Real-world impact of male circumcision on HIV seroprevalence in sub-Saharan Africa: a household fixed-effects analysis among 279,351 men from 29 countries


BACKGROUND: Medical male circumcision reduced the individual-level risk of female-to-male HIV transmission by approximately 60% in randomised-controlled trials, but little is known about the impact of male circumcision on HIV prevention in a 'real-world' setting. Understanding the impact of male circumcision outside of randomised clinical trials is important for understanding how to support the implementation of voluntary medical male circumcision (VMMC) campaigns in high HIV prevalence settings.
METHODS: We pooled individual-level nationally-representative survey data (Demographic and Health Surveys and AIDS Indicator Surveys) from all sub-Saharan African countries that included information on male circumcision status (self-reported) and HIV status (determined using blood-based testing). We estimated the effect of men's circumcision status on HIV-seropositivity using modified Poisson regression models (adjusted for age, educational level, and marital status) with household fixed-effects, which control for heterogeneity in observed and unobserved factors that might confound the association shared by men living in the same household.
RESULTS: We included data from 279,351 male respondents to 48 surveys conducted in 29 countries between 2003 and 2018. Mean survey-level male circumcision prevalence was 65.9% (median 84.5%, IQR 28.8%'68.1%) and mean survey-level HIV prevalence was 5.6% (median 2.5%, IQR 1.2%'10.2%). In our analysis, we found that circumcised men had 0.80 times (95% CI 0.73'0.88) the risk of living with HIV compared to uncircumcised men, implying that circumcision reduces the risk of HIV transmission by roughly 20% (12%'27%).
CONCLUSIONS: The population-level 'real-world' impact of male circumcision on HIV prevention was significant, but 2-to-3-fold less strong than demonstrated in previous randomised-controlled trials. Reasons for this could be suboptimal circumcision procedures (especially in cases of traditional circumcision), lack of abstinence compliance following the procedure, and sexual risk compensation behaviours. Implementation strategies to improve VMMC delivery in high prevalence settings are needed to maximise the full protective effects of the intervention.