Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, An den Tierkliniken 1, 04103, Leipzig, Germany.
Institute of Microbiology of the Bundeswehr, Neuherbergstraße 11, 80937, Munich, Germany.
Parasitol Res. 2020 Apr;119(4):1387-1392. doi: 10.1007/s00436-020-06637-z. Epub 2020 Mar 24.
Southern Germany is known as tick-borne encephalitis (TBE) risk area; however, the north of the country is almost free of human TBE cases. Due to its location in the transition zone between TBE risk areas and areas with only sporadic cases, Saxony is of importance in the surveillance of TBE. Roe deer (Capreolus capreolus), showing high seroprevalence of TBE virus (TBEV) antibodies, are considered to be sentinels for TBE risk assessment. Thus, roe deer could be used as indicators helping to better understand the focality of the TBEV in nature and as a possible source to isolate TBEV. Therefore, the aims of this study were to examine roe deer coats for the presence of ticks to establish the tick burden and to detect the TBEV in attached ticks. One hundred thirty-four roe deer coats were provided by hunters from the Hunting Association in Saxony (August 2017-January 2019). The coats were frozen at - 80 °C and after de-freezing examined on both sides-inside and outside. Attached and nonattached ticks were collected, morphologically identified and tested using real-time RT-PCR for the presence of TBEV. In total, 1279 ticks were found on 48 coats. The predominant species was Ixodes ricinus (99.76%; n = 1276). Three remaining specimens were Ixodes spp. (0.16%, 1 female and 1 nymph) and Dermacentor reticulatus (0.08%, 1 male). The average infestation rate was 26.7 (SD = 69.5), with maximum of 439 ticks per animal. Females were the dominant life stage of ticks (n = 536; 42%), followed by nymphs (n = 397; n = 31.1%), males (n = 175; 13.7%), and larvae (n = 168; 13.2%). Only half of collected ticks were attached (n = 662; 51.8%). TBEV was detected only in one tick out of 1279 tested ticks. It was a female infesting a roe deer from Saxon Switzerland-East Ore Mountain. The results show that the method used in this study is not sufficient as a sentinel marker to predict TBEV spreading in nature. Although previous studies demonstrated the usefulness of serological testing of roe deer in order to trace TBE-endemic regions, using ticks attached to them to get virus isolates is not productive.
德国南部被认为是蜱传脑炎（TBE）的疫区；然而，该国北部几乎没有人类 TBE 病例。由于其位于 TBE 疫区和仅有散发病例地区之间的过渡地带，萨克森州在 TBE 监测方面具有重要意义。长尾鹿（Capreolus capreolus）的 TBE 病毒（TBEV）抗体血清阳性率很高，被认为是评估 TBE 风险的哨兵。因此，长尾鹿可用作帮助更好地了解 TBEV 在自然界中的局部性的指标，并可能成为分离 TBEV 的来源。因此，本研究的目的是检查长尾鹿外套上的蜱虫，以确定蜱虫的负担，并检测附着在蜱虫上的 TBEV。134 件长尾鹿外套由萨克森狩猎协会的猎人提供（2017 年 8 月至 2019 年 1 月）。外套在-80°C 下冷冻，解冻后在内外两侧进行检查。收集附着和不附着的蜱虫，使用实时 RT-PCR 检测 TBEV 的存在。总共在 48 件外套上发现了 1279 只蜱虫。主要物种是硬蜱（Ixodes ricinus；99.76%；n=1276）。其余三个标本为硬蜱属（0.16%，1 雌 1 若虫）和璃眼蜱（0.08%，1 雄）。平均感染率为 26.7（SD=69.5），每只动物最多有 439 只蜱虫。雌性是蜱虫的主要生活阶段（n=536；42%），其次是若虫（n=397；n=31.1%）、雄性（n=175；13.7%）和幼虫（n=168；13.2%）。只有一半收集的蜱虫附着（n=662；51.8%）。在所测试的 1279 只蜱虫中，只有一只蜱虫检测到 TBEV。它是一只雌性，寄生在萨克森瑞士-东 Ore 山的一只长尾鹿身上。结果表明，本研究中使用的方法作为预测 TBEV 在自然界中传播的哨兵标记并不充分。尽管先前的研究表明对长尾鹿进行血清学检测以追踪 TBE 流行地区是有用的，但使用附着在它们身上的蜱虫获得病毒分离物并不是有效的。
