Northward range expansion of Ixodes scapularis evident over a short timescale in Ontario, Canada
Northward range expansion of Ixodes scapularis evident over a short timescale in Ontario, Canada
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DOI：
10.1371/journal.pone.0189393
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发表时间：
2017-12-27
期刊：
影响因子：
3.7
通讯作者：
Jardine, Claire M.
中科院分区：
文献类型：
--
作者：
Clow, Katie M.;Leighton, Patrick A.;Jardine, Claire M.
黑腿蜱（Ixodes scapularis）入侵加拿大安大略对公共卫生构成重大风险，因为它是许多病原体的载体，包括莱姆病的病原体--狭义伯氏疏螺旋体（Borrelia burgdorferi sensu stricto）。2014年和2015年基线实地采样检测到I.肩胛肌和B. burgdorferi在整个南部，东部和中部安大略，包括在东部安大略的热点网站。提出了一个传播速度模型。Leighton及其同事（2012年）开发的肩胛骨估计，蜱虫的活动范围正在以每年46公里的速度向北扩展。2016年，我们重新访问了2014年和2015年抽样的一部分地点，以了解风险的变化性质，并评估蜱虫入侵率是否与传播速度估计一致。在36个站点中的17个站点通过蜱虫拖拽收集蜱虫，其中5个是I的新站点。肩胛肌样本呈B阳性。Burgdorferi在8个站点。没有其他的我。检测到肩胛骨传播的病原体。质心统计显示I.肩胛肌阳性部位位于安大略东部。然后将每个地点的实地数据与模型预测的每个人口普查分区的建立年份进行比较。我们的研究结果表明，I.肩胛肌和B的出现。burgdorferi是正在进行的，并提供与I相关的过程的短时间尺度证据。肩胛肌伸展。范围锋似乎以类似于46公里/年的速度移动，而该范围锋后面的蜱虫定植速度较慢且不均匀。对地点级生态因素的评估并未提供任何有关可能影响I.在特定区域的肩胛骨。需要不断进行实地取样，以监测这一动态过程。这项研究强调了目前与莱姆病相关的地理风险，可用于将公共卫生干预措施针对风险最大的地区。
The invasion of the blacklegged tick, Ixodes scapularis into Ontario, Canada poses a significant risk to public health because it is a vector for numerous pathogens, including Borrelia burgdorferi sensu stricto, the causative agent of Lyme disease. Baseline field sampling in 2014 and 2015 detected I. scapularis and B. burgdorferi at sites across southern, eastern and central Ontario, including a hot spot in eastern Ontario. A "speed of spread" model for I. scapularis developed by Leighton and colleagues (2012) estimated that the tick's range was expanding northward at 46 km/year. In 2016, we revisited a subset of sites sampled in 2014 and 2015 to understand the changing nature of risk, and assess whether the rate of tick invasion is consistent with the speed of spread estimate. Ticks were collected via tick dragging at 17 out of 36 sites, 5 of which were new sites for I. scapularis. Samples were positive for B. burgdorferi at 8 sites. No other I. scapularis-borne pathogens were detected. Centrographic statistics revealed an increase in the dispersion of I. scapularis positive sites in eastern Ontario. Field data for each site were then compared to the model's predicted year of establishment for each census subdivision. Our findings illustrate that the range expansion of I. scapularis and the emergence of B. burgdorferi is ongoing, and provide short timescale evidence of the processes associated with I. scapularis spread. The range front appears to be moving at a rate of similar to 46 km/year, with colonization of the tick behind this range front occurring at a slower and heterogeneous rate. Assessment of site-level ecological factors did not provide any insight into the underlying processes that may be influencing the colonization of I. scapularis in specific areas. Ongoing field sampling is needed to monitor this dynamic process. This study highlights the current geographic risk associated with Lyme disease, which can be used to target public health interventions to the areas of greatest risk.