Introduction
Emerging infectious diseases (EIDs) of wildlife represent a major threat to global biodiversity.1 Although mechanisms behind EIDs are multifactorial, many large-scale wildlife population declines attributed to disease are the result of anthropogenic translocation of infectious agents.2 Such introductions have led to precipitous declines of North American bat populations from white-nose syndrome,3 endangerment of wild mammalian carnivore species by canine distemper,4 and local and global extinctions of amphibians owing to chytridiomycosis.5 As a more recent example, introduction of Batrachochytrium salamandrivorans (Bsal) to Europe is causing catastrophic declines of native salamander species.6 This emergent fungal pathogen is believed to have reached Europe through international trade in wild Asian salamanders,6 underscoring another instance where movement of animals has facilitated translocation of associated pathogens.
Recently published assessments of the global risk that Bsal poses to amphibians indicates that introduction of this pathogen to North America, home to the world's greatest diversity of salamander species, could have catastrophic impacts on these wild populations.7, 8 To further evaluate the risk for introduction of Bsal through legally imported amphibians, we screened salamanders imported from China into the United States for the fungus. The animals did not harbor Bsal but rather tested positive for spring viraemia of carp virus (SVCV), a pathogen not previously known to infect amphibians. Inadvertent introduction of SVCV, the cause of a reportable foreign animal disease in the United States, would present an economic threat to the commercial cyprinid aquaculture industry. Overall, this example highlights the challenges of reducing risks for translocation of pathogens when knowledge of host–pathogen relationships is incomplete.