Silly question I'm pretty sure.
Toilet paper was all gone in my house today but there was what looked like a clean piece sitting in the top of our garbage can. I decided to use it after going for some reason and then got kinda worried. I have a slight tear or something on my anus as I see blood on my own toilet paper from time to time and I don't know if this could increase risk of transmission at all. I live with roommates who all have casual partners that stay over as well. Any chance that an STD of any kind could be transmitted from my using that toilet paper which may or may not have been used for something else?