soluble and does not always require heating in a cooker to be dissolved (depending on the dilutants and adulterants used).
Frontloading involves the parceling out of individual portions from a mixer/distributor's syringe to the other participants' syringes by removing the needles from the receiving syringes. Backloading involves transferring the drug from one syringe to another by removing the plunger from the receiving syringes. The drug solution can also be divided by having the mixer/distributor squirt all but his or her own portion back into the cooker for each participant to draw up his or her own agreed-on individual portion. These behaviors have been described in some detail in the professional literature (Inciardi and Page, 1991; Koester et al., 1990; Koester, 1994; Turner et al., 1989; Grund et al., 1990, 1991; Jose et al., 1993; McCoy et al., 1994; Samuels et al., 1991; Zule, 1992; Page et al., 1990; Auerbach et al., 1994).
Little attention has been given to these risk behaviors in most HIV/AIDS prevention interventions aimed at injection drug users. In an in-depth ethnographic study, Koester and Hoffer (1994) reported that only 7 percent of the injectors they interviewed in their study were aware that these behaviors represented any type of risk of becoming infected. These findings are disturbing, given that over 70 percent of their study participants were participating or had participated in an HIV/AIDS intervention program.
The distinction between direct and indirect needle sharing is not merely academic but reflects a dichotomy that must be considered when evaluating needle exchange and bleach distribution programs. These intervention programs are aimed at direct needle-sharing practices by providing new sterile needles or disinfectant for them. However, neither sterile needles nor their disinfection can be expected to prevent transmission due to sharing of cookers, cotton, rinse water, or frontloading/backloading. Any assessment of the reductions in HIV seroconversion rates for specific programs needs to consider these points. It would seem prudent for prevention programs to educate people about the potential dangers of indirect sharing methods and supply sterile equipment whenever possible.
Finally, it must be noted that infectious agents other than HIV can be transmitted by contaminated injection equipment. Other blood-borne pathogens that have been associated with injection drug use include malaria, syphilis, hepatitis B and C viruses, and human T-lymphotrophic virus type II, as well as other bacterial pathogens that cause sepsis and endocarditis (Cherubin, 1967; Sapira, 1968; Louria et al., 1967; Levine and Sobel, 1991; Stein, 1990; Haverkos and Lange, 1990; Cherubin and Sapira, 1993; Stimmel et al., 1975; Novick et al., 1988; Kreek, 1983; Esteban et al., 1989; Donahue