Originally Posted by AF
It's unknown, but it's not through a conventional STD...they're two completely different types of viruses. It is thought that monkey's through their different DNA strand and the environment of which they lived in spawned the disease.
It's a similar concept to the airbone bird virus that has been scaring everyone forever. It's airbone so it's not a perfect example, but humans cannot get it unless it's transferred to a human. Same concept...it just doesn't randomly appear.
It could have gotten transferred to humans in a number of ways, most likely through blood contact. Who knows.
You say diseases don't just appear...you are right they don't, but they do mutate. Perfect example is a cold since you never catch the same cold twice but you catch a variant or mutation of the cold virus.
You may be right it may have been transmitted through blood contact since it lives within the blood system and is transmitted through blood products...btw all liquids expelled and created by the body are blood products (just an fyi).