Abstract
Emerging infectious diseases are increasing globally and are an additional challenge to species dealing with native parasites and pathogens. Therefore, understanding the combined effects of infectious agents on hosts is important for species' conservation and population management. Amphibians are hosts to many parasites and pathogens, including endemic trematode flatworms (e.g., Echinostoma spp.) and the novel pathogenic amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]). Our study examined how exposure to trematodes during larval development influenced the consequences of Bd pathogen exposure through critical life events. We found that prior exposure to trematode parasites negatively impacted metamorphosis but did not influence the effect of Bd infection on terrestrial growth and survival. Bd infection alone, however, resulted in significant mortality during overwintering-an annual occurrence for most temperate amphibians. The results of our study indicated overwintering mortality from Bd could provide an explanation for enigmatic declines and highlights the importance of examining the long-term consequences of novel parasite exposure.
Highlights
Current trends show that disease-related wildlife declines are occurring at unprecedented rates and that they are spurred by human modification of landscapes [1, 2]
While individuals that survived overwintering maintained their Batrachochytrium dendrobatidis (Bd) infection status (100% infection rate following overwintering), trematode metacercarial cysts were absent in all animals that survived through overwintering
The emergence of novel infectious diseases that successfully spread across the globe bring many potential consequences and in the case of the amphibian chytrid fungus, those consequences have been severe
Summary
Current trends show that disease-related wildlife declines are occurring at unprecedented rates and that they are spurred by human modification of landscapes [1, 2]. The rise of emerging infectious diseases poses an additional challenge to species already managing natural parasite and pathogen infections [3, 4]. Understanding how hosts manage co-infections of either native and/or novel parasites and pathogens is of utmost importance to humans and wildlife given that co-infection is the norm rather than the exception [5]. Amphibians are declining globally at a concerning rate [6], faster than any other vertebrate group [7], due in part to emerging infectious agents [8,9,10].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
