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.
Kubacki J, Lechmann J, Fraefel C, Bachofen C.We present the genome sequence of equid alphaherpesvirus 1 (EHV-1) sequenced directly from the nasal swab of a Swiss horse that attended an international equestrian event in Valencia, Spain, the origin of an outbreak of neurological disorders in horses in several European countries in February 2021.
Bantle CM, Rocha SM, French CT, Phillips AT, Tran K, Olson KE, Bass TA, Aboellail T, Smeyne RJ, Tjalkens RB.Viral infection of the central nervous system (CNS) can cause lasting neurological decline in surviving patients and can present with symptoms resembling Parkinson's disease (PD). The mechanisms underlying postencephalitic parkinsonism remain unclear but are thought to involve increased innate inflammatory signaling in glial cells, resulting in persistent neuroinflammation. We therefore studied the role of glial cells in regulating neuropathology in postencephalitic parkinsonism by studying the involvement of astrocytes in loss of dopaminergic neurons and aggregation of α-synuclein protein fo...
Zhang Y, Wen X, Xiao P, Fan X, Li M, Chahan B.Ticks in Xinjiang distribute widely and account for one third of China. Ticks can carry and transmit bacteria, virus, and parasite. However, the research of tick-borne pathogens in Xinjiang is rather little. To understand the situation of hard tick carry Theileria equi, Babesia caballi and Rickettsia spp. of Zhaosu and Altay in Xinjiang. In this study, 119 tick samples were obtained from horses in Xinjiang, China, Ticks were identified morphologically to determine species and PCR was used to investigate the situation of pathogens by hard ticks. One hundred and seven belong to Dermacentor margi...
Scheurer L, Bachofen C, Hardmeier I, Lechmann J, Schoster A.Equid Gamma herpesvirus (eGHV) infections have been reported worldwide and may be correlated with clinical signs, e.g., affecting the respiratory tract in young horses. eGHV are shed by healthy horses as well as horses with respiratory tract disease. The prevalence in healthy Swiss horses is unknown to date but this data would provide valuable information for causal diagnosis in clinical cases and formulation of biosecurity recommendations. Nasal swabs from 68 healthy horses from 12 Swiss stables and 2 stables near the Swiss border region in Germany were analyzed by panherpes nested PCR. Posit...
Tantely ML, Guis H, Randriananjantenaina I, Raharinirina MR, Velonirina HJ, Cardinale E, Raveloarijaona N, Cêtre-Sossah C, Garros C, Girod R.In Madagascar, the high West Nile virus (WNV) antibody prevalence reported in horse populations suggests a high level of vector-horse contact. This study aims to characterize the mosquito species usually involved in WNV transmission in horse stables in Madagascar. Five horse stables were investigated in October and November 2016 in five distinct inland areas. Mosquitoes were collected using double net traps baited with human, poultry or horse as well as light traps. Blood meal identification from engorged females was performed using host-specific PCRs. A total of 2898 adult mosquitoes were col...
Ruppert S, Lee JK, Marsh AE.A 6-year-old female captive zebra (Equus zebra) had a three-year history of slow progressive neurologic signs that recently worsened with hind limb ataxia, head tilt, and circling. Gross examination including the brain and spinal cord were unremarkable. On histopathology, the brain and brainstem had multiple random areas of severe lymphoplasmacytic meningoencephalitis associated with numerous 15-25 μm in diameter protozoal cysts with a discernible outer wall containing numerous 2 × 4 μm oval to crescent-shaped organisms. Immunohistochemistry and PCR identified the presence of Neospora or...
Higuera A, Herrera G, Jimenez P, García-Corredor D, Pulido-Medellín M, Bulla-Castañeda DM, Pinilla JC, Moreno-Pérez DA, Maloney JG, Santín M.... is frequently reported in fecal samples from animals and humans worldwide, and a variety of subtypes (STs) have been observed in wild and domestic animals. In Colombia, few studies have focused on the transmission dynamics and epidemiological importance of in animals. In this study, we characterized the frequency and subtypes of in fecal samples of domestic animals including pigs, minipigs, cows, dogs, horses, goats, sheep, and llama from three departments of Colombia. Of the 118 fecal samples included in this study 81.4% ( = 96) were positive for using a PCR that amplifies a fragment of t...
