Prevalence and incidence rates of HIV among injection drug users vary considerably by geographic location, so the experiences of different communities also vary. In a 1988 review of 92 studies of intravenous drug users in treatment, Hahn and colleagues (1989) reported HIV seroprevalence rates that range from 0 to 65 percent. Marked geographic differences were noted: HIV rates were highest in the Northeast (ranging from 10 to 65 percent), and lower in the West, the Midwest, and the South—5 percent or lower.
More recent information concerning the prevalence of HIV infection among injection drug users has been consistent with the findings reported by Hahn et al. (1989). In updates (Prevots et al., 1995) of CDC's HIV seroprevalence surveys of injection drug users entering drug treatment centers (most sites were methadone maintenance programs) from 1988 through 1993, seroprevalence rates of 27 percent in the Northeast, 12 percent in the South, 7 percent in the Midwest, and 3 percent in the West were reported for all years combined. Although seroprevalence rates were similar among women and men, observed rates among women were consistently higher than among men in all geographic areas. The South was the only region in