Key Terms

Question 1

What are the four types of disease diffusion?

Answer 1

Expansion Diffusion: Spreading of a phenomenon outward from a source

Contagious Diffusion: Spreading specifically through interaction among neighbours, e.g. flu

Relocation Diffusion: Introduction of a phenomenon from outside its current range, .e.g. when a community migrates and brings its cultures and diseases with it, .e.g. smallpox to the new world.

Hierarchical diffusion: spreading through a social hierarchy, spreading to cities faster than villages due to movement of people and goods, and large cities being more conductive.

Question 2

What is an endemic disease?

Answer 2

A disease that exists permanently within an area.