Injection-related risk behaviors in young urban and suburban injection drug users in Chicago (1997-1999).

We compared injection-related risk practices between urban and suburban injection drug users (IDUs) in a large cross-sectional sample of young IDUs. From 1997 to 1999, we recruited 700 active IDUs aged 18 to 30 years in Chicago and its suburbs. A suburban residence was reported by 38% of participants. Participants were interviewed at four urban locations and screened for HIV and hepatitis C virus antibodies. Receptive sharing of syringes and other paraphernalia by urban and suburban IDUs in the preceding 6 months was compared using univariable and multivariable models. Sharing injection paraphernalia in the total sample was high, with 50% of participants reporting receptive syringe sharing and 70% reporting sharing cotton, cookers, and/or rinse water. After adjusting for demographic characteristics, injection settings, frequency, and duration of injection as well as ease of acquiring new syringes, suburban IDUs were significantly more likely than urban IDUs to share syringes (adjusted odds ratio = 1.7; 95% confidence interval: 1.1-2.5); however, the likelihood of sharing cotton, cookers, or rinse water was roughly equal. Despite overall higher risk profiles among suburban IDUs, HIV and hepatitis C prevalence levels were significantly lower than among urban participants. Current high levels of injection risk behaviors in suburban groups represent a potential for rapid dissemination of infection.