Disease transmission in horses refers to the spread of infectious agents such as bacteria, viruses, fungi, and parasites among equine populations. These pathogens can be transmitted through various routes, including direct contact, vector-borne transmission, or environmental exposure. Factors influencing disease transmission include horse density, management practices, and biosecurity measures. Understanding the mechanisms and conditions that facilitate the spread of diseases is essential for developing effective prevention and control strategies. This page compiles peer-reviewed research studies and scholarly articles that investigate the modes of transmission, risk factors, and management practices related to infectious diseases in horses.
Pelzel-McCluskey AM.Vesicular stomatitis (VS) is a vector-borne livestock disease caused by either VS New Jersey virus or VS Indiana virus. The disease circulates endemically in northern South America, Central America, and Mexico and only occasionally causes outbreaks in the United States. During the past 20 years, VS outbreaks in the southwestern and Rocky Mountain regions occurred periodically with incursion years followed by virus overwintering and subsequent expansion outbreak years. Regulatory response by animal health officials prevents spread from lesioned animals and manages trade impacts. Recent US outb...
Dos Santos CEP, Loreto ES, Zanette RA, Santurio JM, Marques LC.Horse pythiosis is considered an endemic disease in the Brazilian Pantanal region, causing devastating health and economic losses. This study aimed to enhance the understanding of pythiosis epidemiology, map the distribution of horse body lesions, and investigate the correlation between these lesions and warm body surface areas, potentially implicating hematophagous vectors in the disease's transmission. A prospective study was conducted on equids in the Pantanal Mato-grossense and adjacent areas from 2012 to 2022, with 112 horses and three mules diagnosed with pythiosis. Clinical and epidemio...
White N, Pelzel-McCluskey A.Horses are transported in the United States more than any other livestock species and co-mingle at various events; therefore, they are considered to be at an increased risk for infectious disease transmission. The fragmented movement of horses combined with numerous sites of co-mingling makes tracing the potential spread of a disease outbreak a necessary part of an infection control plan, both locally and nationally. The cross-movement of personnel with horses and the persistence of endemic diseases make biosecurity implementation an ongoing challenge. Although many of the risks for infection ...
Phetkarl T, Fungwithaya P, Udompornprasith S, Amendt J, Sontigun N. and tabanid flies are of medical and veterinary importance because they play crucial roles in disease transmission as mechanical vectors of various hemopathogens. However, its role as a hemoprotozoan parasite vector in horse farms has not been studied. Therefore, we investigated the occurrence of hemoprotozoan parasites belonging to the genera , , and in and tabanid flies using conventional polymerase chain reaction (PCR) and DNA sequencing. Unassigned: All samples ( and tabanid flies) were collected using an Nzi trap for three consecutive days each month from November 2022 to March 2023. T...
Pelkola K, Heinikainen S, Pohjanvirta T.In Finland, Taylorella equigenitalis, the causative agent of contagious equine metritis (CEM), was first detected in 1992. The aim of this study was to genotype Finnish T. equigenitalis isolates to investigate the epidemiology of the infection in the Finnish horse population. A total of 34 T. equigenitalis isolates from 24 horses obtained during 1992-2021 were subjected to whole genome sequencing (WGS) and subsequent local ad hoc core genome multi-locus sequence typing (cgMLST) targeting 1259 loci. Classical MLST profiles were extracted from the whole-genome sequence data. Three novel MLST ty...
Knox A, Zerna G, Beddoe T.Horses play an important role throughout the world, whether for work, culture, or leisure, providing an ever-growing significant contribution to the economy. The increase in importation and movement of horses, both nationally and internationally, has inevitably allowed for the global equine industry to grow. Subsequently, however, the potential for transmission of fatal equine bacterial diseases has also escalated, and devasting outbreaks continue to occur. To prevent such events, disease surveillance and diagnosis must be heightened throughout the industry. Current common, or "gold-standard" ...
Nohejl T, Palkovicova J, Nesporova K, Valcek A, Lausova J, Dolejska M.The operon encoding short-chain fructooligosaccharide (scFOS) utilization enables bacteria of the family to grow and be sustained in environments where they would struggle to survive. Despite several cases of the detection of the operon in isolates of avian and equine origins, its global distribution in bacterial genomes remains unknown. The presence of the plasmid-harbored operon among resistant bacteria may promote the spread of antibiotic resistance. A collection of 11,538 antimicrobial-resistant isolates from various sources was screened for the gene encoding the scFOS transporter. O...
