[mamelukesabre]

Here are my thoughts on the subject.

I have read that there are actually alot of people that are totally immune to aids and even more that are "somewhat" immune to aids. I am relying on my memory and I read this in a medical journal at the university library. As I remember, the numbers were something like 10 percent of white europeans are immune and an additional 15 percent or so have a "partial" immunity. The numbers for the other races of the world are practically zero. In north america, there numbers are somewhere inbetween.

Now here's what doesn't make sense to me.
IF africa has the largest population of people engaging in risky behavior, shouldn't Africa have the greatest percent of genetically immune individuals?

[tortoise]

You are referring to a specific genetic sequence found in northern European populations that confers immunity to ~1% of the population and resistance to 10-20%. This is generally true with virtually any disease you can name. There are enough humans alive today with sufficiently diverse genomes that while a particularly nasty plague could make a dent in the population, it would leave enough people alive to have a healthy genome population.

[Neuromancer]

Among the chemokine receptors, CCR5 and CXCR4 are the main coreceptors for HIV entrance. There exists a mutation in the gene that codifies for the CCR5 molecule which confers a high degree of resistance to HIV infection in vitro and in vivo.

This mutation named 32 consists in a 32 base-pair deletion that encodes for a non-functional protein, and as a result it is not expressed in the cell membrane. Homozygous individuals for this mutation do not have any known immunologic or biologic alteration.

The 32 allele is present mainly in Caucasian population.

In the United States the frequency is 8% to 10% in white population but less than 1% in Afro-American individuals. There is also a very low frequency of the mutation among Caucasians in Asia (Pakistan and India) and it has not been reported in China, Japan or pure African population.

[Neuromancer]

Frequency of Mutant Allele in Europe and Africa

Sweden = 13.7%; (probable point of origin)
Russia, 13%.
Italy, 5.3%.
Turkey, 6.3%