Modelling the environmental and ecological drivers of chytridiomycosis
Author(s)
Doddington, Benjamin
Type
Thesis
Abstract
Amphibians are the most threatened taxon assessed by the IUCN Red
List, with over 42% of all species in decline. The emerging infectious
disease chytridiomycosis, caused by the fungus Batrachochytrium
dendrobatidis, has been shown to a driver of many of these declines. The
broad aim of this thesis is to develop mechanistic models that realistically
capture the observed disease dynamics of Bd within Europe, and use
these to help understand its ecological and environmental drivers.
Mathematical modelling, field work and experimental work are used in
order to obtain an understanding of a Bd-host system on Mallorca, and in
combination, to show how the host population response to Bd is highly
context-dependent. The understanding gained is used to help predict the
consequences of an attempt to mitigate (reduce or avoid the negative
effects of) Bd in this system, and the mitigation attempt’s short-comings
are then analyzed in order to better inform future efforts. The context-dependence
of a host-population response to Bd will depend of two
components: a component dependent on the host and a component
dependent on Bd. Modelling of infection experiment results in the frog
species Silurana tropicalis is used to show a temperature-dependent host
response which is separate to the temperature-dependent response of Bd.
Multi-host models of Bd are created and used to show how increasing
species diversity can increase disease risk, and a method of estimating
unknown epidemiological parameters for Bd based on known facts about
the host’s biology is presented.
List, with over 42% of all species in decline. The emerging infectious
disease chytridiomycosis, caused by the fungus Batrachochytrium
dendrobatidis, has been shown to a driver of many of these declines. The
broad aim of this thesis is to develop mechanistic models that realistically
capture the observed disease dynamics of Bd within Europe, and use
these to help understand its ecological and environmental drivers.
Mathematical modelling, field work and experimental work are used in
order to obtain an understanding of a Bd-host system on Mallorca, and in
combination, to show how the host population response to Bd is highly
context-dependent. The understanding gained is used to help predict the
consequences of an attempt to mitigate (reduce or avoid the negative
effects of) Bd in this system, and the mitigation attempt’s short-comings
are then analyzed in order to better inform future efforts. The context-dependence
of a host-population response to Bd will depend of two
components: a component dependent on the host and a component
dependent on Bd. Modelling of infection experiment results in the frog
species Silurana tropicalis is used to show a temperature-dependent host
response which is separate to the temperature-dependent response of Bd.
Multi-host models of Bd are created and used to show how increasing
species diversity can increase disease risk, and a method of estimating
unknown epidemiological parameters for Bd based on known facts about
the host’s biology is presented.
Date Issued
2011-10
Date Awarded
2013-07
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Grassly, Nicholas
Fisher, Matthew
Sponsor
Natural Environment Research Council (Great Britain)
Publisher Department
Public Health
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)