Bohlman T, Waddell H, Schumaker B.The occurrence of zoonotic infections following an animal exposure continues to be an important consideration for all patients, especially those within agricultural communities. Streptococcus equi subspecies equi (S. equi subsp. equi) is a bacteria known to cause a common infection called 'Strangles' in horses. This article highlights a new case of pneumonia and bacteremia in a patient caused by S. equi subsp. equi following strangles exposure in a horse. Rarely has there been reported horse to human transmission of subsp. equi. Methods: A 70-year-old woman attended a rural emergency departmen...
Rule EK, Boyle AG, Stefanovski D, Anis E, Linton J, Lorello O.Equine granulocytic anaplasmosis (EGA) is a common disease in adult horses, but clinical disease in foals is rarely reported. The relationship between equine maternal and neonatal antibodies to Anaplasma phagocytophilum is unclear. Objective: That mares in an endemic region would be seropositive for A. phagocytophilum and that mare and foal serum IgG concentrations for A. phagocytophilum would correlate. Additionally, we hypothesized that foal IgG concentrations for A. phagocytophilum acquired by passive immunity would decline by 6 months of age. Methods: Twenty-two healthy mare-foal pairs. ...
Li H, Kim JV, Pickering BS.Hendra virus (HeV) and Nipah virus (NiV) are biosafety level 4 zoonotic pathogens causing severe and often fatal neurological and respiratory disease. These agents have been recognized by the World Health Organization as top priority pathogens expected to result in severe future outbreaks. HeV has caused sporadic infections in horses and a small number of human cases in Australia since 1994. The NiV Malaysia genotype (NiV-M) was responsible for the 1998-1999 epizootic outbreak in pigs with spillover to humans in Malaysia and Singapore. Since 2001, the NiV Bangladesh genotype (NiV-B) has been t...
Holguin-Rocha AF, Calle-Tobon A, Vásquez GM, Astete H, Fisher ML, Tobon-Castano A, Velez-Tobon G, Maldonado-Ruiz LP, Silver K, Park Y....Ticks are obligatory hematophagous ectoparasites that transmit pathogens among various vertebrates, including humans. The microbial and viral communities of ticks, including pathogenic microorganisms, are known to be highly diverse. However, the factors driving this diversity are not well understood. The tropical horse tick, Dermacentor nitens, is distributed throughout the Americas and it is recognized as a natural vector of Babesia caballi and Theileria equi, the causal agents of equine piroplasmosis. In this study, we characterized the bacterial and viral communities associated with partial...
Zahradnik E, Sander I, Lotz A, Liebers V, Thullner I, Tacke S, Raulf M.The study aimed to determine the allergen, endotoxin and β-(1,3)-glucan concentrations at various areas on a university campus of veterinary medicine. Methods: Dust samples were collected four times a year for three years using electrostatic dust collectors (EDC) at 25 different locations on a campus of veterinary medicine and in laboratories of inorganic chemistry as a control area representing animal-free environment. Major animal allergens from dog, cat, horse, cattle and mouse, domestic mite (DM) allergens, and β-(1,3)-glucan were measured using enzyme immunoassays and endotoxin using th...
Montaner-Angoiti E, Llobat L.Leishmania is a genus of parasitic protozoa that causes a disease called leishmaniasis. Leishmaniasis is transmitted to humans through the bites of infected female sandflies. There are several different species of Leishmania that can cause various forms of the disease, and the symptoms can range from mild to severe, depending on species of Leishmania involved and the immune response of the host. Leishmania parasites have a variety of reservoirs, including humans, domestic animals, horses, rodents, wild animals, birds, and reptiles. Leishmaniasis is endemic of 90 countries, mainly in South Amer...
Hain-Saunders NMR, Knight DR, Bruce M, Byrne D, Riley TV.Clostridioides difficile poses an ongoing threat as a cause of gastrointestinal disease in humans and animals. Traditionally considered a human healthcare-related disease, increases in community-associated C. difficile infection (CDI) and growing evidence of inter-species transmission suggest a wider perspective is required for CDI control. In horses, C. difficile is a major cause of diarrhoea and life-threatening colitis. This study aimed to better understand the epidemiology of CDI in Australian horses and provide insights into the relationships between horse, human and environmental strains...
