In North America, the only endemic focus for Angiostrongylus vasorum (French heartworm) was historically thought to occur in the southeastern part of the island of Newfoundland. However, reports of A. vasorum infection in wild canids in West Virginia, USA, and Nova Scotia, Canada, suggest the introduction of the parasite to mainland North America. We screened for A. vasorum in coyotes from across southern Ontario. Additionally, we evaluated the performance of ELISAs for detection of circulating A. vasorum antigen (Ag-ELISA) and antibodies against A. vasorum (Ab-ELISA) designed for use in sera or blood of foxes for use with coyotes in this region. Autopsies were performed on 397 coyotes, and lung tissue extract prepared from each carcass was tested via both ELISAs. The sensitivity and specificity for both tests were estimated in the absence of a gold standard using a 2-test single population Bayesian model; sensitivity and specificity priors were based on the performance of the assays in foxes in Switzerland. Eight coyotes tested positive for A. vasorum antigen; no animal was antibody positive. The estimated sensitivity and specificity of the Ag-ELISA were 90.8% (95% credible interval [CrI]: 83.8–95.6%) and 95.5% (95% CrI: 93.4–97.2%), respectively. For the Ab-ELISA, the estimated sensitivity and specificity were 41.9% (95% CrI: 32.1–51.9%) and 98.0% (95% CrI: 96.3–99.0%), respectively. Based on these findings and negative postmortem data for the same animals, there is insufficient evidence to suggest the presence of A. vasorum in southern Ontario coyotes.

在北美，历史上一直认为血管丝虫（法国心丝虫）是唯一的地方性病灶，发生在纽芬兰岛的东南部。但是，在美国西弗吉尼亚州和加拿大新斯科舍省的野生犬科动物中，有报道说A. vasorum感染了这种寄生虫，并将其引入了北美大陆。我们从整个安大略南部的土狼中筛选了A. vasorum。此外，我们评估了用于检测循环血管曲霉抗原（Ag-ELISA）和抗血管曲霉抗体的酶联免疫吸附测定的性能（Ab-ELISA）设计用于狐狸的血清或血液中，供该地区的土狼使用。对397只土狼进行尸检，并通过两种ELISA测试从每个car体制备的肺组织提取物。在没有黄金标准的情况下，使用2项检验的单族贝叶斯模型估计了这两种检验的敏感性和特异性。敏感性和特异性先验是基于在瑞士的狐狸中进行的检测的性能。八只土狼测试为A. vasorum阳性抗原; 没有动物是抗体阳性。Ag-ELISA的估计灵敏度和特异性分别为90.8％（95％可信区间[CrI]：83.8–95.6％）和95.5％（95％CrI：93.4–97.2％）。对于Ab-ELISA，估计的敏感性和特异性分别为41.9％（95％CrI：32.1–51.9％）和98.0％（95％CrI：96.3–99.0％）。根据这些发现以及相同动物的阴性尸检数据，没有足够的证据表明在安大略省南部的土狼中存在A. vasorum。