Factors associated with changes in sex behaviour among drug users in Puerto Rico.

Despite available strategies to prevent sex risk behaviours in Puerto Rico, heterosexual transmission of HIV continues to increase. Since 1990, heterosexual contact has been the fastest growing infection risk category among the island's general population, and the primary transmission route for women and children. To understand change in sex risk behaviours and factors related to change, 911 drug injectors and 359 crack smokers were recruited from the San Juan metropolitan area following a stratified cluster design. This study comprised a total of 1,004 (79.1%) drug users who were assessed at follow-up. Abstinence from sex behaviour increased from 54.6% to 61.1% (p < 0.01), use of condoms during vaginal sex also increased from 26.4% to 36.9% (p < 0.01). In multivariate analysis, significant predictors of abstinence were gender, injection drug use, HIV seropositivity and not having a steady partner. Predictors of using condoms during vaginal sex were HIV seropositivity, STD diagnosis and participation in an HIV preventive programme. These findings indicate that additional HIV preventive efforts are needed to reduce sex risk behaviours among drug users who have a steady sex partner, as well as among drug users who are HIV-negative.