Crosby B, Crespo ME.Venezuelan Equine Encephalitis Virus (VEEV) is the causative viral pathogen of Venezuelan Equine Encephalitis (VEE). Outbreaks frequently involve both equines – including horses, donkeys, mules, zebras – and humans. Outbreaks may range over a large geographic area and may last for several months to years. Sporadic epidemic outbreaks occur most commonly in Central and South America. VEEV exists as both a natural pathogen and a laboratory-developed biologic weapon. Outbreaks have been reported in several South and Central American countries, including Venezuela, Colombia, Peru, Ecuador, C...
Topp AK, Springer A, Mischke R, Rieder J, Feige K, Ganter M, Nagel-Kohl U, Nordhoff M, Boelke M, Becker S, Pachnicke S, Schunack B, Dobler G, Strube C.Tick-borne encephalitis virus (TBEV) is a tick-transmitted flavivirus, which can infect humans and animals, sometimes even with a fatal outcome. Since many decades, TBEV is endemic in southern Germany, while only sporadic occurrence has been noted in northern parts of the country so far. Nevertheless, autochthonous human clinical cases are increasing in the federal state of Lower Saxony in north-western Germany, and several natural foci of TBEV transmission have recently been detected in this federal state. In order to shed more light on the current distribution of TBEV in Lower Saxony, the pr...
Nielsen MK, Leathwick DM, Sauermann CW.Over the past three decades, equine strongylid egg reappearance periods (ERPs) have shortened substantially for macrocyclic lactone anthelmintics. The ERPs of ivermectin and moxidectin were originally reported in the 8-10 and 12-16 week ranges, respectively, but several recent studies have found them to be around 4-5 weeks for both actives. This loss of several weeks of suppressed strongylid egg output could have substantial implications for parasite control. This study made use of a computer simulation model to evaluate the impact of shortened ERPs on the anthelmintic performance of ivermecti...
Azhar M, Gadahi JA, Bhutto B, Tunio S, Vistro WA, Tunio H, Bhutto S, Ram T.Babesiosis is a protozoal disease affect livestock and pet animals such as cattle, buffaloes, sheep, goats, horses, donkeys, mules, dogs, and cats. It causes severe economic losses in livestock as well as in pet animals. A large number of dairy animals are imported in order to fulfill the demands of milk, milk, meat and its products. In addition, different pet animals are transported from Pakistan to various parts of the world, therefore, it is important to identify the current status and distribution of babesiosis throughout Pakistan in order to control the disease and draw attention for futu...
Tehrani M, Ownagh A.Q fever is a worldwide zoonosis caused by an obligate intra-cellular pathogen called affecting a broad range of animal hosts including horses. Most of the isolates found carry plasmids which genetic studies of strains suggest a critical role in survival. The correlation between an isolated plasmid type and the chronic or acute nature of the disease has always been controversial. This study was conducted to investigate the prevalence of and plasmids in horses and assess the potential role of these species as reservoirs of infection and transmission. Nested-polymerase chain reaction (PCR) a...
Pusterla N, Kalscheur M, Peters D, Bidwell L, Holtz S, Barnum S, Lawton K, Morrissey M, Schumacher S.Little information is presently available regarding the frequency of the silent shedders of respiratory viruses in healthy sport horses and their impact on environmental contamination. Therefore, the aim of this study was to investigate the detection frequency of selected respiratory pathogens in nasal secretions and environmental stall samples of sport horses attending a multi-week equestrian event during the summer months. Six out of fifteen tents were randomly selected for the study with approximately 20 horse/stall pairs being sampled on a weekly basis. Following weekly collection for a to...
Anderson C, Baha H, Boghdeh N, Barrera M, Alem F, Narayanan A.Zoonotic pathogens that are vector-transmitted have and continue to contribute to several emerging infections globally. In recent years, spillover events of such zoonotic pathogens have increased in frequency as a result of direct contact with livestock, wildlife, and urbanization, forcing animals from their natural habitats. Equines serve as reservoir hosts for vector-transmitted zoonotic viruses that are also capable of infecting humans and causing disease. From a One Health perspective, equine viruses, therefore, pose major concerns for periodic outbreaks globally. Several equine viruses ha...
