Comparing Prevalence of Condom Use Among 15,379 Female Sex Workers Injecting or Not Injecting Drugs in China JOSEPH T. F. LAU, MD,* JIANXIN ZHANG, MD, MSC,† LINGLIN ZHANG, MD, MSC,‡ NING WANG, PHD,§ FENG CHENG, PHD, YUN ZHANG, MBA,¶ JING GU, MSC,* HI-YI TSUI, MPHIL,* AND YAJIA LAN, PHD† Objectives: To compare the prevalence of condom use with clients and regular sex partners between female sex workers (FSWs) who were or were not injecting drug users (IDUs). Methods: Behavioral surveillance data (2002–2004) conducted in Sichuan, China were analyzed. Mapping exercises were done. About 250 to 400 FSWs were anonymously interviewed from selected estab- lishments in 19 surveillance sites. Results: Of all 15,379 FSWs studied, 3.2% were IDUs. This group, when compared with the non-IDU group, was less likely to have used condoms with clients (last episode: 71.1% vs. 81.2%, OR  0.6, P < 0.01; consistent use in the last month: 26.7% vs. 40.4%, OR  0.5, P < 0.01) or to possess a condom (68.7% vs. 77.8%, OR  0.6, P < 0.01). The between-group difference in last month’s consistent condom use with clients remained significant in the multivariate analyses, after adjusting for other significant factors [age, education level, age at first sex, having a regular sex partner, HIV-related knowledge and percep- tions, HIV antibody testing (OR  1.1–2.9, P < 0.05); STD symptoms, type of sex workers, longer duration of sex work, larger number of clients per week, and not having received HIV-related information (OR  0.4 – 0.9)]. Comparable results were obtained for condom use with the last client. Such between-group differences were, however, not observed for condom use with regular sex partners (P > 0.05). Expo- sure to HIV-related services was associated with condom use with clients (OR  1.3–2.8, P < 0.05). Conclusions: Higher sexual risk behaviors were found among FSWs who were also IDUs, when compared with those who were non-IUDs. A double-risk bridging population for HIV transmission thereby exists. AS OF THE END of 2005, 44.3% of all estimated HIV cases in China could be attributed to injecting drug users (IDUs). 1 HIV transmission among IDUs is the driving force of the HIV epidemic in China. 2 The efficiency of the spread of HIV from the IDU population to other populations [e.g., female sex workers (FSW) population] is a determining factor for future HIV prevalence in China. 3–5 A number of studies investigating female IDUs in China and other countries reported that about 21% to 60% of them were also engaged in sex work 4,6–8 and that FSWs who were also IDUs (FSWIs) often engaged in behaviors involving risk of sexual transmission of HIV. 9,10 In contrast, other studies surveying FSWs found only a few percent of them were FSWIs. 11–13 The apparent inconsistency may be explained by the fact that surveys targeting IDUs were often institution-based or community-based, 4,14,15 whereas surveys targeting FSWs were often venue-based (e.g., night clubs, saunas). 16 –18 Moreover, FSWs with IDU behaviors would find it difficult to work in some types of venues (e.g., karaoke clubs or saunas). Many of these reports, however, in- volved a relatively small number of FSWIs. With financial pres- sure resulting from their drug dependency, FSWIs may be less able to insist on consistent condom use with their commercial sex partners. 3 Because there may be around 6 to 8 million FSWs in China, 19 the size of the FSWI population is noteworthy. This study compared data on the FSWIs and FSWs who were not IDUs (FSWNI) obtained from the Behavioral Surveillance Surveys (BSS) of the China-UK HIV/AIDS Prevention and Care Project 20 conducted for FSWs in Sichuan in 2002, 2003, and 2004. The Project also implemented various prevention and care pro- grams for HIV-vulnerable populations in Sichuan and Yunnan, China and was managed by its National and Provincial Manage- ment Offices. 20 Both funding (about 20 million pounds) and tech- nical support have been provided by United Kingdom Department for International Development and Family Health International (FHI). Sichuan has a total population size of about 87 million 21 and was ranked sixth among all China provinces for the number of HIV cases reported. 22 The HIV prevalence among IDUs in Si- chuan was quite high. 15 This study tested the hypotheses that FSWIs and FSWNIs had different background characteristics, HIV-related perceptions, and prevalence of condom use with both sex work clients and regular The authors thank all staff of the China-UK HIV/AIDS Prevention and Care Project and CDC of Sichuan. Thanks are extended to Dr. Jean H. Kim for her help in early drafts of the manuscript. The study was Supported by United Kingdom Department for Interna- tional Development, Family Health International, and the China-UK HIV/ AIDS Prevention and Care Project. Correspondence: Joseph T. F. Lau, Centre for Epidemiology and Bio- statistics, School of Public Health, Faculty of Medicine, The Chinese University of Hong Kong, 5/F., School of Public Health, Prince of Wales Hospital, Shatin, NT, Hong Kong. E-mail: jlau@cuhk.edu.hk. Received for publication January 19, 2007, and accepted March 26, 2007. From the *Centre for Epidemiology and Biostatistics, School of Public Health, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong; †West China School of Public Health, Sichuan University, Chengdu, China; ‡Sichuan Provincial Center for Disease Control and Prevention, Chengdu, China; §National Center for AIDS/STDs Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China; China Country Office of Family Health International, Beijing, China; and ¶Management Office of China-UK HIV/AIDS Prevention and Care Project, Beijing, China Sexually Transmitted Diseases, November 2007, Vol. 34, No. 11, p.908 –916 DOI: 10.1097/OLQ.0b013e3180e904b4 Copyright © 2007, American Sexually Transmitted Diseases Association All rights reserved. 908