Figure 1-1. Chain of disease transmission.
Figure 1-2. Breaking the chain of disease transmission.
c. Healthful Living. Every individual is potentially, to a greater or lesser
degree, a source of disease, a vehicle of transmission, and a person susceptible to
disease. Therefore, universal and unrelenting application of the principles of healthful
living does much to prevent the spread of disease.
d. Control Measures Applicable to the Source
(1) Isolation. Isolation is the separation of infected persons from others
during the period in which the infection is communicable.
Isolation is practiced in the occurrence of such diseases as
pneumonic plague and other highly contagious diseases.
This separation may be accomplished by having the sick person
admitted to hospital isolation or by self-isolation practiced by the infected person.