Ratzlaff FR, Osmari V, da Silva D, de Paula Vasconcellos JS, Pötter L, Fernandes FD, de Mello Filho JA, de Avila Botton S, Vogel FSF, Sangioni LA.Leishmaniasis is a zoonosis caused by protozoan species of the genus Leishmania. It generates different clinical manifestations in humans and animals, and it infects multiple hosts. Leishmania parasites are transmitted by sandfly vectors. The main objective of this systematic review was to identify the host, or reservoir animal species, of Leishmania spp., with the exception of domestic dogs, that were recorded in Brazil. This review included identification of diagnostic methods, and the species of protozoan circulating in the country. For this purpose, a literature search was conducted across...
Holguin-Rocha AF, Calle-Tobon A, Vásquez GM, Astete H, Fisher ML, Tobon-Castano A, Velez-Tobon G, Maldonado-Ruiz LP, Silver K, Park Y....Ticks are obligatory hematophagous ectoparasites that transmit pathogens among various vertebrates, including humans. The composition of the microbial and viral communities in addition to the pathogenic microorganisms is highly diverse in ticks, but the factors driving the diversity are not well understood. The tropical horse tick, , is distributed throughout the Americas and it is recognized as a natural vector of and , the causal agents of equine piroplasmosis. We characterized the bacterial and viral communities associated with partially-fed females collected by a passive survey on hors...
Gothe LMR, Ganzenberg S, Ziegler U, Obiegala A, Lohmann KL, Sieg M, Vahlenkamp TW, Groschup MH, Hörügel U, Pfeffer M.Since 2018, autochthonous West Nile virus (WNV) infections have been regularly reported in eastern-central Germany. While clinically apparent infections in humans and horses are not frequent, seroprevalence studies in horses may allow the tracing of WNV and related flaviviruses transmission, such as tick-borne encephalitis virus (TBEV) and Usutu virus (USUV), and consequently help to estimate the risk of human infections. Hence, the aim of our study was to follow the seropositive ratio against these three viruses in horses in Saxony, Saxony Anhalt, and Brandenburg and to describe their geograp...
Pimenta J, Pinto AR, Saavedra MJ, Cotovio M.Horses are considered as reservoirs of multidrug resistant bacteria that can be spread through the environment and possibly to humans. The aim of this study was to characterize the oral Gram-negative microbiota of healthy horses and evaluate their antimicrobial susceptibility profile in a One Health approach. For this purpose, samples were collected from the gingival margin of healthy horses, free of antimicrobial therapy, cultured in selective mediums, identified, and tested for antimicrobial susceptibility. Fifty-five Gram-negative isolates were identified, with 89.5% being zoonotic and 62% ...
Dorneles EMS, Santana JA, Costa ACTRB, Junqueira DG, Heinemann MB, Lage AP.Brucellosis in equines, including horses, donkeys, and mules, is characterized by abscesses in tendons, bursae, and joints. Reproductive disorders, which are common in other animals, are rare in both males and females. Joint breeding of horses, cattle, and pigs was found as the main risk factor for equine brucellosis, with the transmission from equines to cattle or among equines possible, although unlikely. Hence, evaluation of the disease in equines can be considered an indirect indicator of the effectiveness of brucellosis control measures employed for other domestic species. Generally, the ...
Dilling SC, TenBroeck SH, Hogsette JA, Kline DL.Mosquitoes are pests of horses, but mosquito trap efficacy data, especially the ability of traps to protect horses, are lacking. Studies were conducted to investigate the comparative attraction between traps and horses, increase trap attraction by adding horse odors to the airstream of a trap, determine the spatial distribution of adult mosquitoes, estimate the numbers of mosquitoes feeding on horses, determine the relative attraction of horses to mosquitoes, and estimate the range of mosquitoes' attraction between two horses. When a horse and a mosquito trap were placed 3.5 m apart, there was...
Kamyingkird K, Choocherd S, Chimnoi W, Klinkaew N, Kengradomkij C, Phoosangwalthong P, Thammasonthijarern N, Pattanatanang K, Inpankaew T, Phasuk J....African horse sickness (AHS) was reported as an outbreak in Thailand in 2020. Hematophagous insects from the genus Culicoides are the suspected vector responsible for AHS transmission. Horses in Hua Hin district, Prachuab Khiri Khan province, Thailand, were affected and died from AHS in 2020. However, the potential Culicoides species and its host preference blood meal in the affected areas are unknown. To investigate the potential vectors of AHS, Culicoides were collected using ultraviolet light traps placed near horse stables. Six horse farms, including five farms with AHS history and one far...
