I'm not sure what robinson is confused on, since I don't have time to read every post.
Just wanted to clarify that not all cases of AIDS are caused by HIV. There are many causes of AIDS. Auto-immune deficiency has other causes, but HIV caused AIDS is what this thread is about.
HIV is one cause, and HIV is a virus that infects the T-cells. I posted on this very early on.
If you are looking up studies on HIV caused AIDS, then make sure you access information that includes information on HIV caused AIDS.
HIV ends up in bodily fluids, that is why it can be passed on through needles and via semen, etc.
HIV is a retrovirus. This means that it hides in your dna. Once it is in there, it may hide for years. You have problems once it actively starts making the T-cell replicate the HIV rna. The HIV RNA leaves the T-cell encased in the T-cell cytoplasm. After a while, you have no T-cells left that are actually acting like T-cells. This causes the auto-immune disorder.
I've posted a link to pictoral evidence of this.
There is more here:
http://www.biology.arizona.edu/immunology/tutorials/AIDS/HIVimmune.html
Have fun.
I don't know what is unclear. Perhaps this will help?