FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / BMC Vet Res / Nine-year seroepidemiological study of severe fever with thr...
BMC veterinary research2024; 20(1); 190; doi: 10.1186/s12917-024-04042-7

Nine-year seroepidemiological study of severe fever with thrombocytopenia syndrome virus infection in feral horses in Cape Toi, Japan.

Abstract: Severe fever with thrombocytopenia syndrome (SFTS) is a fatal zoonosis caused by ticks in East Asia. As SFTS virus (SFTSV) is maintained between wildlife and ticks, seroepidemiological studies in wildlife are important to understand the behavior of SFTSV in the environment. Miyazaki Prefecture, Japan, is an SFTS-endemic area, and approximately 100 feral horses, called Misaki horses (Equus caballus), inhabit Cape Toi in Miyazaki Prefecture. While these animals are managed in a wild-like manner, their ages are ascertainable due to individual identification. In the present study, we conducted a seroepidemiological survey of SFTSV in Misaki horses between 2015 and 2023. This study aimed to understand SFTSV infection in horses and its transmission to wildlife. A total of 707 samples from 180 feral horses were used to determine the seroprevalence of SFTSV using enzyme-linked immunosorbent assay (ELISA). Neutralization testing was performed on 118 samples. In addition, SFTS viral RNA was detected in ticks from Cape Toi and feral horses. The overall seroprevalence between 2015 and 2023 was 78.5% (555/707). The lowest seroprevalence was 55% (44/80) in 2016 and the highest was 92% (76/83) in 2018. Seroprevalence was significantly affected by age, with 11% (8/71) in those less than one year of age and 96.7% (435/450) in those four years of age and older (p < 0.0001). The concordance between ELISA and neutralization test results was 88.9% (105/118). SFTS viral RNA was not detected in ticks (n = 516) or feral horses. This study demonstrated that horses can be infected with SFTSV and that age is a significant factor in seroprevalence in wildlife. This study provides insights into SFTSV infection not only in horses but also in wildlife in SFTS-endemic areas.
© 2024. The Author(s).
Get Full Text
Publication Date: 2024-05-11 PubMed ID: 38734647PubMed Central: 7101122DOI: 10.1186/s12917-024-04042-7Google 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.
LinkedInCopy
  • 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 research study examines the spread of severe fever with thrombocytopenia syndrome (SFTS) virus among wild horses in Cape Toi, Japan over a span of nine years. It showed age as a significant factor in infection rates and demonstrated that the disease could be spread to these animals.

Overview

  • The study focuses on the transmission and prevalence of severe fever with thrombocytopenia syndrome virus (SFTSV) in wild horses or Misaki horses living in Cape Toi, Japan, an area where SFTS is endemic.
  • The research spanned nine years, from 2015 to 2023.

Methodology and Data Collection

  • 707 samples were collected from 180 wild horses over the research period to calculate the seroprevalence of SFTSV.
  • An enzyme-linked immunosorbent assay (ELISA) was used to analyze these samples, and neutralization testing was conducted on 118 samples.
  • In addition to the horse samples, viral RNA was extracted from ticks in the area to detect the presence of SFTSV.

Findings

  • The study reported an overall seroprevalence of 78.5% between 2015 and 2023, demonstrating a high rate of SFTSV infection in the wild horses.
  • The prevalence varied from year to year, with the lowest 55% recorded in 2016 and the highest, 92%, in 2018
  • Being affected by age was a significant factor, with horses less than a year old having a lower seroprevalence (11%) than older horses (96.7%).
  • The findings from the ELISA and neutralization tests were very similar (88.9% concordance).
  • Surprisingly, SFTS viral RNA was not detected in the ticks or horses tested.

Implications

  • You can conclude from the study that SFTSV can infect wild horses and that age is a significant factor in susceptibility.
  • The study is valuable for understanding the transmission of SFTS in wildlife, particularly in regions where the disease is endemic.

