Causation of Epidemics and Immunological Diseases

Abstract

This chapter will review the evidence for causation in two contrasting disease groups. In the first, epidemic diseases, the proof of the means of transmission of the infectious agent goes back to the work of John Snow and the transmission of cholera; the proof of the microbiological cause of an epidemic became possible in the late 1800s, when methods for isolating bacteria became possible. The methods employed in epidemic investigation for seeking both the method of transmission and the proof of causation by a specific infectious agent have become quite standardized, particularly through the work of the Centers for Disease Control in the United States. The second disease group, that of immunological diseases, is one in which the criteria for establishing the nature of an immunological disease and for proof of the relationship of pathological changes to autoimmunization are of recent origin. In fact, there are few published guidelines on establishing causal relationships between exposure to a specific agent and most immune-mediated diseases.