Ewan Colman (University of Bristol)

Collaborating across disciplines to model the elimination of an endemic livestock disease

Bovine viral diarrhoea is a non-fatal infectious disease found in cattle. It transmits through close contact, and can spread to other farms when cows are traded as livestock. While the illness is relatively mild for the cow, it can lead to slower growth and lower milk production, resulting in financial losses for the farm – as such, many countries have implemented mandatory elimination schemes. England, however, has put its hopes into farmers taking voluntary action to combat its spread. Many English farms have become “BVD-Free”, however, total elimination is impeded by the reluctance of some farmers to invest in the necessary biosecurity measures.

The models I have developed to explore this problem are the product of a 5-year collaboration with economists, historians, and social scientists. Through a combination of interviews, choice experiments, and questionnaires, we have developed an understanding of the conflicting pressures influencing the biosecurity decisions made by farmers. I will discuss the challenges we faced in trying to use these qualitative findings to inform a quantitative mechanistic model of disease transmission. Our analysis shows that England is unlikely to achieve elimination under its current strategy. Furthermore, I hope that our effort to incorporate perspectives from multiple disciplines will be a useful case study for anyone with ideas to do something similar in the future.