Generally I don't worry a lot about the end of the world. We're well past 2012, as far as I know we're not in immediate danger of being hit by a giant meteor, and I just can't bring myself to view the zombie apocalypse as something that I need to actively concern myself with.
However, there is one end-of-the-world scenario which has an awful plausibility for me: the global pandemic. As such, I've been watching the events surrounding the Ebola outbreak in Western Africa with a certain degree of trepidation.
In an article on CBC.ca about the African outbreak, Ebola is described as "a hemorrhagic fever that can cause its victims to bleed from the ears and nose", which, strictly speaking, is correct. However, it's a bit like describing leprosy as "a minor skin condition". Ebola Zaire, the most virulent strain of the disease, has a 90 percent fatality rate. That means that out of the approximately 529 million people in North America, 476 million would die. To give you a better idea of what that would mean, it would be the equivalent of killing everyone in North America except the populations of New York State and Canada.*
This is a bit deceptive in that, although the fatality rate is 90 percent, the infection rate is much lower. Ebola is passed along through the transfer of infected bodily fluids. In order to increase the possibility of infection, Ebola basically liquifies the body: in the final stages of the disease, victims "crash and bleed out", vomiting extreme amounts of infected blood mixed with stomach tissue, and bleeding from all of the other orifices.
In some odd way, Ebola is too efficient a disease: the debilitating nature of the symptoms means that infectious victims quickly lose the capability to move around and transmit the virus to others. (Sadly, the most likely to be infected are doctors and nurses who are attempting to treat the victims.) We're also fortunate in that there isn't an airborne version of Ebola, which could easily give it the same rate of infection as the common cold, thereby allowing one victim to infect an entire planeload of passengers, one planeload of passengers an entire airport, and so on, and so on.
So far we've been lucky in that the outbreak has been restricted to a rural environment. In saying that, I mean no disrespect to the victims in Africa who have died during the outbreak: the sole positive aspect of the recent epidemic has been that the relatively low population density involved has limited the number of fatalities - there just aren't enough vectors for a full-fledged pandemic burn. The death toll would be staggering if Ebola got a really good foothold in a major urban centre like New York or Beijing.
If you'd like an opportunity to be really frightened by a non-fictional account of Ebola, I strongly recommend Richard Preston's The Hot Zone. It paints a terrifying picture of the realities of Ebola, and graphically describes the effects of the disease - really graphically, this is not a book that you want to be reading over dinner, or perhaps at all if you have a weak stomach.
One of the symptoms that Preston talks about is the point in the disease when the higher brain functions begin to vanish - when "the who has already died while the what continues to live." As clots begin to cut off the flow of blood and portions of the brain begin to liquify, the brain is reduced to the basic functions of the brain stem, the primitive "lizard brain".
All it would take is a small mutation in the virus so that rather than passively suffering, these mindless late-stage victims would become manic and angry, assaulting the people around them, perhaps even infecting them by biting. Almost like, well, zombies...
- Sid
* I don't mean to suggest that Canada would dodge the bullet at the expense of almost all of the United States, it just made the math simple.