Cite This Article

APA
Mekata H, Yamada K, Umeki K, Yamamoto M, Ochi A, Umekita K, Kobayashi I, Hirai T, Okabayashi T. (2024). Nine-year seroepidemiological study of severe fever with thrombocytopenia syndrome virus infection in feral horses in Cape Toi, Japan. BMC Vet Res, 20(1), 190. https://doi.org/10.1186/s12917-024-04042-7

Publication

BMC veterinary research
ISSN: 1746-6148
NlmUniqueID: 101249759
Country: England
Language: English
Volume: 20
Issue: 1
Pages: 190

Researcher Affiliations

Mekata, Hirohisa
  • Division of Research & Inspection for Infectious Diseases, Center for Animal Disease Control, University of Miyazaki, 1-1 Gakuen-kibanadai Nishi, Miyazaki, 889-2192, Japan. mekata@cc.miyazaki-u.ac.jp.
Yamada, Kentaro
  • Division of Research & Inspection for Infectious Diseases, Center for Animal Disease Control, University of Miyazaki, 1-1 Gakuen-kibanadai Nishi, Miyazaki, 889-2192, Japan.
  • Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen-kibanadai Nishi, Miyazaki, 889-2192, Japan.
  • Department of Microbiology, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita, 879-5593, Japan.
Umeki, Kazumi
  • Division of Respirology Rheumatology, Infectious Diseases and Neurology, Internal Medicine, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, 5200-Kihara, Kiyotake, Miyazaki, 889-1692, Japan.
Yamamoto, Mari
  • Division of Research & Inspection for Infectious Diseases, Center for Animal Disease Control, University of Miyazaki, 1-1 Gakuen-kibanadai Nishi, Miyazaki, 889-2192, Japan.
Ochi, Akihiro
  • Equine Research Institute, Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi, 329-0412, Japan.
Umekita, Kunihiko
  • Division of Research & Inspection for Infectious Diseases, Center for Animal Disease Control, University of Miyazaki, 1-1 Gakuen-kibanadai Nishi, Miyazaki, 889-2192, Japan.
  • Division of Respirology Rheumatology, Infectious Diseases and Neurology, Internal Medicine, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, 5200-Kihara, Kiyotake, Miyazaki, 889-1692, Japan.
Kobayashi, Ikuo
  • Division of Research & Inspection for Infectious Diseases, Center for Animal Disease Control, University of Miyazaki, 1-1 Gakuen-kibanadai Nishi, Miyazaki, 889-2192, Japan.
  • Field Science Center, Faculty of Agriculture, University of Miyazaki, 10100-1 Shimanouchi, Miyazaki, 880-0121, Japan.
Hirai, Takuya
  • Division of Research & Inspection for Infectious Diseases, Center for Animal Disease Control, University of Miyazaki, 1-1 Gakuen-kibanadai Nishi, Miyazaki, 889-2192, Japan.
  • Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen-kibanadai Nishi, Miyazaki, 889-2192, Japan.
Okabayashi, Tamaki
  • Division of Research & Inspection for Infectious Diseases, Center for Animal Disease Control, University of Miyazaki, 1-1 Gakuen-kibanadai Nishi, Miyazaki, 889-2192, Japan.
  • Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen-kibanadai Nishi, Miyazaki, 889-2192, Japan.

MeSH Terms

  • Animals
  • Horses
  • Seroepidemiologic Studies
  • Japan / epidemiology
  • Horse Diseases / epidemiology
  • Horse Diseases / virology
  • Horse Diseases / blood
  • Phlebovirus / isolation & purification
  • Severe Fever with Thrombocytopenia Syndrome / epidemiology
  • Severe Fever with Thrombocytopenia Syndrome / veterinary
  • Severe Fever with Thrombocytopenia Syndrome / virology
  • Female
  • Male
  • Antibodies, Viral / blood
  • Ticks / virology
  • Enzyme-Linked Immunosorbent Assay / veterinary
  • Animals, Wild / virology

