HIV risk behavior in drug users: increased blood "booting" during cocaine injection.

The practice of "booting" or "kicking," in which blood is drawn into the syringe and then injected, was assessed as a possible behavioral mechanism contributing to cocaine's association with increased human immunodeficiency virus (HIV) infection. Intravenous drug users (IVDUs) (N = 68) demonstrated (with an empty, needleless syringe) their usual style of injection of cocaine, heroin, and speedball, in random order. The experimenter recorded the injection procedures and the syringe volumes at each step. Total blood volumes and number of pumps of the syringe were each greater during simulated cocaine and speedball use than during heroin use (p less than .05); means for both cocaine and speedball were 2- to 3-fold greater than for heroin. Subjects also described the booting behavior of their needle-sharing partners; the percentage having partners who booted blood was significantly greater during cocaine use than during heroin use (p less than .05). These findings indicate that cocaine use is associated with a behavioral style of injection (increased blood booting) that is more likely to contaminate the injection equipment with blood. Thus, the practice of booting may warrant special attention in AIDS prevention interventions and risk assessments.