Predicting the risk of environment-driven disease in a changing world
15 March 2018
Water-based diseases are one of the biggest threats to humans and animals alike. As global temperatures rise, extreme weather becomes the new norm, and the environment is altered to meet the demands of an increasing population, disease patterns are increasingly changing, with significant implications for health.
In recent decades, liver fluke, a globally-distributed parasite of livestock that develops in the environment and is distributed through watercourses, has become an increasing concern. Places such as South America and the Caspian region include human endemic areas. In the UK, the parasite affects more than 70 per cent of dairy farms, with disastrous consequences for farmers in terms of reduced growth rates, milk yields, and production losses of £300M+ per year.
Recent changes in disease prevalence, seasonality and spatial distribution, have anecdotally been attributed to climate change. Studies by researchers from the University of Bristol, which focus on the epidemiological processes in connection with their underlying environmental drivers, are now quantifying this link.
Crucially, their findings could inform strategies to safeguard against future disease risk.
Until now, farmers have lacked tools with which they can reliably assess disease risk on their farms. Existing models for predicting the likelihood of infection date back to the 1950s, and are based on empirical relationships found between historic climate and disease data. These models are of little value to farmers as historic data and relationships found in the past may no longer hold under changing environmental conditions.
Civil engineers have been working with biologists and experts in global health to develop a new process-based hydro-epidemiological model that can be used more reliably to assess the likelihood of disease transmission in the future, based on environmental conditions, and guide interventions.
PhD student Ludovica Beltrame said:
“This is what farmers need, to be able to devise effective control strategies, whether that’s avoiding grazing their livestock on certain pastures where liver fluke is going to be more prevalent, or knowing when to treat their animals based on when risk of infection will be at its peak.
“We believe that the mitigation of risk of infection with other water-related diseases may also benefit from the use of an approach focussed on the environmental controls on disease transmission such as ours.”
- Ludovica Beltrame, Department of Civil Engineering, University of Bristol, Bristol
- Professor Thorsten Wagener, Department of Civil Engineering, University of Bristol, Bristol
- Toby Dunne, Department of Civil Engineering, University of Bristol, Bristol
- Dr Hannah Rose Vineer, Bristol Veterinary School, University of Bristol, Bristol
- Dr Josephine Walker, Bristol Medical School, University of Bristol, Bristol
- Professor Eric Morgan, School of Biological Sciences, Queen’s University Belfast, Belfast
- Professor Peter Vickerman, Bristol Medical School, University of Bristol, Bristol
- Dr Catherine McCann, Epidemiology Research Unit, Scotland’s Rural College, Inverness
- Professor Diana Williams, Institute of Infection and Global Health, University of Liverpool, Liverpool
Engineering and Physical Sciences Research Council (EPSRC); Elizabeth Blackwell Institute for Health Research, University of Bristol; Wellcome Trust Institutional Strategic Support Fund; Biotechnology and Biological Sciences Research Council (BBSRC).
This project is called ‘Simulating the risk of liver fluke infection in the UK through integrated mechanistic hydro-epidemiological modelling’. For more information, please contact Ludovica Beltrame.