This table presents the findings from a study of female sex workers (FSW) and their male clients in Yunnan, China where there has been a high HIV prevalence (up to 25 percent) in the IDU population during the past decade. Public health officials have been concerned that HIV-infected male IDU would infect many FSW who then would transmit HIV to their clients. This study found over 10% of FSW to be HIV+, but all HIV-infected FSW had a history of IDU and the 213 FSW who denied drug use were all HIV negative. In addition, none of the male clients of FSW in this study were found to be HIV+. This study provides support for the relatively low infectivity of HIV via heterosexual intercourse.
This should not be interpreted to mean that there is no public health threat of HIV transmission from HIV+ FSW to their clients, but this finding reinforces the low risk of HIV transmission via vaginal intercourse from an infected female to a susceptible male. As of 2007, there are no definitive data to suggest that any significant heterosexual HIV epidemic has occurred in Yunnan.