  The use of model experimental systems and mathematical models is important to
further understanding of infectious disease dynamics and strategize disease
mitigation. Gyrodactylids are helminth ectoparasites of teleost fish which have
many dynamical characteristics of microparasites but offer the advantage that
they can be quantified and tracked over time, allowing further insight into
within-host and epidemic dynamics. In this paper, we design a model to describe
host-parasite dynamics of the well-studied guppy-Gyrodactylus turnbulli system,
using experimental data to estimate parameters and validate it. We estimate the
basic reproduction number (R_0), for this system. Sensitivity analysis reveals
that parasite growth rate, and the rate at which the guppy mounts an immune
response have the greatest impact on outbreak peak and timing both for initial
outbreaks and on longer time scales. These findings highlight guppy population
resistance and parasite virulence as key factors in disease control, and future
work should focus on incorporating heterogeneity in host resistance into
disease models and extrapolating to other host-parasite systems.
