Apparently nearly 1/3 are immune to the virus. That is people descent from Europe and Central Asia (including noth africa--supra sahara). They have a gene mutation that protect them. It possible virus had appeared in Europe say 5,000 yrs ago hence the mutation. The same way most affricans are immune to malaria (sickled cell shaped red blood cells).
So this could explain "male circumscion" thing.
Pundit,
Does that mean the Congo origin of the retrovirus is no longer in vogue?
Did it mutate in the 80's, in time for new technologies like PCR to detect it?
How does it account for the low incidence in uncircumcised Brazil? A place with its fair share of the Sub-Saharan Negro.
Is this a new discovery? If you can share some link that would be interesting.
I think the one thing everyone agrees on. The more one looks at HIV. The more confusing it gets. Very confusing.