Zeb Jamrozik, Green Templeton visiting scholar and researcher in the Ethox Centre at Oxford will discuss Mary Mallon, who was kept in isolation by the New York Public Health Department for over 20 years because she was an asymptomatic typhoid carrier in the era before antibiotics. Likewise, when facing a disease without treatment in the recent West African Ebola outbreak, authorities instituted the ancient quarantine tactic of a cordon sanitaire. The threat of infectious disease has been met with various limitations on the liberties of individuals, and sometimes of groups. In this talk Zeb will give examples from the history of such practices before turning to an account of when, why, and to what degree such restrictions are justified, drawing on emerging themes in public health ethics. Finally he will briefly discuss novel ways of thinking about related policy problems including mass vaccination and antibiotic resistance.