Sexual transmissibility of HIV among opiate users with concurrent sexual partnerships: an egocentric network study in Yunnan, China.

AIMS To investigate the patterns of concurrent sexual partnerships among young opiate users and sexual transmissibility of human immunodeficiency virus (HIV) in concurrent sexual partnerships in drug-use and sexual networks. DESIGN Cross-sectional design. PARTICIPANTS A total of 426 young opiate users in Yunnan, China. SETTING Young opiate users recruited from their network ties. MEASUREMENT Respondent-driven sampling (RDS) was used to recruit participants. Multiple logistic regressions were performed to analyze the relationships of concurrent sexual partnerships with egocentric social network components, risky sexual behavior for HIV and drug-use practices. FINDINGS The RDS-adjusted prevalence of concurrent sexual partners was 42.9% among opiate users. Opiate users with concurrent sexual partnerships were more likely to engage in risky HIV-related sexual behavior, compared to those without. Specifically, they were more likely to report having had four or more sexual partners (26.3% versus 2.0%), having had a spouse or boy/girlfriends who also had concurrent sexual partnerships (28.1% versus 8.2%), having exchanged drug for sex (12.4% versus 3.8%), having had sexual partners who were non-injection drug users (22.6% versus 10.1%), having had sexual partners who were injection drug users (25.3% versus 13.5%) and having used club drugs (26.3% versus 13.5%). There were no significant differences in consistent condom use between opiate users with sexual concurrency and those without. The same proportion (25.8%) of opiate users in the two groups reported having consistently used condoms when having sex with regular partners, and 46.3% of opiate users with sexual concurrency and 36.4% of those without such concurrency consistently used condoms with non-regular partners. CONCLUSION The expansion of the human immunodeficiency virus epidemic from high-risk populations to the general population in China may be driven by concurrent sexual partnerships. Behavioral interventions targeting safer sex should be integrated into harm reduction programmes.