China is the largest low or middle income nation, and carries a large amount of rural-to-urban migrants (> 200 million in 2011), which contributes great risk for the spread of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) and other sexually transmitted infections (STIs). According to the most recent surveillance data available, the cumulative reported HIV-infected patients in China exceeded 370,000, including 130,000 who had progressed to AIDS. Four major factors, including drug abuse, migrant workers, unprotected and high-risk sexual activity, and the lack of knowledge about HIV/AIDS, have been identified as significant contributors to the HIV/AIDS epidemic among the general population in China.
Heterosexual contact is now considered the most common mode of transmission of HIV infection in China. Shanghai, one of the largest cities in China, had 1294 new HIV infections in 2011, 82.5% of which were acquired through sexual contact. Eight hundred eighty of the 1294 infections (68.0%) involved rural-to-urban migrant workers. Currently, there are approximately 200 million migrant workers in China, most of whom originated from poorer regions of the country and came to work in the cities as laborers, restaurant workers, and sex workers. The itinerant population is considered as the 'tipping point' for the current HIV/STI epidemic [1
]. It has been suggested that rural-to-urban migration may play a crucial role in shifting the HIV/AIDS epidemic by broadening social and sexual mixing [3
]. In many cases, female sex workers (FSWs) from the itinerant population are considered a significant contributor to the heterosexual transmission rates of HIV/STIs because their unprotected, anonymous sexual activities act as a "bridge" to spread HIV/STIs to the general population [5
]. Most FSWs in large cities migrate from poor rural areas [6
], and are mainly young girls with limited education who are simply unaware of the risk of HIV/STIs. A poor awareness of self-protection is an obstacle to the consistent and proper use of condoms during a commercial transaction. In China, providing commercial sexual services is illegal and most FSWs operate in karaoke bars, massage parlors, saunas, and hair and beauty salons, while some FSWs solicit clients from the street or in parks [7
].The prevalence of HIV in FSWs illustrate the critical need for preventive efforts and health education.
HIV/AIDS prevention has been influenced by cognitive theories of behavioral change that emphasize promoting knowledge, perceptions, beliefs, and skills regarding HIV/AIDS [8
]. Many studies had focused on HIV/STI prevention among FSWs by health education and condom promotion at the individual level. In recent years, health promotion theories of behavioral change have focused not only on the individual , social and psychological predisposing factors, but also enabling and reinforcing factors, such as environmental-structural factors [9
]. The most well-known environmental-structural intervention of HIV/AIDS research is the Thai 100% condom program, which requires condom use in all brothel-based commercial sex acts sponsored by the government [11
]. Ang and Morisky [12
] reported that STI risk among female bar entertainers in the southern Philippines could be reduced by combining manager and peer interventions. Other researchers have concluded that structural and environmental influences, such as the physical, social, policy, and economic environments, are barriers to condom negotiation [13
]. Urada [15
] suggested that interventions should consider the effects of environmental-structural factors on consistent condom use (CCU). The India experience showed a 2.5 times the odds ratio of CCU among those FSWs who were involved in program exposure and high levels of collective agency [16
The initial success of environmental-structural intervention has inspired related intervention research in other countries, and recently in some pilot regions in China. These interventions are difficult to conduct without the support of FSWs, establishment owners, government and establishment-based policies, and support systems. Because commercial sexual service is illegal in China, investigation and research of FSWs is a sensitive issue which is not easy to conduct, thus limiting related studies in Shanghai. The purpose of the current study was to obtain information about social and psychological and environmental-structural factors in determining CCU among rural-to-urban FSW migrants in five districts of Shanghai using cluster randomized sampling.