Grant Funding

  • JP21fk0108495 / Japan Agency for Medical Research and Development
  • JP21fk0108495 / Japan Agency for Medical Research and Development
  • JP21fk0108495 / Japan Agency for Medical Research and Development
  • JP21fk0108495 / Japan Agency for Medical Research and Development

References

This article includes 41 references
  1. Kobayashi Y, Kato H, Yamagishi T, Shimada T, Matsui T, Yoshikawa T. Severe fever with thrombocytopenia syndrome, Japan, 2013–2017. Emerg Infect Dis 2020;26:692–9.
    doi: 10.3201/eid2604.191011pubmed: 32186502pmc: 7101122google scholar: lookup
  2. Miao D, Liu MJ, Wang YX, Ren X, Lu QB, Zhao GP. Epidemiology and ecology of severe fever with thrombocytopenia syndrome in China, 2010–2018. Clin Infect Dis 2021;73:e3851–8.
    doi: 10.1093/cid/ciaa1561pubmed: 33068430google scholar: lookup
  3. Yun SM, Park SJ, Kim YI, Park SW, Yu MA, Kwon HI. Genetic and pathogenic diversity of severe fever with thrombocytopenia syndrome virus (SFTSV) in South Korea. JCI Insight 2020;5:e129531.
    doi: 10.1172/jci.insight.129531pubmed: 31877113pmc: 7098714google scholar: lookup
  4. Yu XJ, Liang MF, Zhang SY, Liu Y, Li JD, Sun YL. Fever with thrombocytopenia associated with a novel bunyavirus in China. N Engl J Med 2011;364:1523–32.
    doi: 10.1056/NEJMoa1010095pubmed: 21410387pmc: 3113718google scholar: lookup
  5. Park SW, Han MG, Yun SM, Park C, Lee WJ, Ryou J. Severe fever with thrombocytopenia syndrome virus, South Korea, 2013. Emerg Infect Dis 2014;20:1880–2.
    doi: 10.3201/eid2011.140888pubmed: 25341085pmc: 4214315google scholar: lookup
  6. Yoshikawa T, Shimojima M, Fukushi S, Tani H, Fukuma A, Taniguchi S. Phylogenetic and geographic relationships of severe fever with thrombocytopenia syndrome virus in China, South Korea, and Japan. J Infect Dis 2015;212:889–98.
    doi: 10.1093/infdis/jiv144pubmed: 25762790google scholar: lookup
  7. Zhang YZ, He YW, Dai YA, Xiong Y, Zheng H, Zhou DJ. Hemorrhagic fever caused by a novel bunyavirus in China: pathogenesis and correlates of fatal outcome. Clin Infect Dis 2012;54:527–33.
    doi: 10.1093/cid/cir804pubmed: 22144540google scholar: lookup
  8. Rattanakomol P, Khongwichit S, Linsuwanon P, Lee KH, Vongpunsawad S, Poovorawan Y. Severe fever with thrombocytopenia syndrome virus infection, Thailand, 2019–2020. Emerg Infect Dis 2022;28:2572–4.
    doi: 10.3201/eid2812.221183pubmed: 36418010pmc: 9707585google scholar: lookup
  9. Tran XC, Yun Y, Van An L, Kim SH, Thao NTP, Man PKC. Endemic severe fever with thrombocytopenia syndrome, Vietnam. Emerg Infect Dis 2019;25:1029–31.
    doi: 10.3201/eid2505.181463pubmed: 31002059pmc: 6478219google scholar: lookup
  10. Win AM, Nguyen YTH, Kim Y, Ha NY, Kang JG, Kim H. Genotypic heterogeneity of orientia tsutsugamushi in scrub typhus patients and thrombocytopenia syndrome co-infection, Myanmar. Emerg Infect Dis 2020;26:1878–81.
    doi: 10.3201/eid2608.200135pubmed: 32687023pmc: 7392420google scholar: lookup
  11. Zohaib A, Zhang J, Saqib M, Athar MA, Hussain MH, Chen J. Serologic evidence of severe fever with thrombocytopenia syndrome virus and related viruses in Pakistan. Emerg Infect Dis 2020;26:1513–6.
