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Home / Equine Research Bank / Can Vet J / Potomac horse fever in Ontario: Clinical, geographic, and di...
The Canadian veterinary journal = La revue veterinaire canadienne2021; 62(6); 622-628;

Potomac horse fever in Ontario: Clinical, geographic, and diagnostic aspects.

Abstract: Clinical findings, geographic locations, laboratory diagnoses, and culture isolation of spp. in Potomac horse fever (PHF) cases diagnosed in Ontario between 2015 and 2019 are described. Forty-six confirmed PHF cases occurred from late June to early September. Of 41 horses admitted to the Ontario Veterinary College, 28 (68%) survived and 13 (32%) were euthanized due to poor prognosis or financial constraints. Most cases were in southern Ontario along the Canada-USA border. Blood and fecal samples from 43 suspect PHF cases were submitted to 2 laboratories for polymerase chain reaction (PCR) testing for . Agreement between both laboratories for detection of DNA was excellent for feces [κ = 0.932, 95% confidence interval (CI): 0.80 to 1], and fair for blood samples (κ = 0.494, 95% CI: 0.13 to 0.85). spp. were isolated from 16 of 41 (39%) blood samples. DNA analysis confirmed 14 isolates were and 2 were , a novel species of recently demonstrated to cause PHF. . Les résultats cliniques, emplacements géographiques, diagnostics de laboratoire et isolement par culture de spp. dans les cas de fièvre équine du Potomac (PHF) diagnostiqués en Ontario entre 2015 et 2019 sont décrits. Quarante-six cas confirmés de PHF sont survenus de la fin juin au début septembre. Sur 41 chevaux admis au , 28 (68%) ont survécu et 13 (32%) ont été euthanasiés en raison d’un mauvais pronostic ou de contraintes financières. La plupart des cas se trouvaient dans le sud de l’Ontario, le long de la frontière canado-américaine. Des échantillons de sang et de matières fécales provenant de 43 cas suspects de PHF ont été soumis à deux laboratoires pour des tests de réaction d’amplification en chaîne par la polymérase (PCR) pour . La concordance entre les deux laboratoires pour la détection de l’ADN de était excellente pour les selles [κ = 0,932, intervalle de confiance (IC) à 95% : 0,80 à 1] et passable pour les échantillons sanguins (κ = 0,494, IC à 95% : 0,13 à 0,85). spp. ont été isolés à partir de 16 des 41 échantillons de sang (39%). L’analyse de l’ADN a confirmé que 14 isolats étaient et deux étaient , une nouvelle espèce de récemment démontrée comme causant le PHF.(Traduit par D Serge Messier).
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Publication Date: 2021-07-06 PubMed ID: 34219771PubMed Central: PMC8118184
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This study provides insight into Potomac horse fever (PHF) cases that occurred over four years in Ontario, detailing the clinical symptoms, locations, lab diagnoses, and the types of pathogens found in infected horses.

Study Background

  • The research focuses on a disease known as Potomac horse fever (PHF), which was diagnosed in many horses in the Ontario region between 2015 and 2019. This disease, caused by the pathogen , often poses severe threats to equine health, occasionally leading to euthanization due to grave prognosis or financial restrictions on treatment.
  • The study seeks to provide insights into the geographical spread, clinical symptoms, laboratory diagnostic procedures and the specifics of culture isolation in these PHF cases.

Key Findings

  • There were 46 confirmed cases of PHF, primarily occurring from June to September. This time frame may suggest a link between the disease outbreak and certain seasonal environmental factors.
  • Of these cases, the majority were recorded in Southern Ontario along the Canada-USA border. This may indicate that PHF has a regional cluster in this geographical area.
  • Out of 41 horses admitted to the Ontario Veterinary College for treatment due to PHF, 28 (68%) survived, but 13 (32%) had to be euthanized, either due to a poor prognosis or financial constraints.

Diagnostic Practices

  • The research involved submitting blood and fecal samples from 43 suspected PHF cases to two separate labs for Polymerase Chain Reaction (PCR) testing—a common method of DNA detection—to detect .
  • Both laboratories reported excellent agreement (κ = 0.932) in detecting DNA in fecal samples, suggesting a high reliability in the testing method for feces. The agreement was fair (κ = 0.494) for blood samples, indicating that this method was less reliably applied to blood samples.
  • isolates were found in 39% (16 of 41) blood samples.
  • Through DNA analysis, the study found that 14 of these isolates were and 2 were —a recently discovered species of that has been shown to cause PHF.

Summary

This study provides insights about Potomac horse fever (PHF) cases in Ontario, including the disease’s prevalence, geographic distribution, and associated factors. Additionally, it highlights the need for reliable diagnostic procedures and methods, particularly for effective disease detection and management.

