“…A history of incarceration is a particularly significant risk factor for HIV (Buavirat et al, 2003;Estébanez et al, 2002;Robles et al, 1993), as a result of unsafe drug injection and unsafe sex in jail/prison (Buavirat et al, 2003;Clarke et al, 2001;Estébanez et al, 2002;Frost and Tchertkov, 2002;Hammett et al, 1999;Mahon, 1996;Saum et al, 1995;Struckman-Johnson et al, 1996;Taylor et al, 1995). Drug injection in prison was reported by more than one fifth of Russian prisoners who had ever injected a drug (Frost and Tchertkov, 2002), and by more than one third of Spanish female injecting drug 1 National Development and Research Institutes, Inc., 71 West 23rd Street, New York 10010.…”