One possibility for a disease created as a weapon of genocide: an airborne and bloodborne sleeper virus, it exists in an inert state disguised as any other common, harmless disease, maybe even one that is easily killed by the immune system (or possibly tricks the body into thinking it's dead). Until a trigger date turns it into something that's just as contagious but constantly mutates, easily overcomes the body's defences and has an almost 100% fatality rate.
This gives the disease a near total spread before it's even detected and will probably kill anyone with the facilities or intelligence to take it on.
"It couldn't. Madagascar would close it's ports."
Well, yeah, but it'd still take out enough hospitals to stop progress on the vaccine, and then it's just a matter of time before the rest of the world goes tits-up.
Also, maybe something with an absurdly long incubation and absurdly high transmission rate, that could also be transmitted from mother to fetus, that ultimately caused sterility.
Or, you know, Communism. Or these numbskulls.
Well natural immunity occurs, even to HIV, so you'd have to send out a slew of weaponised plagues which needs to have very low immunity rates in the human population. If you can reduce humanity to a low enough number then genetic viability drops to zero and the species is wiped out after a few generations post-plague.
You couldn't wipe out Homo Sapiens through disease. Well natural disease anyway.
The human species has a lot of people who are far displaced from major population centers. Pull a Kill Em All of literally every town and city on the planet and you still have hundreds of thousands of surviving humans all over the world at minimum.
Then in such plagues that can wipe out cities, you get survivalist types who abandon ship until the plague passes (because all plagues do given enough time). They'll flee into the mountains where's there's no civilization, the forests, onto remote islands, the works.
Then you have the natural immunity and resistance factors. No disease not even AIDS is 100% infection-causing. Some people will naturally have the immunity to fight off the plague before it can affect them or once affected can fight it off and live.
@wander: They are serious? Wasn't Rainbow Six about a group like that?
immunity only works if it doesn't just kill you off. I'm not sure if a disease could reach that potency (The Black Plague certainly fucked things up) but everything I've learned is that our ability to respond to a mass-disease breakout is pretty poor since all of our services will break apart pretty quickly.
edited 26th Jan '11 9:54:38 AM by saladofstones
Well he's talking about WWII when the Chinese bomb pearl harbor and they commuted suicide by running their planes into the ship.For a single disease to wipe out all humanity itself (I'm not counting a high enough mortality rate that the survivors no longer number enough or are in close enough proximity to each other to form a viable breeding population) it would have to be extremely contagious, have a 100% lethality, but a slow enough progression to allow time for infection of others, carried by as many vectors as possible (airborne, waterborne, contact, and insect- and rodent-borne), and ideally it would have a relatively long contagious-but-not-showing-symptoms stage.
Hypothetically, if you have a very subtle disease (eg. one that causes sterility) such that it slips scientists' notice until it's too late and that disease has the ability to linger in the environment and spread through multiple vectors (airborne, contact, water, animal-transmission etc.) so that the disease can keep massively re-infecting the human population through multiple generation without us being able to do anything about it, you might have something that can cause the surviving human population(s) to be low and/or isolated enough that they fall below the population viability threshold.
So, not really.
edited 26th Jan '11 12:15:52 PM by nightwyrm_zero
As I mentioned on that other doomsday thread: Crop diseases. Starving us to death by infecting our food sources is a better "tactic" for a disease than direct death. If you find an airborne pathogen/parasite that can infect a) rice, b) corn, c) wheat, d) potatoes, and e) grass, it's game fucking over. Fortunately, there's exceedingly low odds that a single disease could hit all our staple crops.
Share it so that people can get into this conversation, 'cause we're not the only ones who think like this.The whole "slow to kill, easy to spread" thing... I mean, to find every man woman and child on earth it would have to kill so slowly that you would basically just live with it. That is, you would have plenty of time to reach sexual maturity and have a child, and the same would go for that child, thus perpetuating the human race.
For anyone who has studied HIV, just think of your imaginary superbug as an HIV treatment and humans as the virus. You simply can't get rid of everyone. Unless, of course, the body dies.
Life is what happens to you while you're busy making other plans. -John Lennon

Having just killed off all the life in Pandemic it got me wondering how a disease could possibly take out the entire human race and everything else in between.