Cite This Article

APA
Arroyo LG, Moore A, Bedford S, Gomez DE, Teymournejad O, Xiong Q, Budachetri K, Bekebrede H, Rikihisa Y, Baird JD. (2021). Potomac horse fever in Ontario: Clinical, geographic, and diagnostic aspects. Can Vet J, 62(6), 622-628.

Publication

The Canadian veterinary journal = La revue veterinaire canadienne
ISSN: 0008-5286
NlmUniqueID: 0004653
Country: Canada
Language: English
Volume: 62
Issue: 6
Pages: 622-628

Researcher Affiliations

Arroyo, Luis G
  • Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1 (Arroyo, Bedford, Gomez, Baird); Ontario Ministry of Agriculture, Food, and Rural Affairs, Guelph, Ontario N1G 4Y2 (Moore); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA (Teymournejad, Xiong, Budachetri, Bekebrede, Rikihisa).
Moore, Alison
  • Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1 (Arroyo, Bedford, Gomez, Baird); Ontario Ministry of Agriculture, Food, and Rural Affairs, Guelph, Ontario N1G 4Y2 (Moore); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA (Teymournejad, Xiong, Budachetri, Bekebrede, Rikihisa).
Bedford, Sofia
  • Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1 (Arroyo, Bedford, Gomez, Baird); Ontario Ministry of Agriculture, Food, and Rural Affairs, Guelph, Ontario N1G 4Y2 (Moore); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA (Teymournejad, Xiong, Budachetri, Bekebrede, Rikihisa).
Gomez, Diego E
  • Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1 (Arroyo, Bedford, Gomez, Baird); Ontario Ministry of Agriculture, Food, and Rural Affairs, Guelph, Ontario N1G 4Y2 (Moore); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA (Teymournejad, Xiong, Budachetri, Bekebrede, Rikihisa).
Teymournejad, Omid
  • Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1 (Arroyo, Bedford, Gomez, Baird); Ontario Ministry of Agriculture, Food, and Rural Affairs, Guelph, Ontario N1G 4Y2 (Moore); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA (Teymournejad, Xiong, Budachetri, Bekebrede, Rikihisa).
Xiong, Qingming
  • Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1 (Arroyo, Bedford, Gomez, Baird); Ontario Ministry of Agriculture, Food, and Rural Affairs, Guelph, Ontario N1G 4Y2 (Moore); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA (Teymournejad, Xiong, Budachetri, Bekebrede, Rikihisa).
Budachetri, Khemraj
  • Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1 (Arroyo, Bedford, Gomez, Baird); Ontario Ministry of Agriculture, Food, and Rural Affairs, Guelph, Ontario N1G 4Y2 (Moore); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA (Teymournejad, Xiong, Budachetri, Bekebrede, Rikihisa).
Bekebrede, Hannah
  • Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1 (Arroyo, Bedford, Gomez, Baird); Ontario Ministry of Agriculture, Food, and Rural Affairs, Guelph, Ontario N1G 4Y2 (Moore); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA (Teymournejad, Xiong, Budachetri, Bekebrede, Rikihisa).
Rikihisa, Yasuko
  • Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1 (Arroyo, Bedford, Gomez, Baird); Ontario Ministry of Agriculture, Food, and Rural Affairs, Guelph, Ontario N1G 4Y2 (Moore); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA (Teymournejad, Xiong, Budachetri, Bekebrede, Rikihisa).
Baird, John D
  • Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1 (Arroyo, Bedford, Gomez, Baird); Ontario Ministry of Agriculture, Food, and Rural Affairs, Guelph, Ontario N1G 4Y2 (Moore); Laboratory of Molecular, Cellular, and Environmental Rickettsiology, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210, USA (Teymournejad, Xiong, Budachetri, Bekebrede, Rikihisa).

MeSH Terms

  • Anaplasmataceae Infections / diagnosis
  • Anaplasmataceae Infections / epidemiology
  • Anaplasmataceae Infections / veterinary
  • Animals
  • Euthanasia, Animal
  • Horse Diseases / diagnosis
  • Horse Diseases / epidemiology
  • Horses
  • Neorickettsia risticii
  • Ontario / epidemiology

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Citations

This article has been cited 8 times.
  1. Normandeau J. Non-surgical correction of nephrosplenic entrapment and colitis in a Quarter Horse. Can Vet J 2022 Dec;63(12):1255-1257.
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  3. Gomez DE, Leclere M, Arroyo LG, Li L, John E, Afonso T, Payette F, Darby S. Acute diarrhea in horses: A multicenter Canadian retrospective study (2015 to 2019). Can Vet J 2022 Oct;63(10):1033-1042.
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