Bibliographical studies on human cases of Hard Tick (Acarina: Ixodidae) bites in Japan (4) Cases of Ixodes nipponensis and I. monospinosus infestation *
This paper reviewed the significant literature on human infestation with the hard ticks, Ixodes nipponensis (Kitaoka & Saito, 1967) and I. monospinosus (Saito, 1967) occurring in Japan between 1953 and 2005, and between 1976 and 2005, respectively. A total of 88 patients (32 males, 44 females, 12 unknown) infested by I. nipponensis, and 32 patients (10 males, 15 females, 7 unknown) infested by I. monospinosus were reported in the literature. These I. nipponensis and I. monospinosus patients were distributed widely in Japan except for the southwest islands for the former, and Hokkaido and Shikoku and the southwest islands for the latter. The highest incidence of cases was found in Ishikawa Prefecture (12.8%) in central Japan for I. nipponensis, and in Nagano Prefecture (22.6%) in central Japan for I. monospinosus. For I. nipponensis, the tick infestation of the reported cases occurred in the period from April to September, with the highest incidence being found in July (30.6%). For I. monospinosus, the tick infestation of the reported cases occurred in the period from April to October except for August, with the highest incidence being found in June (36.8%). The age ranges of the I. nipponensis and I. monospinosus patients were from 1 to 87 and 2 to 83 years of age, respectively. The highest incidence of I. nipponensis and I. monospinosus was found in persons in the seventies (23.7%), and in the fifties (20.0%), respectively. For both species, the most common infestation site of the patients was on the skin of the trunk (50.0% and 45.8%), particularly the abdomen (11.8%) for I. nipponensis, and the neck, thorax and forearm region (12.5% each) for I. monospinosus. For both species, the tick bites in the majority of the cases were principally acquired in mountainous areas. (Accepted on Nobember 5, 2008)
