Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige, Trento, Italy; Center Agriculture Food Environment, University of Trento, 38010 San Michele all'Adige, Trento, Italy.
Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige, Trento, Italy.
Int J Parasitol. 2019 Sep;49(10):779-787. doi: 10.1016/j.ijpara.2019.05.006. Epub 2019 Jul 23.
Tick-borne encephalitis is an important zoonosis in many parts of north-western, central and eastern Europe, Russia and the Far East, with considerable altitudinal and latitudinal shifts described during recent decades. The reported routes of transmission for TBE virus include the saliva-activated non-viraemic transmission between co-feeding ticks taking place on rodent hosts. During the period 2001-2014, a population of the yellow-necked mouse (Apodemus flavicollis), which is considered among the most efficient TBE competent host, especially in central and western Europe, was intensively live-trapped in a known TBE focus in the Province of Trento, Italy. Individual live-trapped mice were checked for the number and position of feeding ticks and serologically screened for TBEv antibodies. A combined effect of climatic conditions and density of both roe deer and mice on the number of co-feeding tick groups was observed. Specifically, the occurrence of co-feeding ticks on mice during the questing season was affected by autumnal cooling in the previous season. On the other hand, co-feeding occurrence was also positively associated with roe deer abundance, while mouse density showed a hump-shaped pattern. Individual features of A. flavicollis such as weight and sex also affected co-feeding occurrence with the heaviest (breeding adult) males carrying more co-feeding ticks. We also found that the overall number of co-feeding ticks on mice positively affected TBEv antibody detection in this species the following year. In conclusion, a specific combination of climatic conditions in conjunction with certain rodent and roe deer densities are the principal determinants of the number of co-feeding ticks on A. flavicollis and, consequently, TBEv circulation. These variables can be used to provide an early warning signal for a TBE hazard, thus representing a useful tool for Public Health authorities to prepare action for prevention and control within TBEv circulation areas.
蜱传脑炎是西北欧、中欧和东欧、俄罗斯和远东地区的重要动物传染病，近几十年来，该病毒的传播有相当大的海拔和纬度变化。TBE 病毒的报告传播途径包括在啮齿动物宿主上共同进食的蜱的唾液激活非病毒血症传播。2001-2014 年期间，在意大利特伦蒂诺省的一个已知 TBE 流行地区，对被认为是最有效的 TBE 宿主之一的黄颈鼠（Apodemus flavicollis）进行了密集的活捕。对捕获的活鼠进行了检查，以确定其取食蜱的数量和位置，并对 TBEv 抗体进行血清学筛查。观察到气候条件以及鹿和老鼠的密度对共同取食蜱组数量的综合影响。具体而言，上一季秋季降温会影响取食季节中蜱在老鼠身上的出现。另一方面，共同取食的出现也与鹿的丰度呈正相关，而老鼠的密度呈驼峰状。A. flavicollis 的个体特征，如体重和性别，也会影响共同取食的出现，最重的（繁殖成年）雄性携带更多的共同取食蜱。我们还发现，次年，在老鼠身上总共出现的共同取食蜱数量与 TBEv 抗体检测呈正相关。总之，特定的气候条件组合与某些啮齿动物和鹿的密度是决定 A. flavicollis 上共同取食蜱数量以及 TBEv 循环的主要因素。这些变量可用于为 TBE 危险提供早期预警信号，从而成为公共卫生当局在 TBEv 循环地区准备预防和控制措施的有用工具。
