There’s only one sure way to avoid AIDS.
Don’t go in through the out door.
Reminds me of:
John 10:1 Verily, verily, I say unto you, He that entereth not by the door into the sheepfold, but climbeth up some other way, the same is a thief and a robber.
Since the blood supply is at best risky, I wouldn’t want to rely on anonymous donors truthfulness about their sexual habits. If I need a transfusion and end up with AIDS I sure don’t want know it alls telling me that I am immoral.