Risk Assessment and Contingency Planning for Exotic Disease Introductions

Globalisation has greatly enhanced opportunities for the spread of infectious diseases throughout the world, giving rise to serious threats to human and animal health. This is illustrated by the recent introduction and subsequent spread of West Nile virus in the USA, and outbreaks of Severe Acute Respiratory Syndrome (SARS) in South-East Asia. It is therefore becoming increasingly important that national (and potentially regional) governments should not only have robust systems in place to reduce the risk of disease introductions, but that they need to also consider how to identify and deal with outbreaks of pathogens in wild and domestic animals. In this chapter we will discuss the roles of risk assessment and contingency planning in the management of exotic disease risks involving wild mammals. The principal purpose of contingency planning is to ensure that a State of preparedness exists in the event of a disease introduction. This requires that the most likely risks of pathogen introduction are identified, that there are adequate means of detecting the pathogen's presence, and that a set of instructions exists describing the best available methods for its rapid and cost-effective containment and control. Contingency planning will involve some of the approaches to disease surveillance (Chapter 10) and management (Chapters 6–8) discussed in other chapters, and so will entail many of the associated challenges, costs and benefits. However, as the aim of a contingency plan is likely to be the rapid containment and subsequent elimination of a pathogen (that is either exotic or endemic but emergent) within a restricted area, the methods of management should reflect this urgency. This may mean that it is appropriate to deploy more severe or costly measures over a short period than would be considered for the sustained control of an endemic pathogen.