It compromises the immune system by destroying immune system cells called T-cells, and this compromises the body's ability to fight infections and cancer. The closer the treatment is following the exposure, the better. If you were to start several hours after a known exposure, this would be the closest thing to a cure we have yet. I had heard a while ago that the virus was evolving and changing at such a rapid rate that it was just a matter of time before it was airborne. There is no data to suggest this.
Risk is tied to the most sexually active group.
Testing at three months and at six months is enough. Please explain the difference between HIV and AIDS please. There's a lot of confusion about it here. HIV means the person has developed antibodies to the virus. With current medicine when it is under control it is possible to lead a normal life span with the same expectancy of life.