoma vivax is one of the diseases threatening the health and productivity of livestock in Africa and Latin America. Trypanosoma vivax is mainly transmitted by tsetse flies; however, the parasite has also acquired the ability to be transmitted mechanically by hematophagous dipterans. Understanding its distribution, host range and prevalence is a key step in local and global efforts to control the disease. Methods: The study was conducted according to the methodological recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRIS...
Gwee SXW, St John AL, Gray GC, Pang J.Dengue is a rapidly spreading mosquito-borne flavivirus infection that is prevalent in tropical and sub-tropical regions. Humans are known to be the main reservoir host maintaining the epidemic cycles of dengue but it is unclear if dengue virus is also maintained in a similar enzootic cycle. The systematic review was conducted in accordance to Cochrane's PRISMA recommendations. A search was done on PubMed, EMBASE, Scopus and Cochrane Library. Key data on animal dengue positivity was extracted and classified according to animal type and diagnostic modes. Of the 3818 articles identified, 56 arti...
Muraro LS, Nogueira MF, Borges AMCM, Souza AO, Vieira TSWJ, de Aguiar DM.Bacteria of the genus Ehrlichia are transmitted by ticks and also are an important cause of infection in wild and domestic mammals. Infection with Ehrlichia spp. has been reported in horses, especially in the USA, Nicaragua and Brazil. In this study, we report the parasitism by Amblyomma sculptum, Rhipicephalus microplus and Dermacentor nitens ticks in horses from a ranch located in south Pantanal wetland. Molecular and serological analyzes to determine infection by Ehrlichia spp. in horses and their respective ticks were carried out. A total of 12 horses were submitted to blood collection to ...
Okely M, Anan R, Gad-Allah S, Samy AM.Ticks are important vectors of emerging health problems in humans and animals. We conducted several field surveillances to investigate the fauna of hard ticks on domestic animals in seven governorates of Egypt during 2018-2019. A total of 3265 individual tick specimens were collected and identified to the species level; the specimens belong to 11 species within three genera (Amblyomma, Hyalomma, and Rhipicephalus). Tick infestation was highest in dromedary camels (70%), followed by dogs (52.5%), cattle (50%), buffaloes (38%), and horses (12%). Ten species were collected from dromedary camels, ...
In the present study, we serosurveyed the exposure of 222 draft horses to different arboviruses in the city of Santa Fe, Argentina. Plaque reduction neutralization tests confirmed exposure to Fort Sherman virus (FSV), Saint Louis encephalitis virus (SLEV), West Nile virus (WNV), and Río Negro virus (RNV). Apparently, Western and Eastern equine encephalitis viruses did not circulate in the population tested. The confirmation of five seroconversions for WNV, FSV, and SLEV and the association between prevalence and age are indicative of recent circulation. These results highlight the importance ...
Fedorka CE, El-Sheikh Ali H, Walker OF, Scoggin KE, Dini P, Loux SC, Troedsson MHT, Ball BA.Ascending placentitis is a leading cause of abortion in the horse, but adaptive immune response to this disease is unknown. To evaluate this, sub-acute placentitis was experimentally-induced via trans-cervical inoculation of S. zooepidemicus, and endometrium and chorioallantois was collected 8 days later (n = 6 inoculated/n = 6 control). The expression of transcripts relating to Th1, Th2, Th17, and Treg maturation was assessed via RNASeq. IHC of transcription factors relating to each subtype in the same tissues (Th1: TBX21, Th2: GATA3, Th17: IRF4, Treg: FOXp3). An immunoassay was utili...
Zarski LM, Weber PSD, Lee Y, Soboll Hussey G.Equine herpesvirus 1 (EHV-1) affects horses worldwide and causes respiratory disease, abortions, and equine herpesvirus myeloencephalopathy (EHM). Following infection, a cell-associated viremia is established in the peripheral blood mononuclear cells (PBMCs). This viremia is essential for transport of EHV-1 to secondary infection sites where subsequent immunopathology results in diseases such as abortion or EHM. Because of the central role of PBMCs in EHV-1 pathogenesis, our goal was to establish a gene expression analysis of host and equine herpesvirus genes during EHV-1 viremia using RNA seq...
