Count Dracula is sitting in a modern day clinic and a doctor enters the room with a clipboard.
Count Dracula: Is it all ok?
Doctor: Well Mr.Dracula, I'm afraid you are HIV positive.
Count Dracula: That's impossible. How could this have happened?
Doctor: Well it seems to me as though the amount of different blood types that you intake each week may have something to do with it. It certainly heightens your risk.
Count Dracula: But I am always very careful - I always take samples of my victims' blood and test it to make sure. This is very odd.
Doctor: The only other way you could have contracted it is through homosexual intercourse.
Count Dracula: (quickly) Actually it makes sense for it to be the blood.