Salmonella in Horses.

Managing Salmonella in equine populations can be challenging due to the epidemiology of this disease. In particular, due to the range of clinical outcomes, the occurrence of subclinical infections, and intermittent shedding. This greatly affects the ability to detect shedding and can lead to widespread environmental contamination and transmission. The veterinary profession can reduce the risk to stablemates and their caretakers, while meeting their ethical obligation, by appropriately managing these risks within animal populations and environments.

The comparative efficacy of disinfectant wipes on common-use computer keyboards in a veterinary teaching hospital.

The efficacies of 3 disinfectant wipes at reducing bacterial contamination on keyboards in a veterinary teaching hospital were studied. Thirty common-use keyboards were randomized into "dirty" and "clean" halves. Cultures were obtained from the "dirty" halves. The "clean" halves were disinfected with a randomly assigned wipe [peroxygen (AHP)-, alcohol-, quaternary ammonium (QAC)-based] or untreated (NT) and cultured. Colony-forming units (CFU) were enumerated after 48 hours. Mean reduction in CFU was 91.5%, 65.3%, 94.9%, and 78.8% for the AHP, alcohol, QAC, and NT groups, respectively. There was a significant reduction in CFUs between the dirty and clean keyboard halves within each group but no statistically significant differences were noted between groups. The reduction in CFUs in the NT group was attributed to the mechanical action of wiping the keyboard surface for culture. The use of disinfectant wipes reduced CFUs on keyboards and may be a useful component of veterinary infection control programs.

Efficacité comparative de lingettes désinfectantes sur des claviers d'ordinateurs en usage commun dans un hôpital d'enseignement vétérinaire. L'efficacité de trois lingettes désinfectantes à réduire la contamination bactérienne sur des claviers dans un hôpital d'enseignement vétérinaire fut étudiée. Trente claviers en usage commun furent séparés de manière aléatoire en moitié « sale ¼ et « propre ¼. Des cultures furent obtenues de la moitié « sale ¼. La moitié « propre ¼ fut désinfectée avec une lingette assignée de manière aléatoire [à base de peroxygène (AHP), alcool, ou ammonium quaternaire (QAC)] ou non traitée (NT) et échantillonnée pour culture. Le nombre d'unités formatrices de colonies (CFU) fut énuméré après 48 heures. La réduction moyenne de CFU était de 91,5 %, 65,3 %, 94,9 %, et 78,8 % pour les groupes AHP, alcool, QAC, et NT, respectivement. Il y avait une réduction significative dans les CFUs entre les claviers des moitiés sale et propre dans chaque groupe mais aucune différence statistiquement significative ne fut notée entre les groupes. La réduction en CFU dans le groupe NT fut attribuée à l'action mécanique de frottage de la surface des claviers. L'utilisation de lingettes désinfectantes a réduit le nombre d'UFC sur les claviers et pourrait être une composante utile des programmes de surveillance des infections vétérinaires.(Traduit par Dr Serge Messier).

Prevention and surveillance of surgical infections: A review.

Optimal patient care cannot be realized without effectively managing risks related to healthcare-associated infections (HAI). Among human hospital admissions in the United States in 2002, there were approximately 4.5 HAI per 100 admissions, with surgical site infections (SSI) accounting for an estimated 20%, or approximately 2 SSI per 100 procedures. When considering the occurrence of disease in a population, it is important to remember that disease does not occur randomly in populations. Therefore, when thinking about managing risks associated with the occurrence of SSI, consideration should be given to key factors in disease development (the agent, the host, and the environment), and a multifaceted approach to prevention efforts should be considered, including the identification of high-risk populations, adherence to aseptic principles, judicious use of antimicrobial drugs, and surveillance targeting SSI to better inform infection control practices within a facility. Although not all HAI are preventable, it is important to focus efforts on the preventable fraction and to take all reasonable precautions to mitigate foreseeable risks.

Managing Salmonella in equine populations.

