Prevalence of human immunodeficiency virus infection and behaviors associated with its transmission among parenteral drug users selected on the street

BACKGROUND: To estimate the prevalence of HIV infection and the associated risk behaviours among intravenous drug users not receiving treatment for their drug dependence. PATIENTS AND METHODS: A cross-sectional study of 200 intravenous drug users recruited from the streets of Barcelona in 1993. Information about the socio-demographic aspects and behaviours was obtained through a personal interview using a standardised questionnaire which was carried out by three ex-drug users. Saliva samples were used to determine anti HIV antibodies. RESULTS: The prevalence of HIV infection was 51%. 57% borrowed used syringes, 65% lended their syringes, and 41% practised back of frontloading. 85% if those who shared syringes always cleaned them, however 59% only used water. 78% had heterosexual relations, in 33% of the cases with a non-injecting sexual partner. 65% always used condoms with sexual clients although only 26% always used them with stable sexual partners and 36% with casual sexual partners. 78% had performed the HIV test and among those who knew they were seropositive, 40% had received some kind of health control in the last 6 months. Not having a legal income, injecting speedball or barbiturates, unknowing self HIV negative status and practicing forms of indirect sharing were found to be independently associated with syringe sharing. CONCLUSIONS: The high prevalence of HIV infection and associated risk behaviours highlights the need to increase and adapt the prevention efforts and investigation to this group. Social marginalization and poliuse of drugs should be addressed in HIV prevention programs.