Published online by Cambridge University Press: 01 January 2021
In 1882 Koch discovered the tubercle bacillus and transformed both the medical and the social history of tuberculosis and the experiences of those who contracted it. For the first time, the absence or presence of the bacillus made it possible to define, in Koch’s terms, “the boundaries of the diseases to be understood as tuberculosis.” And for the first time the sick became subject to oversight and discrimination.
Prior to Koch’s discovery, tuberculosis, or as it was then called, consumption, was considered a hereditary and non-contagious disease, albeit a very deadly and persistent one. Over the first half of the nineteenth century, it was responsible for one out of every five deaths. It crossed all boundaries of geography, social class, age, and sex affecting residents in rural as well as urban areas, the prosperous as well as the poor, the young even more notably than the old, females more often than males. Physicians assumed a familial predisposition existed (as in the case of insanity); following the precepts of humoral medicine, they postulated that the disease originated in “irritations” whose sources were to be found in the interaction of an inherited constitution with a particular lifestyle and environment.