Frisch V, Fuehrer HP, Cavalleri JV.In equine stables and their surroundings, a large number of insects are present that can be a nuisance to their equine hosts. Previous studies about dipterans transmitting infectious agents to Equidae have largely focused on Nematocera. For the preparation of this systematic review, the existing literature (until February 2022) was systematically screened for various infectious agents transmitted to Equidae via insects of the suborder Brachycera, including Tabanidae, Muscidae, Glossinidae and Hippoboscidae, acting as pests or potential vectors. The PRISMA statement 2020 (Preferred Reporting It...
Ching PK, de los Reyes VC, Sucaldito MN, Tayag E, Columna-Vingno AB, Malbas FF, Bolo GC, Sejvar JJ, Eagles D, Playford G, Dueger E, Kaku Y....During 2014, henipavirus infection caused severe illness among humans and horses in southern Philippines; fatality rates among humans were high. Horse-to-human and human-to-human transmission occurred. The most likely source of horse infection was fruit bats. Ongoing surveillance is needed for rapid diagnosis, risk factor investigation, control measure implementation, and further virus characterization.
Zeller HG, Schuffenecker I.West Nile (WN) virus is a mosquito-transmitted flavivirus. It is widely distributed in Africa, the Middle East, Asia, and southern Europe and was recently introduced to North America. Birds are involved in the cycle of transmission as amplifying hosts. Humans and horses are considered accidental dead-end hosts. WN fever was initially considered a minor arbovirosis, usually inducing a nonsymptomatic or a mild flu-like illness in humans, but some cases of encephalitis associated with fatalities were reported in Israel in the 1950s. After two silent decades, several human and equine outbreaks of ...
Weaver SC, Salas R, Rico-Hesse R, Ludwig GV, Oberste MS, Boshell J, Tesh RB.Venezuelan equine encephalomyelitis (VEE) virus has caused periodic epidemics among human beings and equines in Latin America from the 1920s to the early 1970s. The first major outbreak since 1973 occurred in Venezuela and Colombia during 1995, and involved an estimated 75,000 to 100,000 people. We report an epidemiological and virological investigation of this epidemic. Methods: Virus isolates were made in cell culture from human serum, human throat swabs, and brain tissue from aborted and stillborn human fetuses, as well as from horse brain tissue and pooled mosquito collections. Human sera ...
Desquesnes M, Holzmuller P, Lai DH, Dargantes A, Lun ZR, Jittaplapong S.Trypanosoma evansi, the agent of "surra," is a salivarian trypanosome, originating from Africa. It is thought to derive from Trypanosoma brucei by deletion of the maxicircle kinetoplastic DNA (genetic material required for cyclical development in tsetse flies). It is mostly mechanically transmitted by tabanids and stomoxes, initially to camels, in sub-Saharan area. The disease spread from North Africa towards the Middle East, Turkey, India, up to 53° North in Russia, across all South-East Asia, down to Indonesia and the Philippines, and it was also introduced by the conquistadores into Latin ...
Middleton D, Pallister J, Klein R, Feng YR, Haining J, Arkinstall R, Frazer L, Huang JA, Edwards N, Wareing M, Elhay M, Hashmi Z, Bingham J, Yamada M....In recent years, the emergence of several highly pathogenic zoonotic diseases in humans has led to a renewed emphasis on the interconnectedness of human, animal, and environmental health, otherwise known as One Health. For example, Hendra virus (HeV), a zoonotic paramyxovirus, was discovered in 1994, and since then, infections have occurred in 7 humans, each of whom had a strong epidemiologic link to similarly affected horses. As a consequence of these outbreaks, eradication of bat populations was discussed, despite their crucial environmental roles in pollination and reduction of the insect p...
Williamson MM, Hooper PT, Selleck PW, Gleeson LJ, Daniels PW, Westbury HA, Murray PK.To determine the infectivity and transmissibility of Hendra virus (HeV). Methods: A disease transmission study using fruit bats, horses and cats. Methods: Eight grey-headed fruit bats (Pteropus poliocephalus) were inoculated and housed in contact with three uninfected bats and two uninfected horses. In a second experiment, four horses were inoculated by subcutaneous injection and intranasal inoculation and housed in contact with three uninfected horses and six uninfected cats. In a third experiment, 12 cats were inoculated and housed in contact with three uninfected horses. Two surviving horse...