    doi: 10.3201/eid2607.190611pubmed: 32568060pmc: 7323538google scholar: lookup
  12. Kirino Y, Yamanaka A, Ishijima K, Tatemoto K, Maeda K, Okabayashi T. Retrospective study on the possibility of an SFTS outbreak associated with undiagnosed febrile illness in veterinary professionals and a family with sick dogs in 2003. J Infect Chemother 2022;28:753–6.
    doi: 10.1016/j.jiac.2022.02.011pubmed: 35219579google scholar: lookup
  13. Mekata H, Kawaguchi T, Iwao K, Umeki K, Yamada K, Umekita K. Possible transmission of severe fever with the thrombocytopenia syndrome virus to an individual who buried an infected cat. Jpn J Infect Dis 2023;76:211–4.
    doi: 10.7883/yoken.JJID.2022.425pubmed: 36724938google scholar: lookup
  14. Yamanaka A, Kirino Y, Fujimoto S, Ueda N, Himeji D, Miura M. Direct transmission of severe fever with thrombocytopenia syndrome virus from domestic cat to veterinary personnel. Emerg Infect Dis 2020;26:2994–8.
    doi: 10.3201/eid2612.191513pubmed: 33219655pmc: 7706950google scholar: lookup
  15. Matsuu A, Momoi Y, Nishiguchi A, Noguchi K, Yabuki M, Hamakubo E. Natural severe fever with thrombocytopenia syndrome virus infection in domestic cats in Japan. Vet Microbiol 2019;236:108346.
    doi: 10.1016/j.vetmic.2019.06.019pubmed: 31500732google scholar: lookup
  16. Ishijima K, Tatemoto K, Park E, Kimura M, Fujita O, Taira M. Lethal disease in dogs naturally infected with severe fever with thrombocytopenia syndrome virus. Viruses 2022;14:1963.
    doi: 10.3390/v14091963pubmed: 36146769pmc: 9502089google scholar: lookup
  17. Park SC, Park JY, Choi JY, Oh B, Yang MS, Lee SY. Experimental infection of dogs with severe fever with thrombocytopenia syndrome virus: pathogenicity and potential for intraspecies transmission. Transbound Emerg Dis 2022;69:3090–6.
    doi: 10.1111/tbed.14372pubmed: 34716981google scholar: lookup
  18. Gu XL, Su WQ, Zhou CM, Fang LZ, Zhu K, Ma DQ. SFTSV infection in rodents and their ectoparasitic chiggers. PLoS Negl Trop Dis 2022;16:e0010698.
    doi: 10.1371/journal.pntd.0010698pubmed: 36037170pmc: 9423666google scholar: lookup
  19. Kaneko C, Mekata H, Umeki K, Sudaryatma PE, Irie T, Yamada K. Seroprevalence of severe fever with thrombocytopenia syndrome virus in medium-sized wild mammals in Miyazaki, Japan. Ticks Tick Borne Dis 2023;14:102115.
    doi: 10.1016/j.ttbdis.2022.102115pubmed: 36577308google scholar: lookup
  20. Kuan CY, Lin TL, Ou SC, Chuang ST, Chan JP, Maeda K. The first nationwide surveillance of severe fever with thrombocytopenia syndrome in ruminants and wildlife in Taiwan. Viruses 2023;15:441.
    doi: 10.3390/v15020441pubmed: 36851653pmc: 9965706google scholar: lookup
  21. Niu G, Li J, Liang M, Jiang X, Jiang M, Yin H. Severe fever with thrombocytopenia syndrome virus among domesticated animals, China. Emerg Infect Dis 2013;19:756–63.
    doi: 10.3201/eid1905.120245pubmed: 23648209pmc: 3647489google scholar: lookup
  22. Tatemoto K, Mendoza MV, Ishijima K, Kuroda Y, Inoue Y, Taira M. Risk assessment of infection with severe fever with thrombocytopenia syndrome virus based on a 10-year serosurveillance in Yamaguchi Prefecture. J Vet Med Sci 2022;84:1142–5.
    doi: 10.1292/jvms.22-0255pubmed: 35793949pmc: 9412060google scholar: lookup