Längerer L.Bernardino P, James K, Barnum S et al. What have we learned from 7 years of equine rhinitis B virus qPCR testing in nasal secretions from horses with respiratory signs. Vet Rec 2021; 188 (10): e26. DAS EQUINE RHINITIS-B-VIRUS (ERBV) HAT EINE HOHE INZIDENZ, IST IN SEINER BEDEUTUNG JEDOCH NUR WENIG ERFORSCHT. EINE INFEKTION MIT DEM ERBV äUßERT SICH IN SYMPTOMEN WIE FIEBER, ANOREXIE, LETHARGIE, NASENAUSFLUSS, HUSTEN, LYMPHADENOPATHIE UND ÖDEMEN DER DISTALEN GLIEDMAßEN. AUßERDEM TRETEN HäUFIG SUBKLINISCHE INFEKTIONEN AUF. DAS ZIEL DIESER STUDIE WAR, DIE HäUFIGKEIT DES NACHWEISES VON ERBV IM...
Trachsel DS, Drozdzewska K, Bergmann F, Ziegler U, Gehlen H.West Nile virus (WNV) is a mosquito-borne viral pathogen of global importance and is considered to be the most widespread flavivirus. In Germany, first infections with WNV were detected in 2018 and it is expected for these to become more frequent in consequence to warmer winters followed by a rainy/humid springtime. WNV is maintained in an enzootic cycle between ornithophilic mosquitoes and certain wild bird species. Humans and horses are so-called "dead-end hosts" of a WNV infection. They frequently do not fall ill, however occasionally develop overt infections ranging from mild febrile sympt...
Oladunni FS, Oseni SO, Martinez-Sobrido L, Chambers TM.Equine influenza virus (EIV) is a constantly evolving viral pathogen that is responsible for yearly outbreaks of respiratory disease in horses termed equine influenza (EI). There is currently no evidence of circulation of the original H7N7 strain of EIV worldwide; however, the EIV H3N8 strain, which was first isolated in the early 1960s, remains a major threat to most of the world's horse populations. It can also infect dogs. The ability of EIV to constantly accumulate mutations in its antibody-binding sites enables it to evade host protective immunity, making it a successful viral pathogen. C...
Vissani MA, Damiani AM, Barrandeguy ME.Equine coital exanthema (ECE) is a highly contagious, venereally-transmitted mucocutaneous disease, characterized by the formation of papules, vesicles, pustules and ulcers on the external genital organs of mares and stallions, and caused by (EHV-3). The infection is endemic worldwide and the virus is transmitted mainly through direct contact during sexual intercourse and by contaminated instruments during reproductive maneuvers in breeding facilities. The disease does not result in systemic illness, infertility or abortion, yet it does have a negative impact on the equine industry as it forc...
Jelocnik M, Nyari S, Anstey S, Playford N, Fraser TA, Mitchell K, Blishen A, Pollak NM, Carrick J, Chicken C, Jenkins C.C. psittaci has recently emerged as an equine abortigenic pathogen causing significant losses to the Australian Thoroughbred industry, while Equine herpesvirus-1 (EHV-1) is a well-recognized abortigenic agent. Diagnosis of these agents is based on molecular assays in diagnostic laboratories. In this study, we validated C. psittaci and newly developed EHV-1 Loop Mediated Isothermal Amplification (LAMP) assays performed in a real-time fluorometer (rtLAMP) against the reference diagnostic assays. We also evaluated isothermal amplification using commercially available colorimetric mix (cLAMP), and...
Kulikov EE, Golomidova AK, Efimov AD, Belalov IS, Letarova MA, Zdorovenko EL, Knirel YA, Dmitrenok AS, Letarov AV.Tailed bacteriophages constitute the bulk of the intestinal viromes of vertebrate animals. However, the relationships between lytic and lysogenic lifestyles of phages in these ecosystems are not always clear and may vary between the species or even between the individuals. The human intestinal (fecal) viromes are dominated mostly by temperate phages, while in horse feces virulent phages are more prevalent. To our knowledge, all the previously reported isolates of horse fecal coliphages are virulent. Temperate coliphage Hf4s was isolated from horse feces, from the indigenous equine Escherichia ...
Nadal C, Bonnet SI, Marsot M.When studying a vector-borne disease, an eco-epidemiological approach is vital for a comprehensive understanding of how the pathogen circulates amongst populations. Equine piroplasmosis (EP), a tick-borne disease caused by the protozoans Babesia caballi and Theileria equi, is endemic in the Mediterranean basin of Europe and causes both animal health and economic issues for the equine sector. With no vaccine available, defining the episystem of the disease can help to identify which components of the host-pathogen-vector-environment system to target to improve preventive measures. In this syste...
