Evaluation of the prevalence of Echinococcus multilocularis in dogs, and risk factors for infection, in southern Ontario

安大略省南部犬多房棘球绦虫流行率及感染危险因素的评估

• 批准号: 531187-2018
• 负责人: Peregrine, Andrew
• 金额: $ 1.35万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=676979
• 关键词: Evaluation; prevalence; Echinococcus; multilocularis; dogs

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 coyotes and foxes. When mature, eggs are shed in the feces; if ingested by wild rodents, the larval stage develops in the liver causing the disease alveolar echinococcosis (AE). The life cycle is completed when an infected rodent is ingested by wild canids. Despite a broad geographic distribution in wildlife in North America, very few infections have been described in dogs or people. Furthermore, prior to 2012, E. multilocularis had not been diagnosed in Ontario. Since then, seven cases of AE have been reported in dogs and non-human primates in southern Ontario. As a result, the prevalence of E. multilocularis was recently evaluated in wild canids across southern Ontario; 23% of coyotes and foxes were shown to be infected. In addition, an infection hot spot was identified in ten Public Health Units associated with the Golden Horseshoe region (GHR) at the western end of Lake Ontario. Since this is a new, emerging threat to dog and human health, the objectives of this study are to determine the prevalence of E. multilocularis infections in (i) off-leash dogs within the GHR, and to identify risk factors for infection in these dogs, and (ii) rodents in the same area. The first objective will be achieved by collecting fecal samples from 500 dogs visiting 10 off-leash dog parks in the GHR. An additional 50 dogs will be sampled in the Six Nations reserve situated within the infection hotspot. Objective (ii) will be addressed by examining rodents in the same parks. An additional objective is to determine the prevalence of all intestinal parasites in the feces of the dogs using the current gold standard diagnostic tests and a new fecal antigen diagnostic method. All fecal samples will be analysed for E. multilocularis using a molecular method that is used for national surveillance programs in Europe. The results will help determine which dogs should be treated preventively for E. multilocularis, thereby reducing the risk of transmission to people. The project will also help validate the performance of a new fecal parasite diagnostic test for veterinary practitioners.

多房棘球蚴（狐狸绦虫）是一种人畜共患寄生虫，如果不及时治疗，其病死率很高。在北美，成虫多房艾美耳球虫存在于土狼和狐狸的小肠中。成熟后，卵随粪便排出；如果被野生啮齿动物摄入，幼虫阶段会在肝脏中发育，导致肺泡包虫病 (AE)。当受感染的啮齿动物被野生犬科动物吞食时，生命周期就完成了。尽管北美野生动物地理分布广泛，但在狗或人中感染的病例却很少。此外，2012 年之前，安大略省尚未诊断出多房艾美耳球虫。此后，安大略省南部报告了七例狗和非人类灵长类动物的 AE 病例。因此，最近对安大略省南部野生犬科动物中多房肠球菌的流行情况进行了评估； 23% 的土狼和狐狸被证明被感染。此外，在与安大略湖西端金马蹄地区（GHR）相关的十个公共卫生单位中发现了感染热点。由于这是对狗和人类健康的新威胁，本研究的目的是确定 (i) GHR 内未拴绳的狗中多房艾美耳球菌感染的患病率，并确定这些狗中感染的危险因素。狗，以及 (ii) 同一区域的啮齿动物。第一个目标将通过收集 500 只狗的粪便样本来实现，这些狗参观了 GHR 的 10 个不拴绳狗公园。另外，还将在感染热点地区的六国保护区对另外 50 只狗进行采样。目标 (ii) 将通过检查同一公园中的啮齿动物来解决。另一个目标是使用当前的金标准诊断测试和新的粪便抗原诊断方法来确定狗粪便中所有肠道寄生虫的患病率。所有粪便样本都将使用欧洲国家监测计划所用的分子方法来分析多房肠球菌。研究结果将有助于确定哪些狗应该接受多房肠球菌的预防性治疗，从而降低传播给人类的风险。该项目还将帮助兽医验证新的粪便寄生虫诊断测试的性能。