  23. Tatemoto K, Ishijima K, Kuroda Y, Mendoza MV, Inoue Y, Park E. Roles of raccoons in the transmission cycle of severe fever with thrombocytopenia syndrome virus. J Vet Med Sci 2022;84:982–91.
    doi: 10.1292/jvms.22-0236pubmed: 35650167pmc: 9353098google scholar: lookup
  24. Matsuno K, Nonoue N, Noda A, Kasajima N, Noguchi K, Takano A. Fatal tickborne phlebovirus infection in captive cheetahs, Japan. Emerg Infect Dis 2018;24:1726–9.
    doi: 10.3201/eid2409.171667pubmed: 30124411pmc: 6106400google scholar: lookup
  25. Lee H, Kim EJ, Cho IS, Song JY, Choi JS, Lee JY. A serological study of severe fever with thrombocytopenia syndrome using a virus neutralization test and competitive enzyme-linked immunosorbent assay. J Vet Sci 2017;18:33–8.
    doi: 10.4142/jvs.2017.18.1.33pubmed: 27297411pmc: 5366300google scholar: lookup
  26. Han SW, Cho YK, Rim JM, Kang JG, Choi KS, Chae JS. Molecular and serological survey of severe fever with thrombocytopenia syndrome virus in horses from the Republic of Korea. Vector Borne Zoonotic Dis 2023.
    doi: 10.1089/vbz.2022.0101pubmed: 37788402google scholar: lookup
  27. . Overview of SFTS cases notified in the national epidemiological surveillance of infectious diseases diseases. 2023.
  28. Mekata H, Kobayashi I, Okabayashi T. Detection and phylogenetic analysis of Dabieshan tick virus and Okutama tick virus in ticks collected from Cape Toi, Japan. Ticks Tick Borne Dis 2023;14:102237.
    doi: 10.1016/j.ttbdis.2023.102237pubmed: 37595529google scholar: lookup
  29. Umeki K, Yasuda A, Umekita K, Megumi R, Nomura H, Kawaguchi T. Detection of anti-SFTSV nuclear protein antibody in the acute phase sera of patients using double-antigen ELISA and immunochromatography. J Virol Methods 2020;285:113942.
    doi: 10.1016/j.jviromet.2020.113942pubmed: 32781007google scholar: lookup
  30. Sato Y, Mekata H, Sudaryatma PE, Kirino Y, Yamamoto S, Ando S. Isolation of severe fever with thrombocytopenia syndrome virus from various tick species in area with human severe fever with thrombocytopenia syndrome cases. Vector Borne Zoonotic Dis 2021;21:378–84.
    doi: 10.1089/vbz.2020.2720pubmed: 33535015google scholar: lookup
  31. Yoshikawa T, Fukushi S, Tani H, Fukuma A, Taniguchi S, Toda S. Sensitive and specific PCR systems for detection of both Chinese and Japanese severe fever with thrombocytopenia syndrome virus strains and prediction of patient survival based on viral load. J Clin Microbiol 2014;52:3325–33.
    doi: 10.1128/JCM.00742-14pubmed: 24989600pmc: 4313158google scholar: lookup
  32. Nunes M, Parreira R, Carreira T, Inácio J, Vieira ML. Development and evaluation of a two-step multiplex TaqMan real-time PCR assay for detection/quantification of different genospecies of borrelia burgdorferi sensu lato. Ticks Tick Borne Dis 2018;9:176–82.
    doi: 10.1016/j.ttbdis.2017.09.001pubmed: 28927817google scholar: lookup
  33. Taglinger K, Nguyen NV, Helps CR, Day MJ, Foster AP. Quantitative real-time RT-PCR measurement of cytokine mRNA expression in the skin of normal cats and cats with allergic skin disease. Vet Immunol Immunopathol 2008;122:216–30.
    doi: 10.1016/j.vetimm.2007.11.014pubmed: 18191230google scholar: lookup