Arndt S, Kilcoyne I, Vaughan B, Dechant JE.To identify etiology, clinical findings, diagnostic results, treatment, and short- and long-term survival and to report factors associated with nonsurvival and survival in horses with peritonitis. Methods: Retrospective study. Methods: Horses (n = 72). Methods: Medical records at William R. Pritchard Veterinary Medical Teaching Hospital from 2007-2017 were reviewed for horses diagnosed with peritonitis. The essential inclusion criterion was a peritoneal nucleated cell count of ≥25 000 cells/μL. Gastrointestinal rupture and cases in which peritonitis occurred after abdominal surgery or cas...
Willis AT, Barnum S, Pusterla N.This study aimed to validate a point-of-care polymerase chain reaction (PCR) assay for detection of subsp. in rostral nasal swabs from horses with suspected acute strangles and to compare the results against the molecular gold standard of quantitative polymerase chain reaction (qPCR). Two hundred thirty-two individual swabs of rostral nasal passages were characterized by qPCR as positive, subsp. positive, or and negative. The specificity and sensitivity of the point-of-care PCR assay were 89% and 84%, respectively. The limits of detection of the qPCR assay and the point-of-care PCR anal...
Gomez DE, Arroyo LG, Lillie B, Weese JS.The objective of this study was to investigate the nasal bacterial microbiota of healthy horses and horses infected with equine herpesvirus 1 (EHV-1). The nasal bacterial microbiota of 10 horses infected with EHV-1 and 11 control horses from a farm experiencing an outbreak was characterized using the Illumina MiSeq platform targeting the V4 region of the 16S ribosomal RNA gene. The nasal bacterial microbiota of healthy horses and EHV-1 horses was significantly different in community membership and structure. Horses shedding EHV-1 had lower bacterial richness ( = 0.002), evenness ( = 0.008), an...
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...
Lima TS, Silva RAF, Pereira RMF, Soares KL, Santos NTA, Sousa MS, Mendonça FS, Lucena RB.The skin of donkeys and mules represents a promising source of income; however, cultural, productive, and infectious factors can directly interfere with the quality of the integumentary tissue and well-being of these species. The objective of this study is to present a literature review on equine dermatopathies. This literature review included scientific articles related to equine medicine and breeding according to pre-established search terms and expressions published in recently articles. The evaluation of the clinical and pathological behavior of dermatopathies implies the use of control st...
León B, Jiménez-Sánchez C, Retamosa-Izaguirre M.Venezuelan equine encephalitis virus (VEEV) is an arbovirus transmitted by arthropods, widely distributed in the Americas that, depending on the subtype, can produce outbreaks or yearly cases of encephalitis in horses and humans. The symptoms are similar to those caused by dengue virus and in the worst-case scenario, involve encephalitis, and death. MaxEnt is software that uses climatological, geographical, and occurrence data of a particular species to create a model to estimate possible niches that could have these favorable conditions. We used MaxEnt with a total of 188 registers of VEEV pr...
Bertram FM, Thompson PN, Venter M.Although West Nile virus (WNV) is endemic to South Africa (RSA), it has only become recognized as a significant cause of neurological disease in humans and horses locally in the past 2 decades, as it emerged globally. This article describes the epidemiological and clinical presentation of WNV in horses across RSA during 2016-2017. In total, 54 WNV-positive cases were identified by passive surveillance in horses with febrile and/or neurological signs at the Centre for Viral Zoonoses, University of Pretoria. They were followed up and compared to 120 randomly selected WNV-negative controls with t...
Salant H, Rojas A, Yardeny D, Brenner O, Schvartz G, Baneth G, Dvir E.Draschia megastoma, Habronema microstoma, and Habronema muscae are the etiological agents of cutaneous habronemosis, commonly known as summer sores, an inflammatory cutaneous and ocular parasitic disease of horses and other equids transmitted by flies. Here, we describe a cluster of cutaneous habronemosis in five horses that showed single or multiple typical cutaneous ulcerative wounds located on the face, lower forelegs or hindquarters in Israel with the presence of typical "sulphur granules." All affected animals were confirmed by histopathological and/or molecular methods to be infected by ...