Lee K, Pusterla N, Barnum SM, Lee DH, Martínez-López B.Equine influenza virus (EIV) is a major infectious pathogen causing significant respiratory signs in equids worldwide. Voluntary surveillances in the United States recently reported EIV detection in horses with respiratory signs even with adequate vaccine protocols and biosecurity programs and posed a concern about suboptimal effectiveness of EIV vaccine in the United States. This study aims to determine the genetic characteristics of 58 field EIV H3N8 strains in the United States from 2012 to 2017 using the phylogenetic analysis based on the haemagglutinin (HA) gene. Amino acid substitution a...
Biral NV, Azevedo Santos H, Senne NA, Paulino PG, Camilo TA, Tassinari WS, Silva VL, Santos FN, Angelo IDC.Equine leishmaniasis is a neglected tropical disease caused by the protozoan of the Leishmania genus, and it has been reported in several countries around the world, especially Brazil. Therefore, the present investigation aims to conduct a cross-sectional study to determine the prevalence, spatial distribution, and associated factors with seropositivity for Leishmania spp. in draft horses from the Distrito Federal, Brazil. The serological survey was conducted on 411 animals, employing the Indirect Immunofluorescence Test (IFA) and Enzyme-Linked Immunosorbent Assay (ELISA). The Kappa (κ) and g...
Sundstrom KD, Lineberry MW, Grant AN, Duncan KT, Ientile MM, Little SE.Ticks are common on horses, but recent publications characterizing equine tick infestations in North America are lacking. Methods: To further understand attachment site preferences of common ticks of horses, and to document the seasonality of equine tick infestation in northeastern Oklahoma, horses from eight farms were evaluated twice a month over a 1-year period. Each horse was systematically inspected beginning at the head and moving caudally to the tail. Attachment sites of ticks were recorded and all ticks collected were identified to species and stage. Results: Horses (26 males and 62 fe...
Altan E, Hui A, Li Y, Pesavento P, Asín J, Crossley B, Deng X, Uzal FA, Delwart E.Six foals with interstitial pneumonia of undetermined etiology from Southern California were analyzed by viral metagenomics. Spleen, lung, and colon content samples obtained during necropsy from each animal were pooled, and nucleic acids from virus-like particles enriched for deep sequencing. The recently described equine copiparvovirus named eqcopivirus, as well as three previously uncharacterized viruses, were identified. The complete ORFs genomes of two closely related protoparvoviruses, and of a bocaparvovirus, plus the partial genome of a picornavirus were assembled. The parvoviruses were...
Sebastian PS, Benitez-Ibalo AP, Flores FS, Debárbora VN, Martinez EI, Thompson CS, Mangold AJ.To investigate the presence of Theileria equi in an endemic area of equine piroplasmosis 42 horses (Equus caballus) from Corrientes City, Argentina were sampled. Eighty-one percent (34 blood samples) of the analyzed horses were tested positive to the presence of piroplasmid 18S rDNA. All these samples could be identified as T. equi by amplifying the specific EMA-1 (merozoite antigen 1) gene of this species. Phylogenetic analysis of an obtained 18S rDNA complete sequence from one strain resulted in the identification of this sample as T. equi sensu stricto (genotype A). This study presents the ...
Kopper JJ, Willette JA, Kogan CJ, Seguin A, Bolin SR, Schott HC.Rates of detecting ≥1 potential enteric pathogens (PEP) or toxins (PEP-T) in feces, blood, or both of horses ≥6 months of age with enteric disease and impact of multiple detections on outcome of horses with colitis has not been reported. Objective: To determine detection rates of PEP/PEP-T in feces, blood, or both of horses with enteric disease and effect of detecting multiple agents on outcome of horses with colitis. Methods: Thirty-seven hundred fifty-three fecal samples submitted to IDEXX Laboratories and 239 fecal and blood samples submitted to Michigan State University's Veterinary D...
Zehetner V, Cavalleri JV, Klang A, Hofer M, Preining I, Steinborn R, Ramsauer AS.There is strong evidence that equine parvovirus-hepatitis (EqPV-H) is associated with the onset of Theiler's disease, an acute hepatic necrosis, in horses. However, the impact of this virus on other hepatopathies remains unknown. The objective of this retrospective study was to evaluate the prevalence and quantify the viral loads of EqPV-H in formalin-fixed, paraffin-embedded equine and donkey livers with various histopathologic abnormalities. The pathologies included cirrhosis, circulatory disorders of the liver, toxic and metabolic hepatic diseases as well as neoplastic and inflammatory dise...
