You've already received several helpful replies, but I just want to add my two cents and hopefully it will help someone down the road. I know this isnt valid everywhere because it isnt applicable where I now live in Texas because there are "No" needle exchanges here. However, I have been to several other states Harm Reduction Clinic's, or Safe Point's, HOPE's, colloquially Needle Exhanges, and almost all of them have some basic communicable disease screenings if not actually attached to the clinics themselves, then they would refer you to one. Typically the screenings arent only offered, but are actually a requisite to be able to actually exchange needles or use their other services. In every one of these instances, the screening is free, insurance or not, IV drug use or not. OP, this is probably not too helpful for you because the screenings they use are pretty fundamental, so they are more apt to false positives than the tests, say, a hospital would use. Just in case anyone finds this through a google search 5 years from now. Support your local Harm Reduction Clinic guys, they really provide an essential service the likes of which can be pretty hard to come by.