Infection control is achieved through all efforts used to prevent the introduction and limit the spread of contagious pathogens within a facility or population, with the goal of eliminating sources of potentially pathogenic microorganisms and to disrupt infectious disease transmission. Congregating animals from multiple sources, as occurs at veterinary hospitals, racetracks, equestrian events, and boarding and training facilities, increases the risk for transmission of infectious diseases such as salmonella. There is a recognizable standard of practice for infection control and due effort must be given to control and prevention of infectious disease transmission within animal populations and facilities.

Infection control in equine critical care settings.

There is a recognizable standard of practice for infection control in veterinary medicine. Effort must be given to control and prevention of infectious disease transmission within a facility and among animal populations. In the critical care setting, patients typically have a high degree of systemic illness and immune compromise, are commonly subjected to invasive procedures and placement of indwelling devices, and frequently receive antimicrobials and gastric protectants. Every equine critical care unit is distinctive in its physical and operational features and the types of patients that are managed. Infection control programs must therefore be tailored to each facility's needs.

Pharmacologic interventions for the treatment of equine herpesvirus-1 in domesticated horses: A systematic review.

BACKGROUND: Equine herpes virus type 1 (EHV-1) infection in horses is associated with upper respiratory disease, neurological disease, abortions, and neonatal death. REVIEW QUESTION: Does pharmacological therapy decrease either the incidence or severity of disease or infection caused by EHV-1 in domesticated horses? METHODS: A systematic review was preformed searching AGRICOLA, CAB Abstracts, Cochrane, PubMed, Web of Science, and WHO Global Health Index Medicus Regional Databases to identify articles published before February 15, 2021. Selection criteria were original research reports published in peer reviewed journals, and studies investigating in vivo use of therapeutic agents for prevention or treatment of EHV-1 in horses. Outcomes assessed included measures related to clinical outcomes that reflect symptomatic EHV-1 infection or virus infection. We evaluated risk of bias and performed a GRADE evaluation of the quality of evidence for interventions. RESULTS: A total of 7009 unique studies were identified, of which 9 met the inclusion criteria. Two studies evaluated valacyclovir or small interfering RNAs, and single studies evaluated the use of a Parapoxvirus ovis-based immunomodulator, human alpha interferon, an herbal supplement, a cytosine analog, and heparin. The level of evidence ranged between randomized controlled studies and observational trials. The risk of bias was moderate to high and sample sizes were small. Most studies reported either no benefit or minimal efficacy of the intervention tested. CONCLUSIONS AND CLINICAL IMPORTANCE: Our review indicates minimal or limited benefit either as a prophylactic or post-exposure treatment for any of the studied interventions in the mitigation of EHV-1-associated disease outcome.

Updated ACVIM consensus statement on equine herpesvirus-1.

Equine herpesvirus-1 (EHV-1) is a highly prevalent and frequently pathogenic infection of equids. The most serious clinical consequences of infection are abortion and equine herpesvirus myeloencephalopathy (EHM). The previous consensus statement was published in 2009 and considered pathogenesis, strain variation, epidemiology, diagnostic testing, vaccination, outbreak prevention and control, and treatment. A recent survey of American College of Veterinary Internal Medicine large animal diplomates identified the need for a revision to this original consensus statement. This updated consensus statement is underpinned by 4 systematic reviews that addressed key questions concerning vaccination, pharmaceutical treatment, pathogenesis, and diagnostic testing. Evidence for successful vaccination against, or effective treatment of EHV-1 infection was limited, and improvements in experimental design and reporting of results are needed in future studies of this important disease. This consensus statement also updates the topics considered previously in 2009.

Vaccination for the prevention of equine herpesvirus-1 disease in domesticated horses: A systematic review and meta-analysis.

