Circumcision prevents three out of four female-to-male HIV infections

The first ever randomised controlled trial (RCT) of male circumcision as an HIV prevention measure has produced such strong evidence of a protective effect, that the trial has been halted early and all participants have been offered circumcision, the Third International IAS Conference on HIV Pathogenesis and Treatment in Rio de Janeiro heard on July 26th.

There were only 35% as many infections in the circumcision arm as opposed to the control arm, implying that circumcision can prevent at least six out of 10 female-to-male HIV transmissions. However, when the results were analysed according to true circumcision status rather than by intervention group, the protective effect went up to 75%. This is because there were crossovers between the intervention and control arms in that some men randomised to be circumcised were not, and some in the control arm were.

The trial, the first of four RCTs of circumcision being conducted in Africa, randomised 3 273 men aged 16 to 24 to be circumcised at the start of the trial or to be offered circumcision at the end of it 21 months later. The men lived in the Orange Farm township near Johannesburg, South Africa.

Circumcisions in the intervention arm were carried out by a surgeon under local anaesthesia and with post-operative pain relief given. HIV incidence was measured at three and 12 months into the trial, and finally at 21 months, though the average follow-up period was in fact 20 months due to the premature termination of the trial.

Although all participants received intensive safer sex counselling and condoms, there were 51 HIV sero-conversions in the control arm versus 18 in the circumcision arm. This translates as HIV incidences of 2.2% and 0.77% a year respectively.

(Source: Gus Cairns, AIDSMap, July 27, 2005)

Reference: Auvert, B. et al. Impact of male circumcision on the female-to-male transmission of HIV. IAS Conference on HIV Pathogenesis and treatment, Rio de Janeiro, Abstract TuOa0402, 2005