BACKGROUND: In Sub-Saharan African (SSA), the HIV dynamic in different regions varies between generalized and mixed epidemics. Prevalence is high in men who have sex with men (MSM), a population that experiences strong social stigma and pressure to have female partners. This suggests that MSM could be a bridging group for HIV transmission to women. We provided an overview of the proportions of bisexual MSM and MSM who have condomless sex with women in various SSA regions.
METHODS: Following the PRISMA guidelines, we conducted a systematic review of published peer-reviewed articles containing the following data on MSM: self-reported bisexuality, recent sex (i.e., previous 12 months or 1 month depending on the region), and condomless sex with female partners. We performed a meta-analysis, separately for each region, when the proportion was reported in at least four studies (Fig1). Pooled proportions were calculated using a random-effects model.

RESULTS: The pooled proportion of self-declared bisexual MSM was 22% (95% CI [16;19]) in Southern Africa, 36%[29;43] in Eastern Africa, and 51%[45;56] in Western Africa. In Southern and Western Africa, 29%[22;38] and 47%[36;58] of MSM had =1 female partner in the prior 12 months, respectively. In Eastern Africa, 23%[9;47] of MSM had =1 female partner in the prior month. The pooled proportion of condomless most recent sex with a female partner was 27%[21;35] in Southern Africa, 30%[10;63] in Eastern Africa, and 20%[13;28]) in Western Africa.
CONCLUSIONS: A significant proportion of MSM in SSA reported bisexual orientation, especially in Western Africa. Condomless sex with female partners was frequent in all three regions, which highlights the risk of HIV bridging to this population. HIV research, prevention, and care programmes, as well as community-based support for MSM, should be adapted to MSM who have female partners, in order to reduce the HIV bridging risk to the general female population.