Individual-based vs. deterministic models for macroparasites: host cycles and extinction

Our understanding of the qualitative dynamics of host–macroparasite systems is mainly based on deterministic models. We study here an individual-based stochastic model that incorporates the same assumptions as the classical deterministic model. Stochastic simulations, using parameter values based on...

Full description

Saved in:
Bibliographic Details
Published in:Theoretical population biology 2003-06, Vol.63 (4), p.295-307
Main Authors: Rosà, Roberto, Pugliese, Andrea, Villani, Alessandro, Rizzoli, Annapaola
Format: Article
Language:English
Subjects:
Animals
Host-Parasite Interactions
Humans
Models, Theoretical
Stochastic Processes
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Our understanding of the qualitative dynamics of host–macroparasite systems is mainly based on deterministic models. We study here an individual-based stochastic model that incorporates the same assumptions as the classical deterministic model. Stochastic simulations, using parameter values based on some case studies, preserve many features of the deterministic model, like the average value of the variables and the approximate length of the cycles. An important difference is that, even when deterministic models yield damped oscillations, stochastic simulations yield apparently sustained oscillations. The amplitude of such oscillations may be so large to threaten parasites’ persistence. With density-dependence in parasite demographic traits, persistence increases somewhat. Allowing instead for infections from an external parasite reservoir, we found that host extinction may easily occur. However, the extinction probability is almost independent of the level of external infection over a wide intermediate parameter region.
ISSN:0040-5809
1096-0325
DOI:10.1016/S0040-5809(03)00021-2