Evaluating alternative approaches to managing animal disease outbreaks--the role of modelling in policy formulation

Modelling is a powerful tool for informing development of policies for the control of animal diseases. By permitting the study of 'what if' scenarios, this tool can be used to help identify and evaluate strategies to reduce the number of animals destroyed to eradicate diseases. To be useful, models need to be fit for purpose and appropriately verified and validated. For informing disease control policy, modelling will be most useful when used before an outbreak, particularly in the areas of retrospective analysis of previous outbreaks, contingency planning, resource planning, risk assessments and training. Recent experience suggests that predictive modelling during actual outbreaks needs to be viewed and used with caution. It is important to recognise that models are just one tool for providing scientific advice and should not be considered in isolation from experimental studies and collection and analysis of epidemiological data. Collaborative studies and international cooperation can help address validation issues and improve the utility of models for emergency disease management. One such initiative, involving the 'Quadrilateral countries' (Australia, Canada, New Zealand and the United States), Ireland and the United Kingdom is discussed.