Whitlock GC, Estes DM, Torres AG.Burkholderia mallei, the etiologic agent of the disease known as glanders, is primarily a disease affecting horses and is transmitted to humans by direct contact with infected animals. The use of B. mallei as a biological weapon has been reported and currently, there is no vaccine available for either humans or animals. Despite the history and highly infective nature of B. mallei, as well as its potential use as a bio-weapon, B. mallei research to understand the pathogenesis and the host responses to infection remains limited. Therefore, this minireview will focus on current efforts to elucida...
Murgue B, Murri S, Zientara S, Durand B, Durand JP, Zeller H.On September 6, 2000, two cases of equine encephalitis caused by West Nile (WN) virus were reported in southern France (Hérault Province), near Camargue National Park, where a WN outbreak occurred in 1962. Through November 30, 76 cases were laboratory confirmed among 131 equines with neurologic disorders. The last confirmed case was on November 3, 2000. All but three cases were located in a region nicknamed "la petite Camargue," which has several large marshes, numerous colonies of migratory and resident birds, and large mosquito populations. No human case has been confirmed among clinically ...
Murray KO, Mertens E, Despres P.Zoonotic West Nile virus (WNV) circulates in natural transmission cycles involving certain mosquitoes and birds, horses, humans, and a range of other vertebrates are incidental hosts. Clinical infections in humans can range in severity from uncomplicated WNV fever to fatal meningoencephalitis. Since its introduction to the Western Hemisphere in 1999, WNV had spread across North America, Central and South America and the Caribbean, although the vast majority of severe human cases have occurred in the United States of America (USA) and Canada. By 2002-2003, the WNV outbreaks have involved thousa...
Bunning ML, Bowen RA, Cropp CB, Sullivan KG, Davis BS, Komar N, Godsey MS, Baker D, Hettler DL, Holmes DA, Biggerstaff BJ, Mitchell CJ.A total of 12 horses of different breeds and ages were infected with West Nile virus (WNV) via the bites of infected Aedes albopictus mosquitoes. Half the horses were infected with a viral isolate from the brain of a horse (BC787), and half were infected with an isolate from crow brain (NY99-6625); both were NY99 isolates. Postinfection, uninfected female Ae. albopictus fed on eight of the infected horses. In the first trial, Nt antibody titers reached >1:320, 1:20, 1:160, and 1:80 for horses 1 to 4, respectively. In the second trial, the seven horses with subclinical infections developed Nt a...
Komar N, Clark GG.West Nile virus (Flavivirus: Flaviviridae; WNV) has spread rapidly throughout the Caribbean Basin since its initial detection there in 2001. This report summarizes our current knowledge of WNV transmission in tropical America. Methods: We reviewed the published literature and consulted with key public health officials to obtain unpublished data. Results: West Nile virus infections first appeared in human residents of the Cayman Islands and the Florida Keys in 2001, and in apparently healthy Jamaican birds sampled early in 2002. Serologic evidence of WNV infection in 2002 was detected in horses...
Carrera JP, Forrester N, Wang E, Vittor AY, Haddow AD, López-Vergès S, Abadía I, Castaño E, Sosa N, Báez C, Estripeaut D, Díaz Y, Beltrán D....The eastern equine encephalitis (EEE) and Venezuelan equine encephalitis (VEE) viruses are pathogens that infect humans and horses in the Americas. Outbreaks of neurologic disease in humans and horses were reported in Panama from May through early August 2010. Methods: We performed antibody assays and tests to detect viral RNA and isolate the viruses in serum samples from hospitalized patients. Additional cases were identified with enhanced surveillance. Results: A total of 19 patients were hospitalized for encephalitis. Among them, 7 had confirmed EEE, 3 had VEE, and 1 was infected with both ...
Boyle AG, Timoney JF, Newton JR, Hines MT, Waller AS, Buchanan BR.This consensus statement update reflects our current published knowledge and opinion about clinical signs, pathogenesis, epidemiology, treatment, complications, and control of strangles. This updated statement emphasizes varying presentations in the context of existing underlying immunity and carrier states of strangles in the transmission of disease. The statement redefines the "gold standard" for detection of possible infection and reviews the new technologies available in polymerase chain reaction diagnosis and serology and their use in outbreak control and prevention. We reiterate the impo...
