Białowieża National Park, Park Pałacowy 11, 17-230, Białowieża, Poland; Faculty of Civil Engineering and Environmental Sciences, Institute of Forest Sciences, Białystok University of Technology, Wiejska 45 E, 15-351, Białystok, Poland.
Department of Food Hygiene and Public Health Protection, Institute of Veterinary Medicine, Warsaw University Of Life Sciences (WULS), ul. Nowoursynowska 166, Warszawa 02-786, Poland.
Ticks Tick Borne Dis. 2021 Nov;12(6):101799. doi: 10.1016/j.ttbdis.2021.101799. Epub 2021 Jul 30.
Tick-borne encephalitis (TBE) is one of the most common zoonotic diseases in Europe transmitted by Ixodidae vectors. While small mammals such as bank voles and ticks constitute the main reservoirs for virus transmission, large sylvatic species act as a food source for ticks. Cervids such as roe deer and red deer are considered sentinel species for TBE in natural foci. In addition, an increase of the population size and density of large wild mammals in an area corresponds to an increase in the tick burden and may potentially increase the prevalence of TBE virus (TBEV) in ticks and tick hosts and further exposure risk in humans. Humans are considered accidental hosts. The prevalence of TBE relies on interactions between host, vector and environment. The present study examines the exposure of the largest European herbivore, the European bison (Bison bonasus) to TBEV infection. Assessed using the IMMUNOZYM FSME ELISA (PROGEN), the overall TBEV seroprevalence was 62.7% in the 335 European bison that were studied. ELISA results were confirmed by the gold-standard virus neutralization test (VNT) with 98.7% sensitivity and thus giving a true prevalence of 63.5%. TBEV seroprevalence was significantly correlated to the origin, age group, sex, population type (free living/captive) and sanitary status (healthy/selectively eliminated/found dead/killed in accident) of the European bison in the univariable analysis. The highest seroprevalences were observed in the three largest north-eastern wild populations (Białowieska, Borecka and Knyszyńska forests), which corresponded with the highest incidence of human cases reported in the country. The risk of TBEV seropositivity increased with age and was higher in female and free-ranging European bison. Additionally, to the epidemiological investigation, the continuous detection of TBEV antibodies was studied by repetitive testing of animals over the course of 34 months. Two of six seropositive animals remained seropositive throughout the study. The presence of antibodies was followed throughout the study in seropositive European bison and for at least a year in animals that seroconverted during the observation period.
蜱传脑炎（TBE）是欧洲最常见的由硬蜱传播的人畜共患病之一。虽然小型哺乳动物如田鼠和蜱是病毒传播的主要宿主，但大型森林物种是蜱的食物来源。狍和马鹿等鹿科动物被认为是自然疫源地 TBE 的哨点物种。此外，一个地区大型野生动物种群数量和密度的增加，对应着蜱虫和蜱宿主中 TBE 病毒（TBEV）的流行率增加，以及人类进一步暴露的风险增加。人类被认为是偶然宿主。TBE 的流行取决于宿主、媒介和环境之间的相互作用。本研究检查了最大的欧洲食草动物欧洲野牛（Bison bonasus）对 TBEV 感染的暴露情况。使用 IMMUNOZYM FSME ELISA（PROGEN）进行评估，在所研究的 335 头欧洲野牛中，TBEV 的总血清阳性率为 62.7%。ELISA 结果通过病毒中和试验（VNT）得到证实，其敏感性为 98.7%，因此真实阳性率为 63.5%。TBEV 血清阳性率与欧洲野牛的起源、年龄组、性别、种群类型（自由生活/圈养）和卫生状况（健康/选择性淘汰/发现死亡/意外死亡）在单变量分析中呈显著相关。在三个最大的东北部野生种群（比亚沃维耶扎森林、博雷卡森林和克尼斯纳森林）中观察到最高的血清阳性率，这与该国报告的人类病例最高发病率相对应。TBEV 血清阳性率随年龄增长而增加，在雌性和自由放养的欧洲野牛中更高。此外，除了流行病学调查外，还通过对动物进行 34 个月的重复测试，研究了 TBEV 抗体的连续检测。在整个研究过程中，6 只血清阳性动物中有 2 只一直保持血清阳性。在整个研究过程中，对血清阳性的欧洲野牛进行了抗体跟踪检测，在观察期间发生血清转换的动物中至少跟踪了一年。
