The growing uptake of medical male circumcision by men in the Rakai district of Uganda is leading to a substantial reduction in HIV incidence among men in one of the districts of the country worst affected by HIV, Xiangrong Kong of Johns Hopkins Bloomberg School of Public Health told the Conference on Retroviruses and Opportunistic Infections (CROI 2015) in Seattle, USA, on Thursday.
Three large clinical trials in sub-Saharan Africa, including one conducted in the Rakai district, have shown that medical male circumcision reduces the risk of acquiring HIV by between 50% and 60%. These findings have led to the scale up of services offering medical circumcision to men, especially to adolescents and young men.
However, until now, the only evidence of an impact of medical male circumcision on HIV incidence in the communities where it is offered has come from a cross-sectional study in the Orange Farm community in South Africa, where another of the clinical trials showing efficacy took place. That study showed that the roll out of circumcision had reduced HIV incidence by between 57% and 61%.
The study conducted in Rakai set out to assess the impact of scaling up circumcision in Rakai district since 2007, through analysis of annual cross-sectional surveys of adults aged 15-49 carried out by the Rakai Community Cohort Study. The analysis excluded Muslim men who would have been circumcised in any case, and sought to assess the impact of circumcision as an HIV prevention intervention. The analysis also assessed and controlled for the level of antiretroviral coverage over time in women, since increased antiretroviral coverage would be expected to reduce HIV transmission to men, regardless of the level of circumcision.
The study found that circumcision coverage in non-Muslim men increased from 9% during the Rakai circumcision study to 26% by 2011, four years after the trial concluded. Every 10% increase in circumcision coverage was associated with a 12% reduction in HIV incidence (0.88, 95% confidence interval 0.80-0.96).
However, there was no evidence of a reduction of incidence in women as a consequence of the reduction in HIV prevalence in men due to circumcision. Dr Xiangrong Kong said that previous modelling studies suggested it may take up to a decade for medical male circumcision to have an impact on HIV incidence in women.
Preliminary data for 2013-14 show that the proportion of non-Muslim men who have undergone medical circumcision in the Rakai Community Cohort has increased to 49%.