PNAS：亚洲气候事件与欧洲鼠疫

一项研究发现，在14世纪延伸到19世纪的欧洲鼠疫大流行期间，鼠疫的暴发可能一直是由于间歇性气候驱动的亚洲鼠疫菌株的重新引入造成的，而不是由于持续存在的欧洲啮齿动物储存宿主造成的。

1347年到19世纪欧洲鼠疫的持续存在通常被归因于鼠疫耶尔森氏菌(Yersinia pestis)在其最初被传入欧洲后在欧洲啮齿动物种群中存留了下来。为了寻找重复出现的鼠疫的储存宿主，Nils Chr. Stenseth及其同事研究了来自欧洲和亚洲的15个树木年轮气候记录，以及7711个历史上的鼠疫暴发的数据集。

这组作者发现，没有证据表明啮齿动物鼠疫储存宿主在欧洲持续存在。相反，研究人员在巴基斯坦的喀喇昆仑山脉的刺柏年轮记录中发现气候条件曾经出现了变化，这种变化的气候条件已知可以影响今天亚洲野生生物鼠疫的暴发。这些亚洲的气候事件总是比鼠疫重新进入欧洲早大约15年。

这组作者说，这些结果提示鼠疫感染可能是通过贸易路线从亚洲储存宿主传到欧洲的，其暴发的时机与气候波动有关，而且可能并没有存在于欧洲储存宿主之中。

原文链接：

Climate-driven introductions of the Black Death and successive plague epidemics into europe

The Black Death, originating in Asia, arrived in the Mediterranean harbors of Europe in 1347 CE, via theland and sea trade routes of the ancient Silk Road system. This epidemic marked the start of the secondplague pandemic, which lasted in Europe until the early 19th century. This pandemic is genErally understood as the consequence of a singular introduction of Yersinia pestis, after which the disease estABLished itself in European rodents over four centuries. To locate these putative plague reservoirs, we studied the climate fluctuations that preceded regional plague epidemics, based on a dataset of 7,711 georeferenced historical plague outbreaks and 15 annually resolved tree-ring records from Europe andAsia. We provide evidence for repeated climate-driven reintroductions of the bacterium into European harbors from reservoirs in Asia, with a delay of 15 ± 1 y. Our analysis finds no support for the existence ofpermanent plague reservoirs in medieval Europe.(doi: 10.1073/pnas.1412887112)

作者：Boris V. Schmid