History of Medicine Lecture – Sponsored by the Fogarty International Center, National Institutes of Health.
Monday, January 14, 2013, 4:00 p.m.
Bldg. 16, Stone House, FIC, NIH, Bethesda, MD
“Theobald Smith, a pioneer in bacteriology, and the legacy of his ‘law of declining virulence’ in the 20th century”
By Dr. Pierre-Olivier Méthot
Institute for the History of Medicine and Health Geneva University, Switzerland
From the last quarter of the nineteenth century to the late 1970s, it was often considered that evolution towards harmlessness was the expected outcome of long-term biological associations between hosts and pathogens, as it would ensure the survival of both species. This perspective was widely defended by some of those who pioneered an ecological, even evolutionary view of disease in the early-twentieth century, and was often ascribed to American bacteriologist and comparative pathologist Theobald Smith (1859-1934). Since the early 1980s, however, the mathematical model of the trade-off – based on the idea that pathogens face several compromises between their mode of transmission, the level of virulence, and the cost of resistance – has challenged the assumed tendency towards harmlessness and has gained currency, particularly among theoretical biologists.
This lecture will first analyse Theobald Smith’s conception of disease, his experimental work on Texas cattle fever, and his formulation of the “law of declining virulence” at the turn of the past century, and then discuss the legacy of this model of disease evolution from circa 1900 to its widespread acceptance in the mid-twentieth century until it was challenged by the trade-off model and emerging ‘new’ diseases from the 1980s onwards. Particular attention will be given to the case of the myxoma virus in Australia and how it acted as an empirical confirmation of Smith’s model in the 1950s and 1960s. Finally, the talk will reflect on some of the implications of Smith’s law of declining virulence for global public health medicine.
After completing a BA and a MA in philosophy at the Université de Montréal (Québec, Canada), Dr. Méthot obtained his Ph.D. (2012) in philosophy at the University of Exeter and at the Institut d’histoire et de philosophie des sciences et des techniques of Université Paris 1 Panthéon-Sorbonne. From August until November 2011 he was a visiting investigator at the Brocher Foundation (Hermance, Switzerland) and in 2008 he participated in the Institute Vienna Circle Summer School in the History and Philosophy of the Biomedical Sciences (Vienna). Funded by a two-year scholarship from the Fonds de Recherche Société et Culture (Québec), he is now a postdoctoral investigator at the Institute for the History of Medicine and Health at the University of Geneva, working on a project titled “Diseases as Historical Objects”.
Due to current security measures at NIH, off-campus visitors are advised to consult the NLM Visitors and Security website: