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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).
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Publication Date: 2024-05-11 PubMed ID: 38734647PubMed Central: 7101122DOI: 10.1186/s12917-024-04042-7Google Scholar: Lookup
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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

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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).
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  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).
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  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.
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