Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Acute clinical, hematologic, serologic, and polymerase chain reaction findings in horses experimentally infected with a European strain of Anaplasma phagocytophilum.
Abstract: Six horses were experimentally infected by administration of horse blood containing a Swedish strain of Anaplasma phagocytophilum. The polymerase chain reaction (PCR) signal was consistently detected 2-3 days before appearance of clinical signs and persisted 4-9 days beyond abatement of clinical signs, whereas diagnostic inclusion bodies were 1st noted on average 2.6 +/- 1.5 (SD) days after onset of fever. Clinical signs and hematologic changes were largely indistinguishable from those previously reported for diseases caused by A phagocytophilum (formerly Ehrlichia equi--"Californian agent") and the human-derived human granulocytic ehrlichiosis agent. Horses 1st demonstrated antibody response 12-16 days after inoculation, 2 cases of which were still febrile, and serotiters rapidly peaked within 3-7 days of clinical illness. One horse died during the acute stage of disease, but initial clinical signs and hematologic changes were similar to those of other infected horses. This report shows that, despite minor genetic differences, a European equine-derived strain of A. phagocytophilum may be similar in pathogenicity to the Californian agent. The PCR used holds promise to widen the diagnostic window and would also be diagnostic during the initial days of clinical disease when inclusions in neutrophils in blood smears are not yet apparent.
Publication Date: 2005-04-13 PubMed ID: 15822569DOI: 10.1892/0891-6640(2005)192.0.co;2Google Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
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.
The research article details an experiment where six horses were intentionally infected with a Swedish strain of Anaplasma phagocytophilum, studying the resultant clinical, hematological, serological, and molecular effects. The study found that despite minor genetic differences, the European strain proved similar to a Californian strain, with Polymerase chain reactions (PCR) providing considerable promise for early diagnosis.
Experimental Procedure and Findings
- The research commenced with six horses being experimentally infected with a Swedish variant of Anaplasma phagocytophilum, administered through horse blood.
- The team discovered that the PCR signal – a primary indicator of the presence of infection – could be consistently perceived between two and three days before any external clinical signs became visible. They also noted that this signal continued for four to nine days after the medical symptoms had subsided.
- Inclusions, which are structures formed inside the cell after infections, first emerged an average of 2.6 days after the fever kicked in.
Comparison with Other Findings
- The clinical signs and hematologic changes observed in the horses closely resembled those previously reported for diseases caused by A. phagocytophilum and other human-derived agents.
- These signs and changes were indistinguishable, suggesting an overall similarity between the European strain and others, despite minor genetic differences.
- There was an initial delay in antibody response, which was noted 12-16 days after inoculation, peaking rapidly within 3-7 days of clinical illness.
Conclusions and Implications
- Although one horse did die during the acute stage of the disease, its initial clinical signs and hematologic changes did not differ from the other horses, further supporting the consistent nature of the infection.
- The researchers concluded that the European equine-derived strain of A. phagocytophilum might be almost as pathogenic as the Californian agent.
- Significantly, the team expressed confidence in the PCR testing ability to enlarge the diagnostic window, enabling diagnosis during the early days when inclusions are not yet visible in blood smears.
Cite This Article
APA
Franzén P, Aspan A, Egenvall A, Gunnarsson A, Aberg L, Pringle J.
(2005).
Acute clinical, hematologic, serologic, and polymerase chain reaction findings in horses experimentally infected with a European strain of Anaplasma phagocytophilum.
J Vet Intern Med, 19(2), 232-239.
https://doi.org/10.1892/0891-6640(2005)192.0.co;2 Publication
Researcher Affiliations
- Department of Large Animal Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden. peter.franzen@nshorse.se
MeSH Terms
- Anaplasma phagocytophilum / immunology
- Anaplasma phagocytophilum / isolation & purification
- Animals
- Antibodies, Bacterial / blood
- Blood Cell Count / veterinary
- Body Temperature
- Ehrlichiosis / blood
- Ehrlichiosis / immunology
- Ehrlichiosis / physiopathology
- Ehrlichiosis / veterinary
- Horse Diseases / blood
- Horse Diseases / immunology
- Horse Diseases / physiopathology
- Horses
- Polymerase Chain Reaction / veterinary
Citations
This article has been cited 18 times.- Karbowiak G, Klich D, Werszko J, Świsłocka-Cutter M, Slivinska K, Wojciechowska M, Kloch M, Asman M, Olech W. Arthropod-borne pathogens in European bison Bison bonasus (Linnaeus, 1758). Int J Parasitol Parasites Wildl 2025 Aug;27:101110.
- Bogdan AM, Mitrea IL, Ionita M. Equine Granulocytic Anaplasmosis: A Systematic Review and Meta-Analysis on Clinico-Pathological Findings, Diagnosis, and Therapeutic Management. Vet Sci 2024 Jun 13;11(6).
