Prostitutes represent another important social group for HIV transmission, and similar to injecting drug users, their numbers have been steadily increasing in recent years. According to the Ministry of Public Security, 137,000 prostitutes and their clients were arrested in 1990, 240,000 in 1992 and 400,000 in 1993 (2) . This number had risen to 700,000 by the late 1990s (1). The overall number of prostitutes in modern China is now believed to exceed 3 million. Among them, high levels of HIV and other sexually transmitted disease have been revealed. Research in Yunnan and Guangxi demonstrated the HIV prevalence among sex workers to be about 5% and 11%, respectively (6) . Concurrent gynaecological infections may also facilitate sexual transmission of HIV, particularly in rural communities (6) . In this regard, prostitute arrest records have revealed that the majority of commercial sex workers have at least one active, sexually-transmitted disease (17) . Prophylactic usage is not widely practiced among Chinese sex workers. Estimates of condom usage among prostitutes ranges from 1% to 30% (1). Condom usage usually depends on the customer. Some studies have shown that most prostitutes have never had formal sex education (17) . Many of them are also intravenous drug users, while sexually transmitted diseases are commonly treated with over-the-counter medicines. As prostitution is officially illegal in China, many infected sex workers are understandably reluctant to seek help or make themselves available for HIV testing and counselling.