Investigation of the prevalence of Echinococcus multilocularis, and risk of infection, in wild canids in Ontario, Canada

多房棘球绦虫（狐狸绦虫）是一种人畜共患寄生虫，在未经治疗的情况下，人的病死率很高。在北美，成年E.多房性肠炎发生在狐狸和郊狼的小肠中。成熟时，卵在粪便中脱落;如果被中间宿主（例如野生啮齿动物）摄入，则在肝脏中形成泡状棘球蚴囊肿。当中间宿主被野生犬科动物吞食时，生命周期就结束了。历史上，北美有两个公认的流行区：北方苔原区和中北区，包括加拿大的三个省和美国的13个相邻州。奇怪的是，尽管这种广泛的地理分布，很少有E。在狗、猫或人中描述了多房性。2012年以前，E.安大略从未诊断出多房性青光眼。然而，从那时起，安大略南部报告了6例泡状棘球蚴病; 4例发生在狗身上，2例发生在非人类灵长类动物身上。其中五只动物没有离开过安大略南部。由于这是一个新的，正在出现的威胁犬和人类健康，本研究的目的是：（i）确定流行和地理分布的E。在安大略南部的郊狼和狐狸中发现多房棘球绦虫，（ii）确定与E.在郊狼和狐狸的多房感染，和（iii）确定高风险地区的狗和人在这一地区的感染。这些目标将通过在2年内从386头郊狼和386头狐狸尸体中收集粪便样本来实现。此后，样本将在瑞典使用聚合酶链反应分析被认为是最敏感的诊断方法为E。粪便中发现多房菌使用空间分析技术，诊断数据和有关每个尸体原产地的地理信息将用于绘制整个安大略南部的狗和人的感染风险图。E.还将确定郊狼和狐狸中的多房感染。需要这些信息来确定该地区的公共和动物健康风险。

Echinococcus multilocularis (the fox tapeworm) is a zoonotic parasite that has a high case fatality rate in people when untreated. In North America, adult E. multilocularis occur in the small intestine of foxes and coyotes. When mature, eggs are shed in the feces; if ingested by the intermediate host (e.g. wild rodents) an alveolar hydatid cyst develops in the liver. The life cycle is completed when the intermediate host is ingested by wild canids. Historically, there are two recognized endemic areas in North America; the Northern Tundra Zone, and the North Central Region that includes three Canadian provinces and 13 contiguous US states. Strangely, despite this broad geographic distribution, very few cases of E. multilocularis have been described in dogs, cats or people. Prior to 2012, E. multilocularis had never been diagnosed in Ontario. However, since then, six cases of alveolar echinococcosis have been reported in southern Ontario; four in dogs, two in non-human primates. Five of the animals had not travelled outside southern Ontario. Since this is a new, emerging threat to canine and human health, the objectives of this study are: (i) to determine the prevalence and geographic distribution of E. multilocularis in coyotes and foxes across southern Ontario, (ii) to identify risk factors associated with E. multilocularis infection in coyotes and foxes, and (iii) to identify high risk areas for infection in dogs and people in this region. These objectives will be accomplished through the collection of fecal samples from 386 coyote and 386 fox carcasses over 2 years. Thereafter, the samples will be analyzed in Sweden using a polymerase chain reaction assay considered the most sensitive diagnostic method for E. multilocularis in feces at the current time. Using spatial analysis techniques, the diagnostic data and information about the geographic place of origin of each carcass will be used to map the risk of infection for dogs and humans across southern Ontario. Risk factors for E. multilocularis infection in coyotes and foxes will also be determined. Such information is needed to determine public and animal health risks across this region.