Murcia PR, Baillie GJ, Daly J, Elton D, Jervis C, Mumford JA, Newton R, Parrish CR, Hoelzer K, Dougan G, Parkhill J, Lennard N, Ormond D, Moule S....Determining the evolutionary basis of cross-species transmission and immune evasion is key to understanding the mechanisms that control the emergence of either new viruses or novel antigenic variants with pandemic potential. The hemagglutinin glycoprotein of influenza A viruses is a critical host range determinant and a major target of neutralizing antibodies. Equine influenza virus (EIV) is a significant pathogen of the horse that causes periodical outbreaks of disease even in populations with high vaccination coverage. EIV has also jumped the species barrier and emerged as a novel respirator...
Morales MA, Barrandeguy M, Fabbri C, Garcia JB, Vissani A, Trono K, Gutierrez G, Pigretti S, Menchaca H, Garrido N, Taylor N, Fernandez F, Levis S....West Nile virus (WNV) was isolated from the brains of 3 horses that died from encephalitis in February 2006. The horses were from different farms in central Argentina and had not traveled outside the country. This is the first isolation of WNV in South America.
Schmiedel J, Falgenhauer L, Domann E, Bauerfeind R, Prenger-Berninghoff E, Imirzalioglu C, Chakraborty T.Multiresistant Gram-negative bacteria producing extended-spectrum β-lactamases (ESBLs) are an emerging problem in human and veterinary medicine. This study focused on comparative molecular characterization of β-lactamase and ESBL-producing Enterobacteriaceae isolates from central Hesse in Germany. Isolates originated from humans, companion animals (dogs and cats) and horses. Results: In this study 153 (83.6%) of the human isolates (n = 183) and 163 (91.6%) of the animal isolates (n = 178) were confirmed as ESBL producers by PCR and subsequent sequencing of the PCR amplicons. Predomin...
Baptiste KE, Williams K, Willams NJ, Wattret A, Clegg PD, Dawson S, Corkill JE, O'Neill T, Hart CA.We determined the molecular characteristics of methicillin-resistant staphylococci from animals and staff at a small animal and equine hospital. Methicillin-resistant Staphylococcus aureus (MRSA) identical to human EMRSA-15 was found in dogs and hospital staff. In contrast, 5 distinct MRSA strains were isolated from horses but not from hospital staff.
Pelkonen S, Lindahl SB, Suomala P, Karhukorpi J, Vuorinen S, Koivula I, Väisänen T, Pentikäinen J, Autio T, Tuuminen T.Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is a zoonotic pathogen for persons in contact with horses. In horses, S. zooepidemicus is an opportunistic pathogen, but human infections associated with S. zooepidemicus are often severe. Within 6 months in 2011, 3 unrelated cases of severe, disseminated S. zooepidemicus infection occurred in men working with horses in eastern Finland. To clarify the pathogen's epidemiology, we describe the clinical features of the infection in 3 patients and compare the S. zooepidemicus isolates from the human cases with S. zooepidemicus isolates...
Journal of medical entomologyOctober 5, 2006
Volume 43, Issue 5 936-946 doi: 10.1603/0022-2585(2006)43[936:hbahba]2.0.co;2
Balenghien T, Fouque F, Sabatier P, Bicout DJ.After 35 yr of disease absence, West Nile virus (family Flaviviridae, genus Flavivirus, WNV) circulation has been regularly detected in the Camargue region (southern France) since 2000. WNV was isolated from Culex modestus Ficalbi, which was considered the main vector in southern France after horse outbreaks in the 1960s. Recent WNV transmissions outside of the Cx. modestus distribution suggested the existence of other vectors. To study potential WNV vectors, horse- and bird-baited traps and human landing collections of mosquitoes were carried out weekly from May to October 2004 at two Camargu...
Wise LN, Kappmeyer LS, Mealey RH, Knowles DP.Equine piroplasmosis is caused by one of 2 erythrocytic parasites Babesia caballi or Theileria equi. Although the genus of the latter remains controversial, the most recent designation, Theileria, is utilized in this review. Shared pathogenesis includes tick-borne transmission and erythrolysis leading to anemia as the primary clinical outcome. Although both parasites are able to persist indefinitely in their equid hosts, thus far, only B. caballi transmits across tick generations. Pathogenesis further diverges after transmission to equids in that B. caballi immediately infects erythrocytes, wh...
