Transmission through urine?

[Katagat]

This feels like an irrational thing to be worried about, but it’s such a bizarre and kind-of-embarrassing situation that I’m not really sure where else to ask. I went to the bathroom at a house party last night, but I didn’t realise until I sat down on the toilet that there was urine on the seat. I wiped it off my thighs with toilet paper and then... wiped my genitals without thinking. I know urine is typically sterile, but since I have no idea who it came from or the state of their health, I’m kind of concerned that it might have picked up bacteria or a virus from the urinary tract/their genitals as it passed through. Am I at risk of infection?

[Amanda F.]

Hi Katagat, and welcome to the boards.

This seems pretty unlikely, for a couple of reasons.

First, most infections you're probably worried about aren't transmitted through urine. Most STIs are associated with the genitals, and won't be transmitted through a small amount of urine that ends up on the seat.

(side note: It's actually a common myth that urine is sterile. Urine is full of bacteria - but not ones that cause issues, for the most part. Everyone has a microbiome in their bladders, just like we do in our guts, mouths, on our skin...etc. So bacteria are normal there. You can search "bladder microbiome" if you want to learn more!)

Second, you can't get an infection of any kind unless you get exposed to *enough* of the pathogen. A bit of urine on the seat, even if it did come from a person with some kind of infection, is very unlikely to have enough of a virus or bacteria to then transmit the infection to you. That's especially true because you soaked it up with toilet paper first, so much of whatever was in the urine will have gotten trapped in the toilet paper.

In sum, you don't need to worry. If you still do feel concerned, you can always get screened for STIs after a few weeks have gone by.