BACKGROUND: Equine herpes virus type 1 (EHV-1) infection in horses is associated with respiratory and neurologic disease, abortion, and neonatal death. HYPOTHESIS: Vaccines decrease the occurrence of clinical disease in EHV-1-infected horses. METHODS: A systematic review was performed searching multiple databases to identify relevant studies. Selection criteria were original peer-reviewed research reports that investigated the in vivo use of vaccines for the prevention of disease caused by EHV-1 in domesticated horses. Main outcomes of interest included pyrexia, abortion, neurologic disease, viremia, and nasal shedding. We evaluated risk of bias, conducted exploratory meta-analyses of incidence data for the main outcomes, and performed a GRADE evaluation of the quality of evidence for each vaccine subtype. RESULTS: A total of 1018 unique studies were identified, of which 35 met the inclusion criteria. Experimental studies accounted for 31/35 studies, with the remainder being observational studies. Eight vaccine subclasses were identified including commercial (modified-live, inactivated, mixed) and experimental (modified-live, inactivated, deletion mutant, DNA, recombinant). Risk of bias was generally moderate, often because of underreporting of research methods, and sample sizes were small leading to imprecision in the estimate of the effect size. Several studies reported either no benefit or minimal vaccine efficacy for the primary outcomes of interest. Meta-analyses revealed significant heterogeneity was present, and our confidence in the quality of evidence for most outcomes was low to moderate. CONCLUSIONS AND CLINICAL IMPORTANCE: Our review indicates that commercial and experimental vaccines minimally reduce the incidence of clinical disease associated with EHV-1 infection.

Viremia and nasal shedding for the diagnosis of equine herpesvirus-1 infection in domesticated horses.

BACKGROUND: Equine herpesvirus type 1 (EHV-1) infection is associated with upper respiratory disease, EHM, abortions, and neonatal death. RESEARCH QUESTIONS: Are nasal secretions a more sensitive biological sample compared to blood for the detection of EHV-1 infection? How long is EHV-1 detectable after primary infection by PCR? METHODS: MedLine and Web of Science searches identified original peer-reviewed reports evaluating nasal shedding and viremia using virus isolation methods or PCR published in English before October 9, 2023. RESULTS: Sixty experimental and 20 observational studies met inclusion criteria. EHV-1 detection frequency by qPCR in nasal secretions and blood from naturally-infected horses with fever and respiratory signs were 15% and 9%, respectively; qPCR detection rates in nasal secretions and blood from horses with suspected EHM were 94% and 70%, respectively. In experimental studies the sensitivity of qPCR matched or exceeded that seen for virus isolation from either nasal secretions or blood. Detection of nasal shedding typically occurred within 2 days after EHV-1 inoculation with a detection period of 3 to 7 days. Viremia lasted 2 to 7 days and was usually detected ≥1 days after positive identification of EHV-1 in nasal secretions. Nasal shedding and viremia decreased over time and remained detectable in some horses for several weeks after inoculation. CONCLUSIONS AND CLINICAL IMPORTANCE: Under experimental conditions, blood and nasal secretions have similar sensitivity for the detection of EHV-1 when horses are sampled on multiple consecutive days. In contrast, in observational studies detection of EHV-1 in nasal secretions was consistently more successful.

Relationship between equine herpesvirus-1 viremia and abortion or equine herpesvirus myeloencephalopathy in domesticated horses: A systematic review.

BACKGROUND: Equine herpes virus type 1 (EHV-1) infection in horses is associated with upper respiratory disease, neurological disease, abortions, and neonatal death. OBJECTIVE: To determine if there is an association between the level and duration of EHV-1 viremia and either abortion or equine herpesvirus myeloencephalopathy (EHM) in domesticated horses? METHODS: A systematic review was performed searching numerous databases to identify peer reviewed reports that evaluated viremia and EHM, or viremia and abortion published before January 19, 2021. Randomized controlled trials and observational studies were assessed for risk of bias or publication quality. RESULTS: A total of 189 unique studies were identified, of which 34 met the inclusion criteria. Thirty studies evaluated viremia and neurologic outcomes including 4 observational studies. Eight experimental studies examined viremia and abortion, which used the Ab4 and OH03 virus strains or recombinant Ab4 derivatives. Incidence rates for both EHM and abortion in experimental studies varied among the studies as did the level of evidence. Viremia was generally detectable before the onset of either EHM or abortion. Risk of bias was generally low to moderate, sample sizes were small, and multiple studies reported negative outcome data. CONCLUSIONS AND CLINICAL IMPORTANCE: The results of this study support that viremia is regularly present before EHM or abortion occurs. However, no inferences could be made about the relationship between the occurrence of either neurological signs or abortion and the magnitude or duration of viremia.

Prevalence of antibiotic use for dogs and cats in United States veterinary teaching hospitals, August 2020.

