HIV present, risks high, among men who have sex with men in Shanghai

A cross-sectional study of men who have sex with men (MSM) in Shanghai, China has found prevalence rates of 1.5% for HIV and 13.5% for markers of syphilis. Researchers from the Center for AIDS Prevention Studies at the University of California, San Francisco, say that prevention work in China needs to target and strengthen the social networks of men who have sex with men. The study was published in the May 1^st issue of the Journal of Acquired Immune Deficiency Syndromes.

The study found that men were at lower risk for syphilis if they had larger social contact networks or had steady female sexual partners. However, they were more likely to have unprotected intercourse if they had larger male sexual contact networks, were or had been married, or had steady sexual partners (male or female).

As of the end of 2005, there were a confirmed 141,000 and an estimated 650,000 HIV-positive persons in China. Most of the infections are in injection drug users; however, HIV prevalence among MSM has been found to range between 1% (in northeast areas) to 3.1% (in Beijing). HIV among Chinese MSM has been understudied overall.

In this study, researchers from the Center for AIDS Prevention Studies at the University of California, San Francisco investigated MSM in China’s largest city, Shanghai. The study focused on the men’s social and sexual networks and how these influenced HIV and sexually transmitted infection (STI) rates.

Participants were recruited between September 2004 and June 2005. An initial 52 participants recruited from MSM venues including bars, clubs and restaurants led to an overall “snowball” sample of 515 men screened. Of these, 477 participated in the study: all were men who self-reported as having sex with men (57% “homosexual”, 38% “bisexual” by self-report), 18 years or older (mean age 28), and residents of Shanghai. Most (78%) were never married; 73% had no college education.

Most of the men were knowledgeable about HIV transmission (mean 6.9 correct responses to a set of eight questions) but felt themselves to be at low (52%) or no risk (38%) for HIV. Yet 57% reported unprotected anal sex with men in the past six months, 63% had unprotected intercourse with men or women, and 13% had unprotected sex with both men and women. Of the 475 who provided blood samples, 7 (1.47%) tested positive for HIV, 64 (13.47%) had markers for syphilis, and two (0.42%) were co-infected with both.

Men with stronger social networks were at lower risk of syphilis infection. Multivariate analysis found that syphilis was less likely in those with three to five (vs. six or more) sexual partners, meeting other MSM at the gym or through the Internet rather than other venues, having a steady female partner, and having social and sexual networks that overlapped more strongly (i.e., having more partners who were also social rather than purely sexual contacts).

Men were more likely to have unprotected anal and/or vaginal sex if they: were married, were more knowledgeable about HIV, had more lifetime male sex partners (six or more vs. three to five), and were part of larger male sexual networks.

The study did find that sexual and social networks tended to overlap strongly – more than half of the sample had male social contacts as sexual partners, and 22% had a sex partner (male or female) in their social contact network. The researchers believe “[t]hese data suggest that HIV prevention programs should target the social and sexual networks of Chinese MSM”, and suggest that such programs could aim to strengthen social networks for MSM, and to promote safer sex among such networks.