  34. Mekata H, Umeki K, Yamada K, Umekita K, Okabayashi T. Nosocomial severe fever with thrombocytopenia syndrome in companion animals, Japan, 2022. Emerg Infect Dis 2023;29:614–7.
    doi: 10.3201/eid2903.220720pubmed: 36823498pmc: 9973679google scholar: lookup
  35. Hofmann H, Li X, Zhang X, Liu W, Kühl A, Kaup F. Severe fever with Thrombocytopenia virus glycoproteins are targeted by neutralizing antibodies and can use DC-SIGN as a receptor for pH-dependent entry into human and animal cell lines. J Virol 2013;87:4384–94.
    doi: 10.1128/JVI.02628-12pubmed: 23388721pmc: 3624395google scholar: lookup
  36. . The situation in the horse production area. 2023.
  37. Killick R, Eckley IA. Changepoint: an R package for changepoint analysis. J Stat Softw 2014;58:1–19.
    doi: 10.18637/jss.v058.i03google scholar: lookup
  38. Hashimoto T, Yahiro T, Yamada K, Kimitsuki K, Okuyama MW, Honda A. Distribution of severe fever with thrombocytopenia syndrome virus and antiviral antibodies in wild and domestic animals in oita prefecture, Japan. Am J Trop Med Hyg 2022;106:1547–51.
    doi: 10.4269/ajtmh.21-1130pubmed: 35226873pmc: 9128675google scholar: lookup
  39. Matsuu A, Hamakubo E, Yabuki M. Seroprevalence of severe fever with thrombocytopenia syndrome virus in animals in Kagoshima Prefecture, Japan, and development of gaussia luciferase immunoprecipitation system to detect specific IgG antibodies. Ticks Tick Borne Dis 2021;12:101771.
    doi: 10.1016/j.ttbdis.2021.101771pubmed: 34218054google scholar: lookup
  40. Hayasaka D, Fuxun Y, Yoshikawa A, Posadas-Herrera G, Shimada S, Tun MM. Seroepidemiological evidence of severe fever with thrombocytopenia syndrome virus infections in wild boars in Nagasaki, Japan. Trop Med Health 2016;44:6.
    doi: 10.1186/s41182-016-0009-6pubmed: 27433125pmc: 4940765google scholar: lookup
  41. Kirino Y, Yamamoto S, Nomachi T, Mai TN, Sato Y, Sudaryatma PE. Serological and molecular survey of tick-borne zoonotic pathogens including severe fever with thrombocytopenia syndrome virus in wild boars in Miyazaki Prefecture, Japan. Vet Med Sci 2022;8:877–85.
    doi: 10.1002/vms3.696pubmed: 34953052google scholar: lookup

Citations

This article has been cited 3 times.
  1. Mekata H, Yamamoto M, Matsuu A, Maeda K, Isawa H, Yoshii K, Umeki K, Okabayashi T. Development of a Double-Antigen Sandwich ELISA for Oz Virus and a Seroepidemiological Survey in Wild Boars in Miyazaki, Japan. Pathogens 2025 Dec 14;14(12).
    doi: 10.3390/pathogens14121288pubmed: 41471243google scholar: lookup
  2. Mekata H, Yamamoto M, Kaneko Y, Yamada K, Okabayashi T, Saito A. Urine of Cats with Severe Fever with Thrombocytopenia Syndrome: A Potential Source of Infection Transmission. Pathogens 2025 Mar 5;14(3).
    doi: 10.3390/pathogens14030254pubmed: 40137739google scholar: lookup
  3. Iijima H, Watari Y, Doi K, Yasuo K, Okabe K. Forest Fragmentation and Warmer Climate Increase Tick-Borne Disease Infection. Ecohealth 2025 Mar;22(1):124-137.
    doi: 10.1007/s10393-025-01702-4pubmed: 39864039google scholar: lookup
Subscribe to our newsletter
Join 99,001 horse owners like you who receive our email updates on horse health and nutrition.