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Oral: Schroth Faces of the Future Symposium: Epidemiology and Management


Modelling landscape-scale spread to inform plant health policy
N. CUNNIFFE (1) (1) University of Cambridge, United Kingdom

I introduce a flexible framework to model large-scale spread of disease that can be used to investigate potential management strategies. This model can be – and indeed in the UK already has been – used to inform plant health policy. I introduce the methodology by analysing a counterfactual control of sudden oak death in California. I use that epidemic as a case study illustrating the following – general - questions. How can spread be modelled and parameterised? How quickly must control start for it to be effective? When is an epidemic so large that effective control is impossible? How should local treatment be deployed around infected sites? How does this depend on the available budget and level of risk aversion? Which sites should be targeted for control when there is insufficient resource to treat all infected locations? What is the effect of a budget that changes over time? In practice, when an invading pathogen is first detected, policy makers must necessarily answer similar questions rather quickly, while epidemiological data remains scant. I show how the underlying framework can readily be adapted to new pathogens, integrating over epidemiological uncertainty to make useable predictions. Here I use the example of Chalara ash dieback in the United Kingdom. The real-time modelling results I present were fundamental in setting the UK government’s response to this pathogen directly after it was first detected in the UK.