The ecology of wildlife disease surveillance: demographic and prevalence fluctuations undermine surveillance

Walton, Laura; Marion, Glenn; Davidson, Ross S.; White, Piran C.L.; Smith, Lesley A.; Gavier-Widen, Dolores; Yon, Lisa; Hannant, Duncan; Hutchings, Michael R.

Abstract

1. Wildlife disease surveillance is the first line of defence against infectious disease. Fluctuations in host populations and disease prevalence are a known feature of wildlife disease systems. However, the impact of such heterogeneities on the performance of surveillance is currently poorly understood.
2. We present the first systematic exploration of the effects of fluctuations prevalence and host population size on the efficacy of wildlife disease surveillance systems. In this study efficacy is measured in terms of ability to estimate long term prevalence and detect disease risk.
3. Our results suggest that for many wildlife disease systems fluctuations in population size and disease lead to bias in surveillance-based estimates of prevalence and over-confidence in assessments of both the precision of prevalence estimates and the power to detect disease.
4. Neglecting such ecological effects may lead to poorly designed surveillance and ultimately to incorrect assessments of the risks posed by disease in wildlife. This will be most problematic in systems where prevalence fluctuations are large and disease fade-outs occur. Such fluctuations are determined by the interaction of demography and disease dynamics and although particularly likely in highly fluctuating populations typical of fecund short lived hosts, can’t be ruled out in more stable populations of longer lived hosts.
5. Synthesis and Applications: Fluctuations in population size and disease prevalence should be considered in the design and implementation of wildlife disease surveillance and the framework presented here provides a template for conducting suitable power calculations. Ultimately understanding the impact of fluctuations in demographic and epidemiological processes will enable improvements to wildlife disease surveillance systems leading to better characterisation of, and protection against endemic, emerging and re-emerging disease threats.

Citation

Walton, L., Marion, G., Davidson, R. S., White, P. C., Smith, L. A., Gavier-Widen, D., …Hutchings, M. R. (2016). The ecology of wildlife disease surveillance: demographic and prevalence fluctuations undermine surveillance. Journal of Applied Ecology, 53(5), 1460-1469. https://doi.org/10.1111/1365-2664.12671

• Journal Article Type: Article
• Acceptance Date: Apr 4, 2016
• Online Publication Date: Apr 29, 2016
• Publication Date: Oct 31, 2016
• Deposit Date: Oct 26, 2016
• Publicly Available Date: Oct 26, 2016
• Journal: Journal of Applied Ecology
• Print ISSN: 0021-8901
• Electronic ISSN: 1365-2664
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 53
• Issue: 5
• Pages: 1460-1469
• DOI: https://doi.org/10.1111/1365-2664.12671
• Keywords: demographic fluctuations, disease surveillance, disease transmission models, stochastic population models, wildlife disease systems, wildlife ecology, wildlife populations
• Public URL: https://nottingham-repository.worktribe.com/output/820895
• Publisher URL: http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.12671/abstract
• Additional Information: This is the peer reviewed version of the following article: Walton, L., Marion, G., Davidson, R. S., White, P. C.L., Smith, L. A., Gavier-Widen, D., Yon, L., Hannant, D., Hutchings, M. R. (2016), The ecology of wildlife disease surveillance: demographic and prevalence fluctuations undermine surveillance. Journal of Applied Ecology, 53: 1460–1469., which has been published in final form at http://dx.doi.org/ 10.1111/1365-2664.12671. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."