Yuen KY, Fraser NS, Henning J, Halpin K, Gibson JS, Betzien L, Stewart AJ.Hendra virus (HeV) continues to pose a serious public health concern as spillover events occur sporadically. Terminally ill horses can exhibit a range of clinical signs including frothy nasal discharge, ataxia or forebrain signs. Early signs, if detected, can include depression, inappetence, colic or mild respiratory signs. All unvaccinated ill horses in areas where flying foxes exist, may potentially be infected with HeV, posing a significant risk to the veterinary community. Equivac® HeV vaccine has been fully registered in Australia since 2015 (and under an Australian Pesticides and Veteri...
Reemers S, van Bommel S, Cao Q, Sutton D, van de Zande S.Equine influenza virus (EIV) is a major cause of respiratory disease in horses. Vaccination is an effective tool for infection control. Although various EIV vaccines are widely available, major outbreaks occurred in Europe in 2018 involving a new EIV H3N8 FC1 strain. In France, it was reported that both unvaccinated and vaccinated horses were affected despite >80% vaccination coverage and most horses being vaccinated with a vaccine expressing FC1 antigen. This study assessed whether vaccine type, next to antigenic difference between vaccine and field strain, plays a role. Horses were vaccin...
Saiz JC.West Nile virus (WNV) is a widely distributed enveloped flavivirus transmitted by mosquitoes, which main hosts are birds. The virus sporadically infects equids and humans with serious economic and health consequences, as infected individuals can develop a severe neuroinvasive disease that can even lead to death. Nowadays, no WNV-specific therapy is available and vaccines are only licensed for use in horses but not for humans. While several methodologies for WNV vaccine development have been successfully applied and have contributed to significantly reducing its incidence in horses in the US, n...
Stothart MR, Greuel RJ, Gavriliuc S, Henry A, Wilson AJ, McLoughlin PD, Poissant J.Studies of microbiome variation in wildlife often emphasize host physiology and diet as proximate selective pressures acting on host-associated microbiota. In contrast, microbial dispersal and ecological drift are more rarely considered. Using amplicon sequencing, we characterized the bacterial microbiome of adult female (n = 86) Sable Island horses (Nova Scotia, Canada) as part of a detailed individual-based study of this feral population. Using data on sampling date, horse location, age, parental status, and local habitat variables, we contrasted the ability of spatiotemporal, life history...
Cursino AE, Lima MT, Nogueira MF, de Aguiar DM, Franco Luiz APM, Alves PA, Araujo Junior JP, Kroon EG.The aetiological agent of equine infectious anaemia (EIA) is the retrovirus equine infectious anemia virus (EIAV) that infects all members of the Equidae family. The EIA is widely disseminated in the Brazilian territory with a high seroprevalence in the Brazilian Pantanal and is mainly diagnosed using agar gel immunodiffusion (AGID). There are few complete EIAV genome sequences available in GenBank, which had an impact on molecular detection studies. In this study, we conducted molecular detection and sequencing of EIAV proviral DNA from Brazilian horses. We analysed the genomic region from ex...
Kinoshita Y, Takechi M, Uchida-Fujii E, Miyazawa K, Nukada T, Niwa H.Bacterial placentitis in horses commonly results in abortion, premature birth or compromised neonatal foal health. Although mycobacterial infections are generally uncommon in horses, 10 equine abortion cases caused by Mycobacterium avium subsp. hominissuis (MAH) infections occurred between 2018 and 2019 in Japan. They occurred on seven Thoroughbred horse farms in the Hidaka district of Hokkaido, but direct contact among the mares on different farms was not recorded. Most cases were characterized by extensive pathological lesions of the placenta, which are not typical in cases of common pathoge...
Sato W, Sukmawinata E, Uemura R, Kanda T, Kusano K, Kambayashi Y, Sato T, Ishikawa Y, Toya R, Sueyoshi M.In this study, we investigated the occurrence of antimicrobial resistance in commensal Escherichia coli isolated from healthy Thoroughbred (TB) racehorses in Japan. A total of 212 fecal samples were individually collected from TB racehorses from March 2017 to August 2018 at Japan Racing Association training centers. E. coli was isolated by using selective agar media, deoxycholate-hydrogen sulfide-lactose (DHL) and eosin methylene blue (EMB). A total of 417 E. coli isolates were examined against 10 antimicrobial agents by using the broth microdilution method. The 417 E. coli isolates were phylo...
