what do blood banks screen for

Why are homosexual and bisexual men banned from giving blood?
I’m not here to argue whether or not they should be allowed to donate blood, as it’s not something on which I really hold an opinion. However, with the fact that everyone’s blood that is donated is screened for HIV etc before it is ever used, what risk does the blood of gay and bi men pose to the blood bank?
Unless you have real information, could you not bother posting? I’ve said it’s tested for HIV etc.
JDJ&J, before you post your vitriolic nonsense, haven’t you got problems with your husband sending money to his ex-wife that you need to sort out?
This isn’t a queer-bashing thread, this was a mere question.
Because tests are not 100% secure, something can go wrong, and they do have a higher risk of being infected with something that a test wont get right away.
Bon Iver-Blood Bank Lyrics