BEIJING, March 20 (Xinhua) -- Social expectations that men must get married is forcing homosexual males into heterosexual marriages and exposing married women to HIV infection, a Chinese expert warned Thursday.

    Zhang Beichuan, professor from the Qingdao University, said the fact that gay men are often forced into heterosexual marriages boosts the risk of HIV infection among other social groups in the country.

    "The stigma and discrimination against homosexuals in Chinese society have prevented gay men from revealing their sexual orientation or taking HIV/AIDS tests and treatments, holding back the efforts to curb the disease," Zhang told Xinhua Thursday by phone.

    Zhang and his team conducted a survey in nine major cities including Shanghai, Nanjing, Harbin, Chengdu, Zhengzhou, Shenyang, Xian, Wuhan and Chongqing in 2006. It shows that about 94.8 percent of the 2,250 homosexual males polled have had sex with other men in the past six months, and 20.7 percent have already married women. The survey targeted what it perceived as the most sexually active group among homosexuals.

    With the help of local gay communities, the survey organizers went to urban bars and public bath houses which gay men often visit. Before filling out the anonymous questionnaires, the respondents were asked to confirm that they had had sexual experience with other males. The median age of the respondents is 26.

    "In western countries, only a fraction of homosexuals would get into heterosexual marriages. But in China, about 70 to 80 percent of gay men had the intention of marrying a woman sooner or later," Zhang added.

    The survey showed that about half of the men polled had looked for strangers to have sex in places where male homosexuals usually hang out. About 18.6 percent participated in mass sexual activities and 13.2 percent paid for sex.

    Also, about 22.4 percent have experienced symptoms of venereal disease during the past six months, and 24.4 percent have taken HIV/AIDS tests, with 2.2 percent positive.

    Zhang urged society to show more understanding and tolerance toward homosexuals, and provide better access to HIV/AIDS intervention services for this high-risk group. "In the meantime, the country should continue to promote safe sex," he said.