An ethnographic comparison of HIV risk behaviors among heroin and methamphetamine injectors.

Drug injection and other practices affecting the risk of human immunodeficiency virus (HIV) infection were studied among 154 heroin users and 45 methamphetamine users in San Antonio, Texas. Amphetamine users were younger, mostly white, and had less-severe drug dependence. Heroin users had significantly higher levels of needle risk, as indicated by frequency of injection, number of persons sharing equipment, and place of injection. Methamphetamine users tended to buy syringes in lots of 10 or more from pharmacies and to use a syringe less than 5 times before discarding it. Heroin users tended to buy 1 needle at a time from an illicit source and to use it more than 20 times. Of methamphetamine users, 71% had more than one sex partner, compared to 39% of heroin users. Partners of methamphetamine users were more likely to be drug injectors than were partners of heroin users. Fewer methamphetamine users reported a behavior change in response to the acquired immunodeficiency syndrome (AIDS) epidemic, and fewer had been contacted by AIDS Education/Outreach. We suggest that efforts to promote risk reduction among methamphetamine users be stepped up because this population has been underserved and because less-sweeping behavior changes are needed to reduce needle-related risks to acceptable levels.