Löwen Levy Chalhoub F, Maia de Queiroz-Júnior E, Holanda Duarte B, Eielson Pinheiro de Sá M, Cerqueira Lima P, Carneiro de Oliveira A....In June 2019, a horse with neurological disorder was diagnosed with West Nile virus (WNV) in Boa Viagem, a municipality in the state of Ceará, northeast Brazil. A multi-institutional task force coordinated by the Brazilian Ministry of Health was deployed to the area for case investigation. A total of 513 biological samples from 78 humans, 157 domestic animals and 278 free-ranging wild birds, as well as 853 adult mosquitoes of 22 species were tested for WNV by highly specific serological and/or molecular tests. No active circulation of WNV was detected in vertebrates or mosquitoes by molecular...
von Samson-Himmelstjerna G, Janssen IJI, Ramünke S, Goday C, Borges FA, Koudela B, Niedźwiedź A, Tomczuk K, Studzińska MB, Kornas S, Krücken J.Equines were over decades considered to be infected by two morphologically virtually indistinguishable ascarid species, Parascaris univalens and Parascaris equorum. Reliable species discrimination is only possible using enzyme isoelectric focussing and karyotyping with P. univalens having one and P. equorum two chromosome pairs. However, presumably the complexity of both methods prevented their routine use in nearly all previous studies about prevalence and drug resistance of Parascaris spp. These have barely been performed on the species level although most studies stated presence of one or t...
Staji H, Yousefi M, Hamedani MA, Tamai IA, Khaligh SG.Anaplasma spp. are among the most recognized arthropod-borne infectious agents. Although the novel A. capra has been isolated from wildlife, livestock, and hard ticks from many parts of the world, there is no report regarding the identification of this pathogen from equines and little is known about the epidemiology of A. capra in Equidae. In this study, A. capra was identified in two out of ten blood specimens of wild onagers (Equus hemionus onager) during a routine health check-up in Semnan, Iran by light microscopy and molecular analyses while other pathogens were not detected. First, inclu...
Beachler TM, Papich MG, Andrews NC, Von Dollen KA, Ellis KE, Withowski K, Bailey CS.Transcervical intrauterine infusion of antibiotics may more effectively treat pathogens associated with fetal and neonatal disease in pregnant mares than standard systemic routes. The objective of this study was to assess the safety of transcervical antibiotic infusion by characterizing the gestational outcome in nine healthy pregnant pony mares following a single transcervical infusion of 2.4 million IU of procaine penicillin and 200 mg of gentamicin in a 10 mL volume during late gestation. Assessment of fetal-placental health was performed through serial measurement of the combined thickness...
Laus F, Corsalini J, Mandara MT, Bazzano M, Bertoletti A, Gialletti R.Equine grass sickness (EGS) has been reported in several European and extra-European countries. Despite this, no scientific paper about clinical cases of EGS in Italy has been published. EGS is a disease affecting almost exclusively horses kept on pasture, characterized by clinical signs related to lesions in autonomic nervous system (ANS), particularly in the enteric nervous system (ENS). According to clinical presentation, acute, subacute and chornic syndromes can be observed, with various sympthoms including dullness, anorexia, dysphagia, drooling of saliva, tachycardia, ptosis, patchy swea...
Souto EPF, Maia LA, Neto EGM, Kommers GD, Junior FG, Riet-Correa F, Galiza GJN, Dantas AFM.The epidemiologic, clinical, pathologic, microbiological and immunohistochemical findings of pythiosis in equidae in northeastern Brazil are described. From January 1985 to December 2020 the Laboratory of Animal Pathology of the Federal University of Campina Grande received 1,331 tissue samples of equidae, 202 (15.17%) of which were diagnosed as pythiosis. Equidae of both sexes with ages varying from 4 months to 25 years were affected. Most animals were mixed breed (79.7%) and reared in an extensive system (73.26%). The disease occurred throughout the year but the highest incidence (70.29%) wa...
Alsing-Johansson T, Pedersen A, Bergström K, Sternberg-Lewerin S, Penell J, Bergh A.Equine dentistry has developed immensely and human dental equipment, such as handpieces, are often used. Measures to avoid the spread of infectious microorganisms are important, but this is challenging since handpieces are difficult to decontaminate. Thus, it is necessary to develop effective IPC measures in equine dentistry. The aim of this study was to contribute to the evidence needed for future evidence-based guidelines on IPC by investigating hygiene in equine dentistry. Used handpieces and dummies (i.e., handpieces not used during dental procedure, reflecting environmental bacterial cont...
