Endemicity of chytridiomycosis features pathogen overdispersion

Pathogens can be critical drivers of the abundance and distribution of wild animal populations. The presence of an overdispersed pathogen load distribution between hosts (where few hosts harbour heavy parasite burdens and light infections are common) can have an important stabilizing effect on host-pathogen dynamics where infection intensity determines pathogenicity. This may potentially lead to endemicity of an introduced pathogen rather than extirpation of the host and/or pathogen. Overdispersed pathogen load distributions have rarely been considered in wild animal populations as an important component of the infection dynamics of microparasites such as bacteria, viruses, protozoa and fungi. Here we examined the abundance, distribution and transmission of the model fungal pathogen Batrachochytrium dendrobatidis (Bd, cause of amphibian chytridiomycosis) between wild-caught Litoria…