IAP-26-070

Modelling the dengue, chikungunya and Zika risks from Aedes aegypti range expansion into novel environments

The spread of the highly invasive mosquito, Aedes aegypti, across the world, combined with climate change and human travel and trade, has led to new epidemic threats from mosquito-borne diseases, most significantly dengue, chikungunya and Zika. Once considered a tropical species, this mosquito is undergoing range expansion into subtropical environments bringing substantial public health risks with it. However, subtropical environments are subjected to annual environmental variation that imposes differences in public health responses compared to their tropical counterparts. Consequently, new modelling tools are required to predict future scenarios of transmission to help inform decision-makers.

In this studentship new state-of-the-art models will be developed to predict the seasonal abundance of Ae. aegypti in subtropical regions with a particular focus on southern South America. Coupled to this model, the student will develop dengue, chikungunya and Zika transmission models, validated by outbreak data collated in the region. These models will then be used to explore global sub-tropical transmission risks under climate change.

This project will focus on modelling the population dynamics of the highly invasive mosquito species Aedes aegypti, and outbreaks of dengue, chikungunya and Zika arboviruses. The modelling approach will be to use systems of environmentally driven stage-structured delayed differential equation models (see References & Further Reading for related work on Ae. albopictus) to predict current and future disease risk and how these change under environmental variation. The models will be fitted and validated against a broad range of global datasets and further tested and validated against outbreak data, with a particular focus on southern South American countries. The models will be driven by an ensemble of climate change models to predict future risk. Model outputs will be disseminated through key stakeholder and community engagement activities such as international epidemiology conferences and community events held by continental Public Health organisations such as the WHO.

Year 1

Training in deriving, analysing and coding stage-structured delayed differential equations. Derive and analyse theoretical models of mosquito abundance for Aedes aegypti, and the transmission of outbreaks of dengue, chikungunya and Zika arboviruses. Models will be parameterised from existing experimental literature.

Year 2

Curate mosquito abundance and location specific arbovirus outbreak data. Validation of the models against data, revising the models as appropriate. Disseminate model findings to South American stakeholders.

Year 3

Using climate projection scenarios, predict how transmission risks of dengue, chikungunya and Zika may change in the future, especially for novel sub-tropical locations. Disseminate model findings to South American stakeholders.

Year 3.5

If the data becomes available, predict the outcome of novel arbovirus outbreaks in real-time. Build a pipeline for using the models in real-time.

The successful candidate will have a strong background in mathematics, statistics, theoretical physics or quantitative ecology. In addition, the candidate will have demonstrated substantial knowledge of mathematical or population modelling, and simulation techniques for solving models in a suitable scientific programming language (e.g. Julia, Python, R, Matlab etc). A demonstrated interest in population ecology, population modelling and/or vector-borne disease ecology is desirable. Knowledge of statistical modelling would also be beneficial.

The student will receive training in a number of quantitative skills as well as ecological skills including mathematical modelling and analysis, high-level scientific computing on cluster environments, statistical model fitting, handling large datasets, mosquito biology, and disease and vector ecology. The student will engage in the IAPETUS DTP training activities as well as transferable skills training provided by UKCEH and University of Glasgow. The student will be registered for a Postgraduate Certificate in Environmental Methods, which will recognise the transferable skills training, and carry out training in Entrepreneurship training through a Mini-MBA. IAPETUS funded placements for work experience with an external organisation are also possible. The student will gain first-hand experience of engaging with global stakeholders.