Gil LHVG, Magalhaes T, Santos BSAS, Oliveira LV, Oliveira-Filho EF, Cunha JLR, Fraiha ALS, Rocha BMM, Longo BC, Ecco R, Faria GC, Furtini R....Madariaga virus (MADV) is a member of the eastern equine encephalitis virus (EEEV) complex that circulates in Central and South America. It is a zoonotic, mosquito-borne pathogen, belonging to the family . Disturbances in the natural transmission cycle of this virus result in outbreaks in equines and humans, leading to high case fatality in the former and acute febrile illness or neurological disease in the latter. Although a considerable amount of knowledge exists on the eco-epidemiology of North American EEEV strains, little is known about MADV. In Brazil, the most recent isolations of MADV ...
Ortega-García MV, Salguero FJ, García N, Domínguez M, Moreno I, Berrocal A.Cutaneous forms of leishmaniosis due to Leishmania braziliensis have been reported in horses in the New World. Domestic animals play a role in the transmission of the disease. In Costa Rica, human cases of L. braziliensis, L. panamensis and L. infantum have been reported. The present report describes five cases of equine cutaneous leishmaniosis in Costa Rica. The aetiological diagnosis was based on the presence of the parasite within the lesions. Skin biopsies were used to perform histopathological analyses of the lesions. Immunohistochemistry was used to detect the presence of the Leishmania ...
Vázquez-Morón S, Avellón A, Echevarría JE.The Lyssavirus genus includes seven species or genotypes named 1-7. Rabies genotypes correlate with geographical distribution and specific hosts. Co-circulation of different lyssaviruses, imported cases, and the presence of unknown viruses, such as Aravan, Khujand, Irkut and West Caucasian Bat Virus, make it necessary to use generic methods able to detect all lyssaviruses. Primer sequences were chosen from conserved regions in all genotypes in order to optimise a generic RT-PCR. Serial dilutions of 12 RNA extracts from all seven Lyssavirus genotypes were examined to compare the sensitivity of ...
Song SD, Barker SC, Shao R.The genus Haematopinus contains 21 species of blood-sucking lice, parasitizing both even-toed ungulates (pigs, cattle, buffalo, antelopes, camels and deer) and odd-toed ungulates (horses, donkeys and zebras). The mitochondrial genomes of the domestic pig louse, Haematopinus suis, and the wild pig louse, Haematopinus apri, have been sequenced recently; both lice have fragmented mitochondrial genomes with 37 genes on nine minichromosomes. To understand whether the composition of mitochondrial minichromosomes and the gene content and gene arrangement of each minichromosome are stable within the g...
Mares-Guia MA, Rozental T, Guterres A, Gomes R, Almeida DN, Moreira NS, Barreira JD, Favacho AR, Santana AL, Lemos ER.Over the last recent years, the number of Q fever cases have has increased throughout the world. An epidemiological investigation was performed in the area in which the first molecular documentation of Q fever in Brazil was previously reported. Methods: Indirect immunofluorescence assay (IFA) and PCR of Coxiella burnetii targeting the htpAB gene were performed in samples from 14 dogs (blood); 1 cat (blood); 10 goats (blood, milk, vaginal swab and anal swab); 3 sheep (blood); and 2 horses (blood). Results: Two dogs, two sheep and five goats were seroreactive. DNA was amplified from 6 milk and 2...
Paillot R, Kydd JH, Sindle T, Hannant D, Edlund Toulemonde C, Audonnet JC, Minke JM, Daly JM.In horses, equine influenza virus (EIV) is a leading cause of respiratory disease. Conventional inactivated vaccines induce a short-lived immune response. By comparison, natural infection confers a long-term immunity to re-infection. An aim of new equine influenza vaccines is to more closely mimic natural infection in order to achieve a better quality of immunity. A new live recombinant vaccine derived from the canarypox virus vector and expressing haemagglutinin genes of EIV (subtype H3N8) has been developed. Stimulation of the immune system was studied after immunisation with this canarypox-...
Raabe ML, Issel CJ, Cook SJ, Cook RF, Woodson B, Montelaro RC.We have previously reported that immunization of ponies with a baculovirus-expressed recombinant surface unit envelope protein (rgp90) for equine infectious anemia virus (EIAV) resulted in enhancement of disease symptoms and virus replication in 4 of 4 vaccine recipients subjected to a heterologous virus challenge (rpg90 I vaccine trial) (Wang et al., 1994). To extend these studies of EIAV vaccine enhancement, two additional and independent rgp90 vaccine trials (rgp90 II and rgp90 III) were performed. Combined, a total of 13 ponies were immunized with the rgp90 immunogen using our standard vac...
