Basic Epidemic Models - Dynamic Modeling of Diseases and Pests - page 42

Fig. 2.13

Fig. 2.14

The CONTRACTION is a function of susceptible, healthy people coming into
contact with people who are aware that they are contagious or people that are un-
aware that they are contagious, or people who come into contact with sick people.
BETA is the corresponding contact rate:

BETA ∗ (( ) ∗ 3

CONTRACTION = CONTAGIOUS-UNAWARE CONTAGIOUS / 5

) ∗ NONIMMUNE
(2.8)

+ UNAWARE CONTAGIOUS+SICK / 2