Background: Male circumcision (MC) offers men lifelong partial protection from heterosexually-acquired HIV infection. The impact of MC on HIV incidence has not been quantified in nationally-representative samples. Data from the Population-based HIV Impact Assessments (PHIAs) were used to compare incidence by MC status in countries implementing voluntary medical MC (VMMC) programs.

Methods: Data were pooled from PHIAs conducted in Eswatini, Lesotho, Malawi, Namibia, Tanzania, Uganda, Zambia and Zimbabwe from 2015-2017. Incidence was measured using a recent infection testing algorithm, and analyzed by self-reported MC status distinguishing between medical and non-medical MC. Country, marital status, urban setting, sexual risk behaviors, and mean population HIV viral load among women as an indicator of treatment scale-up were included in a random effects logistic regression model using pooled survey weights. Analyses were age-stratified (15-34 and 35-59 years). Annualized incidence rates and 95% confidence intervals (CIs) and incidence differences were calculated between medically circumcised and uncircumcised men.

Results: Men 15-34 years reporting medical MC had lower HIV incidence than uncircumcised men (0.04% [95% CI: 0.00, 0.10%] versus 0.34% [95% CI: 0.10, 0.57%], respectively; p-value = 0.01); whereas among men 35-59 years, there was no significant incidence difference (1.36% [95% CI: 0.32, 2.39%] versus 0.55% [95% CI: 0.14, 0.67%], respectively; p-value = 0.14).

Discussion: Medical MC was associated with lower HIV incidence in men aged 15-34 years in nationally-representative surveys in Africa. These findings are consistent with the expected ongoing VMMC program impact and highlight the importance of VMMC for the HIV response in Africa.