I used a public toilet the other day, and without thinking, sat down on the seat without placing any toliet paper on it. When I was through with my "business", I stood up and noticed a spot of reddish brown on the back of the seat. I wouldn't have given it a second thought, but then I recalled the patch of acne that I have on my backside. I'm wondering if in fact the reddish brown spot was blood (or, more specifically, HIV-infected blood), would the acne on my behind be a route of transmission for it? I do not believe the acne is severe, just a few red bumps - no whiteheads, as far as I know, but if I DID have whiteheads, would that increase the risk of transmission? I appreciate any response you can supply me with. Thank you.
Acne is not a known route for HIV transmission. More importantly, people don't get infected with HIV or other STIs through public restrooms (sometimes called casual contact). The CDC hasn't documented any cases of transmission occurring this way.