Vecchiato Marco, Lawson Becki, Seilern-Moy Katharina, White Mia L, Jones Nicola, Brown Faye, Yaffy Dylan, Medlock Jolyon M, Hansford Kayleigh M
Institute of Zoology, Zoological Society of London, London, NW1 4RY, UK; Royal Veterinary College, University of London, London, NW1 0TU, UK.
Institute of Zoology, Zoological Society of London, London, NW1 4RY, UK.
Ticks Tick Borne Dis. 2025 May;16(3):102475. doi: 10.1016/j.ttbdis.2025.102475. Epub 2025 Apr 4.
Borrelia burgdorferi sensu lato (Bbsl) are multi-host bacteria and the causative agents of the zoonotic disease, Lyme borreliosis, for which Ixodes spp. are the vectors. In Great Britain (GB), research to date has primarily focussed on Ixodes ricinus as the main tick transmitting this pathogen, while the role that the European hedgehog (Erinaceus europaeus) and the hedgehog tick (Ixodes hexagonus) might have in the transmission cycle requires investigation. This study aimed to examine the occurrence of Bbsl infection in hedgehogs and I. hexagonus in GB; to characterise the species if present; and to better inform our understanding of these species as potential hosts or vectors. Post-mortem examinations have been conducted on hedgehogs found dead from across GB over the period 2013-2022 inclusive. We collated the available convenience sample archive from 96 hedgehogs for which both frozen ear tissue and Ixodes spp. (comprising 563 I. hexagonus, 18 I. ricinus and one Ixodes frontalis) in 70 % ethanol were available. Supplementary tissue samples were analysed from the hedgehogs where either ear tissue or ticks tested Borrelia DNA-positive, to investigate whether the infection was localised or disseminated. An additional 86 I. hexagonus collected from 14 hedgehogs with no ear tissue available were included to increase the sample size. DNA from tissue and tick samples was tested using a pan-Borrelia qPCR assay. Only 4.2 % (4/96) of hedgehogs and 1.2 % (4/335 total: 0.6 %, 2/329 I. hexagonus; 40 %, 2/5 I. ricinus) of tick pools were qPCR-positive suggesting that Bbsl infrequently circulate in hedgehog and I. hexagonus in GB. Therefore, both species may play a limited role in wider transmission cycles in this country. Borrelia afzelii was the sole species characterised by subsequent sequence analysis in both hedgehogs and ticks, providing some evidence of host-vector interaction at larval and nymph life stages, as all the positive ticks were collected from B. afzelii DNA-positive hedgehogs. Histopathological examination of hedgehog tissues found no evidence of borreliosis and therefore no clinical significance of B. afzelii infection to hedgehog health. The low occurrence of B. afzelii detected in I. hexagonus, combined with the lower frequency of human biting behaviour of I. hexagonus when compared with I. ricinus, suggests that the public health risk of infection from I. hexagonus bites is lower than for I. ricinus. Notably, our dataset found minimal co-feeding of these tick species on hedgehog hosts in contrast to studies in mainland Europe, which could influence pathogen dynamics in GB.
广义伯氏疏螺旋体（Borrelia burgdorferi sensu lato，Bbsl）是一种多宿主细菌，也是人兽共患病莱姆病的病原体，硬蜱属（Ixodes spp.）是其传播媒介。在英国，迄今为止的研究主要集中在蓖麻硬蜱（Ixodes ricinus）作为传播这种病原体的主要蜱虫，而欧洲刺猬（Erinaceus europaeus）和刺猬蜱（Ixodes hexagonus）在传播循环中可能发挥的作用仍有待研究。本研究旨在调查英国刺猬和刺猬蜱中Bbsl感染的发生情况；如果存在感染，对其物种进行鉴定；并更好地帮助我们了解这些物种作为潜在宿主或媒介的情况。对2013年至2022年（含）期间在英国各地发现死亡的刺猬进行了尸检。我们整理了来自96只刺猬的现有便利样本档案，这些刺猬都有冷冻耳部组织以及保存在70%乙醇中的硬蜱属蜱虫（包括563只刺猬蜱、18只蓖麻硬蜱和1只额突硬蜱）。对耳部组织或蜱虫检测出伯氏疏螺旋体DNA呈阳性的刺猬，分析其补充组织样本，以调查感染是局部性的还是扩散性的。另外还纳入了从14只没有耳部组织的刺猬身上采集的86只刺猬蜱，以增加样本量。使用泛伯氏疏螺旋体qPCR检测法对组织和蜱虫样本的DNA进行检测。只有4.2%（4/96） 的刺猬和1.2%（共4/335：0.6%，2/329只刺猬蜱；40%，2/5只蓖麻硬蜱）的蜱虫样本qPCR呈阳性，这表明Bbsl在英国的刺猬和刺猬蜱中很少传播。因此，这两个物种在该国更广泛的传播循环中可能发挥的作用有限。伯氏阿氏疏螺旋体（Borrelia afzelii）是在刺猬和蜱虫后续序列分析中唯一鉴定出的物种，这为幼虫和若虫生命阶段的宿主-媒介相互作用提供了一些证据，因为所有阳性蜱虫均采集自伯氏阿氏疏螺旋体DNA呈阳性的刺猬。对刺猬组织的组织病理学检查未发现莱姆病的迹象，因此伯氏阿氏疏螺旋体感染对刺猬健康没有临床意义。在刺猬蜱中检测到的伯氏阿氏疏螺旋体发生率较低，再加上与蓖麻硬蜱相比刺猬蜱叮咬人类的频率较低，这表明刺猬蜱叮咬导致感染的公共卫生风险低于蓖麻硬蜱。值得注意的是，与欧洲大陆的研究相比，我们的数据集中发现这些蜱虫物种在刺猬宿主上的共同取食极少，这可能会影响英国病原体的动态变化。
