Drug and Alcohol Dependence, 29 (1992) 263-268 Elsevier Scientific Publishers Ireland Ltd. 263 Drug use and HIV risk-taking behaviour among clients in methadone maintenance treatment Shane Darkea, Amanda Baker”, Julie Dixon”, Alex Wodakb and Nick Heather” eNational Drug and Alcohol Research Centre, University zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGF of New South Wales, NSW and bAlcohol and Drug Service, St. Vincent’s Hospital, Sydney (Australia) (Accepted October 24, 1991) Current drug use and HIV risk-taking behaviour of a sample of 95 methadone maintenance clients was investigated. Subjects had been on their current programme for an average of 70.9 weeks with a mean daily dose of methadone of 65.6 mg. Two-thirds had injected heroin, and 82% had injected a street drug in the month prior to interview. Over 20% of subjects had shared a needle in the month before interview, all with only one other person. Subjects who had injected cocaine in the month before interview had significantly higher levels of injecting risk-taking behaviour than those subjects who had injected but not used cocaine. Condom use among subjects was low, particularly in regular relationships. While knowledge concerning HIV was high among subjects, there was no relation between level of knowledge and actual behaviour. It is concluded that knowledge alone is not sufficient to ensure behaviour change. Key u~ords: methadone; maintenance; HIV; drug use; knowledge; cocaine Introduction Injecting drug users (IDU) now represent the second largest risk group of diagnosed AIDS cases in Europe and the United States (Centers for Disease Control, 1989; Des Jarlais, Fried- man and Casriel, 1990). This population is generally considered to be the most likely transmission route for dissemination of Human Immunodeficiency Virus (HIV) infection to the non-drug using heterosexual community in most western countries. Overall, 33% of AIDS cases reported in the United States in 1988 had injec- ting drug use as an associated risk factor (Centers for Disease Control, 1990) with 34% of European AIDS cases having injecting drug use as the only known risk factor (Des Jarlais et al., 1990). In Australia, the prevalence of HIV infec- tion among Sydney IDU is estimated in recent studies to be between 3 and 5% (Morlet, Darke, Guinan, Wolk and Gold, 1990; Ross, Gold, Correspondence to: S. Darke, National Drug and Alcohol Research Centre, University of New South Wales, P.O. Box 1, Kensington, NSW, Australia, 2033. Wodak and Miller, 1991; Wolk, Wodak, Morlet, Guinan and Gold, 1990). Injecting drug use is reported as a single or combined risk factor in 4% of Australian AIDS cases (National Centre in AIDS Epidemiology and Clinical Research, 1991). Unsafe drug injecting and sexual practices are both areas of concern in relation to the spread of HIV among IDU and, through sexual transmis- sion, to the non-drug using population. High rates of needle sharing have been consistently reported in the United States, Europe, and Australia (e.g. Darke, Hall and Carless, 1990; Lishner and Look, 1990; Rahman, Ditton and Forsyth, 1939). The sexual behaviour of IDU is of major importance, both from the perspective of the spread of HIV within that population, and in relation to the spread of the virus to the non- IDU population. In the United States, 52% of non-IDU women who have been infected with HIV through heterosexual intercourse have done so through an IDU male partner (Cohen, Haver and Wofsey, 1989). Furthermore, a sub- stantial proportion of IDU engage in prostitu- 0376~871ti/92/$05.00 @ 1992 Elsevier Scientific Publishers Ireland Ltd Printed and Published in Ireland