Parasitology

Research Article

The effect of host movement on viral transmission dynamics in a vector-borne disease system

E. J. WATTSa1a2, S. C. F. PALMERa1 c1, A. S. BOWMANa1, R. J. IRVINEa3, A. SMITHa4 and J. M. J. TRAVISa1

a1 Institute of Biological and Environmental Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, UK

a2 NERC Centre for Ecology and Hydrology, Hill of Brathens, Banchory AB31 4BW, UK

a3 Macaulay Institute, Craigiebuckler, Aberdeen AB15 8QH, UK

a4 Game and Wildlife Conservation Trust, Drumochter Lodge, Dalwhinnie PH19 1AF, UK

SUMMARY

Many vector-borne pathogens whose primary vectors are generalists, such as Ixodid ticks, can infect a wide range of host species and are often zoonotic. Understanding their transmission dynamics is important for the development of disease management programmes. Models exist to describe the transmission dynamics of such diseases, but are necessarily simplistic and generally limited by knowledge of vector population dynamics. They are typically deterministic SIR-type models, which predict disease dynamics in a single, non-spatial, closed patch. Here we explore the limitations of such a model of louping-ill virus dynamics by challenging it with novel field data. The model was only partially successful in predicting Ixodes ricinus density and louping-ill virus prevalence at 6 Scottish sites. We extend the existing multi-host model by forming a two-patch model, incorporating the impact of roaming hosts. This demonstrates that host movement may account for some of the discrepancies between the original model and empirical data. We conclude that insights into the dynamics of multi-host vector-borne pathogens can be gained by using a simple two-patch model. Potential improvements to the model, incorporating aspects of spatial and temporal heterogeneity, are outlined.

(Received October 09 2008)

(Revised February 02 2009)

(Revised April 22 2009)

(Accepted April 27 2009)

(Online publication July 27 2009)

Correspondence:

c1 Corresponding author: Institute of Biological and Environmental Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, UK. Tel: +44 (0) 1224 272693. E-mail: s.palmer@abdn.ac.uk

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