Severity of heroin dependence and HIV risk. II. Sharing injecting equipment

One of the most conspicuous risks of HIV transmission among drug injectors involves sharing injecting equipment which has been contaminated by infected blood. The present study investigates the relationship between severity of dependence upon heroin and the sharing of previously used injecting equipment (passive sharing). Four-hundred-and-eight heroin users were contacted and interviewed. Two-hundred-and-eighty-one (69% of the total heroin sample) had injected drugs on at least one occasion, and 204 of the 281 injectors (73%) had shared injecting equipment on at least one occasion after it had been used by someone else. The more severely dependent heroin injectors were more likely to have shared injecting equipment. As users become more dependent upon heroin, the types of factors which predispose them towards sharing may change. Less dependent users were more likely to use in public and 'social' settings, and they may be more likely to share injecting equipment with people they do not know well. The more dependent users appear to use heroin in private settings and to be at greater risk of sharing with dealers, perhaps because of the urgency of their need for drugs at times when they are in withdrawal. One of the most frequently cited reasons for sharing was that sterile injecting equipment was difficult to obtain. It is a matter for some concern that many of the sharers in our sample (24%) reported having shared used injecting equipment while in custody. There was good overall awareness of the risks of health problems associated with injecting among our subjects. However, awareness of risk was not associated with avoidance of sharing behaviour.