Department of Biology, University of Ottawa, Ottawa, Canada.
Department of Biology, McGill University, Montréal, Canada.
Vector Borne Zoonotic Dis. 2022 Nov;22(11):535-544. doi: 10.1089/vbz.2022.0036. Epub 2022 Oct 19.
The spread of emerging tick-borne pathogens has steadily increased in Canada with the widespread establishment of tick vectors and vertebrate hosts. At present, , the bacterium causing Lyme disease, is the most common tick-borne pathogen in Canada and primarily transmitted by . A low prevalence of other emerging tick-borne pathogens, such as , species, , and have also been detected through surveillance efforts in Canada. Although has been historically detected in in Canada, the current prevalence and geographic extent of this pathogen is unknown. In this study, we assessed the presence and prevalence of several emerging tick-borne pathogens in ticks and hosts collected through tick dragging and small mammal trapping in Central Canada. Nested PCR testing detected three pathogen species in ticks, with and in in addition to in . Three pathogen species were detected in small mammals by nested PCR including in , in , and a species in and . and species were the pathogens most often detected in our samples, suggesting they are widely distributed across Central Canada. We also detected and beyond their known geographic distribution. Our results provide evidence that emerging tick-borne pathogens may be present outside defined risk areas identified by current surveillance efforts in Canada. As a result, emerging tick-borne pathogens introduced by the dispersal of infected ticks by migratory birds or maintained by hosts and vectors through cryptic transmission cycles may go undetected. More comprehensive testing including all tick life stages and additional tick-borne pathogens will help detect the spread and potential risk of emerging or re-emerging tick-borne pathogens for human and wildlife populations throughout Canada.
随着蜱虫媒介和脊椎动物宿主的广泛建立，加拿大新兴蜱传病原体的传播稳步增加。目前，导致莱姆病的细菌是加拿大最常见的蜱传病原体，主要通过硬蜱传播。通过在加拿大的监测工作，也检测到了其他一些新兴蜱传病原体的低流行率，如安第斯病毒、巴尔通体属和埃立克体属。虽然加拿大历史上曾在鹿蜱中检测到无形体属，但目前该病原体的流行率和地理范围尚不清楚。在本研究中，我们评估了通过在加拿大中部的蜱虫拖拽和小型哺乳动物诱捕收集的蜱虫和宿主中几种新兴蜱传病原体的存在和流行率。巢式 PCR 检测在蜱虫中检测到三种病原体，除了在硬蜱中检测到伯氏疏螺旋体外，还在鹿蜱中检测到无形体属和巴尔通体属。通过巢式 PCR 在小型哺乳动物中检测到三种病原体，包括在白足鼠中检测到无形体属，在棉鼠中检测到巴尔通体属，以及在鼩鼱和白足鼠中检测到一种埃立克体属。无形体属和巴尔通体属是我们样本中最常检测到的病原体，表明它们在加拿大中部广泛分布。我们还在已知地理分布之外检测到了安第斯病毒和埃立克体属。我们的结果表明，新兴蜱传病原体可能存在于加拿大当前监测工作确定的有定义风险区域之外。因此，通过候鸟传播感染蜱虫或通过隐匿传播循环由宿主和媒介维持的新兴蜱传病原体可能会被漏检。更全面的检测，包括所有蜱虫的生活阶段和其他蜱传病原体，将有助于检测新兴或重现的蜱传病原体在加拿大各地的人类和野生动物种群中的传播和潜在风险。