Dor Z, Shnaiderman-Torban A, Kondratyeva K, Davidovich-Cohen M, Rokney A, Steinman A, Navon-Venezia S. is a major causative pathogen of human and animal gastroenteritis. Antibiotic resistant strains have emerged due to the production of extended-spectrum β-lactamases (ESBLs) posing a major health concern. With the increasing reports on ESBL-producing Enterobacterales that colonize companion animals, we aimed to investigate ESBL dissemination among ESBL-producing (ESBL-S) in hospitalized horses. We prospectively collected ESBL-S isolates from hospitalized horses in a Veterinary-Teaching Hospital during Dec 2015-Dec 2017. Selection criteria for ESBL-S were white colonies on CHROMagarESBL plate...
Corrin T, Ackford R, Mascarenhas M, Greig J, Waddell LA. Eastern equine encephalitis virus (EEEV) is a mosquito-borne virus that is primarily found in North America and the Caribbean. Over the past decade there has been an increase in virus activity, including large outbreaks in human and horse populations. Predicted climate change is expected to affect the range of mosquitoes including vectors of EEEV, which may alter disease risk posing a public health concern. A scoping review (ScR) was conducted to identify and characterize the global evidence on EEEV. A thorough search was conducted in relevant bibliographic databases and government websites....
Harvey AB, Bordin AI, Rocha JN, Bray JM, Cohen ND.Evidence regarding the efficacy of equine hyperimmune plasma to prevent pneumonia in foals caused by Rhodococcus equi is limited and conflicting. Objective: Opsonization with R. equi-specific hyperimmune plasma (HIP) will significantly increase phagocytosis and decrease intracellular replication of R. equi by alveolar macrophages (AMs) compared to normal plasma (NP). Methods: Fifteen adult Quarter Horses were used to collect bronchoalveolar lavage cells. Methods: In the first experiment, AMs from 9 horses were pretreated (incubated) with either HIP, NP, or media only (control) and then infecte...
Wagner HM, Balasuriya UB, James MacLachlan N.In an effort to further characterize the humoral immune response of horses to equine arteritis virus (EAV), direct and competitive enzyme-linked immunosorbent assays (c-ELISAs) were developed using monoclonal and polyclonal anti-sera to structural (G(L), N and M) and non-structural (nsp1) viral proteins. A nsp1-specific monoclonal antibody was produced to facilitate development of a c-ELISA to this protein. Data obtained using the various c-ELISAs confirm that the M protein is a major target of the antibody response of horses to EAV. However, none of the c-ELISAs that were developed were as se...
Napp S, Llorente F, Beck C, Jose-Cunilleras E, Soler M, Pailler-García L, Amaral R, Aguilera-Sepúlveda P, Pifarré M, Molina-López R, Obón E....The surveillance for West Nile virus (WNV) in Catalonia (northeastern Spain) has consistently detected flaviviruses not identified as WNV. With the aim of characterizing the flaviviruses circulating in Catalonia, serum samples from birds and horses collected between 2010 and 2019 and positive by panflavivirus competition ELISA (cELISA) were analyzed by microneutralization test (MNT) against different flaviviruses. A third of the samples tested were inconclusive by MNT, highlighting the limitations of current diagnostic techniques. Our results evidenced the widespread circulation of flaviviruse...
Guthrie AJ, Maclachlan NJ, Joone C, Lourens CW, Weyer CT, Quan M, Monyai MS, Gardner IA.Blood samples collected from 503 suspect cases of African horse sickness (AHS) and another 503 from uninfected, unvaccinated South African horses, as well as 98 samples from horses from an AHS free country, were tested with an AHS virus (AHSV) specific duplex real-time reverse transcription quantitative PCR (RT-qPCR) assay and virus isolation (VI). The diagnostic sensitivity and specificity of this AHSV RT-qPCR assay and VI were estimated using a 2-test 2-population Bayesian latent class model which made no assumptions about the true infection status of the tested animals and allowed for the p...
Bredtmann CM, Krücken J, Murugaiyan J, Kuzmina T, von Samson-Himmelstjerna G.Human and animal health is globally affected by a variety of parasitic helminths. The impact of co-infections and development of anthelmintic resistance requires improved diagnostic tools, especially for parasitic nematodes e.g., to identify resistant species or attribute pathological effects to individual species or particular species combinations. In horses, co-infection with cyathostomins is rather a rule than an exception with typically 5 to 15 species (out of more than 40 described) per individual host. In cyathostomins, reliable morphological species differentiation is currently limited ...
