Things like being HIV+ and what medication you are or are not taking are very private matters and you don't owe this information to anyone, no matter how close they are to you as friends. Each of us have areas that are just not open for discussion, and that's up to us.
Sometimes a guy will escape from an uncomfortable situation by withholding the truth. But he hasn't done that for the purpose of misleading and deceiving, but because for whatever reason he doesn't want to get into this subject with anyone. A true friend will see the difference between this and just bald-faced lying, and I'm sure your friends here don't hold this against you. For what it's worth, I certainly don't.
It's always better to present ourselves as honestly as possible, but the operative phrase is "as possible", especially where really sensitive personal matters are concerned.
Nobody living can ever stop me
As I go walking my freedom highway.
Nobody living can make me turn back:
This land was made for you and me. (Woody Guthrie)