A Survey of Spotted Fever Group Rickettsia and Anaplasmataceae Bacteria in Questing Ticks in Hokkaido, Japan.

IF 1.8 4区医学 Q3 INFECTIOUS DISEASES

Vector borne and zoonotic diseases Pub Date : 2026-06-01 Epub Date: 2026-02-24 DOI:10.1177/15303667261424704

Masakatsu Taira, Thillaiampalam Sivakumar, Yihong Ma, Rika Umemiya-Shirafuji, Naoaki Yokoyama, Ken Maeda

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Abstract

Background: Tick-borne diseases caused by spotted fever group (SFG) Rickettsia and members of the family Anaplasmataceae are important public health concerns. Given that previous studies on SFG in Hokkaido, the northernmost prefecture of Japan, have been limited by small sample sizes or limited to specific pathogens or tick species, the epidemiology of tick-borne bacteria remains unclear. This study investigated the prevalence of SFG Rickettsia and Anaplasmataceae bacteria in multiple tick species in Hokkaido.

Methods: DNA was extracted from 1,115 questing ticks representing six species (548 Ixodes ovatus, 368 Ixodes persulcatus, 95 Haemaphysalis concinna, 74 Haemaphysalis japonica, 28 Haemaphysalis megaspinosa, and 2 Haemaphysalis longicornis) collected from six districts in Hokkaido. Samples were screened using PCR assays targeting the gltA gene of SFG Rickettsia species and the groEL gene of Anaplasmataceae. Amplicons were sequenced for species identification.

Results: SFG Rickettsia DNA was found only in I. persulcatus (48.9%, 180/368), including R. helvetica (32.1%) and Candidatus R. tarasevichiae (16.8%). Anaplasmataceae DNA was detected in 3.9% (44/1,115) of ticks, including I. persulcatus, I. ovatus, H. japonica, and H. megaspinosa. In I. persulcatus, Ehrlichia muris, Candidatus Neoehrlichia mikurensis, and Anaplasma phagocytophilum were detected in 4.6%, 3.3%, and 0.3%, respectively. Ehrlichia japonica was found in I. ovatus (0.9%), while unclassified Ehrlichia spp. were detected in H. japonica (1.4%) and H. megaspinosa (3.6%). Seventeen I. persulcatus (4.6%) carried both SFG Rickettsia and Anaplasmataceae.

Conclusions: The findings showed that questing ticks in Hokkaido harbor zoonotic bacteria. While I. persulcatus appears to be the principal vector, the detection of pathogens in I. ovatus, H. japonica, and H. megaspinosa suggests the potential for additional vectors in the region. These findings underscore the importance of continuous surveillance and heightened clinical awareness of tick-borne diseases in northern Japan.

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日本北海道地区斑点热群立克次体及无形体科蜱类调查。

背景：由斑点热组（SFG）立克次体和无形体科成员引起的蜱传疾病是重要的公共卫生问题。鉴于之前在日本最北部的北海道对SFG的研究受到小样本量或限于特定病原体或蜱类的限制，蜱传细菌的流行病学仍不清楚。本研究调查了北海道多种蜱类中SFG立克次体和无形体科细菌的流行情况。方法：对北海道6个区采集的6种蜱类1115只（卵形血蜱548只、过角血蜱368只、细腹血蜱95只、日本血蜱74只、巨棘血蜱28只、长角血蜱2只）进行DNA提取。采用PCR方法对SFG立克次体gltA基因和无形体科立克次体groEL基因进行筛选。扩增子测序用于物种鉴定。结果：仅在过sulsulcatus中检出SFG立克次体DNA(48.9%, 180/368)，包括helvetica（32.1%）和taraseviciae（16.8%）。在3.9%（44/ 1115）的蜱中检出无原体科DNA，包括过狭蜱、卵形蜱、日本蜱和巨棘蜱。在过乳杆菌中，分别检出鼠立体、mikurenis新立体和嗜吞噬细胞无形体，检出率分别为4.6%、3.3%和0.3%。卵形姬蚊中检出日本埃立体（0.9%），日本姬蚊中检出未分类埃立体（1.4%），大棘球绦虫中检出埃立体（3.6%）。17株（4.6%）同时携带SFG立克次体和无形体菌科。结论：北海道口岸人畜共患病细菌中蜱类的调查结果。虽然过乳蜱似乎是主要的病媒，但在卵形蜱、日本血吸虫和大棘棘蜱中检测到的病原体表明，该地区可能存在其他病媒。这些发现强调了在日本北部持续监测和提高对蜱传疾病临床认识的重要性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Vector borne and zoonotic diseases 医学-传染病学

CiteScore

4.70

自引率

4.80%

发文量

审稿时长

3-8 weeks

期刊介绍： Vector-Borne and Zoonotic Diseases is an authoritative, peer-reviewed journal providing basic and applied research on diseases transmitted to humans by invertebrate vectors or non-human vertebrates. The Journal examines geographic, seasonal, and other risk factors that influence the transmission, diagnosis, management, and prevention of this group of infectious diseases, and identifies global trends that have the potential to result in major epidemics. Vector-Borne and Zoonotic Diseases coverage includes: -Ecology -Entomology -Epidemiology -Infectious diseases -Microbiology -Parasitology -Pathology -Public health -Tropical medicine -Wildlife biology -Bacterial, rickettsial, viral, and parasitic zoonoses