Parasites and the Germ Theory of Disease

Abstract

{ ( T*-HERE HAS ARISEN, NOTED DR. AUGUST HIRSCH * (1885, vol. 2, 279) in his Handbook of Geographical and Historical Pathology, prospect of adding to this department of pathology. The department to which he referred was that of and what was to be added to it, he thought, were Such diseases, he estimated, may well be of parasitic nature, or that there occur in them organisms of the lowest rank of organic development-the micrococci and bacilli. Hirsch, like many others at that time, stood on the brink of accepting a generalized parasitic theory of disease. In this article I will examine the history of parasitology in the nineteenth and early twentieth century, and suggest ways in which models drawn from the study of parasitic organisms may have influenced debates over the etiology of infectious diseases. I shall argue that a generalized parasitic theory of disease only appeared very briefly, if at all, at the end of the nineteenth century. Both before and after this short period, those who studied parasites seemed to have little to offer those concerned with infectious diseases; parasites made minimal contributions to the modern germ theory of disease. The professional study of parasitic organisms long predated the era of Pasteur and Koch; it began essentially in Germany at the beginning of the nineteenth century. In 1810, for example, Carl Rudolphi, who began his career at the University of Greifswald in Sweden after