Parasites and the germ theory of disease

Particular options for framing disease are not equally available to would-be framers. The history of parasitology in the nineteenth and early twentieth centuries suggests ways in which models drawn from the study of parasitic organisms might have influenced debates over the etiology of infectious diseases and led to a unified theory if parasitology had not been segregated intellectually. Intellectual and institutional history thus determined that the study of parasites would offer little to the modern germ theory of disease by making its models unavailable to physicians and biologists seeking to understand particular ills.