- Athanasiou LV, Katsogiannou EG, Tyrnenopoulou P, Gougoulis D, Apostolidis KN, Papadakis SM, Kokkinaki KCG, Papatsiros VG, Tsokana CN. Evidence of Horse Exposure to Anaplasma phagocytophilum, Borrelia burgdorferi, and Leishmania infantum in Greece through the Detection of IgG Antibodies in Serum and in an Alternative Diagnostic Sample-The Saliva. Biomolecules 2023 Sep 11;13(9).
- Gehlen H, Inerle K, Bartel A, Stöckle SD, Ulrich S, Briese B, Straubinger RK. Seroprevalence of Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum Infections in German Horses. Animals (Basel) 2023 Jun 14;13(12).
- Athanasiou LV, Tsokana CN, Gougoulis DA, Tzivara AH, Dedousi A, Katsoulos PD. Natural Co-Exposure to Borrelia burgdorferi s.l. and Anaplasma phagocytophilum: Unraveling the Hematological Profile in Sheep. Life (Basel) 2023 Feb 8;13(2).
- Bauer BU, Răileanu C, Tauchmann O, Fischer S, Ambros C, Silaghi C, Ganter M. Anaplasma phagocytophilum and Anaplasma ovis-Emerging Pathogens in the German Sheep Population. Pathogens 2021 Oct 9;10(10).
- Campos JBV, Martins FS, de Oliveira CE, Taveira AA, Oliveira JR, Gonçalves LR, Cordeiro MD, Calchi AC, de Campos Binder L, Serpa MCA, Barbieri ARM, Labruna MB, Machado RZ, de Andrade GB, André MR, Herrera HM. Tick-borne zoonotic agents infecting horses from an urban area in Midwestern Brazil: epidemiological and hematological features. Trop Anim Health Prod 2021 Sep 22;53(5):475.
- Costa SCL, de Souza Freitas J, Carvalho FS, Pereira MJS, Cordeiro MD, da Fonseca AH, Gomes Jusi MM, Machado RZ, Munhoz AD. Frequency and factors associated of potential zoonotic pathogens (Borrelia spp., Rickettsia spp., Leishmania spp., and Anaplasma phagocytophilum) in equids in the state of Bahia, Brazil. Parasit Vectors 2021 May 22;14(1):275.
- Ebani VV. Serological Evidence of Anaplasma phagocytophilum and Spotted Fever Group Rickettsia spp. Exposure in Horses from Central Italy. Pathogens 2019 Jun 26;8(3).
- Grandi G, Aspán A, Pihl J, Gustafsson K, Engström F, Jinnerot T, Söderlund R, Chirico J. Detection of Tick-Borne Pathogens in Lambs Undergoing Prophylactic Treatment Against Ticks on Two Swedish Farms. Front Vet Sci 2018;5:72.
- Schvartz G, Epp T, Burgess HJ, Chilton NB, Pearl DL, Lohmann KL. Seroprevalence of equine granulocytic anaplasmosis and lyme borreliosis in Canada as determined by a point-of-care enzyme-linked immunosorbent assay (ELISA). Can Vet J 2015 Jun;56(6):575-80.
- Malmsten J, Widén DG, Rydevik G, Yon L, Hutchings MR, Thulin CG, Söderquist L, Aspan A, Stuen S, Dalin AM. Temporal and spatial variation in Anaplasma phagocytophilum infection in Swedish moose (Alces alces). Epidemiol Infect 2014 Jun;142(6):1205-13.
- Stuen S, Granquist EG, Silaghi C. Anaplasma phagocytophilum--a widespread multi-host pathogen with highly adaptive strategies. Front Cell Infect Microbiol 2013;3:31.
- Uehlinger FD, Clancey NP, Lofstedt J. Granulocytic anaplasmosis in a horse from Nova Scotia caused by infection with Anaplasma phagocytophilum. Can Vet J 2011 May;52(5):537-40.
- Silaghi C, Liebisch G, Pfister K. Genetic variants of Anaplasma phagocytophilum from 14 equine granulocytic anaplasmosis cases. Parasit Vectors 2011 Aug 16;4:161.
- Severinsson K, Jaenson TG, Pettersson J, Falk K, Nilsson K. Detection and prevalence of Anaplasma phagocytophilum and Rickettsia helvetica in Ixodes ricinus ticks in seven study areas in Sweden. Parasit Vectors 2010 Aug 4;3:66.
- Hansen MG, Christoffersen M, Thuesen LR, Petersen MR, Bojesen AM. Seroprevalence of Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum in Danish horses. Acta Vet Scand 2010 Jan 18;52(1):3.
- Stuen S. Anaplasma phagocytophilum - the most widespread tick-borne infection in animals in Europe. Vet Res Commun 2007 Aug;31 Suppl 1:79-84.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
