Transition to injection and sharing of needles/syringes: potential for HIV transmission among heroin users in Chengdu, China.

This cross-sectional survey interviewed heroin injectors admitted in three detoxification centres from August 2003 to June 2004 in Chengdu City, China. Logistic regression and survival analysis were performed to identify factors associated with sharing of needles/syringes and time from initiation of heroin to adoption of injection, respectively. Out of 266 subjects studied, 206 (77.44%) were males, 103 (38.72%) never shared injecting materials, 113 (42.48%) were non-Chengdu residents and 9 (3.38%) belonged to ethnic minorities. Those with short history of heroin injection (P<0.05) and those belonged to ethnic minorities (P<0.05) were more likely to share injecting materials. Only age, ethnicity and duration of heroin use were associated with time to first injection. Median time to injection was 6 months for those who used heroin for the duration up to 1 year and 21 months for those who used heroin for 2-5 years. The study suggests that there is early initiation of injection and sharing of injecting materials is high among heroin users, a major risk for HIV transmission. Ethnic minorities have been identified to be the most risky group, which needs further attention.