In most cases, yes, but women can get it from a variety of sources aside from that. I had an ex who wasn't too hygienic and she got them now and then. never really wanted to touch her too much after. Probably why she left. She must have found some hobo who didn't mind the smell. lol
Okay, but it means she was unhygienic. Touched herself after handling the infection, etc (stairwells, toilets, you choose.).
It doesn't develop by itself; bacteria must be acquired.