Silva ASG, Matos ACD, da Cunha MACR, Rehfeld IS, Galinari GCF, Marcelino SAC, Saraiva LHG, Martins NRDS, Maranhão RPA, Lobato ZIP, Pierezan F....Mosquito-borne arboviruses are a major public health concern worldwide and are responsible for emerging and re-emerging diseases. Taken together, the arboviruses have a strong impact on public health and are the most common causes of equine encephalitis. In-depth diagnostic investigation of equine viral encephalitis is of utmost importance for the epidemiological surveillance and control of this disease. Regarding neurological disorders in equids, in April-May 2018, at least 12 cases of equid mortality with acute neurological signs were reported in six farms from Espirito Santo state, Brazil. ...
Meister TL, Tegtmeyer B, Postel A, Cavalleri JV, Todt D, Stang A, Steinmann E.An equine parvovirus-hepatitis (EqPV-H) has been recently identified in association with equine serum hepatitis, also known as Theiler's disease. This disease was first described by Arnold Theiler in 1918 and is often observed after applications with blood products in equines. So far, the virus has only been described in the USA and China. In this study, we evaluated the presence of EqPV-H in several commercial serum samples to assess the potential risk of virus transmission by equine serum-based products for medical and research applications. In 11 out of 18 commercial serum samples, EqPV-H D...
Bourély C, Fortané N, Calavas D, Leblond A, Gay É.For public health reasons, increasing attention has focused on more rational use of antimicrobials in farm animals. Guidance concerning the prescription of antibiotics and antimicrobial susceptibility testing (antibiograms in this case) are beneficial tools to help control the development of antimicrobial resistance. Nevertheless, even though there are already several qualitative studies analysing the determinants of antimicrobial prescription and use in veterinary medicine, little is known about decision-making concerning the use of antibiograms. The aim of this study was to provide a better ...
Hoffman AM, Viel L, Prescott JF, Rosendal S, Thorsen J.Undifferentiated distal respiratory tract disease (nasal discharge, cough, pneumonia) in foals (1 to 8 months old) is a burdensome economic problem on breeding farms; yet, the infective agents associated with these episodes have not been well described. Possible causes of these episodes of illness were investigated by culturing specimens of proximal and distal airways of clinically diseased foals (n = 101), prior to any treatment, for aerobic and anaerobic bacteria and viruses (rhinoviruses, equine arteritis virus, equine herpesvirus subtype 1 [EHV-1], influenza virus, and adenovirus). Pairs o...
Assaid N, Mousson L, Moutailler S, Arich S, Akarid K, Monier M, Beck C, Lecollinet S, Failloux AB, Sarih M.West Nile virus (WNV) is one of the most widely distributed mosquito-borne viruses in the world. In North Africa, it causes human cases of meningoencephalitis with fatalities in Algeria and in Tunisia, whereas only horses were affected in Morocco. The aims of this study were to detect WNV in mosquitoes and to determine seroprevalence of WNV in Moroccan horses by the detection of IgG antibodies. A total of 1455 mosquitoes belonging to four different species were grouped by collection site, date, and sex with 10 specimens per pool and tested for 38 arboviruses using a high-throughput chip based ...
Burgess BA, Tokateloff N, Manning S, Lohmann K, Lunn DP, Hussey SB, Morley PS.There is little information on the duration of nasal shedding of EHV-1 from horses with naturally occurring equine herpesvirus myeloencephalopathy (EHM). Objective: To evaluate the duration of nasal shedding of EHV-1 in horses affected by EHM. Methods: One hundred and four horses naturally exposed to EHV-1, 20 of which had clinical signs of EHM. Methods: All horses on affected premises were monitored. Those horses developing EHM were sampled in a longitudinal outbreak investigation. Nasal swabs were collected daily from 16 of 20 horses affected by EHM. A qPCR was performed on 98 of 246 nasal s...
