The starts of a eventual plot :D
I've been thinking this would happen eventually. What with the amount of people who bleed and well the amount of times Aidou hurts himself this week, but at some point within the next few weeks Aidou will bite someone. The blood pills just aren't to his tastes at times when you're surrounded by so many tasty looking people.
Anyway I would need a volunteer to be the one to get bitten. Only two things I might put before you do:
1) Usually he goes for people who smell nice. By that I mean he only went for Yuuki because her blood smelled nice, so I don't know if he would just go for women or not, but what The Kiss Of The Vampire can apparently mean... I believe that he would go for a girl.
2) Afterwards he would make sure that person he does it to would forget as I realized when canon reviewing that all vampires of his level have the ability to seal memories. So whoever it does happen to will forget what happened to them and think it was something else.
As for everyone else, they can either believe that:
A) It's just Anemia. This is for people who know nothing about vampires or don't believe they exist.
B) Figure out it was a vampire, but not knowing just who it is. This is for people who believe they exist and notice the bite marks on the victims neck, but don't know Aidou's dirty little secret.
C) Know it was vampire who did and find out just who did it. This last one only applies to people who know what he is. Since no one knows except Claudia knows this is the least likely to happen with most.
Anyway, this is something I've been planning for a good while as you can tell. This might lead to him being outted to everyone, but not right away.