- Circumcision is likely to protect men who have sex with men (MSM) from HIV infection, particularly in countries of low and middle income, and from herpes simplex virus (HSV) and penile human papillomavirus (HPV) infection.
- MSM should be included in campaigns promoting circumcision among men in countries of low and middle income.
- Well-designed longitudinal studies including MSM only are needed because of the low quality of evidence and a substantial proportion of bisexual men in the samples.
MSM are disproportionately affected by HIV and other sexually transmitted infections (STIs, including syphilis, HSV, gonorrhoea, chlamydia, and HPV) worldwide. Male circumcision is effective in preventing HIV among heterosexual men, but its role in MSM remain unclear. Authors conducted a systematic review and meta-analysis to investigate whether MSM similarly benefits from circumcision.
Authors searched for interventional or observational studies reporting estimates of associations between circumcision status and incidence or prevalence of HIV infection and other STIs among MSM, published before 2018. Studies were excluded if MSM could not be distinguished from men who have sex with women only.
The review included 62 observational studies.
43 studies (105,009 participants) were included in the meta-analysis of the association between circumcision and HIV infection. Circumcision was associated with 23% lower odds of HIV infection among MSM overall (OR 0.77; 95% CI 0.67-0.89; number of estimates [k]=45; heterogeneity I²=77%). In subgroup analyses, circumcision was protective among MSM in countries of low and middle income (OR 0.58; 0.41-0.83; k=23; I²=77%) but not in high-income countries (0.99; 0.90-1.09; k=20; I²=40%).
27 studies (61,411 participants) were included in the meta-analysis of associations between circumcision and other STIs. Circumcision was associated with reduced odds of HPV infection (0.71; 0.51-0.99; k=3; I²=0%) only among HIV-infected MSM. Circumcision was protective for HSV infection among MSM overall (0.84; 0.75-0.95; k=5; I²=0%).
Results differ from those of two previous systematic reviews, but this review included 22 additional studies. Further designed longitudinal studies differentiating MSM only and bisexual men are needed to better characterise the effect of circumcision on HIV and other STIs male-to-male transmission.
Limitations: the meta-analysis was based on observational data. This could result in an overestimation of the protective effect of circumcision. Few studies were included in several subgroup categories.