Sexual partnerships with men and women among men who have sex with men in Beijing and Chongqing, China, 2010.

HIV is spreading among Chinese MSM and may possibly lead to infection of female partners. Pressure to marry may drive a greater proportion of Chinese MSM to have female partners than MSM elsewhere in the world. Measurement of the size of the potential risk to female partners of Chinese MSM is inconsistent in the literature. From samples of MSM in two Chinese cities, we documented numbers of sexual partners and sexual activity with those partners. About 500 MSM were sampled in each city. 11.0 and 12.6 % of men reported having any female partners in the past 6 months in Chongqing and Beijing, respectively. Men also reported that only 7.3 and 6.7 % of their entire partnerships were with women in Chongqing and Beijing, respectively. Defining transmission risk accounting for receptive anal sex among men and condom non-use with both male and female partners, 3.4 % of MSM in both Chongqing and Beijing would have the potential to transmit HIV to female partners. Only 9 (1.8 ) men in Chongqing and 2 (0.4 %) in Beijing were HIV-positive and also had unprotected intercourse with females. The majority of HIV transmission risk among MSM in China is not from MSM to females.