Riesenberg A, Feßler AT, Erol E, Prenger-Berninghoff E, Stamm I, Böse R, Heusinger A, Klarmann D, Werckenthin C, Schwarz S.The aim of this study was to determine the MICs of 32 antimicrobial agents for 200 isolates of Rhodococcus equi of animal origin by applying a recently described broth microdilution protocol, and to investigate isolates with distinctly elevated rifampicin MICs for the genetic basis of rifampicin resistance. Methods: The study included 200 R. equi isolates, including 160 isolates from horses and 40 isolates from other animal sources, from the USA and Europe. MIC testing of 32 antimicrobial agents or combinations thereof followed a recently published protocol. A novel PCR protocol for the joint ...
Haussler KK.The clinical assessment of pain is subjective; therefore, variations exist between practitioners in their ability to identify and localize pain. Due to differing interpretations of the signs or severity of pain equine practitioners may assign varying levels of clinical significance and treatment options. There is a critical need to develop better tools to qualify and quantify pain in horses. Palpation is the most common method to detect local tenderness or sensitivity. To quantify this applied pressure, pressure algometry has been used to gradually apply pressure over specified landmarks until...
Bantle CM, Rocha SM, French CT, Phillips AT, Tran K, Olson KE, Bass TA, Aboellail T, Smeyne RJ, Tjalkens RB.Viral infection of the central nervous system (CNS) can cause lasting neurological decline in surviving patients and can present with symptoms resembling Parkinson's disease (PD). The mechanisms underlying postencephalitic parkinsonism remain unclear but are thought to involve increased innate inflammatory signaling in glial cells, resulting in persistent neuroinflammation. We therefore studied the role of glial cells in regulating neuropathology in postencephalitic parkinsonism by studying the involvement of astrocytes in loss of dopaminergic neurons and aggregation of α-synuclein protein fo...
Roth D, Henry B, Mak S, Fraser M, Taylor M, Li M, Cooper K, Furnell A, Wong Q, Morshed M.In 2009, an expansion of West Nile virus (WNV) into the Canadian province of British Columbia was detected. Two locally acquired cases of infection in humans and 3 cases of infection in horses were detected by ELISA and plaque-reduction neutralization tests. Ten positive mosquito pools were detected by reverse transcription PCR. Most WNV activity in British Columbia in 2009 occurred in the hot and dry southern Okanagan Valley. Virus establishment and amplification in this region was likely facilitated by above average nightly temperatures and a rapid accumulation of degree-days in late summer....
Deardorff ER, Weaver SC.The mosquito Culex (Melanoconion) taeniopus is a proven vector of enzootic Venezuelan equine encephalitis virus (VEEV) subtype IE in Central America. It has been shown to be highly susceptible to infection by this subtype, and conversely to be highly refractory to infection by other VEEV subtypes. During the 1990s in southern coastal Mexico, two VEE epizootics in horses were attributed to subtype IE VEEV. These outbreaks were associated with VEEV strains with an altered infection phenotype for the epizootic mosquito vector, Aedes (Ochlerotatus) taeniorhynchus. To determine the infectivity for ...
Binz T, Lebelt J, Niemann H, Hagenau K.By reverse transcriptase/PCR amplification and subsequent sequence determination of the p24 gene, the relatedness of Borna disease virus (BDV) in various naturally infected animal species was determined. These results are indicative of a common ancestral virus pool and a remarkably low species barrier of BDV. Comparison of 11 sequences to that of tissue culture adapted virus revealed that the homology among all isolates was at least 96.2% at the nucleotide level, and 97% at the amino acid level. Viral sequences from sheep, donkey and horse were found to be not more distantly related to each ot...
Kishi M, Arimura Y, Ikuta K, Shoya Y, Lai PK, Kakinuma M.A cDNA fragment of the Borna disease virus (BDV) open reading frame II (ORF-II), which encodes a 24-kDa phosphoprotein (p24 [P protein]), was amplified from total RNA of peripheral blood mononuclear cells (PBMC) from three psychiatric inpatients. The amplified cDNA fragments were cloned, sequenced, and analyzed. A total of 15 clones, 5 from each patient, were studied. Intrapatient divergencies of the BDV ORF-II nucleotide sequence were 4.2 to 7.3%, 4.8 to 7.3%, and 2.8 to 7.1% for the three patients, leading to differences of 7.7 to 14.5%, 10.3 to 17.1%, and 6.0 to 16.2%, respectively, in the ...
