Patterns of sexual and injecting risk behaviours in French intravenous drug users not reporting HIV and hepatitis C virus seropositivities.

AIMS: To characterize and identify determinants of risk behaviour patterns of intravenous drug users (IDUs) independently of changes due to knowledge of HIV or hepatitis C Virus (HCV) seropositivity.

DESIGN: A cross-sectional survey using a structured questionnaire concerning sexual, injecting and HIV and HCV antibody testing practices.

SETTING: IDUs were interviewed in the Paris region at 10 treatment or psychosocial centres.

PARTICIPANTS: Six hundred and twelve consecutive sexually active IDUs over 18 years able to answer the questionnaire.

MEASUREMENTS: Five hundred and ninety-five IDUs completed the questionnaire. The risk-behaviour patterns of the 328 IDUs not reporting HIV or HCV seropositivity were analysed by phi correlation. Risk factors for each risk behaviour were determined by regression logistic models yielding odds ratios (OR) and their 95% confidence intervals (95% CI).

FINDINGS: Several risk behaviour patterns were suggested: (1) lending, borrowing; (2) not or inconsistently testing HIV and HCV serology and not or inconsistently using condoms; (3) having multiple partners and prostitution; and (4) not using clean equipment. Alcohol abuse was independently and specifically associated with lending (OR = 3.8; 95% CI: 2.1-7.0) and borrowing (OR = 3.3; 95% CI: 1.8-6.1); homelessness with injecting risk behaviours and with prostitution (OR = 2.7; 95% CI: 1.2-6.1); low educational level and having children with not or inconsistently using condom and serology testing; and cocaine use with not or inconsistently using condoms (OR = 0.4; 95% CI: 0.3-0.7) and serology testing and not using clean equipment (OR = 0.4; 95% CI: 0.2-0.8). Having multiple partners and prostitution had no common risk factors.

CONCLUSIONS: Identifying specific risk factors could help to target drug harm reduction programmes for each risk behaviour pattern among IDUs not reporting HIV and HCV seropositivity.