HIV-related risk-taking behaviour, knowledge and serostatus of intravenous drug users in Sydney.

This study was carried out in 1987 to investigate the relationships between human immunodeficiency virus (HIV)-related risk-taking behaviour, demographic characteristics and serostatus of 181 intravenous drug users in Sydney. Subjects were predominantly heterosexual men in their late twenties with limited secondary education. The majority (77%) had been injecting drugs for more than two years and were daily (91%) injectors of heroin (87%). Eighty per cent had shared injection equipment. Condom use was uncommon (15%) except during prostitution (72%). Sixty-nine per cent of all subjects were at risk of HIV infection due to either unsafe sexual practices or sharing of injection equipment. Thirty per cent of the sample had been in prison at some time since 1981 and half of these (15%) had used intravenous drugs and shared injection equipment while in custody. Thirteen per cent of men who had been imprisoned reported anal intercourse with other male prisoners. HIV antibody test results were available from 132 subjects of whom 12 (9%) (95% confidence intervals [CI], 4%-14%) were seropositive. The majority (67%) of seropositive subjects were homosexual/bisexual men but no other behavioural or demographic factor differentiated seropositive from seronegative subjects. The HIV seroprevalence (9%) found in this study of intravenous drug users in Sydney is significantly higher than a 1985 estimate of 0.5% (P less than 0.001). This finding and the level of risk-taking behaviour by this sample indicates that strategies introduced at the time may have been inadequate to prevent HIV infection among intravenous drug users in Sydney. Widespread HIV infection in Australian intravenous drug users may be imminent unless major changes in HIV-related risk-taking behaviour occur in the near future.