The JEMS study was a collaborative effort between the Wits University in Johannesburg, the Human Sciences Research Council (HSRC) and the Medical Research Council.2 Before the survey, the researchers conducted extensive background research with a literature review, focus group discussions and interviews with key ‘informants’ from the LGBT community in Johannesburg, Durban, Cape Town, Pretoria and Pietermaritzburg. The survey of HIV prevalence and behaviour was focused on Johannesburg and Durban, because other groups were conducting similar surveys in Cape Town and Pretoria.
The survey recruited men using respondent-driven sampling (RDS) — a form of chain sampling which has been used extensively in other studies to recruit members of “hard to reach” populations. Eligibility requirements for the study included being male, aged 18 years or more, and having had sex with at least one other male in the past 12 months, and living, working or socializing in Johannesburg or Durban. With RDS, the initial participants are called “seeds” and these were deliberately chosen to be diverse in terms of age, race, socio-economic status, and to have large social networks. Each participant was asked to recruit up to three more participants. They were reimbursed for their participation, with a R40 (£3) cash and R40 voucher and were also reimbursed R40 for each additional participant they recruited (max. R120) (these amounts were thought to be enough of an incentive without being coercive).
After answering the survey questionnaire, 95% of the subjects provided dried blood spot samples that were linked to his answers and sent to the laboratory anonymously. Participants were also offered free VCT using a rapid HIV test with same-day results as an additional optional service to participants.
JEMs Results
The study accrued 285 participants in all (204 JHB and 81 Durban). 88% were black African (in a separate poster presentation, the researchers noted that despite their efforts and use of RDS, the population wasn’t as diverse as they would have liked, with very few white men for instance).3
Most of the participants were young — ages ranged from 18 to 61 years old — but two-thirds were under 25 years old (mean age 24.5 years; median age 22 years). 78% self-identified as homosexual or gay; 19% bisexual; 2% heterosexual or straight and 2% as (which included transgender individuals. 54% had greater than or equal to a grade 12 education.
In the 266 who tested, the unadjusted HIV prevalence was 43.6% among the participants. However, the researchers made some adjustments for the RDS-method to take into account that people tend to recruit people similar to themselves (and with similar HIV status), and came up with a prevalence of 38.3% that should be more representative for the MSM in this setting.
This prevalence was “at least twice as high as what one would expect from the general population,” said Dr Carol Metcalf, one of JEM’s investigators. In the national household survey conducted in 2005, the HIV prevalence among men aged 30 to 49 was 11.7%; and the ASSA (Actuarial Society of South Africa) estimate for 2008 of men aged 30 to 49 was 15.9%.4
In general, high-risk sexual behaviour was more common among people who were HIV-positive than those who were HIV-negative. In the previous 12 months, almost one in two participants — around 46% — reported having unprotected anal intercourse within the past year. The HIV-positive participants were more than twice as likely to have receptive unprotected anal intercourse within the past year. HIV-negative men reported an average of five partners in the past year while HIV-positive men reported an average of 7.5.
The participants reported that condoms were often unavailable and condom accidents were common. 55% of the respondents reported that they didn’t have a condom available when they needed one. 42% reported at least one instance of condom slippage and 58% reported an instance of condom breakage in the past year. In addition, many participants reported using lubricants that actually reduced the protective effect of condoms, such as Vaseline or lotion (which are more readily available in South Africa and much less expensive that the water-based lubricants).
Seventy three per cent of the participants reported that they had sex under the influence of alcohol in the past year (and there was no difference between HIV-negative or HIV-positive participants). Another interesting finding was that more than a third of participants reported having experienced sexual coercion — which was significantly associated with being HIV-positive.5
Of note, the men in the sample generally perceived their risk to be low. Prof Rispel said that one reason for this, which came out of focus group discussions, was that most thought that heterosexuals in South Africa were at greater risk of getting HIV than MSM. 57% of the participants reported that they knew their HIV status, but only two-thirds of those who knew their status had disclosed it to a sexual partner within the past year.
Dr Metcalf noted that the survey also included some questions about sex with women. “What is striking from these findings is that the vast majority of HIV-positive men in our study (reported) that they have never had sex with a women,” she said. Only 36 reported ever having had sex with women, and only one out of five of the HIV-positive participants. In the last year very few had had sex with women, and even fewer had unprotected or regular sex. Since there was such a low degree of sexual interaction with women, the JEMS team concluded that the epidemic of HIV among MSM probably does not overlap much with the larger HIV epidemic in South Africa; it is rather running in parallel.
However, Dr Metcalf stressed that this cohort may not be absolutely representative of MSM in South Africa:
“Our participants were predominantly young, gay, black Africans who do not think they were ‘representative of MSM in general or even MSM in the two cities. They don’t actually know what a representative sample would look like,” she said.
But it isn’t clear that the other samples described at the South African AIDS conference were entirely representative either.