Because HIV can sneak up on you rather slowly, many do not know they even have it.
A simple blood test can confirm it and there are medicines to slow it down, but not believing it exists, could be a moral error. Consider anyone who has had multiple unprotected sexual experiences, and hasn't got it, extremely lucky! HIV can spread faster than a chain letter. One case can infect hundreds of people. In parts of the world, it is an epidemic because these people cannot be educated fast enough. We, most of us, somewhat intelligent, able to read and write, know right from wrong simply have no excuse! Talk to one HIV infected person and they will set you straight.