Considering that emerging infectious diseases are one of the major drivers of global amphibian decline, controlling the spread of infections are even more challenging. Amphibian skin disease chytridiomycosis, which is caused by two species of fungi belonging to the Batrachochytrium genus, has been detected in at least 700 amphibian species causing mass mortalities in all continents where amphibians occur. Most Alytes species, including the Betic midwife toad (A. dickhilleni), are highly susceptible to B. dendrobatidis (Bd) with lethal consequences. The presence of Bd infection in A. dickhilleni was confirmed ten years ago in just three localities across the entire distribution range of this threatened species. Here we report the extraordinary Bd expansion through the entire distribution range of A. dickhilleni and analyse if former infected populations acted as the source of transmission events to current infected populations. Currently, Bd infection is broadly distributed across the entire distribution range of the species and the increase of infection prevalence reached 30–50% during a decade. The populations where the infection was detected a decade ago could be identified as likely sources of infection for some locations where the pathogen is now present. The introduction of infected amphibian hosts into previously naïve A. dickhilleni breeding sites, and other anthropogenic processes, are seeming to be the most plausible way of Bd range expansion, motivating mass mortalities, population declines and extirpation events of this threatened amphibian species.

考虑到新出现的传染病是全球两栖动物数量下降的主要驱动因素之一，控制感染的传播就更具挑战性。两栖类皮肤病性壶菌病是由属于嗜盐杆菌属的两种真菌引起的，至少在两栖动物出现的所有大陆上，至少有700种两栖动物中发现了这种病。大多数Alytes物种，包括Betic助产士蟾蜍（A. dickhilleni），极易受到B. dendrobatidis（Bd）的杀伤，并具有致命的后果。迪克希氏菌中存在Bd感染十年前，在这一受威胁物种的整个分布范围内的三个地方证实了这一点。在这里，我们报告了A. dickhilleni整个分布范围内非凡的Bd扩展，并分析了以前的感染人群是否充当了向当前感染人群的传播事件的来源。目前，Bd感染广泛分布于该物种的整个分布范围内，十年内感染率的增加达到了30–50％。在现在存在病原体的某些地方，可以将十年前发现感染的人群确定为可能的感染源。将受感染的两栖动物宿主引入以前的幼稚状态A. dickhilleni的繁殖地点和其他人为过程，似乎是扩大Bd范围，诱使这种死亡的两栖类物种大量死亡，种群减少和灭绝事件的最合理的方式。