Syringe and needle exchange programs: Part I.

Syringe and needle exchange (SANE) programs appear to be a pragmatic approach to reducing the rising incidence of human immunodeficiency virus (HIV) infection among intravenous drug users (IVDUs). One purported indication of the effectiveness of SANE programs is lower prevalence rates of cases of AIDS or of HIV seropositivity in cities with SANE programs than in cities without such programs. In each positive comparison cited, however, the lower levels of HIV seropositivity were already present before the establishment of SANE programs. A second indicator of SANE effectiveness is a reduction in prevalence of hepatitis B in SANE program participants. Multiple factors working in concert, not simply the SANE programs, however, account for such progress; such factors include reductions in sharing of uncleaned injection equipment; legal exchange or sale of syringes at pharmacies; regular rinsing of used "works" with bleach; and epidemiologic fluctuations in the prevalence or a saturation level of the hepatitis B virus in IVDUs. A third indicator of the value of SANE programs is that they enable some otherwise unreachable IVDUs to make contact with a social or health facility. SANE programs do not facilitate the induction of new IVDUs or increase the frequency of injection by older addicts. From 60% to 90% of SANE attenders will return borrowed used injection equipment. Most participants reported that they reduced the frequency of lending or borrowing unclean injection equipment. Counterbalancing the above, SANE programs attract only a minority of all IVDUs in most cities, and they fail to attract the youngest subset of IVDUs. The attrition rate is high; only a small percentage of attenders remain with the program for more than a few months. Although many of the initial concerns about SANE programs have not been realized and there have been important public health gains to those who continue to attend them, SANE programs deserve more careful, unbiased, longitudinal research before they are established on a wide scale in the United States.