Background: To compare the prevalence of syringe-sharing behaviors and other HIV-related characteristics among female injecting drug users (IDU) engaging and not engaging in sex work and to identify factors associated with such risk behaviors in the two groups.
Methods: Data were obtained from 1923 female respondents of behavioral surveillance studies conducted in Sichuan, China.
Results: The prevalence of having at least one of the three syringe-sharing behaviors (borrowing, lending, or injecting from pre-filled syringes) was 45.3% in the female sex workers (FSW) group and 37.2% in the non-FSW group (adjusted OR=1.28, p<0.05). Compared with non-FSW, FSW were more likely to have injected drugs for 3 or more years, have non-regular sex partners, believe that condom use could prevent HIV, and have received free condoms/lubricants (OR=1.34-5.08, p<0.05); FSW were less likely to be older, better educated, and have attempted quitting drugs (OR=0.31-0.68, p<0.05). Being FSW, older, longer injecting drug use, higher drug injection frequency, and having regular sex partner were associated with injecting with others' used syringes (multivariate OR=1.26-1.92, p<0.05) while the reverse was true for education level and voluntary HIV antibody testing (multivariate OR=0.44-0.64, p<0.05). Of all sampled FSW, 39.3% did not use a condom in the last episode of sex work.
Conclusions: Female IDU involving in sex work are at high risk of HIV transmission and the risk may even be higher than their non-FSW counterparts. The bridging effect poses a threat to the HIV epidemic in China and effective preventive services are warranted.