Understanding how international food trade networks influence gastrointestinal disease outbreaks in the UK

Background:

In addition to their harmful effects on animal health, zoonotic foodborne pathogens infect around 2.4 million people in the UK each year, resulting in an annual economic burden of £9.1 billion. This infection rate is expected to rise due to growing demand for animal-based products and fresh produce, both of which can act as vectors for gastrointestinal (GI) pathogens. Despite this, there is a significant gap in our understanding of how international trade networks contribute to the spread of GI diseases and their role in disease outbreaks.

This project aims to investigate how global food trade networks influence the transmission of GI diseases, by integrating trade network analysis, molecular epidemiology, and mathematical modelling. The research will focus on Salmonella enterica serovar Enteritidis, the most commonly reported GI pathogen in the UK, which is predominantly associated with poultry products. The study will model historical food trade dynamics using network analysis and compare these with the incidence of human outbreaks linked to individual countries. The results will then be used to develop risk models associated with international trade. The project's findings will help shape public and animal health policies that aim to reduce the incidence of gastrointestinal infections.

Aims and objectives:

This project aims to investigate how global food trade networks influence the transmission of gastrointestinal diseases. The research will be conducted through three distinct work packages (WPs):

WP1: Identify long- and short-term dynamics of food networks which contribute to dissemination of foodborne pathogens.

WP2: Integrate genomic datasets with trade network analysis to identify the incidence of Salmonella outbreaks linked to food trade. 

WP3: Develop predictive models to assess and forecast outbreak risks linked to specific trading partners.

Methods:

The project will integrate multiple methodologies, including network analysis, molecular epidemiology, and mathematical modelling. In WP1, trade network analysis will be conducted using publicly available datasets on global food trade volumes in high-risk foodstuffs. The student will model bidirectional food trade networks to examine how shifts in trade patterns affect the importation of potentially contaminated food into the UK. This will involve constructing and analysing large, dynamic trade networks using software such as R or Python, alongside network analysis libraries. In WP2, genomic epidemiology will be used to contextualise disease outbreaks. The student will work with a dataset of 20,000 Salmonella Enteritidis genomes, provided by the UK Health Security Agency, to identify genetic clusters linked to specific exporter countries, tracing their incidence through time and its relationship to shifting trade dynamics (WP1). In WP3, the student will perform mathematical modelling to predict outbreak risks based on trade volume. The student will develop risk models that estimate the probability of future outbreaks associated with particular trading partners. Through these tasks, the student will gain expertise in bioinformatics, network science, statistical modelling, and epidemiological data analysis, with an opportunity to contribute directly to public health strategies.

Key references:

https://pubmed.ncbi.nlm.nih.gov/37042517/

https://www.sciencedirect.com/science/article/pii/S0032579121003564

https://pubmed.ncbi.nlm.nih.gov/34280649/

 Supervisors:

Dr Sion Bayliss, Prof Paul Wigley, Dr Selina Bruns, Dr Tristan Cogan

University of Bristol Scholarship - How to apply

You can submit an application via the University of Bristol application portal: Start your application | Study at Bristol | University of Bristol. Select the programme “Veterinary Science (PhD) (4yr)” and see the available start dates. Select ‘Sept 2025’ to begin your application.

In the funding section of the application form, please indicate “University of Bristol Scholarship”.

In the research section please enter the project title of the scholarship you are applying for along with the supervisor's name. You can upload a blank document instead of the research statement, which is not needed.

We are keen to support applicants from minority and under-represented backgrounds (based on protected characteristics) and those who have experienced other challenges or disadvantages. We encourage you to use your personal statement to ensure we can take these factors into account.

If you want to apply for more than one Bristol Veterinary School project you will need to select a different start date for your second/third application(s) - this is so the applications system can accept multiple applications. The start date can easily be amended by the university if you are made an offer.

We will also be running a pre-application online workshop and Q&A session on how to prepare a PhD application on 5^th December 2024 04:00 PM GMT; if you would like to register for this workshop then please sign up here.

The application deadline is 4pm Monday 6th January 2025. 

Candidate requirements: Standard University of Bristol eligibility rules apply. Please visit PhD Veterinary Sciences | Study at Bristol | University of Bristol for more information.

Contacts: please contact fohs-pgadmissions@bristol.ac.uk with any queries about your application. Please contact the project supervisor for project-related queries: s.bayliss@bristol.ac.uk