Atasheva S, Garmashova N, Frolov I, Frolova E.Venezuelan equine encephalitis virus (VEEV) represents a continuous public health threat in the United States. It has the ability to cause fatal disease in humans and in horses and other domestic animals. We recently demonstrated that replicating VEEV interferes with cellular transcription and uses this phenomenon as a means of downregulating a cellular antiviral response. VEEV capsid protein was found to play a critical role in this process, and its approximately 35-amino-acid-long peptide, fused with green fluorescent protein, functioned as efficiently as did the entire capsid. We detected a...
Nedland H, Wollman J, Sreenivasan C, Quast M, Singrey A, Fawcett L, Christopher-Hennings J, Nelson E, Kaushik RS, Wang D, Li F.Influenza D virus (IDV) is a newly described influenza type of the Orthomyxoviridae virus family that was first isolated from diseased swine in 2011 and has subsequently been detected in cattle around the world in 2014. In addition, serological evidence for IDV infection in humans has been recently established. Despite all the progress, the full range of susceptible hosts for this novel virus has yet to be determined, but includes swine, bovine, small ruminants and human. This study was designed to determine if equine is a possible host to this newly emerging influenza virus. Three hundred and...
Marfin AA, Gubler DJ.In 1999, an epidemic of West Nile virus (WNV) encephalitis occurred in New York City (NYC) and 2 surrounding New York counties. Simultaneously, an epizootic among American crows and other bird species occurred in 4 states. Indigenous transmission of WNV had never been documented in the western hemisphere until this epidemic. In 2000, the epizootic expanded to 12 states and the District of Columbia, and the epidemic continued in NYC, 5 New Jersey counties, and 1 Connecticut county. In addition to these outbreaks, several large epidemics of WNV have occurred in other regions of the world where t...
Paz S, Malkinson D, Green MS, Tsioni G, Papa A, Danis K, Sirbu A, Ceianu C, Katalin K, Ferenczi E, Zeller H, Semenza JC.In the summer of 2010, Europe experienced outbreaks of West Nile Fever (WNF) in humans, which was preceded by hot spells. The objective of this study was to identify potential drivers of these outbreaks, such as spring and summer temperatures, relative humidity (RH), and precipitation. Methods: Pearson and lag correlations, binary and multinomial logistic regressions were used to assess the relationship between the climatic parameters and these outbreaks. Results: For human morbidity, significant (<0.05) positive correlations were observed between a number of WNF cases and temperature, with...
Takai S.An overview of epidemiology of R. equi infection in foals is presented, emphasizing the importance of the virulence-associated antigens and plasmids as epidemiological markers. The monoclonal antibody-based colony blot test has been developed to identify rapidly and accurately virulent R. equi. Epidemiological studies conducted during the recent 5 years have revealed that: (1) avirulent R. equi are widespread in the feces of horses and their environment on every farm; (2) the feces of horses and the environment of the horse farms having endemic R. equi infections demonstrated heavy contaminati...
Blitvich BJ.West Nile virus (WNV) is a flavivirus that is maintained in a bird-mosquito transmission cycle. Humans, horses and other non-avian vertebrates are usually incidental hosts, but evidence is accumulating that this might not always be the case. Historically, WNV has been associated with asymptomatic infections and sporadic disease outbreaks in humans and horses in Africa, Europe, Asia and Australia. However, since 1994, the virus has caused frequent outbreaks of severe neuroinvasive disease in humans and horses in Europe and the Mediterranean Basin. In 1999, WNV underwent a dramatic expansion of ...
Komar N.West Nile virus (WNV) has emerged in recent years in temperate regions of Europe and North America, presenting a threat to both public and animal health. The most serious manifestation of infection is fatal encephalitis in humans and horses, as well as mortality in certain domestic and wild birds. A recent development in the epizootiology of this mosquito-borne flavivirus was the occurrence of a severe outbreak in New York City and surrounding areas. During this outbreak, mortality was observed in humans, horses, a cat and numerous species of wild birds, particularly members of the family Corv...
Reperant LA, Rimmelzwaan GF, Kuiken T.Highly pathogenic avian influenza viruses of subtype H5N1 are remarkable because of their expanding non-avian host range and wide tissue tropism. They have caused severe or fatal respiratory and extra-respiratory disease in seven naturally infected species of carnivore. However, they are not unique in their ability to cross the species barrier, to cause clinical disease and mortality, or to replicate in extra-respiratory organs. Low pathogenic avian influenza viruses have crossed from birds to swine, horses, harbour seals, whales and mink; have resulted in severe respiratory disease and mortal...
