What was his name? If there is a US patient zero who was a gay man, what was his name?
It might have been a gay man, but it could have been a gay woman. It could have been a straight woman who slept with an infected male somewhere in Africa and then came back home and slept with her bisexual boyfriend who at some point had sex with one of his make escorts. It could have been a government conspiracy. It could have been aliens... Whatever and however isn't important, is it?
It exists, it's split 50/50 between the genders and dealing with it is all that matters. Worrying about who did what is a worthless chore.
And I'm pretty sure you're going to use the argument that promiscuity among both genders is the cause for all of these great ills and probably recommend that following the wisdom found in the Bible about heterosexual (monogamous, I'm going to assume) relationships would have been a better alternative than the current state of affairs - but what's the point of that either? Education about sexually transmitted diseases and as much promiscuity as a heathen could want would be just as effective, wouldn't it?