Data from: Reconstructing the emergence of a lethal infectious disease of wildlife supports a key role for spread through translocations by humans

There have been few reconstructions of wildlife disease emergences, despite their extensive impact on biodiversity and human health. This is in large part attributable to the lack of structured and robust spatio-temporal datasets. We overcame logistical problems of obtaining suitable information by using data from a citizen science project and formulating spatio-temporal models of the spread of a wildlife pathogen (genus Ranavirus, infecting amphibians). We evaluated three main hypotheses for the rapid increase in disease reports in the UK: that outbreaks were being reported more frequently, that climate change had altered the interaction between hosts and a previously widespread pathogen, and that disease was emerging due to spatial spread of a novel pathogen. Our analysis characterized localized spread from nearby ponds, consistent with amphibian dispersal, but also revealed a highly significant trend for elevated rates of additional outbreaks in localities with higher human population density—pointing to human activities in also spreading the virus. Phylogenetic analyses of pathogen genomes support the inference of at least two independent introductions into the UK. Together these results point strongly to humans repeatedly translocating ranaviruses into the UK from other countries and between UK ponds, and therefore suggest potential control measures.

尽管野生动物新发疾病对生物多样性与人类健康造成广泛影响，但针对此类疾病暴发的溯源重建研究仍寥寥无几。这在很大程度上可归因于缺乏结构化且可靠的时空数据集（spatio-temporal datasets）。我们通过利用公民科学项目（citizen science project）的数据，并构建了针对一种野生动物病原体——蛙病毒属（Ranavirus，感染两栖动物）——传播的时空模型，解决了获取适配研究所需信息的后勤难题。针对英国地区疾病报告数量快速增长的现象，我们评估了三大核心假说：一是疫情报告频率有所提升；二是气候变化改变了宿主与此前广泛流行的病原体之间的相互作用；三是新型病原体的空间传播引发了疾病新发。我们的分析显示，病毒存在从邻近池塘局部扩散的特征，这与两栖动物的自然扩散模式相符；但同时也发现，在人口密度更高的地区，新增暴发的概率显著升高——这表明人类活动同样参与了病毒的传播。对病原体基因组的系统发育分析（phylogenetic analyses）支持了“至少存在两次独立引入英国”的推论。综合上述结果，我们有充分依据推断人类反复从其他国家向英国输入蛙病毒，且在英国境内的池塘之间也存在病毒传播，因此本研究提出了潜在的防控策略。