Someone recently infected with HIV can potentially pass it on to others whilst not being detectably infected. It makes sense to limit those who engage in high risk activities until sufficient time has passed that they will now test positive. The full criteria is here:
"You should not give blood if you have AIDS or have ever had a positive HIV test, or if you have done something that puts you at risk for becoming infected with HIV.
You are at risk for getting infected if you:
have used needles to take any drugs, steroids, or anything not prescribed by your doctor in the last 3 months
are a male who has had sexual contact with another male, in the last 3 months
have taken money, drugs or other payment for sex in the last 3 months
have had sexual contact in the past 3 months with anyone described above"
Not to be gross here but I think a lot of this is lost in conversation because people shy away from the particulars. Vaginal and oral sex are rather ineffective at spreading HIV. There has been a rise in recent decades of HIV in African American women in particular, however it is known that this is due to an increase in that population of unprotected anal sex with a larger number of partners than previously. If they did this simply because they hate gay people why did they not include lesbian women?
I'd say a better policy would be excluding those who engage in nonmonogamous anal sex more generally, however I don't think the public has an appetite for that discussion.
"You should not give blood if you have AIDS or have ever had a positive HIV test, or if you have done something that puts you at risk for becoming infected with HIV.
You are at risk for getting infected if you:
have used needles to take any drugs, steroids, or anything not prescribed by your doctor in the last 3 months
are a male who has had sexual contact with another male, in the last 3 months
have taken money, drugs or other payment for sex in the last 3 months
have had sexual contact in the past 3 months with anyone described above"
https://www.redcrossblood.org/donate-blood/how-to-donate/eli...