Determinants of HIV prevalence amongst female IDU in Madrid

To explore the multitude possible factors associated with HIV in a population of female injecting drug users (IDUs) in Madrid, Spain.

A cross-sectional study was undertaken and because of the lack of sampling frame in this population, a convenience sample was recruited from drug treatment, methadone services and street settings.

Face to face interviews were conducted with 304 female IDUs during October 1995-March 1996. HIV status was determined from antibody testing of blood samples or from written confirmation of HIV test results from a physician. A hierarchical logistic regression model was used to identify direct and indirect relationships with HIV prevalence.

HIV prevalence in the sample of female IDUs for which HIV status was known (n = 262) was 63%. Factors independently associated with HIV prevalence in the regression analysis included: having a regular HIV positive sexual partner [odds ratio (OR): 12.2], age over 34 years (OR: 3.4), no fixed address (OR: 2.9), co-infection with a sexually transmitted infection (STI) in the last year (OR: 2.8) and ever shared needles (OR: 2.6).

The documentation of the context of risk behaviour in female IDU is important to predict the course of the epidemic and to develop prevention strategies. The sexual partners of female IDUs in Spain are important components in explaining the HIV epidemic in this population as other risk factors, including high risk drug taking behaviour. The findings also highlight the need to target homeless IDUs women and inmate women with outreach services offering preventive interventions. More effective STI prevention and control strategies are also warranted.