Globalized infectious diseases are causing species declines worldwide, but their source often remains elusive. We used whole-genome sequencing to solve the spatiotemporal origins of the most devastating panzootic to date, caused by the fungus Batrachochytrium dendrobatidis, a proximate driver of global amphibian declines. We traced the source of B. dendrobatidis to the Korean peninsula, where one lineage, BdASIA-1, exhibits the genetic hallmarks of an ancestral population that seeded the panzootic. We date the emergence of this pathogen to the early 20th century, coinciding with the global expansion of commercial trade in amphibians, and we show that intercontinental transmission is ongoing. Our findings point to East Asia as a geographic hotspot for B. dendrobatidis biodiversity and the original source of these lineages that now parasitize amphibians worldwide.

Emerging disease in UK amphibians THE recently discovered fungal pathogen Batrachochytrium salamandrivorans is causing the rapid loss of infected fire salamander (Salamandra salamandra) populations in continental Europe (Martel and others 2013). The fungus is thought to be endemic to Asia, with introduction to Europe via the pet trade. Many species of salamander and newt (urodeles) have been shown experimentally to be susceptible to fatal infection, including the UK protected species, the great crested newt (Triturus cristatus) (Martel and others 2014). Frogs and toads appear to be resistant to infection. Routine testing of quarantined amphibians, newly acquired from a UK amphibian breeder by a zoological collection, demonstrated infection in three imported species of urodele using pathogen-specific qPCR (Blooi and others 2013). Infected animals either died while in quarantine or were euthanased. Epidemiological investigations so far have detected the infection in an additional urodele species at the breeder's premises, with associated morbidity and mortality. Studies to locate the source of the infection and to determine if there has been further dissemination among the UK amphibian trade are ongoing through the use of contacttracing and molecular epidemiology. All efforts must be made to prevent this pathogen entering the wild amphibian population (eg, via release of infected animals or the discarding of contaminated water or fomites in amphibian habitats such as garden settings). It would be most helpful if veterinary surgeons, amphibian breeders, retailers and hobbyists advised their clients and colleagues to use appropriate disinfection and biosecurity measures. Such measures for preventing the spread of the amphibian fungus, Batrachochytrium dendrobatidis (see http://static.zsl.org/files/ biosecurity-arguk4-511.PDF), are suitable for the control of B salamandrivorans. Additionally, measures to minimise the likelihood of further imports of this pathogen into the UK should be put in place.

Emerging fungal pathogens are a growing threat to global health, ecosystems, food security, and the world economy. Over the last century, environmental change and globalized transport, twinned with the increasing application of antifungal chemical drugs have led to increases in outbreaks of fungal diseases with sometimes catastrophic effects. In order to tackle contemporary epidemics and predemic threats, there is a pressing need for a unified approach in identification and monitoring of fungal pathogens. In this paper, we discuss current high throughput technologies, as well as new platforms capable of combining diverse data types to inform practical epidemiological strategies with a focus on emerging fungal pathogens of wildlife.