How bad can an Ebola pandemic be?

How bad can an Ebola pandemic be? Just think of this childhood riddle. But first read a few news reports.

1 infected person flies on an airplane. Number of passengers 132. Then the airplane flies on 5 more flights before it is fumigated. Total number of passengers with possible contact is unknown but the airline is trying to track down 800 people. 

1 infected person rides on a bus. Number of passengers 32. Condition uncertain.

1 infected person goes on a Caribbean cruise. From The Noisy Room: A Carnival cruise ship with 4,633 on board was refused docking in Belize to offload a married couple, one with possible Ebola symptoms for emergency transport. The wife, a nurse, had treated Ebola patient Thomas Duncan. The ship has departed Belizian waters and is headed for Texas. Condition uncertain.

Mortality rate for Ebola is anywhere from 50 to 90%. There is no known cure.  

Get the picture.

Now back to the riddle. This illustrates the mathematical progression of a contagious disease.

A penny a day doubled each day for 64 days. Doesn't sound like much, right? Then just try to figure it out.

Day 1,      1
Day 2,      3   
Day 3,      7
Day 4,      15
Day 5,      31
Day 6,      63
Day 7,      127
Day 8,      265
Day 9,      431
Day 10,    863       
Day 11,    1,727
Day 30,    1,073,741,823
Day 64,    18,446,744,073,709,551,615

Substitute people for pennies. The last number is greater than the entire population of the world.

Game Over.

Only good thing is dead people don't walk so there won't be any Zombie Apocalypse to worry about. 

Uh, Oh, I stand corrected. The CDC, Center for Disease Control seems to think there WILL BE a Zombie Apocalypse and they have issued a 36-page preparedness manual. You can download a copy at that link. This is not a Halloween joke.