Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Canada.
Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Canada.
Vet Parasitol. 2021 Apr;292:109400. doi: 10.1016/j.vetpar.2021.109400. Epub 2021 Mar 5.
Prompt and reliable diagnostic tests for taeniid infection in canids are important due to the risk of zoonoses like Echinococcus spp. Current diagnostic methods relying on fecal flotation lack sensitivity and specificity, but this has rarely been quantified due to the challenges in performing adult cestode recovery (the gold standard) in domestic dogs (Canis familiaris). Therefore, we recovered adult Taenia and Echinococcus spp. from intestines, as well as fecal/intestinal material from 484 wild canids trapped for fur in two Canadian provinces (276 foxes - primarily Vulpes vulpes, coyotes - Canis latrans, and wolves - Canis lupus in Québec and 208 coyotes in Saskatchewan). The performances of a newly developed coproPCR for tapeworm DNA detection in dogs, and centrifugal fecal flotation using Sheather's solution, were evaluated against adult cestode recovery. Overall, adult taeniid cestode prevalence (Taenia and/or Echinococcus) was 28 % (95 % CI: 23-33 %) in Québec (62 % (CI: 51-73%) of 74 coyotes, 65 % (CI: 44-82) of 23 wolves, and 11 % (CI: 7-16%) of 179 foxes) and 79 % (CI: 73-84%) of 208 coyotes in Saskatchewan. In Québec, E. canadensis and Taenia spp. were detected in coyotes and wolves, and foxes were only infected with Taenia spp., whereas Saskatchewan coyotes were predominantly infected with E. multilocularis (at significantly higher prevalence, but not intensity, than coyotes in Québec). Compared with centrifugal fecal flotation, the new coproPCR had at least double the sensitivity (58 % vs 23 % in QC coyotes, 57 % vs 23 % in QC wolves, 24 % vs 0% in QC foxes, and 80 % vs 25 % in SK coyotes). Notably, no taeniid eggs were detected on flotations from foxes infected with Taenia spp., and the new coproPCR had highest sensitivity in Saskatchewan coyotes, which were predominantly infected with E. multilocularis. CoproPCR has promising prospects for use in Veterinary clinics and diagnostic laboratories to detect taeniid cestode infections because of its higher sensitivity than faecal flotation methods. This is particularly important for zoonotic Echinococcus spp. where, from a public health perspective, false negatives are a much greater concern than false positives.
由于犬类感染带绦虫可能导致包虫病等动物传染病，因此，对于犬类带绦虫感染，及时、可靠的诊断检测非常重要。目前，基于粪便漂浮法的诊断方法虽然灵敏度和特异性都不高，但由于在家犬（Canis familiaris）中进行成虫绦虫回收（金标准）具有挑战性，因此很少对其进行定量评估。因此，我们从加拿大两个省份（魁北克省的 276 只狐狸-主要是赤狐（Vulpes vulpes）、郊狼（Canis latrans）和狼（Canis lupus），以及萨斯喀彻温省的 208 只郊狼）的 484 只野生犬科动物的肠道以及粪便/肠道中回收了成年带绦虫和包虫属（Echinococcus）物种。我们评估了一种新开发的用于检测犬类绦虫 DNA 的粪便聚合酶链反应（coproPCR）和使用 Sheather 溶液的离心粪便漂浮法的性能，将其与成虫绦虫回收进行了比较。总的来说，在魁北克省，成年带绦虫流行率（包括绦虫和/或包虫属）为 28%（95%CI：23-33%）（74 只郊狼中有 62%（CI：51-73%），23 只狼中有 65%（CI：44-82%），179 只狐狸中有 11%（CI：7-16%）），而在萨斯喀彻温省，208 只郊狼中的流行率为 79%（CI：73-84%）。在魁北克省，在郊狼和狼中检测到了加拿大包虫和绦虫属物种，而狐狸仅感染了绦虫属物种，而萨斯喀彻温省的郊狼则主要感染了多房棘球绦虫（感染率明显更高，但感染强度不如魁北克省的郊狼）。与离心粪便漂浮法相比，新的 coproPCR 具有至少两倍的灵敏度（在魁北克省的郊狼中为 58%，在魁北克省的狼中为 57%，在魁北克省的狐狸中为 24%，在萨斯喀彻温省的郊狼中为 80%）。值得注意的是，在感染了绦虫属物种的狐狸的粪便漂浮物中未检测到带绦虫卵，而新的 coproPCR 在萨斯喀彻温省的郊狼中具有最高的灵敏度，这些郊狼主要感染了多房棘球绦虫。由于其灵敏度高于粪便漂浮法，粪便聚合酶链反应有望在兽医诊所和诊断实验室中用于检测带绦虫感染，这一点非常重要，因为从公共卫生的角度来看，假阴性比假阳性更令人担忧。
