The time during which the germs remain in the body is called the period of invasion.
Degree of Infection
The vital resistance of the body, the portal of entry and the character of the invading germs determines the degree of infection.
We wish again to call the student’s attention to the fact that these expressions are not used chiropractically to explain the cause of dis-ease nor the different stages through which dis-ease passes.
Contagious
A contagious dis-ease is one that is thought to be transferred from one individual to another by personal contact. From the etymology of the term (contingere, to touch) we would conclude that only such dis-eases as syphilis would come under this category. But as the term is generally understood it includes such dis-eases as smallpox, measles and chickenpox.
Infectious
An infectious dis-ease is one that is supposed to be conveyed from one individual to another indirectly through some medium. Typhoid fever has been given as an infectious dis-ease.
Today it is generally considered that the terms, contagious and infectious, do not have a precise meaning which will scientifically differentiate them, for most of the so-called communicable dis-eases may be conveyed in many different ways. The so-called infectious dis-eases may be contagious and the so-called contagious dis-eases are infectious; so we see the terms lack scientific precision and this has led to confusion many times.