BACKGROUND: Awareness of prescribing practices helps identify opportunities to improve antibiotic use (AU). OBJECTIVES: To estimate AU prevalence in dogs and cats in U.S. veterinary teaching hospitals (VTHs) and identify antibiotic drugs commonly prescribed, indications for use, and evidence of bacterial infection. ANIMALS: Medical record data were collected from dogs and cats examined at 14 VTHs. METHODS: Data were collected from VTH medical records of dogs and cats examined by primary care, urgent care, emergency and critical care, internal medicine, and surgery services on a single day during August 13-September 3, 2020. Data included signalment; clinical service; inpatient or outpatient status; clinical conditions; diagnostic tests; evidence of bacterial infection; intended reason for AU; name and route of antibiotics prescribed. RESULTS: Of 883 dogs and cats, 322 (36.5%) were prescribed at least 1 antibiotic. Among 285 antibiotics administered systemically intended for treatment of infection, 10.9% were prescribed without evidence of infection. The most common class of antibiotics presribed for systemic administration was potentiated penicillin for dogs (115/346, 33.3%) and cats (27/80, 33.8%). For dogs and cats, first-generation cephalosporins (93/346, 26.9% and 11/80, 13.8%, respectively) and fluoroquinolones (51/346, 14.7% and 19/80, 23.8%, respectively) was second or third most-prescribed. Common AU indications included skin, respiratory, and urinary conditions, and perioperative use. CONCLUSIONS AND CLINICAL IMPORTANCE: Collaborative data collection provides a sustainable methodology to generate national AU prevalence estimates and bring attention to areas requiring additional research and detailed data collection. These efforts can also identify practice improvement opportunities in settings where future veterinarians are trained.

Effects of restricted antimicrobial exposure on antimicrobial resistance in fecal Escherichia coli from feedlot cattle.

OBJECTIVES: The primary objective was to evaluate differences in antimicrobial resistance among enteric bacteria recovered from feedlot cattle that were being raised without exposure to antimicrobial drugs (AMDs) and those reared using conventional practices. MATERIALS: Forty pens of feedlot cattle (4557 total animals) that were being fed without AMD exposures were selected for enrollment as were 44 pens of cattle (4913 total animals) being fed for production of conventional beef products at the same feedlots. Fecal samples were collected from the floors of pens approximately biweekly through the middle of the feeding period and again prior to slaughter. Samples were cultured to recover nontype-specific Escherichia coli (NTSEC) and Salmonella enterica, and isolates were evaluated for susceptibility to a panel of AMDs. RESULTS: Cattle enrolled in the study did not differ between groups in entry weight or finish weight, but cattle with restricted AMD and hormone exposures were fed for an average of 50 days longer than conventionally reared cattle (p < 0.001). Resistance among NTSEC isolates was most common to tetracycline, streptomycin, and sulfamethoxazole, and there were slightly higher prevalence of resistance among NTSEC isolates recovered from conventionally reared cattle. Therapeutic AMD exposures did not have a detectable impact on the prevalence of resistance among NTSEC. Although there were detectable temporal trends through the feeding period for resistance to tetracycline, naladixic acid, chloramphenicol, and cephalothin, the direction of trends differed among drugs and these trends were not associated with study groups. S. enterica was recovered rarely (0.73%) but at similar prevalences from cattle with both rearing methods. CONCLUSIONS: These findings suggest that conventional feedlot production methods (including parenteral and in-feed use of AMDs) do not predictably or uniformly increase the prevalence of antimicrobial resistance among fecal NTSEC when compared with rearing methods that restrict exposure to AMDs.

Environmental persistence of equid herpesvirus type-1.

