I am an applied mathematical modeller working at the intersection of biology, ecology and epidemiology, with a particular interest in modelling parasite populations and disease vectors. I am passionate about building models that are not just theoretically rigorous but genuinely useful and impactful in guiding real world decisions. Much of my work focuses on predicting how populations of pests, parasites and vectors will respond to environmental change and exploring how the risks that these populations pose can be mitigated.

Modelling vector-borne disease risk

A central theme of my research is the development of models for organisms that develop through multiple distinct life stages, where environmental conditions shape seasonal abundance patterns in ways that drive disease and pest risk. This work included the development of mechanistic modelling framework to assess the risk of West Nile virus establishment in the UK under climate change, built on stage-structured delay-differential equation models of Culex pipiens mosquito populations. That work demonstrated that climate change is expected to make West Nile virus outbreaks of a size similar to those currently observed in Southern Europe in the UK plausible by the middle of this century (figure below). I am currently applying these methods to understand the seasonal driver of midge population abundance and what this means for the emerging risk of midge-borne disease such as bluetongue in Scotland.

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Ewing DA, Purse BV, Cobbold CA and White SM. 2021 A novel approach for predicting risk of vector-borne disease establishment in marginal temperate environments under climate change: West Nile virus in the UK. Journal of the Royal Society Interface 20210049.

Controlling agricultural pests, parasites and diseases

I led the development of a systems-level individual-based model of gastrointestinal nematode transmission on sheep farms. This work integrates some of the stage-structured modelling approaches discussed above into a farming system to explore the efficacy of different anti-parasitic treatment strategies to explore options by which anti-parasitic drugs could be used more sustainably. I have developed similar models for cabbage stem flea beetle and potato cyst nematodes. I am currently working with colleagues at the Moredun Research Institute on projects exploring how early diagnosis of ovine pulmonary adenocarcinoma in sheep could manage the disease within flocks and on the potential efficacy of vaccination to reduce sheep scab at a large scale.

Benson L, Kyriazakis I, Fox N, Howell A, Innocent GT, Kenyon F, Williams D, Ewing DA. 2025 GI-NemaTracker – A farm system-level mathematical model to predict the consequences of gastrointestinal parasite control strategies in sheep International Journal for Parasitology, 55 (10), 509-523

Inference tools for mathematical models

Finally, I am interested in the development of statistical inference tools to fit mechanistic models to real-world data, particularly when data is limited. I have developed exact Bayesian inference approaches for estimating epidemiological parameters from early-outbreak mortality records of African swine fever in pig farms from carcass monitoring of avian influenza within a colony of common terns.

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Ewing DA, & Bouwhuis, S. (2025). Estimating epidemiological parameters of highly pathogenic avian influenza in common terns using exact Bayesian inference. Journal of Animal Ecology, 94, 2491–2503.