Virtual Epidemic

Using the Epidemic Stimulation, one can determine the effects of a contagious disease over a population.
The factors, distribution, contagion, and deadliness, all have a factor in this.

Out of the three, contagion appears to have the largest impact, followed by distribution and then deadliness.

Using the following:        Results in:(5th Pass)                Distribution:

H>C:80                         Healthy:291
C>S:40                         Carrier:49
S>D:30                         Sick:39                                   Towards the middle of the
S>I:20                          Dead:16                                  population
I>H:5                            Immune:5

H>C:60                         Healthy:321
C>S:50                         Carrier:24
S>D:30                         Sick:40                                    Towards the middle
S>I:20                          Dead:9

I>H:5                            Immune:6

H>C:60                         Healthy:333
C>S:40                         Carrier:28
S>D:40                         Sick:28                                     Towards the middle
S>I:20                          Dead:9 
I>H:5                            Immune:2

H>C:80                         Healthy:349
C>S:40                         Carrier:18
S>D:30                         Sick:17                                    Touching the Edge
S>I:20                          Dead:8 
I>H:5                            Immune:8

As the data displays, the position of the original carrier matters greatly as it determines how many people the carrier will come in contact with.

(The more people come in contact with the carrier, then there are more chances the disease spreads to more people) 
After the contact, how contagious the disease is will determine to how many people it spreads to.

(Likewise, the more people the disease spreads to, then there is a larger amount of chances the disease has to kill)
Finally the rate of death decides how many of the people die.