Bacciarini LN, Boerlin P, Straub R, Frey J, Gröne A.Clostridia-associated intestinal disease in horses was generally reported to be due to infection with Clostridium perfringens type A, which harbors the cpa-encoded alpha-toxin. A recent study demonstrated a high incidence of beta2-toxigenic C. perfringens in horses suffering or dying from typhlocolitis, suggesting that this novel type of C. perfringens might play an important role in typhlocolitis and possibly other equine intestinal diseases. A retrospective study was conducted to assess the presence of the beta2-toxin in tissues of the equine gastrointestinal tract. Monospecific polyclonal a...
Prow NA, Tan CS, Wang W, Hobson-Peters J, Kidd L, Barton A, Wright J, Hall RA, Bielefeldt-Ohmann H.In 2011 an unprecedented epidemic of equine encephalitis occurred in south-eastern (SE) Australia following heavy rainfall and severe flooding in the preceding 2-4 months. Less than 6% of the documented cases occurred in Queensland, prompting the question of pre-existing immunity in Queensland horses. A small-scale serological survey was conducted on horses residing in one of the severely flood-affected areas of SE-Queensland. Using a flavivirus-specific blocking-ELISA we found that 63% (39/62) of horses older than 3 years were positive for flavivirus antibodies, and of these 18% (7/38) had ne...
Poulin MF, Boivin G.Human infections with Streptococcus equi subspecies zooepidemicus, a group C streptococcus, are very rare and are generally associated with contact with horses, and consumption of unpasteurized milk products, goat cheese or pork. In most cases S zooepidemicus leads to fulminant infections. The case of a middle-aged woman who had sporadic contact with horses is described in the present report. She developed a bacteremia with severe and extensive complications that included meningitis, mitral endocarditis and blindness due to bilateral endophthalmitis. To the authors' knowledge, this is the firs...
Rodríguez-Lázaro D, Lewis DA, Ocampo-Sosa AA, Fogarty U, Makrai L, Navas J, Scortti M, Hernández M, Vázquez-Boland JA.We developed a novel quantitative real-time PCR (Q-PCR) method for the soil actinomycete Rhodococcus equi, an important horse pathogen and emerging human pathogen. Species-specific quantification was achieved by targeting the chromosomal monocopy gene choE, universally conserved in R. equi. The choE Q-PCR included an internal amplification control (IAC) for identification of false negatives. A second Q-PCR targeted the virulence plasmid gene vapA, carried by most horse isolates but infrequently found in isolates from other sources. The choE-IAC and vapA assays were 100% sensitive and specific ...
Borchers K, Wolfinger U, Ludwig H.Equine herpesvirus type 4 (EHV-4) is a major respiratory pathogen of horses. Unlike most other members of the Alphaherpesvirinae, EHV-4 was regarded as non-neurotropic. Here, neural and lymphoid tissues of 17 horses have been analysed post-mortem. EHV-4 DNA was detected in 11 cases (65%) by PCR, exclusively in the trigeminal ganglia. In order to define the transcriptional activity, RNA preparations of 10 EHV-4 DNA-positive ganglia were investigated by nested RT-PCR. EHV-4-specific transcripts derived from genes 63 [herpes simplex virus type 1 (HSV-1) ICPO gene homologue] and 64 (HSV-1 ICP4 gen...
Peckle M, Pires MS, Dos Santos TM, Roier EC, da Silva CB, Vilela JA, Santos HA, Massard CL.The aim of this study was to detect Theileria equi (Laveran 1901) DNA in horses and ticks using real-time PCR and to list the factors associated with infection in animals located in the Seropedica and Petropolis municipalities of the state of Rio de Janeiro. We tested blood samples from 314 horses and samples from 300 ticks, including 191 Amblyomma cajennense, 104 Dermacentor nitens, and 5 Ixodida larvae. Factors inherent to the horse, the ownership, and animal management were obtained from an epidemiological questionnaire and were evaluated in association with the presence of T. equi DNA in t...
Jiménez-Clavero MÁ.Environmental changes have an undoubted influence on the appearance, distribution, and evolution of infectious diseases, and notably on those transmitted by vectors. Global change refers to environmental changes arising from human activities affecting the fundamental mechanisms operating in the biosphere. This paper discusses the changes observed in recent times with regard to some important arboviral (arthropod-borne viral) diseases of animals, and the role global change could have played in these variations. Two of the most important arboviral diseases of animals, bluetongue (BT) and West Ni...
