IDU Sharing needles puts you in a very high risk category for contracting HIV infection. Even tattooing is risky, if the needle has not been thoroughly cleaned. You can often find Urban Peak Outreach workers on the 16th Street Mall, where youth congregate. Usually they are carrying bleach kits.
Many addicts feel that the only people who understand addicts are other addicts.
They are probably right. They help other addicts get and stay clean. Meanwhile, protect yourself as best you can. GOD Bless the addicts.