Where I come from, STD stands for 'sexually transmitted disease'. On reading your topic title I was already admiring your chutzpah in not only admitting the nature of your ailment but setting out to parlay it into some kind of an entitlement ...
I will agree that when I read the subject line, my reaction was "hell yeah, if you had sex with someone who later thinks they have an STD, yes, you are ethically entitled to an update.
But then I realized the discussion wasn't that straight forward.