Drug use and HIV risk practices of secondary and primary needle exchange users.

This study examines HIV risk practices associated with secondary needle exchange, obtaining needles from a needle exchange program (NEP) through others who attend in person. We analyzed data from NEP logs, a survey and HIV testing from 901 drug injectors who (a) always visited NEPs themselves to get needles (primary-only NEP users), (b) obtained at least some NEP needles by having others exchange for them (mixed/secondary NEP users), and (c) obtained no needles from an NEP. About 22% of 40,000 NEP visits involved secondary exchanges, and these accounted for over half of all needles exchanged. In multiple logistic regression analyses, primary-only needle exchange was significantly associated with lower levels of receptive needle sharing, backloading, sharing other injection equipment and lending used needles, and positively associated with obtaining drug treatment. Mixed/secondary needle exchange was associated with less receptive needle sharing and a greater likelihood of drug treatment. Secondary exchange facilitated HIV risk reduction but the salutary effects of NEPs were attenuated in mixed/secondary exchangers.