Disease Theory Before Germ Theory

Medicine Through Time – Germ Theory and the Bacteriological Revolution, 1860-1900

In this course, Professor Michael Worboys (University of Manchester) explores the Germ Theory of Disease and the Bacteriological Revolution in the period 1860 to 1900. In the first module, we look at the ideas that existed about the causes and spread of infectious diseases before Germ Theory. We then turn to examine the theory itself. After this, we look at whether the Bacteriological Revolution can truly be called a revolution. The fourth module discusses Louis Pasteur’s work on vaccines. The fifth follows the career of Robert Koch and his creation of laboratory methods to investigate germs and their actions. In the final module, we review the key ideas of the course by showing how the understanding, prevention, and treatment of tuberculosis changed over the period.

Disease Theory Before Germ Theory

In this module, we look at the ideas that existed about the causes and spread of infectious diseases before Germ Theory. We start by exploring the key questions that surround Germ Theory: (i) What was it? (ii) When was it developed? (iii) Who were the key figures in its development? (iv) Why was it important?. We then turn to examine what theories existed about the causes and spread of disease before Germ Theory to show that two ideas predominated: (i) Infection by contact (ii) Infection by environment. Louis Pasteur’s work, which was applied in Lister’s operating theatre, sought to tackle the fundamental issues which plagued these earlier theories.