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Nematode parasites of sheep: extension of a simple model to include host variability

Published online by Cambridge University Press:  18 November 2004

K. LOUIE ,
A. VLASSOFF  and
A. MACKAY
K. LOUIE
Affiliation:
AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton, New Zealand
A. VLASSOFF
Affiliation:
AgResearch, Wallaceville Animal Research Centre, P.O. Box 40-063, Upper Hutt, New Zealand
A. MACKAY
Affiliation:
AgResearch, Grasslands Research Centre, Private Bag 11008, Palmerston North, New Zealand
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Abstract

We use results from a simulation-based model of nematode infection of sheep to refine the parameters in a simpler generic model of host–parasite population dynamics. These parameters describe the following host–parasite traits: probability of establishment of ingested larvae, mortality rate of adult parasites, and fecundity of adult female parasites. This simple model is then extended by allowing those parameters to vary amongst individual hosts. A sensitivity analysis is performed to determine which parameters have most influence on host parasite burden. The establishment parameter has the greatest effect on the peak value of parasite burden whilst the other two parameters have more effect on the duration of the burden. A comparison is made with results from the flock model after discussion of the definition of an average host. By allowing these parameters to vary simultaneously within the individual hosts we are able to reproduce the over-dispersed distribution of adult parasites frequently seen in nematode infections of sheep flocks.

Keywords

sheephost–parasite modelsnematodesmathematical modelshost variability
Type
Research Article
Information
Parasitology , Volume 130 , Issue 4 , April 2005 , pp. 437 - 446
Copyright
2005 Cambridge University Press

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