This reminded me of the ban on blood donations from MSM (one instance since 1977). There is a recent detailed article on the issue in the Atlantic ("Tainted"), from October 2012, here. Why not use a one-year self-deferral policy instead now, given the advances in detection of all known STD's?
The ban does not affect lesbians.
I am 69, with persistent negative tests, and no "activity" since 1999. Yet I am banned.