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Circumcision Still Effective for HIV Prevention After 6 Years


Voluntary adult male circumcision continued to be associated with about a 60% reduction in the risk of HIV infection after 6 years of follow-up, according to a study in Kenya described in the November 28, 2013, issue of AIDS.

In 2005 researchers first reported that a study in Orange Farm township near Johannesburg, South Africa, showed that elective adult circumcision reduced men's risk of HIV infection by 61%. Soon thereafter a pair of large controlled studiesin Kisumu, Kenya, and Rakai, Uganda, again demonstrated that circumcision can reduce the risk of HIV infection by more than half.

The World Health Organization and UNAIDS therefore recommended in 2007 that voluntary male circumcision should be offered as part of comprehensive HIV risk reduction programs in settings with generalized HIV epidemics.

Now, Robert Bailey from the University of Illinois at Chicago School of Public Health and fellow investigators with the Kisumu study have estimated the long-term efficacy of adult circumcision among men retained in this trial after 6 years of follow-up.

In the initial study, between 2002 and 2005, a total of 2784 HIV negative men aged 18-24 years enrolled in the trial. All participants expressed interest in circumcision, and they were randomly assigned to undergo the procedure either immediately or after a waiting period. At the end of the trial in December 2006, men in the control group were offered free circumcision. Follow-up continued through September 2010.


  • The cumulative 72-month incidence of HIV infection was 4.81% among circumcised men compared with 11.0% among uncircumcised men.
  • The crude hazard ratio of HIV seroconversion for circumcised versus uncircumcised men was 0.38, or about a 60% reduction.
  • In an adjusted regression analysis, the hazard ratio was 0.42, or a 58% reduction.

"The efficacy of [medical male circumcision] was sustained at 58% at 72 months, similar to overall findings of the three trials under conditions of randomization," the study authors concluded.

"These findings provide an estimate of the long-term efficacy of circumcision against HIV acquisition," they added. "Our results support programmatic scale-up recommendations that are based on assumptions of sustained efficacy."



SD Mehta, S Moses, K Agot, RC Bailey, et al. The long-term efficacy of medical male circumcision against HIV acquisition. AIDS 27(18):2899-2709. November 28, 2013.