Biology Department, Muhlenberg College, Allentown, PA.
Mathematics and Computer Science Department, Muhlenberg College, Allentown, PA.
J Med Entomol. 2019 Jun 27;56(4):1122-1134. doi: 10.1093/jme/tjz043.
Questing ticks were surveyed by dragging in forested habitats within the Lehigh Valley region of eastern Pennsylvania for four consecutive summers (2015-2018). A high level of inter-annual variation was found in the density of blacklegged tick nymphs, Ixodes scapularis Say, with a high density of host-seeking nymphs (DON) in summer 2015 and 2017 and a relatively low DON in summer 2016 and 2018. Very few American dog ticks (Dermacentor variabilis Say) and Ixodes cookei Packard were collected. Lone star ticks (Amblyomma americanum L.) and longhorned ticks (Haemaphysalis longicornis Neumann) were not represented among the 6,398 ticks collected. For tick-borne pathogen surveillance, DNA samples from 1,721 I. scapularis nymphs were prepared from specimens collected in summers 2015-2017 and screened using qPCR, high resolution melting analysis, and DNA sequencing when necessary. The overall 3-yr nymphal infection prevalence of Borrelia burgdorferi was 24.8%, Borrelia miyamotoi was 0.3%, Anaplasma phagocytophilum variant-ha was 0.8%, and Babesia microti was 2.8%. Prevalence of coinfection with B. burgdorferi and B. microti as well as B. burgdorferi and A. phagocytophilum variant-ha were significantly higher than would be expected by independent infection. B. burgdorferi nymphal infection prevalence is similar to what other studies have found in the Hudson Valley region of New York, but levels of B. microti and A. phagocytophilum variant-ha nymphal infection prevalence are relatively lower. This study reinforces the urgent need for continued tick and pathogen surveillance in the Lehigh Valley region.
在宾夕法尼亚州东部的利哈伊谷地区的森林生境中，连续四个夏天（2015-2018 年）进行了 Questing 蜱的调查。黑腿蜱幼虫（Ixodes scapularis Say）的密度存在很大的年际变化，2015 年和 2017 年有大量的宿主寻找幼虫（DON），而 2016 年和 2018 年的 DON 相对较少。收集到的美洲犬蜱（Dermacentor variabilis Say）和 Ixodes cookei Packard 非常少。在收集到的 6398 只蜱中，没有 Lone star 蜱（Amblyomma americanum L.）和长角血蜱（Haemaphysalis longicornis Neumann）。为了进行蜱传病原体监测，从 2015 年至 2017 年夏季收集的标本中准备了 1721 只 I. scapularis 幼虫的 DNA 样本，并使用 qPCR、高分辨率熔解分析和必要时的 DNA 测序进行了筛查。3 年总体幼虫感染率为 24.8%的伯氏疏螺旋体（Borrelia burgdorferi），0.3%的米氏疏螺旋体（Borrelia miyamotoi），0.8%的嗜吞噬细胞无形体变体-ha（Anaplasma phagocytophilum variant-ha），2.8%的微小巴贝斯虫（Babesia microti）。伯氏疏螺旋体和微小巴贝斯虫以及伯氏疏螺旋体和嗜吞噬细胞无形体变体-ha 的合并感染率明显高于独立感染的预期。伯氏疏螺旋体幼虫感染率与其他在纽约哈德逊河谷地区的研究相似，但微小巴贝斯虫和嗜吞噬细胞无形体变体-ha 的幼虫感染率相对较低。这项研究强调了在利哈伊谷地区继续进行蜱和病原体监测的迫切需要。
