Angela Cassidy

Associate Professor
University of Exeter


Angela Cassidy is an Associate Professor in Science and Technology Studies at the University of Exeter. She started her career in the life sciences, migrated disciplines as a postgraduate, and now works across the history and social studies of science and medicine. Her research combines approaches from histories of environment and biomedicine with those of science and technology studies (STS), with a topical focus on environments, agriculture, nonhuman animals, shared health, and interdisciplinarity. This approach is exemplified in her work on the UK controversy over bovine TB and badger culling, ongoing for over fifty years and published in her monograph ‘Vermin, Victims and Disease: British Debates over Bovine Tuberculosis and Badgers’ (2019). This work investigated the roles played by badgers, cows, microbes, scientists, campaigners, policymakers, and politicians in the mutual shaping of agricultural policy and government science with the history of British ecology, and in re-ordering 20th century human-animal relations. She has also explored these themes in earlier case studies of ‘One Health’ (the convergence of human and animal health); food risk; and popular evolutionary psychology; and continues to develop them in ongoing research on the science and governance of ‘pest control’; and of past and present collaborative practice in interdisciplinary conservation and biodiversity research.



"From Shared to Separated Health - and Back Again? The Multiple Lives of Mycobacteria" 

Since their identification as the causative agent of the disease tuberculosis in the late 19th century, the family of microbes known as mycobacteria have undergone multiple transformations – in their biological classification; causal connections to disease in humans and other animals; evolutionary and ecological roles; and their roles in policy, public health, food and agricultural systems.  This chapter will trace the changing, multiple lives of mycobacteria through the 20th and early 21st C, with a particular - although not exclusive - focus on the organism currently known as Mycobacterium bovis, colloquially known as ‘bovine TB'.  Building upon Rosenberg’s ideas of disease framing, I will tell the story of how M.bovis has become visible as a causative agent of disease and has participated in a process of framing and reframing across the domains of human and nonhuman health. These framings have moved from Koch’s identification of ‘tubercle bacilli’ as a single cause of tuberculosis in humans and cattle in 1882; to the classification of M.bovis as a separate species to M.tuberculosis at the turn of the 20th century; and the much more recent reclassification of both (plus other host specific) back into varying subspecies of the ‘MTB Complex’ since 2018.  I argue that these merges and separations have brought with them a parallel, although not equivalent, framing/reframing of M.bovis/tuberculosis back and forth across the social, economic and regulatory domains of public health, veterinary medicine, agriculture and food systems.   I raise the question of how the most recent ‘merging’ of mycobacteria across longstanding human/nonhuman divides may be driving, but also driven by 21st century imperatives for ‘One Health’.  Finally, the chapter will explore broader implications for the historiography of mycobacteria and tuberculosis: how can insights from the separated histories of human and animal health be mutually applied, and how might they be applied to create new understandings of this very old disease?