Garaicoechea L, Miño S, Ciarlet M, Fernández F, Barrandeguy M, Parreño V.P[12]G3 and P[12]G14 equine rotaviruses (ERVs) are epidemiologically important in horses. In Argentina, the prevalent ERV strains have been historically P[12]G3. The aim of this study was the detection and characterization of ERV strains circulating in foals in Argentina during a 17-year study (1992-2008). Additionally, the gene sequences of VP7, VP4 and NSP4 encoding genes of representative Argentinean ERV strains were determined and phylogenetic analyses were performed to elucidate the evolutionary relationships of the ERV strains in Argentina. ERVs were detected in 165 (21%) out of 771 diar...
Lin C, Holland RE, Donofrio JC, McCoy MH, Tudor LR, Chambers TM.Equine influenza virus (EIV) is the leading cause of acute respiratory infection in horses worldwide. In recent years, the precise mechanism by which influenza infection kills host cells is being re-evaluated. In this report, we examined whether caspases, a group of intracellular proteases, are activated following EIV infection and contribute to EIV-mediated cell death. Western blotting analysis indicated that a nuclear target of caspase-3, poly(ADP-ribose) polymerase (PARP) was proteolytically cleaved in EIV-infected MDCK cells, but not in mock-infected cells. In comparison with caspase-3 spe...
Fritzen B, Rohn K, Schnieder T, von Samson-Himmelstjerna G.Increasing prevalence of anthelmintic resistance in equine nematodes calls for a reexamination of current parasite control programmes to identify factors influencing control efficacy and development of resistance. Objective: To investigate if associations occur between prevalence of parasitic nematodes and management practices. Methods: German horse farms (n = 76) were investigated in 2003 and 2004. Information on farm and pasture management with respect to endoparasite control measures obtained using a questionnaire survey. Faecal examinations were performed in parallel. Results: Horses (n = ...
Sack A, Oladunni FS, Gonchigoo B, Chambers TM, Gray GC. Worldwide, horses play critical roles in recreation, food production, transportation, and as working animals. Horses' roles differ by geographical region and the socioeconomic status of the people, but despite modern advances in transportation, which have in some ways altered humans contact with horses, potential risks for equine zoonotic pathogen transmission to humans occur globally. While previous reports have focused upon individual or groups of equine pathogens, to our knowledge, a systematic review of equine zoonoses has never been performed. Using PRISMA's systematic review guidelines...
Turtinen LW, Allen GP, Darlington RW, Bryans JT.The molecular and serologic relatedness of 2 recent respiratory tract isolates of equine herpesvirus type 1, designated T1 and T2, were compared with the Army 183, Kentucky-A hamster-adapted (KyA-ha), and L-M cell-adapted (KyA-LM) strains. Electrophoresis in polyacrylamide gels revealed differences in virion structural proteins among 4 purified strains. Seven envelope glycoproteins (molecular weight of 93,000, 65,000, 62,000, 60,000, 36,000, 20,000, and 18,000) corresponding to virion proteins 13, 16, 17, 18, 23, 25, and 26a, respectively, found in both the Army 183 and KyA-ha strains had slig...
Isa P, Wood AR, Netherwood T, Ciarlet M, Imagawa H, Snodgrass DR.DIG-labelled ssRNA probes were prepared from variable regions of VP4 and VP7 cognate genes, and used in hybridization assays for P and G genotyping of group A cell culture-adapted equine rotaviruses and fecal samples collected from foals with and without diarrhea. The probes confirmed known P and G serotypes of sixteen cell culture-adapted strains. From one-hundred and twenty-one rotavirus-positive samples, 83 reacted when tested for their P and G genotype specific probes. From these, 71 were found to contain G3 P12 genotypes, and 11 G14 P12 genotypes. No sample reacted with H1 or L338 P and G...
