Ljungan Virus - an undetected but dangerous zoonotic agent

1998年，Niklasson等人报道了瑞典三种人类疾病的发病率，即人类心肌炎、糖尿病和格林-巴利综合征，随着库田鼠3-4年的丰度周期而变化。随后，从瑞典糖尿病库田鼠中分离出一种新病毒，即Ljungan病毒（LV）。LV也存在于丹麦和美国的野生田鼠中，最近在瑞典北方的几种其他野生田鼠和旅鼠中分离出LV，并报告了心肌炎和临床糖尿病。利物浦正在进行的一项研究一直在观察野生啮齿动物的一系列感染（但不是LV），特别关注生活在英格兰-苏格兰边境的基尔德森林的人群。尼克拉森访问了利物浦，并对从基尔德种群中移走的田鼠进行了检查。初步分析提供了一个强有力的初步证据的情况下，LV在这些人群中的存在。1型糖尿病在儿童和年轻人中的分布尚不清楚，尽管遗传和环境因素都可能参与其中。许多研究表明感染和/或免疫反应可能起作用。时空聚集（在有限的时间内在小的地理位置观察到的病例数量过多）特别提示感染。一些研究已经确定了儿童糖尿病的时空聚集性。这一拟议项目将：1）调查Kielder种群和附近其他啮齿动物种群（包括围家养大鼠和小鼠），以启动LV标测（和可能的人类风险）在英国啮齿动物;和2）分析人类流行病学数据库在啮齿动物种群的区域，以寻求相关性，1型糖尿病的发病率与啮齿动物丰度或活动的测量之间（区域性）或时间上的差异;如果这些试点研究在其中一个方面或特别是两个方面都提供了负面结果，（没有确认Ljungan病毒和/或公共卫生记录中没有明显的模式），那么在瑞典观察到的模式不太可能适用于英国，关于这一主题的研究可被视为低优先事项。但是，如果其中一项或特别是两项研究都提供了积极的结果，那么永根病毒有可能成为英国最重要的野生动物人兽共患病，进一步的工作将是必不可少的。

In 1998, Niklasson and others reported that the incidence of three human diseases in Sweden, human myocarditis, diabetes and Guillain-Barre syndrome, varied with the 3-4 year abundance cycles of the bank vole. Subsequently, a new virus, Ljungan virus (LV) was isolated from Swedish diabetic bank voles. LV is also present in wild voles in Denmark and the USA and has recently been isolated, and myocarditis and clinical diabetes reported, in several other species of wild voles and lemmings in northern Sweden. An on-going study at Liverpool has been looking at a range of infections (but not LV) in wild rodents, focusing especially on populations living in Kielder Forest, on the English-Scottish border. Niklasson has visited Liverpool and examined voles removed from the Kielder populations. Preliminary analyses have provided a strong prima facie case for the presence of LV in these populations. The distribution of type 1 diabetes amongst children and young adults is not well understood, although both genetic and environmental factors are likely to be involved. A number of studies suggest a possible role for infections and/or immunological responses. Space-time clustering (excess numbers of cases observed within small geographical locations for limited periods of time) is especially suggestive of an infection. Several studies have identified space-time clustering in childhood diabetes. This proposed project would: 1) survey the Kielder populations and those of other rodent species nearby (including peri-domestic rats and mice) in order to initiate a mapping of LV (and possible human risk) in UK rodents; and 2) analyse human epidemiological data bases in the region of the rodent populations to seek correlations either spatially (regionally) or temporally between incidences of type 1 diabetes and measures of rodent abundance or activity; If these pilot studies provide negative results in either or especially both respects (no confirmation of Ljungan virus and/or no overt patterns in the public health records), then it will be unlikely that patterns observed in Sweden also apply in the UK, and research on this topic can be considered of low priority. But if either or especially both studies provide positive results, then Ljungan virus has the potential to become the most important wildlife zoonosis in the UK and further work will be essential.