Abstract

Bovine tuberculosis (bTB) is one of the most challenging livestock diseases globally, causing a huge economic burden on cattle industries in industrialised and pre-industrialised countries alike. In Britain, the role of badgers in transmission is often the focus of debate, while epidemiological principles of interrupting transmission via core groups have been neglected. In this talk, I’ll present a brief history of bTB in cattle and its relationship with the human pathogen mycobacterium tuberculosis. Motivated by the importance of contact patterns in human disease transmission, we developed an age-structured transmission model of bTB based on mixing patterns derived from cattle movement data. The results are the first evidence of how infection risks vary with cattle age. Cattle aged 3 to 4 years old act as teenagers do for human TB, with high rates of infection and high numbers of contacts. Consequences for beef and dairy herds are particularly striking: we estimate a similar annual force-of-infection in beef and dairy herds, however due to differences in age and mixing patterns, the mean effective reproduction number is lower in beef.