Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, 1816 S. Oak Street, Urbana, IL 61820, USA.
Vector Borne Zoonotic Dis. 2011 Oct;11(10):1351-8. doi: 10.1089/vbz.2010.0160. Epub 2011 Jun 20.
The distributions of the tick vector, Ixodes scapularis, and of the etiologic agent of Lyme disease, Borrelia burgdorferi (Bb), have continued expanding in Illinois over the past 20 years, but the extent of their spread is not well known. The role of multiple habitats in the establishment and maintenance of I. scapularis and Bb at local scales is not well understood, and the use of integrated approaches to evaluate local scale dynamics is rare. We evaluated habitat diversity and temporal changes of I. scapularis occurrence and Bb infection within a natural area in Piatt County, Illinois, where I. scapularis were first detected in 2002. Small mammals were trapped and attached ticks were collected in young forest, prairie, mature forest, and flood plain sites from 2005 to 2009. Small mammal abundance, and the prevalence (% mammals infested), mean intensity (I. scapularis per infested mammal), and relative density (I. scapularis per mammal trapped) of I. scapularis were computed for each habitat type and compared. Immature I. scapularis were tested for Bb infection using polymerase chain reaction techniques. Out of 2446 trapped small mammals, 388 were infested with I. scapularis. The prairie had the highest diversity of small mammal hosts. Prevalence, mean intensity, and relative density of I. scapularis and prevalence of Bb infection were highest for the prairie and young forest sites; in the former, all infection was associated with the prairie vole, Microtus ochrogaster. The minimum Bb infection prevalence of on-host I. scapularis collected in the natural area was 14% (n=56). Unlike previous studies solely focused on forested areas and Peromyscus leucopus, our study is the first to provide evidence of I. scapularis collected from prairie habitat and other reservoir hosts, particularly M. ochrogaster.
在过去的 20 年里，伊利诺伊州的蜱虫传播媒介、Ixodes scapularis 和莱姆病病原体 Borrelia burgdorferi（Bb）的分布继续扩大，但它们的传播范围尚不清楚。在当地尺度上，多种生境在 I. scapularis 和 Bb 的建立和维持中的作用尚不清楚，很少使用综合方法来评估当地尺度的动态。我们评估了伊利诺伊州皮亚特县一个自然区的生境多样性和 I. scapularis 发生和 Bb 感染的时间变化，该地区于 2002 年首次发现 I. scapularis。2005 年至 2009 年，在幼林、草原、成熟林和洪泛区地点捕获小型哺乳动物并采集附着的蜱虫。计算了每种生境类型的小型哺乳动物丰度、感染率（%受感染的哺乳动物）、平均强度（每只受感染的哺乳动物感染的 I. scapularis）和相对密度（每只捕获的哺乳动物感染的 I. scapularis），并进行了比较。使用聚合酶链反应技术测试未成熟的 I. scapularis 是否感染了 Bb。在 2446 只捕获的小型哺乳动物中，有 388 只被 I. scapularis 感染。草原的小型哺乳动物宿主多样性最高。草原和幼林地点的 I. scapularis 感染率、平均强度和相对密度以及 Bb 感染率最高；在前一种情况下，所有感染都与草原田鼠 Microtus ochrogaster 有关。从自然区采集的寄生 I. scapularis 的最小 Bb 感染率为 14%（n=56）。与以前仅关注森林地区和 Peromyscus leucopus 的研究不同，我们的研究首次提供了从草原栖息地和其他宿主收集的 I. scapularis 的证据，特别是 M. ochrogaster。
