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CABI Book Chapter

Biosecurity surveillance: quantitative approaches.

Book cover for Biosecurity surveillance: quantitative approaches.


Biosecurity surveillance plays a vital role in protection against the introduction and spread of unwanted plants and animals. It involves not just collecting relevant information, but also analysing this information. This book focuses on methods for quantitative analysis of biosecurity surveillance data, where these data might arise from observations, sensors, remote imaging, expert opinion and so...

Chapter 9 (Page no: 167)

Ad hoc solutions to estimating pathway non-compliance rates using imperfect and incomplete information.

This chapter provides ad hoc tools to assist in estimating the non-compliance rate of biosecurity risk material (BRM) in a given pathway when certain data are unavailable. We use the inspection of international mail as a case study. Estimating the noncompliance rate of a pathway is essential in order to assess the risk of the environment, and to make defensible decisions about the allocation of inspection effort. Counts of articles inspected and articles found to have BRM are necessary for estimating the pathway non-compliance rate, and inspection counts by cohort (sub-pathway) are needed in order to perform profiling within a pathway, for example, identifying and prioritizing high-risk countries of origin for mail articles. Detailed information is usually kept on non-compliant mail articles that have been intercepted, but sometimes not on the articles that were inspected and passed, which is needed to report the inspection effort undertaken. Hence, the inspection effort by cohort may be unknown. In many pathways, endpoint surveys are performed after all inspection activity has been completed in order to estimate the efficacy of the inspection. We can estimate the number of mail articles of each cohort that undergo each type of inspection just using the endpoint survey. However, extra information is usually available, such as the totals by cohort or by inspection method, which could make the estimate of the number of mail articles more accurate. We present and demonstrate raking, which is a simple statistical tool that improves the estimates of cohort counts that arise from a survey using the known marginal totals of the process. The endpoint survey is also used for estimating the amount of undetected non-compliance, called leakage, by cohort, which is needed for profiling. However, leakage estimates by cohorts are usually variable because sample sizes are low. We demonstrate an empirical Bayes approach for reducing the variability of leakage estimates, and other ad hoc solutions. Finally, we suggest the use of Receiver Operating Characteristic (ROC) and leakage curves to assess the effect of these and other approaches upon the inspectorate's performance.

Other chapters from this book

Chapter: 1 (Page no: 1) Introduction to Biosecurity surveillance: quantitative approaches. Author(s): Jarrad, F.
Chapter: 2 (Page no: 9) Biosecurity surveillance in agriculture and environment: a review. Author(s): Quinlan, M. Stanaway, M. Mengersen, K.
Chapter: 3 (Page no: 43) Getting the story straight: laying the foundations for statistical evaluation of the performance of surveillance. Author(s): Low-Choy, S.
Chapter: 4 (Page no: 75) Hierarchical models for evaluating surveillance strategies: diversity within a common modular structure. Author(s): Low-Choy, S.
Chapter: 5 (Page no: 109) The relationship between biosecurity surveillance and risk analysis. Author(s): MacLeod, A.
Chapter: 6 (Page no: 123) Designing surveillance for emergency response. Author(s): Havre, Z. van Whittle, P.
Chapter: 7 (Page no: 137) The role of surveillance in evaluating and comparing international quarantine systems. Author(s): Mittinty, M. Whittle, P. Burgman, M. Mengersen, K.
Chapter: 8 (Page no: 151) Estimating detection rates and probabilities. Author(s): Hauser, C. E. Garrard, G. E. Moore, J. L.
Chapter: 10 (Page no: 181) Surveillance for soilborne microbial biocontrol agents and plant pathogens. Author(s): Whittle, P. Sundh, I. Neate, S.
Chapter: 11 (Page no: 203) Design of a surveillance system for non-indigenous species on Barrow Island: plants case study. Author(s): Murray, J. Whittle, P. Jarrad, F. Barrett, S. Stoklosa, R. Mengersen, K.
Chapter: 12 (Page no: 217) Towards reliable mapping of biosecurity risk: incorporating uncertainty and decision makers' risk aversion. Author(s): Yemshanov, D. Koch, F. H. Ducey, M. Haack, R. A.
Chapter: 13 (Page no: 238) Detection survey design for decision making during biosecurity incursions. Author(s): Kean, J. M. Burnip, G. M. Pathan, A.
Chapter: 14 (Page no: 253) Inference and prediction with individual-based stochastic models of epidemics. Author(s): Gibson, G. Gilligan, C. A.
Chapter: 15 (Page no: 265) Evidence of absence for invasive species: roles for hierarchical Bayesian approaches in regulation. Author(s): Stanaway, M.
Chapter: 16 (Page no: 278) Using Bayesian networks to model surveillance in complex plant and animal health systems. Author(s): Johnson, S. Mengersen, K. Ormsby, M. Whittle, P.
Chapter: 17 (Page no: 296) Statistical emulators of simulation models to inform surveillance and response to new biological invasions. Author(s): Renton, M. Savage, D.
Chapter: 18 (Page no: 313) Animal, vegetable, or ...? A case study in using animal-health monitoring design tools to solve a plant-health surveillance problem. Author(s): Hester, S. Sergeant, E. Robinson, A. P. Schult, G.
Chapter: 19 (Page no: 334) Agent-based Bayesian spread model applied to red imported fire ants in Brisbane. Author(s): Keith, J. M. Spring, D.

Chapter details

  • Author Affiliation
  • Centre of Excellence for Biosecurity Risk Analysis (CEBRA), School of Botany, The University of Melbourne, Parkville, Victoria 3010, Australia.
  • Year of Publication
  • 2015
  • ISBN
  • 9781780643595
  • Record Number
  • 20153099597