The study's authors were the first to examine HIV and the community of men who have sex with men in the Soweto Township, an area on the periphery of Johannesburg reserved for black South Africans during apartheid.
The researchers found that Soweto MSM identified themselves as straight, bisexual or gay, with the highest HIV rate among gay identified men, at 33.9 percent. The researchers estimated the rate of HIV infection for bisexual MSM in Soweto to be 6.4 percent and 10 percent for straight identified MSM.
"Our findings clearly indicate that targeted prevention and treatment for men who have sex with men in townships are urgently needed. We also found that, despite South Africa's legal advances in gay rights, stigma and de facto segregation are reflected in the disproportionate rates of HIV infection," said the study's principal investigator, Tim Lane, PhD, MPH, assistant professor at the UCSF Center for AIDS Prevention Studies.
The findings are now available in the online edition of the journal AIDS and Behavior and are scheduled for publication in an upcoming print issue.
Of the study's 378 participants, 34.1 percent identified as gay, 30.4 percent as bisexual and 31.7 percent as straight. All but one of the participants were black South Africans and all of South Africa's black African ethnic groups were represented in the sample.
The study showed that MSM's sexual identities predicted their sexual behavior with other men.
Gay identity was highly correlated with the exclusive practice of receptive anal intercourse and straight and bisexual self-identification was highly correlated with the exclusive practice of insertive anal intercourse with male partners.
"With the correlation of sexual identity and sexual practice, control of condom use in same-sex partnerships tends to be in the hands of bisexual and straight MSM. This finding demonstrates the pressing need to promote condom use among bisexual and straight-MSM for same-sex as well as heterosexual relationships," said Lane.
The authors also looked at other risk factors and found that HIV infection was also associated with being older than 25, lower incomes, purchasing alcohol or drugs for a male partner in exchange for sex, having receptive anal intercourse and having any unprotected anal intercourse with a man.
HIV infection was significantly less likely among men who have sex with men who were circumcised, smoked marijuana, had a regular female partner or reported unprotected vaginal intercourse with women.
"The circumcision findings clearly suggest that for this population of MSM, circumcision could be protective and that MSM should not be excluded from circumcision programs," said Lane.