Objectives: To study drug-injecting practices, particularly indirect sharing of injecting paraphernalia (ISIP), and sexual risk behavior.
Methods: We performed a cross-sectional study of 1638 users of needle exchange programs (NEPs). Different types of ISIP were studied: taking diluted drugs in a syringe used by others, placing the needle in a recipient with other used needles, and reusing cleaning liquid previously used by others.
Results: The prevalence of injecting with syringes already used by others was 16% in Galicia, 4.7% in Madrid, 17.6% in Seville and 13.2% in Valencia (p < 0.001). With geographical variations, other types of ISIP (Galicia: 32.4%; Madrid: 28.5%; Seville: 42.6%; Valencia: 27.4% -p < 0.001-) were more frequent than injecting with syringes already used by others (Galicia: 32.4%; Madrid: 28.5%; Seville: 42.6%; Valencia: 27.4% -p < 0.001-). The percentage not injecting with syringes used by others but performing ISIP was 21.7%, 25.3%, 28.2% and 18.1% (p < 0.01) respectively. In all geographical areas, sexual risk practices were more prevalent with steady sex partners (68.6%, 72.0%, 77.8%, 72.8% [NS]) than with casual partners (36.6%, 40.9%, 37.9%, 23.9% [NS]). Among injectors with a stable partner, 81.3% in Galicia, 75.9% in Madrid, 86.1% in Seville and 79.7% in Valencia reported that his/her serological status was negative for HIV or was unknown (p < 0.001).
Conclusions: ISIP is more prevalent than injection with syringes already used by others. For a substantial percentage of injectors, ISIP is the only risk practice. ISIP and the low use of condoms, particularly with steady partners, could be a contributory factor to the spread of HIV, hepatitis C virus, and hepatitis B virus infection.