Koch’s Postulates : Solving the Puzzle of New Diseases
An essential aim the study of infection and disease is determining the precise etiologic, or causative ,
agent. In our modern technological age, we take for granted that a certain infection is caused by a certain microbe, but such has not always been the case. More than 130 years ago, Robert Koch realized that in order to support the germ theory of disease he would have to develop a standard for determining causation that would stand the test of scientific scrutiny. Out of his experimental observations on the transmission of anthrax in cows came a series of proofs, called Koch’s Postulates , that established the principal criteria for etiologic studies . A summary of these postulates is as follows:
1. Find evidence of a particular microbe in every case of a disease,
2. Isolate that microbe from an infected subject and cultivate it artificially in laboratory
3. Inoculate a susceptible healthy subject with the laboratory isolate and observe the same resultant disease,and
4. Reisolate the agent from this subject.