BACKGROUND: Equid herpesvirus type 1 (EHV-1) is ubiquitous in equine populations causing respiratory disease, and complications including late-term abortion and neurological disease. Eradication of EHV-1 from housing environments that typically contain unsealed wood and porous bedding materials can be challenging. However, consideration should be given to take advantage of the viral envelope's susceptibility to environmental conditions. OBJECTIVE: To determine environmental persistence of EHV-1 on materials and in environmental conditions commonly found in equine facilities. We hypothesised that environmental conditions and materials would limit environmental persistence of EHV-1 in horse housing environments. STUDY DESIGN: Experimental study. METHODS: Standard inoculum of EHV-1 strain OH03 was applied to leather, polyester-cotton fabric, two bedding materials (pinewood shavings and wheat straw) and polystyrene (plastic), and placed under three different environmental conditions (4°C, indoors and outdoors). Virus titration and quantitative PCR (qPCR) were performed at six time points between 0 and 48 hours and the number of plaque-forming units (PFUs) was determined. RESULTS: Viable EHV-1 was recovered up to 48 hours from all material-environmental condition combinations, with persistence decreasing over time. In general, outdoor environment had the greatest impact, irrespective of material tested, followed by indoor environment and 4°C. On average, wood shavings had the greatest impact on persistence, followed by leather, straw, fabric and polystyrene. MAIN LIMITATIONS: The inoculum used in this study was not in a milieu consistent with nasal secretions. As such, virus particles may have been more sensitive to the materials and/or environmental conditions evaluated. CONCLUSIONS: Environmental factors had variable effects on environmental persistence. Although there were significant reductions in PFUs within the first 3 hours, irrespective of environment-material evaluated, viable virus was still recovered at 48 hours likely representing a transmission risk. Barrier precautions should be used to prevent spread of EHV-1 from unrecognised environmental reservoirs.

Excessive sulfate and poor water quality as a cause of sudden deaths and an outbreak of diarrhea in horses.

Sudden deaths and an outbreak of diarrhea in horses occurred in southern Saskatchewan in 2006. Five horses died while survivors presented with diarrhea and, in 1 case, acute neurologic signs attributed to hyponatremia. Diagnostic testing of affected horses and environmental testing suggested poor water quality, specifically high salinity and high sulfate concentration as the cause.

Comparison of detection methods for Salmonella enterica shedding among reptilian patients at a veterinary teaching hospital.

In the United States, ~1.4 million sporadic human Salmonella enterica infections occur annually, with an estimated 6% attributable to reptile exposure. Detection of Salmonella in reptiles can be challenging given the limitations among detection methods. We evaluated sampling and detection methods for S. enterica in a cross-sectional study of reptilian patients (n = 45) over the course of 13 mo. Two sampling methods (cloacal swabs, electrostatic cloth body-feet samples) and 3 detection methods (enriched culture, lateral flow immunoassay [LFI], real-time PCR) were compared using McNemar and Fisher exact tests. Results varied by species, sample type, and detection method. In total, 14 of 45 (33%) patients were positive by culture, 10 of 45 (22%), and/or 13 of 45 (29%) by rtPCR. Among rtPCR-positive results, cloacal swabs (12 of 45 [27%]) resulted in a higher detection than body-feet wipes (4 of 45 [9%]; p = 0.01). Among culture-positive results, shedding was most commonly detected after additional incubation at room temperature when testing cloacal swabs (9 of 45 [20%]). However, there was significant disagreement between sampling methods (cloacal vs. body-feet; p = 0.03). No samples were positive by LFI. In general, cloacal swabs yielded the highest test-positive rates, irrespective of testing method. Our study highlights the importance of using detection methods optimized for the sample being tested.

Genomic diversity of class I integrons from antimicrobial resistant strains of Salmonella Typhimurium isolated from livestock, poultry and humans.

