Development of a diagnostic system for definitive hosts of taeniid cestodes and an epizootiological survey for echinococcosis in urban area

多房棘球绦虫是北海道特有的一种人畜共患寄生虫。食肉动物寄生虫的最终宿主，如狐狸和狗，中间宿主是啮齿动物。人类通过不小心摄入寄生虫卵而感染。近十年来，北海道狐狸的感染率约为40%，宠物狗的感染率为0.3%-0.7%。为了应对日益恶化的情况，日本自2004年开始实施犬类包虫病报告制度。这项研究旨在通过结合特异性DNA检测和t检测来改进确定宿主的诊断系统，调查札幌市及其郊区寄生虫的生活周期和感染风险。在诊断研究中，针对粪卵检查中发现的形态不明显的带绦虫的虫卵，建立了多房棘球绦虫的系统、多房棘球绦虫特异引物的聚合酶链式反应和其他带绦虫尾虫的PCR-RFLP方法。此外，通过检测驱虫后粪便中的TH，证明了在潜伏期前寄主粪便中不排卵的DNA诊断是可行的。此外，在日本和其他国家采集的样本表明，正在开发的可整合到诊断系统中的辅原抗原检测试剂盒具有很高的可靠性。在评估过程中，首次在日本发现了一只猫排泄素多房棘球菌卵。在一次城市生活周期调查中发现，札幌和小太郎地区的狐狸患病率较高。狐狸在选择它们的巢穴时表现出地理偏好。因此，有可能成为感染狐狸的家园，从而可以估算出市区棘球绦虫感染的危险区域。

Echinococcus multilocularis is a zoonotic parasite endemic in Hokkaido. The definitive host of the parasite carnivore animal such as fox and dog, and the intermediate host is rodent. Humans get infection by accidentally ingestin; the parasite eggs. The prevalence in foxes in Hokkaido was about 40% in the last decade and that in pet dogs is 0.3-0.7% In response to a deteriorating situation, reporting system for canine echinococcosis has been enforced since 2004 in Japan. This study has aimed to improve a diagnostic system for the definitive hosts by incorporating specific DNA detection and t, investigate an urban life cycle of the parasite and risk for infection in Sapporo and its suburbs. In research for diagnosti, system, PCR with specific primers for E. multilocularis and PCR-RFLP for other taeniid cestodes were developed for the egg of taeniid cestodes that were found in fecal egg examination but morphologically indistinguishable among the family. Moreover DNA diagnosis in prepatent period in which eggs are not excreted in host feces was shown to be feasible by examining th, post-dewormed feces. In addition, high reliability of a developing coproantigen detection kit which can be incorporated i the diagnostic system was shown using the samples collected in Japan and other countries. During the evaluation, a cat excretin E. multilocularis eggs were found at first in Japan. In investigation on an urban life cycle, high prevalence was found i foxes inhabiting in Sapporo and Otaru. Foxes showed geographical preference for selecting their den sites. Therefore, potentia home range of infected foxes, thus a risk area for Echinococcus infection in the urban area could be estimated.