Mbu'u CM, Mbacham WF, Gontao P, Sado Kamdem SL, Nlôga AMN, Groschup MH, Wade A, Fischer K, Balkema-Buschmann A.Nipah virus (NiV) and Hendra virus (HeV) are closely related members within the genus Henipavirus, family Paramyxoviridae, for which fruit bats serve as the reservoir. The initial emergence of NiV infections in pigs and humans in Malaysia, and HeV infections in horses and humans in Australia, posed severe impacts on human and animal health, and continues threatening lives of humans and livestock within Southeast Asia and Australia. Recently, henipavirus-specific antibodies have also been detected in fruit bats in a number of sub-Saharan African countries and in Brazil, thereby considerably inc...
Hedegaard CJ, Heegaard PM.Immunisation by administration of antibodies (immunoglobulins) has been known for more than one hundred years as a very efficient means of obtaining immediate, short-lived protection against infection and/or against the disease-causing effects of toxins from microbial pathogens and from other sources. Thus, due to its rapid action, passive immunisation is often used to treat disease caused by infection and/or toxin exposure. However immunoglobulins may also be administered prior to exposure to infection and/or toxin, although they will not provide long-lasting protection as is seen with active...
Ochoa M, Bárcena J, de la Luna S, Melero JA, Douglas AR, Nieto A, Ortín J, Skehel JJ, Portela A.Characterization of the epitopes recognized by 21 monoclonal antibodies (MAbs) specific for the influenza A virus PA (13 MAbs) and PB2 (8 MAbs) polypeptides (Bárcena et al. (1994) J. Virol. 68, 6900-6909) raised against denatured polypeptides produced in E. coli is described. MAbs were characterized by: (1) competitive binding ELISAs; (2) mapping of the protein regions that specify their binding sites; and (3) analyses of their ability to recognize the corresponding viral protein in a number of viral isolates. Five and three non-overlapping antigenic areas were defined by the anti-PA and anti...
Staiger EA, Tseng CT, Miller D, Cassano JM, Nasir L, Garrick D, Brooks SA, Antczak DF.The common equine skin tumors known as sarcoids have been causally associated with infection by bovine papillomavirus (BPV). Additionally, there is evidence for host genetic susceptibility to sarcoids. We investigated the genetic basis of susceptibility to sarcoid tumors on a cohort of 82 affected horses and 270 controls genotyped on a genome-wide platform and two custom panels. A Genome Wide Association Study (GWAS) identified candidate regions on six chromosomes. Bayesian probability analysis of the same dataset verified only the regions on equine chromosomes (ECA) 20 and 22. Fine mapping us...
Sprague LD, Zachariah R, Neubauer H, Wernery R, Joseph M, Scholz HC, Wernery U.The internationally mandatory complement fixation test (CFT) for testing of equine sera for the absence of glanders has repeatedly led to discrepant results. Not only do "false positive" sera pose a problem for the diagnostician and the animal health authorities but they can also result in significant financial losses for the animal owners.Due to the very low prevalence of glanders in the horse population it is of major importance to use tests with a high specificity to overcome unreliable predictive values. We have compared formalin-fixed B. mallei whole cell antigen and a well characterised ...
Gibney KB, Robinson S, Mutebi JP, Hoenig DE, Bernier BJ, Webber L, Lubelczyk C, Nett RJ, Fischer M.Eastern equine encephalitis (EEE) is one of the most severe arboviral encephalitides in North America. Before 2009, limited nonhuman EEE virus activity had been reported in Maine, all from the southernmost area of the state. No human case has been reported in a Maine resident. Methods: We review all EEE virus activity reported to Maine Centers for Disease Control in 2009 and describe current testing practices for possible human EEE cases. Results: In 2009, fatal cases of EEE were identified in 15 horses, 1 llama, and 3 flocks of pheasants in Maine, with activity extending into the central part...
Angulo-Valadez CE, Scholl PJ, Cepeda-Palacios R, Jacquiet P, Dorchies P.Larvae causing obligatory myiasis are numerous and they may affect cutaneous and subcutaneous tissues, wounds, nasopharyngeal cavities (nasal bots), internal organs and the digestive tract (bots) of domestic and wild animals and humans as well. Nasal bots belong to the Family Oestridae, Subfamily Oestrinae, which includes several important genera: Oestrus, Kirkioestrus, and Gedoelstia infecting Artiodactyla (except Cervidae) in Africa and Eurasia, Cephenemyia and Pharyngomyia infecting Cervidae, Rhinoestrus infecting horses, Cephalopina infecting camels, Pharyngobolus infecting African elephan...
