It is, as Simon indicated, an outline: a few short paragraphs describing the germ theory of disease in simplest terms, and a few more about practices to prevent contagion.
The example of cholera is given, and the specific method of transmission: drinking water or eating food contaminated by the waste of someone ill.
no subject
The example of cholera is given, and the specific method of transmission: drinking water or eating food contaminated by the waste of someone ill.