Mainstream thought asserts HIV causes AIDS. There are three alternate theories about HIV's relationship with the catastrophic immune collapse we now call AIDS that doesn't get much press. For your review:
[1] HIV exists, is sexually transmitted, infectious and pathogenic, but can only destroy the immune system in the presence of chemical, physical, biological, mental, and/or nutritional co-factors.
[2] HIV is a harmless retrovirus and therefore not the cause, but just another opportunistic infection that accompanies AIDS. A harmless passenger on the train, if you will, not the driver.
[3] HIV doesn't exist and therefore cannot be sexually transmitted nor is it pathogenic. The various lab phenomena (antibodies, proteins, DNA) that are collectively known as HIV are nothing more biochemical symptoms/markers/waste byproducts of immune breakdown.
Here's some reading material:
http://robertogiraldo.com/eng/papers/TheCausesOfAids.html
What do you think?