Control of Echinococcus multilocularis in rural area by anthelminthics application for definitive hosts

多房棘球绦虫是分布于北海道的重要人畜共患寄生虫之一。1996年，狐狸体内寄生虫的感染率达到40%。在知床（国家公园）、清水（农村地区）和札幌（城市地区）进行了3次多房棘球绦虫终末宿主的调查。第一次调查在知床国家公园进行，以应用粪抗原检测方法监测经常观察到人与狐狸密切接触的旅游景点的流行情况。在这个地区，已经确定了8个狐狸家族的领地。粪抗原和虫卵的检出主要局限于一个家庭，提示知床县的流行率很低。第二项研究在Koshimizu进行。在200 km^2的研究区域内共发现狐穴168个，狐穴内有31个狐科。粪便标本粪抗原阳性率为48.5%。这表明Koshimizu的患病率较高，幼崽的患病率较高。近20年来，在北海道的城市地区也发现了赤狐。这是一个严重的公共卫生问题。在第三项研究中，调查了札幌市区（242.4 km^2）狐狸的分布。在冬季，在市区均匀分布的130个公园和林地检查了雪地上的狐狸足迹。结果表明，狐狸在城区内分布广泛，但分布不均匀。狐狸密集地居住在城市的边缘地区。在市区及周边地区的17个地点发现了狐狸繁殖窝点。采集狐穴周围狐粪，用粪抗原检测法进行棘球蚴感染的检测。粪抗原阳性者7例。这说明感染多房棘球蚴的狐狸已经侵入市区。

Echinococcus multilocularis is one of the most important zoonotic parasites distributed in Hokkaido. In 1996, the prevalence of the parasite in foxes reached to 40%. Three surveys for E.multilocularis in definitive hosts were carried out in Shiretoko (National Park), Koshimizu (Rural area) and Sapporo (Urban area).First survey was conducted in the Shiretoko National Park to apply coproantigen detection method in monitoring for the prevalence at touring spots where close contact between human and foxes are frequently observed. In this area, 8 fox family territories have been determined. Detection of coproantigen and eggs was mostly restricted in one family, suggesting the prevalence in Shiretoko was very low. The second study was conducted in Koshimizu. In total 168 fox dens were found in about 200km^2 study area and 31 fox families living there. Faeces collected around dens were 48.5% coproantigen positive. These suggested high prevalence in Koshimizu and higher prevalence in pups. In the two decades, red foxes have been observed in urban area in Hokkaido. This cause a serious public health thread. In the third study, the distribution of foxes in the urban area (242.4km^2) of Sapporo were investigated. In winter, fox trails on the snow were checked at 130 parks and woodland areas distributed evenly in urban area. It is showed that foxes were all over the urban area, but were not evenly distributed. Foxes inhabited densely the urban peripheral area. Fox breeding dens were found at 17 spots in and around the urban area. Fox feces were collected around the dens and were checked for the Echinococcus infection by the coproantigen detection method. Coproantigen positive feces were found at 7 spots. This shows that the foxes infected E.multilocularis have invaded into the urban area.