Many zoonotic diseases are weather sensitive, raising concern how their distribution and outbreaks will be affected by climate change. At northern high latitudes, the effect of global warming on especially winter conditions is strong. By using long term monitoring data (1980–1986 and 2003–2013) from Northern Europe on temperature, precipitation, an endemic zoonotic pathogen (Puumala orthohantavirus, PUUV) and its reservoir host (the bank vole, Myodes glareolus), we show that early winters have become increasingly wet, with a knock-on effect on pathogen transmission in its reservoir host population. Further, our study is the first to show a climate change effect on an endemic northern zoonosis, that is not induced by increased host abundance or distribution, demonstrating that climate change can also alter transmission intensity within host populations. Our results suggest that rainy early winters accelerate PUUV transmission in bank voles in winter, likely increasing the human zoonotic risk in the North.

许多人畜共患疾病对天气敏感，引起人们的关注气候变化将如何影响它们的分布和爆发。在北部高纬度地区，全球变暖对冬季条件的影响尤其严重。通过使用北欧关于温度、降水、地方性人畜共患病病原体（普马拉正汉坦病毒，PUUV）及其储存宿主（田鼠，Myodes glareolus）的长期监测数据（1980-1986年和2003-2013年），我们发现早期冬季变得越来越潮湿，对病原体在宿主种群中的传播产生了连锁反应。此外，我们的研究首次表明气候变化对北方地方性人畜共患病的影响，这种影响不是由宿主丰度或分布增加引起的，这表明气候变化也可以改变宿主群体内的传播强度。我们的研究结果表明，多雨的初冬加速了冬季河岸田鼠的 PUUV 传播，可能增加了北方人类人畜共患病的风险。