title: The alternate role of direct and environmental transmission in fungal infectious disease in wildlife: threats for biodiversity conservation.
abstract: Emerging fungal pathogens have substantial consequences for infected hosts, as revealed by the global decline of amphibian species from the chytrid fungus. According to the "curse of the Pharaoh" hypothesis, free-living infectious stages typical of fungal pathogens lengthen the timespan of transmission. Free-living infectious stages whose lifespan exceeds the infection time of their hosts are not constrained by virulence, enabling them to persist at high levels and continue transmitting to further sensitive hosts. Using the only Mesomycetozoea fungal species that can be cultured, Sphaerothecum destruens, we obtained tractable data on infectivity and pathogen life cycle for the first time. Here, based on the outcomes of a set of infectious trials and combined with an epidemiological model, we show a high level of dependence on direct transmission in crowded, confined environments and establish that incubation rate and length of infection dictate the epidemic dynamics of fungal disease. The spread of Mesomycetozoea in the wild raise ecological concerns for a range of susceptible species including birds, amphibians and mammals. Our results shed light on the risks associated with farming conditions and highlight the additional risk posed by invasive species that are highly abundant and can act as infectious reservoir hosts.
authors.affiliation: Bournemouth University, Fern Barrow, Talbot Campus, Poole, Dorset, BH12 5BB, UK.
authors.forename: Farah N
authors.initials: FN
authors.lastname: Al-Shorbaji
authors.affiliation: UMR BOREA IRD-MNHN-Université Pierre et Marie Curie, Muséum National d'Histoire Naturelle, 47 rue Cuvier, 75231 Paris cedex 5, France.
authors.forename: Rodolphe E
authors.initials: RE
authors.lastname: Gozlan
authors.affiliation: International Research Unit UMMISCO (IRD/UPMC 209), Center for Mathematical and Computational Modeling of Complex Systems, 32 Avenue Henri Varagnat, 93143 Bondy Cedex, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Roche
authors.affiliation: Bournemouth University, Fern Barrow, Talbot Campus, Poole, Dorset, BH12 5BB, UK.
authors.forename: J Robert
authors.initials: JR
authors.lastname: Britton
authors.affiliation: Bournemouth University, Fern Barrow, Talbot Campus, Poole, Dorset, BH12 5BB, UK.
authors.forename: Demetra
authors.initials: D
authors.lastname: Andreou
mesh_terms: D000818:Animals; D044822:Biodiversity; D003530:Cyprinidae / Q000254:growth & development / Q000469:parasitology; D050298:Mesomycetozoea / Q000502:physiology*; D050738:Mesomycetozoea Infections / Q000453:epidemiology / Q000473:pathology / Q000635:transmission*; D008954:Models, Biological