/ 11 November 2014

HIV infection highest among men who have sex with men

Almost half of the men who have sex with men in Durban are HIV infected and about a quarter of such men in Johannesburg and Cape Town have HIV, according to a Human Sciences Research Council (HSRC) study that was released on Tuesday.

The Durban figure of 48.2% is significantly higher than the 37.4% HIV infection rate among pregnant women who attend government clinics in Kwazulu-Natal, the country’s highest rate in this category, according to government data. 

The term “men who have sex with men” (MSM) refers to “all biological males who have sex with other biological males, irrespective of the person’s sexual orientation and gender expression”, the study authors point out. In other words, MSM does not only refer to gay men, but also to bisexual men, some of them in stable heterosexual relationships.

According to infectious diseases physician Kevin Rebe from the Anova Health Institute’s Health4men project in Cape Town, South Africa does not have reliable figures on what percentage of men who identify as heterosexual also engage in male-to-male sex. At Health4Men’s Siseko Men’s clinic, that offers treatment and screening for HIV and sexually transmitted infections in Khayelitsha, Cape Town, about 10% of men who are heterosexual also report having sex with men.

HIV transmission and anal sex
The HSRC study, known as the Marang Men’s Project, was conducted in Johannesburg, Cape Town and Durban from 2012 to 2013 with 925 men who have sex with men. The respondents’ median age was 24 and most participants were black, except in Cape Town where just more than half of the sample described themselves as coloured. It is the largest study that has been conducted among MSM in South Africa.

About half of the respondents in Johannesburg and Durban had a matric and only 17% in Cape Town.

In Durban 48.2% of MSM were HIV infected, in Johannesburg 26.8% and in Cape Town 22.3%.

According to Rebe, MSM are at particular risk of contracting and transmitting HIV because, biologically, “unprotected receptive anal sex is about 16 times more likely to transmit HIV than unprotected vaginal sex”.

“This is due to the friable nature of the rectal mucosa, which does not contain mucous-producing cells as compared to the thicker, self-lubricating lining of the vagina,” Rebe says.

He cautioned that the Marang study’s figures would need to be scrutinised as they were significantly higher than other HIV infection rate figures among MSM. “The study’s figures might not be ‘generalisable’ of MSM across the country, as the samples that were collected might not be representative of the MSM HIV epidemic in South Africa.”

A number of partners
The Marang study found that in each of the three cities, more than half of the respondents reported that they had had three or more male sex partners in the previous six months.

And 16% of respondents in Cape Town, 2.8% in Durban and 38.7% in Johannesburg reported having a regular female sex partner in the previous six months, in addition to their male sex partners.

In each city, at least a fifth of MSM respondents reported being married or cohabitating (marriage refers to male-female and gay marriages): 28.8% in Cape Town, 19.3% in Durban and 21.6% in Johannesburg.

Married or cohabiting respondents had a higher HIV prevalence (31.1%) than their single counterparts (18.9%) among respondents in Cape Town.

“Similarly, in Durban married or cohabiting respondents had a higher HIV prevalence (51%) and a nonsignificant increased risk of HIV infection than those who were single,” the study notes. “The opposite was, however, the case in Johannesburg, where married or cohabiting respondents had a lower HIV prevalence (14.4%) than respondents who were single (31.6%).”

HIV prevalence was found to increase with age in each of the three cities. HIV prevalence was higher among MSM aged 25 years and older than among MSM in the 18- to 24-year age category.

Sexual identity and HIV
According to the authors: “Concerning the association between HIV prevalence and sexual orientation, results demonstrated that self-identified gay men were more likely to be HIV positive than those who identified as bisexual or straight among MSM sampled in each of the three study cities.”

For instance, in Cape Town self-identified gay MSM were “three times more likely to be living with HIV than their bisexual counterparts were. The statistical difference between the two was significant.”

Survey respondents in Durban who identified as gay had higher HIV prevalence (47.7%) than those who identified as bisexual (41.0%), although the difference was not significant. In Johannesburg, the HIV prevalence found for those who identified as gay was significantly higher (43.7%) than for respondents who identified as bisexual (17.9%) or straight (9.8%).

Among respondents in Cape Town, those who were more educated were 1.5 times more likely to be HIV positive than those with lower educational attainment.

Among MSM sampled in Durban, students had the highest HIV prevalence (31%), followed by those who were unemployed (23.9%), and HIV prevalence was lowest among those who were employed (17.0%).

In Johannesburg, employed men had the highest HIV prevalence (47.7%), followed by those who were unemployed (25.8%), while students had the lowest HIV prevalence (13.8%).