Hagos A, Goddeeris BM, Yilkal K, Alemu T, Fikru R, Yacob HT, Feseha G, Claes F.Trypanocidal sensitivity studies were conducted to assess the efficacy of Diminazene diaceturate (Diminasan) and Bis (aminoethylthio) 4-melaminophenylarsine dihydrochloride (Cymelarsan) against Trypanosoma equiperdum (isolated from two mares with chronic cases of dourine) 713/943 and 834/940 Dodola strains in experimentally infected mice and horses. Diminasan at doses from 3.5 mg/kg to 28 mg/kg and Cymelarsan at doses of 0.25 mg/kg and 0.5 mg/kg body weight failed to cure any of the mice, indicating a clear dose dependent relationship in the mean time of relapse observed in mice. Indeed, mice ...
Hasebe R, Sasaki M, Sawa H, Wada R, Umemura T, Kimura T.We investigated the mechanism by which equine herpesvirus-1 (EHV-1) enters primary cultured equine brain microvascular endothelial cells (EBMECs) and equine dermis (E. Derm) cells. EHV-1 colocalized with caveolin in EBMECs and the infection was greatly reduced by the expression of a dominant negative form of equine caveolin-1 (ecavY14F), suggesting that EHV-1 enters EBMECs via caveolar endocytosis. EHV-1 entry into E. Derm cells was significantly reduced by ATP depletion and treatments with lysosomotropic agents. Enveloped virions were detected from E. Derm cells by infectious virus recovery a...
Elschner MC, Scholz HC, Melzer F, Saqib M, Marten P, Rassbach A, Dietzsch M, Schmoock G, de Assis Santana VL, de Souza MM, Wernery R, Wernery U....The in vivo diagnosis of glanders relies on the highly sensitive complement fixation test (CFT). Frequently observed false positive results are troublesome for veterinary authorities and cause financial losses to animal owners. Consequently, there is an urgent need to develop a test with high specificity. Hence, a Western blot assay making use of a partly purified lipopolysaccaride (LPS) containing antigen of three Burkholderia mallei strains was developed. The test was validated investigating a comprehensive set of positive and negative sera obtained from horses and mules from endemic and non...
Kanai Y, van Rijn PA, Maris-Veldhuis M, Kaname Y, Athmaram TN, Roy P.African horse sickness (AHS) is an equine disease with a mortality of up to 90% for susceptible horses. The causative agent AHS virus (AHSV) is transmitted by species of Culicoides. AHSV serogroup within the genus Orbivirus of the Reoviridae family consists of nine serotypes that show no or very limited cross-neutralization. Of the seven structural proteins (VP1-VP7) of AHSV, VP2 is the serotype specific protein, and the major target for neutralizing antibodies. In this report, recombinant VP2 proteins of all nine serotypes were expressed individually by the baculovirus expression system and t...
Guerrero-Carvajal F, Bravo-Barriga D, Martín-Cuervo M, Aguilera-Sepúlveda P, Ferraguti M, Jiménez-Clavero MÁ, Llorente F, Alonso JM, Frontera E.West Nile virus (WNV) is a mosquito-borne emerging virus in Europe with capacity to cause neurological complications such as encephalitis or meningoencephalitis in humans, birds or equids. In Spain, WNV is actively circulating in mosquitoes, birds and horses in different regions, but never has been deeply studied in Extremadura. Therefore, the aim of this study was to evaluate the seroprevalence of WNV in equids of those areas and to analyse the risk factors associated with exposure to the virus. A total of 199 out of 725 equids presented antibodies against WNV by competition ELISA (27.45%), w...
Salim B, Bakheit MA, Kamau J, Nakamura I, Sugimoto C.This is a molecular epidemiological investigation on Theileria equi, a causative agent of equine piroplasmosis. Blood samples were collected from 127 horses from different geographical locations in Sudan. The small subunit of rRNA gene (18S; ~1,600 bp) was amplified from 20 positive field samples and subsequently subjected to direct sequencing and analysis to reveal possible strain differences and the presence of a novel species or genotypes. Sequences were compared with published sequences mainly from South African and Spanish isolates. Eleven distinct T. equi sequences within 18S rRNA gene w...
