Men who have sex with men have an up to 58 times greater risk of being infected with HIV than the general population in low- and middle-income countries, according to an article published in the December edition of PLoS Medicine. Investigators conducted a meta-analysis of 83 studies from 38 countries with a per-capita income below $10725. Men who have sex with men overall had a 19 times greater risk of HIV, but there were significant differences between world regions.
“These results constitute a clear call to action on three fronts: surveillance, research and prevention”, write the investigators, who note that fewer than one in ten men who have sex with men globally have access to appropriate HIV prevention and that homophobia is a barrier to such work in many countries.
Sex between men has been an important mode of HIV transmission since the infection was first observed some 25 years ago, and the HIV epidemics in many industrialised countries are predominately or significantly located in men who have sex with men.
Men who have sex with men (MSM) is a term that was coined in the mid-1990s in an attempt to encompass non-gay-identified men who have sex with men, and to describe their HIV risk. It is not a particularly nuanced epidemiological term and many gay-identified men find it offensive as they believe it strips them of a hard-won, and in many countries still threatened, cultural identity.
Investigators were aware of reports of high HIV prevalence amongst gay men in several low- and middle-income settings, including Asia, Africa, Latin America and the countries of the former Soviet Union. But the HIV risks of men who have sex with men in these settings are often poorly described in medical literature, not least because men who have sex with men are under-represented in national HIV surveillance, in targeted prevention programmes, and in care.
Investigators therefore conducted a meta-analysis of studies looking at HIV-prevalence in men who have sex with men in low- and middle-income countries. A total of 83 studies from 38 countries were included in their analysis.
This analysis showed that overall men who have sex with men had a 19 times greater risk of infection with HIV than the general population (OR: 19.3; 95% CI: 18.8 – 19.8). But there were significant variations between countries. In countries with a very low HIV prevalence (below 0.5%), men who have sex with men were 58 times more likely to have HIV (OR: 58.4; 95% CI: 56.3 – 60.6). In low prevalence countries (prevalence between 0.5% - 1%), the risk was 14 times higher (OR: 14.4; 95% CI: 13.8 – 14.9). Men who have sex with men in medium and high prevalence countries (1.1% - 5% adult HIV prevalence) were almost ten times more likely than the general population to have HIV (OR: 9.6; 95% CI: 8.9 - 10.2).
Men who have sex with men are at a higher risk of HIV infection than the general population in settings where injecting drug use was not a major driver of the HIV epidemic (OR: 24.5; 95% CI: 22.8 – 26.3). But where injecting drug use was fuelling the spread of HIV, for example in the former Soviet Union, men who have sex with men had a risk of HIV 13 times greater than that of the general population (OR: 12.8; 95% CI: 12.3 – 13.4).
The investigators noted that men who have sex with men had a higher risk of HIV infection in middle-income countries (OR: 23.4; 95% CI: 22.8 – 24.0) than in low-income countries (OR: 7.8; 95% CI: 7.2 – 8.4).
Finally, the investigators stratified their results by region. They found important differences. Men who have sex with men in Central and Latin America were 33 times more likely to have HIV than the general population (OR: 33.3; 95% CI: 32.3 – 34.2), those in Asia had a 18 times increased risk (OR: 18.7; 95% CI: 17.7 – 19.7), those in Africa were four times more likely to be HIV-infected (OR: 3.4; 95% CI: 3.3 – 4.3), with the risk for men who have sex with men in the countries of the former Soviet Union being 1.3 times higher (OR: 1.3; 95% CI: 1.1 – 1.6).
“Overall, the odds of having HIV infection are markedly higher among men who have sex with men than among the general population of adults of reproductive age across Asia, Africa, the Americas and the countries of the former Soviet Union”, comment the investigators.
They note that additional data regarding the severity of the HIV epidemic amongst men who have sex with men in Africa are emerging and support their findings. Epidemics of HIV amongst men who have sex with men in low- and middle-income countries “appear to be driven, in part, by marked stigma and homophobia…and a lack of specific prevention strategies”, note the investigators. They add, “although these data indicate that men who have sex with men populations are in desperate need of targeted prevention campaigns, social tolerance currently limits prevention efforts.”
The investigators conclude, “men who have sex with men have largely been ignored by both social and public health structures in many countries for too long…Surveillance, research, and prevention efforts should work together to begin to curb HIV transmission in this marginalised population.”