At 17%, if you do it a long period of time you definitely get it. Even if it isn't deadly virus, you get something nasty and most likely permanently.

9% of the workers reported never using a condom and a further percentage only use them sometimes. I suspect those are the majority of the 17% with an std.

Actually none of the zero-condom users reported getting a STD. My theory is that zero-condom users tend to be much more exclusive and to have fewer clients, or to do this closer to part-time?

I find it a bit surprising that 17% report STDs while only 9% report not using a condom at all. I would have expected causality.

Do you think condoms are always 100% effective at preventing all STDs?

No, but I'm surprised because 8 points of difference is a frigging lot.

"even if it isn't a deadly virus" is the relevant part here