Henderson BE, Chappell WA, Johnston JG, Sudia WD.Henderson, B. E., W. A. Chappell, J. G. Johnston, Jr. and W. D. Sudia (CDC, Atlanta, Ga. 30333). Experimental Infection of horses with three strains of Venezuelan equine encephalomyelitis virus. I. Clinical and virological studies. Amer J Epidem 93: 194–205, 1971.—Clinical effect, viremias and antibody responses were compared in horses inoculated with the following strains of Venezuelan equine encephalomyelitis (VEE) virus: Fe3-7C, isolated from Culex (Melano-conion) spp. mosquitoes collected In 1963 in the Florida Everglades; TC-83, the Fort Detrick live, attenuated vaccine strain; and GJ...
Ocansey BK, Kosmidis C, Agyei M, Dorkenoo AM, Ayanlowo OO, Oladele RO, Darre T, Denning DW.Histoplasmosis is a chronic granulomatous disease caused by the thermally dimorphic fungus Histoplasma capsulatum. The 2 variants Histoplasma capsulatum var. capsulatum (Hcc) and Histoplasma capsulatum var. duboisii (Hcd) causes infection in humans and commonly termed classical or American histoplasmosis and African histoplasmosis, respectively. Histoplasma capsulatum var. farciminosum (Hcf) affects equines. In recent times, there have been heightened sensitization on fungal infections such as histoplasmosis in Africa, aimed at improving awareness among relevant stakeholders, particularly heal...
Garton NJ, Gilleron M, Brando T, Dan HH, Giguère S, Puzo G, Prescott JF, Sutcliffe IC.Rhodococcus equi is a major cause of foal morbidity and mortality. We have investigated the presence of lipoglycan in this organism as closely related bacteria, notably Mycobacterium tuberculosis, produce lipoarabinomannans (LAM) that may play multiple roles as virulence determinants. The lipoglycan was structurally characterized by gas chromatography-mass spectrometry following permethylation, capillary electrophoresis after chemical degradation, and (1)H and (31)P and two-dimensional heteronuclear nuclear magnetic resonance studies. Key structural features of the lipoglycan are a linear alph...
Wagnerová P, Sak B, McEvoy J, Rost M, Matysiak AP, Ježková J, Kváč M.Faecal samples were collected from 352 horses on 23 farms operating under six different management systems in the Czech Republic and Poland during 2011 and 2012. Farms were selected without previous knowledge of parasitological status. All faecal samples were screened for Cryptosporidium spp. presence using microscopy, following aniline-carbol-methyl violet staining and PCR analysis of the small-subunit (SSU) rRNA and the 60-kDa glycoprotein (gp60) genes. Cryptosporidium muris-positive samples were additionally genotyped at four minisatellite markers: MS1 (encoding a hypothetical protein), MS2...
van Maanen C, Bruin G, de Boer-Luijtze E, Smolders G, de Boer GF.The purpose of the study was twofold. First, using two groups of 22 foals each, we investigated the extent to which maternal antibodies interfere with the humoral response against equine influenza. The foals were born to mares that had been vaccinated twice yearly against influenza since 1982. Foals of group I were vaccinated three times at early ages (12, 16, and 32 weeks of age), and foals of group II were likewise vaccinated but a later ages (24, 28, and 44 weeks of age). After the first and second vaccinations, neither group showed an increase in antibodies that inhibit haemagglutination. ...
Halbert ND, Reitzel RA, Martens RJ, Cohen ND.To evaluate sensitivity and specificity of a multiplex polymerase chain reaction (PCR) assay for simultaneous detection of Rhodococcus equi and differentiation of strains that contain the virulence-associated gene (vapA) from strains that do not. Methods: 187 isolates of R equi from equine and nonequine tissue and environmental specimens and 27 isolates of bacterial species genetically or morphologically similar to R equi. Methods: The multiplex PCR assay included 3 gene targets: a universal 311-bp bacterial 16S ribosomal RNA amplicon (positive internal control), a 959-bp R equi-specific targe...
Laatamna AE, Wagnerová P, Sak B, Květoňová D, Aissi M, Rost M, Kváč M.Faecal samples from two horse farms in Algeria keeping Arabian, Thoroughbred, and Barb horses were examined for the presence of Cryptosporidium in 2010-2011. A total of 138 faecal samples (16 from a farm keeping 50 animals and 122 from a farm with 267 horses) were screened for Cryptosporidium spp. infection using molecular tools. DNA was extracted from all samples. Nested PCR was performed to amplify fragments of the SSU rDNA and gp60 genes to determine the presence of Cryptosporidium species and genotypes. Sequence analyses of SSU and gp60 genes revealed four animals positive for the presence...
