Susuto

Pathogens can’t cross species lines? That’s about nine truck-loads of stupid. Rabies. Plague. Cowpox. Avian Flu. Toxoplasmosis. Viruses, bacteria and parasites jump the so-called "species barrier" all the time.

Just how good was our genetic technology back in the thirties anyway? Not that great, I suspect, since we didn’t really even know how the hell DNA even worked until the fifties, but HIV, once we know what to look for, has been found in tissue samples as early as 1931.

But the real genius of the evil white medical wizards was in killing off about half of their own population by using the ironically-named black plague - starting as early as the thirteenth century. This brilliant bit of bioengineering left the Euros with a significant population possessing the delta32 mutation of the CCR5 gene - which not only makes the host less susceptible to bubonic plague, but is also a binding site for HIV.

Sheer genius. A bio-eugenics terrorist plot that goes back centuries. Or really dumb paranoia. Occam’s razor doesn’t have to be too sharp to slice through that bullshit.