TY  - JOUR
JF  - Acarologia
T1  - Clinical surveillance of tick-bite cases and ecological background of Amblyomma testudinarium biting in satoyama landscapes of northern Kanto, Japan
VL  - 66
IS  - Suppl
SP  - 178
EP  - 178
PY  - 2026
SN  - 0044-586X
SN  - 2107-7207
PB  - Les Amis d'Acarologia
AU  - Mizuho, Shimada
AU  - Yumie, Kobayashi
AU  - Yoshie, Hiirose
AU  - Hiroko, Kikuchi
AU  - Kandai, Doi
AU  - Takeo, Yamauchi
AU  - Hiroki, Kawabata
AU  - Shuji, Ando
AU  - Satoru, Komatsumoto
AU  - Toshimitsu, Murohisa
AU  - Jun, Gotoh
AU  - Satoshi, Shimano
UR  - https://doi.org/10.24349/2c0e-65ac
DO  - 10.24349/2c0e-65ac
DA  - 2026-07-20
ET  - 2026-07-20
KW  - Deer
KW  - Patients
KW  - Satoyama
KW  - Tick-borne infectious diseases
KW  - Wild boar
AB  - Tick-borne infections in Japan (e.g., scrub typhus, Japanese spotted fever, and severe fever with thrombocytopenia syndrome [SFTS]) show considerable epidemiological variation driven by vector ticks and wildlife hosts. To clarify determinants of tick-bite risk in northern Kanto, Japan, we combined >10-year clinical surveillance of tick-bite cases with field surveys of ticks in village-adjacent rural mosaic landscapes (satoyama), focusing on the dominant biting species Amblyomma testudinarium. A total of 216 tick-bite cases were recorded consecutively at a regional hospital for 10 years, from the first confirmed A. testudinarium case onward. In the same region, 1,223 ticks were collected from wild boars (Sus scrofa) and 2,297 ticks from sika deer (C ervus nippon) captured by wildlife pest control and 249 ticks by flagging in and aroundresidential gardens, small fields, and nearby trails. Host associations and seasonal dynamics were compared between two neighboring municipalities surveyed in consecutive years (2021–2022) to evaluate reproducibility across sites. Tick bites occurred mainly from spring to autumn, peaking in May–June, across all age classes; about 60% of patients were women, and bites were frequently on the lower body. Amblyomma testudinarium burdens were far higher on boars than on deer (ca. 10-fold in 2021 and ca. 45-fold in 2022) and the species was rarely recovered by flagging even around bite locations; adults were detected only on boars and increased in abundance from June. In contrast, Haemaphysalis longicornis was scarce on boars but abundant on deer, with a strong summer peak and consistent detection in flagged samples. These concordant, host- and stage-specific patterns suggest that boars using satoyama at the human–forest interface act as key bridge hosts that deliver heavily infested A. testudinarium into peri-domestic settings, helping explain its predominance among biting ticks, whereas deer likely sustain H. longicornis and contribute to persistent background exposure. Integrated clinical–ecological surveillance can therefore support targeted prevention (e.g., managing boar incursions, vegetation control, and post-exposure tick checks) and risk communication in this region.
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