INTRODUCTION: Multidrug resistance (MDR) is a serious issue prevalent in various agriculture-related foodborne pathogens including Salmonella enterica (S. enterica) Typhimurium. Class I integrons have been detected in Salmonella spp. strains isolated from food producing animals and humans and likely play a critical role in transmitting antimicrobial resistance within and between livestock and human populations. OBJECTIVE: The main objective of our study was to characterize class I integron presence to identify possible integron diversity among and between antimicrobial resistant Salmonella Typhimurium isolates from various host species, including humans, cattle, swine, and poultry. METHODS: An association between integron presence with multidrug resistance was evaluated. One hundred and eighty-three S. Typhimurium isolates were tested for antimicrobial resistance (AMR). Class I integrons were detected and sequenced. Similarity of AMR patterns between host species was also studied within each integron type. RESULTS: One hundred seventy-four (95.1%) of 183 S.Typhimurium isolates were resistant to at least one antimicrobial and 82 (44.8%) were resistant to 5 or more antimicrobials. The majority of isolates resistant to at least one antimicrobial was from humans (45.9%), followed by swine (19.1%) and then bovine (16.9%) isolates; poultry showed the lowest number (13.1%) of resistant isolates. Our study has demonstrated high occurrence of class I integrons in S. Typhimurium across different host species. Only one integron size was detected in poultry isolates. There was a significant association between integron presence of any size and specific multidrug resistance pattern among the isolates from human, bovine and swine. CONCLUSIONS: Our study has demonstrated a high occurrence of class I integrons of different sizes in Salmonella Typhimurium across various host species and their association with multidrug resistance. This demonstration indicates that multidrug resistant Salmonella Typhimurium is of significant public health occurrence and reflects on the importance of judicious use of antimicrobials among livestock and poultry.

Predictive Value of Veterinary Student Application Data for Class Rank at End of Year 1.

Student applications for admission to the University of Georgia College of Veterinary Medicine include the following information: undergraduate grade point average (GPA), GPA in science courses (GPAScience), GPA for the last 45 credit hours (GPALast45hrs), results for the Graduate Record Examination Quantitative and Verbal Reasoning Measures (GRE-QV), results for the GRE Analytical Writing Measure (GRE-AW), and grades received for 10 required prerequisite courses. In addition, three faculty members independently review and score subjective information in applicants' files (FileScore). The admissions committee determines a composite Admission Score (AdmScore), which is based on GPA, GPAScience, GPALast45hrs, GRE-QV, GRE-AW, and the FileScore. The AdmScore is generally perceived to be a good predictor of class rank at the end of year 1 (CREY1). However, this has not been verified, nor has it been determined which components of the AdmScore have the strongest correlation with CREY1. The present study therefore compared each component of the AdmScore for correlation with CREY1, for the three classes admitted in 2015, 2016 and 2017 (Class15, Class16, Class17). Results suggest that only a few components of the application file are needed to make strong predictive statements about the academic success of veterinary students during the first year of the curriculum.

Hepatic lobe torsion in a horse.

A 4-year-old Belgian mare was presented with a 1-week history of fever, suspected of being caused by peritonitis. The mare died before the diagnostic procedures had been completed; postmortem examination revealed torsion of the left medial lobe of the liver, resulting in diffuse necrosis of liver tissue and severe peritoneal effusion.

Risk factors for shedding of Salmonella enterica among hospitalized large animals over a 10-year period in a veterinary teaching hospital.

BACKGROUND: Transmission of Salmonella in veterinary hospitals is typically associated with environmental contamination. Links between isolates recovered from hospitalized large animals and environment suggest animals as the likely source. Therefore, understanding factors influencing shedding is key in control. Shedding in hospitalized animals has been investigated, but many studies focused on subsets of animals limiting generalizability. OBJECTIVE: (1) Investigate factors associated with fecal shedding of Salmonella among hospitalized large animals at a veterinary hospital. (2) Compare results obtained using 2 comparison groups for risk factor analysis-large animals with high confidence in negative shedding status and those with potential for misclassification of shedding status. ANIMALS: Large animals admitted from March 2002 through December 2012. METHODS: A case-control study was conducted among all hospitalized large animals that were routinely cultured as part of infection control efforts. Animal and hospital factors were evaluated. Data on factors of interest were collected retrospectively from electronic medical records. Multivariable conditional logistic regression was used to evaluate associations between animal factors and fecal shedding of Salmonella enterica. RESULTS: During the study period, 5.9% (648/11 061) of hospitalized large animals were culture positive for Salmonella, with the majority being cattle (72%; 467/648) and horses (22%; 143/648). Although the odds of shedding varied by comparison group, overall, 69.4% of animal shedding could be attributed to systemic illness (population attributable fraction) in this study. CONCLUSIONS AND CLINICAL IMPORTANCE: Findings of this study inform our understanding of factors affecting Salmonella shedding in hospitalized large animals, thus improving our ability for implementation of evidence-based control measures.