Simulating the risk of liver fluke infection in the UK through mechanistic hydro-epidemiological modelling

  • Ludovica Beltrame

Student thesis: Doctoral ThesisDoctor of Philosophy (PhD)


Control of many environment-driven infectious diseases is increasingly challenged by climate change and the emergence of drug resistance, calling for new approaches such as prevention through simulation of future risk and more comprehensive strategies, rather than exclusively relying on treatment. The role environmental processes play in mediating climate impacts on disease transmission may offer opportunities to use environmental interventions for complementing treatment in reducing disease burdens.
However, most current models do not represent these mechanisms explicitly, which limits their ability to assess infection risk under changing conditions and test interventions. By focusing on the parasitic liver fluke disease in the UK as a case study, this research aims at investigating how process-based knowledge of the environment and water environment can be used in support of the study and management of infectious diseases under current and potential future conditions. Firstly, we develop a new mechanistic hydroepidemiological model that simulates disease risk in connection with key underlying environmental processes (HELF). We show that the model can reproduce observed infection patterns, but also introduce an expert-driven calibration strategy to make it more robust to data with limited reliability and in the presence of climate change. Secondly, we use HELF with sensitivity analysis to investigate disease risk drivers across the UK, and
explore opportunities for risk reduction through environmental management. We demonstrate that where landscape heterogeneity plays a larger role on disease transmission, risk avoidance management strategies can provide a valuable alternative to treatment. Finally, by driving HELF with climate projection data, we assess potential climate change impacts on future infection risk patterns. We find that projected changes are not spatially nor temporally homogeneous, but that altered parasite-specific climatic characteristics result in longer transmission seasons in most UK regions. This reduces the effectiveness of current drug-based control, further highlighting the need for alternative approaches.
Date of Award23 Jan 2020
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorThorsten Wagener (Supervisor) & Eric R Morgan (Supervisor)

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