Moerbeck Leonardo, Parreira Ricardo, Seixas Gonçalo, Velez Rita, Domingos Ana, Antunes Sandra
Global Health and Tropical Medicine- Institute of Hygiene and Tropical Medicine, NOVA University of Lisbon, Rua da Junqueira 100, 1349-008, Lisbon, Portugal.
Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisbon, Rua da Junqueira 100, 1349-008, Lisboa, Portugal.
Parasit Vectors. 2024 Dec 24;17(1):538. doi: 10.1186/s13071-024-06627-5.
Tick-borne rickettsioses (TBR) are emerging, neglected, zoonoses, caused by intracellular α-proteobacteria of the genus Rickettsia, that pose a growing public health concern. The aim of the present study was to evaluate rickettsial infections in questing ticks collected from four different ecological areas in mainland Portugal.
Over a two-year period, a total of 707 questing ticks were collected. Individual adult ticks and pooled nymphs were submitted to DNA extraction, followed by qPCR assays targeting the gltA rickettsial gene. Positive samples were then submitted to conventional PCR targeting the gltA and the ompA genes for phylogenetic analysis.
In total, eight tick species were identified: Dermacentor marginatus, Haemaphysalis inermis, Haemaphysalis punctata, Hyalomma lusitanicum, Ixodes frontalis, Ixodes ricinus, Rhipicephalus pusillus, and Rhipicephalus sanguineus sensu lato. Additionally, rickettsial infection was associated with seven of these species, with I. frontalis being the exception. Notably, the prevalence of Rickettsia spp. was 26.35%, with phylogenetic validation confirming infections with R. helvetica, R. massiliae, R. monacensis, Candidatus R. rioja, and R. slovaca.
The present study highlights the necessity for ongoing surveillance to map and monitor both questing and feeding ticks, along with their vertebrate hosts. Effective control strategies are of utmost importance to mitigate the escalating threat of TBR. Additionally, the present study provides valuable epidemiological insights into TBR in Portugal, including the identification of R. slovaca infecting I. ricinus - an unconventional tick-pathogen relationship - and the first report of Candidatus R. rioja infecting D. marginatus in Portugal. In conclusion, this study contributes with valuable data regarding epidemiological results on ticks and TBR circulating in Portugal, emphasizing the importance of proactive measures to address this emerging public health challenge.
蜱传立克次体病（TBR）是由立克次体属的细胞内α-变形菌引起的新发、被忽视的人畜共患病，对公共卫生构成日益严重的威胁。本研究的目的是评估从葡萄牙大陆四个不同生态区域采集的 questing 蜱中的立克次体感染情况。
在两年时间里，共采集了 707 只 questing 蜱。将单个成年蜱和混合若虫进行 DNA 提取，随后进行针对立克次体 gltA 基因的 qPCR 检测。阳性样本接着进行针对 gltA 和 ompA 基因的常规 PCR 检测，用于系统发育分析。
总共鉴定出 8 种蜱：边缘革蜱、无角血蜱、斑点血蜱、卢氏璃眼蜱、额部硬蜱、蓖麻硬蜱、微小扇头蜱和广义血红扇头蜱。此外，立克次体感染与其中 7 种蜱有关，额部硬蜱除外。值得注意的是，立克次体属的患病率为 26.35%，系统发育验证证实感染了瑞士立克次体、马赛立克次体、蒙纳立克次体、候选里奥哈立克次体和斯洛伐克立克次体。
本研究强调了持续监测的必要性，以绘制和监测 questing 蜱和吸血蜱及其脊椎动物宿主。有效的控制策略对于减轻 TBR 不断升级的威胁至关重要。此外，本研究为葡萄牙的 TBR 提供了有价值的流行病学见解，包括鉴定出感染蓖麻硬蜱的斯洛伐克立克次体——一种非常规的蜱-病原体关系——以及在葡萄牙首次报道候选里奥哈立克次体感染边缘革蜱。总之，本研究提供了关于葡萄牙蜱和 TBR 传播的流行病学结果的宝贵数据，强调了采取积极措施应对这一新兴公共卫生挑战的重要性。
