A study into the spread of HIV, the virus that leads to AIDS, has found that male circumcision significantly protects men from picking up the infection.
The finding, though cautiously welcomed, presents a headache for health officials who fear that communities where male circumcision is common might neglect more effective protective measures such as using condoms and reducing their number of sexual partners.
The study, which followed infection rates in more than 3,000 heterosexual men over nearly two years, found that circumcision reduced a man's risk of acquiring HIV by 60 percent.
Scientists had suspected circumcision might offer some protection against the virus after noticing differences in HIV infection between groups where circumcision was a cultural right of passage and others where few were circumcised. Until now, no large-scale studies had been carried out to investigate the effect.
Adrian Puren at the National Institute for Communicable Diseases in Johannesburg and a team of researchers in Paris recruited 3,274 uncircumcised volunteers from South Africa aged between 18 and 24, who were considering circumcision. Half underwent the operation. The researchers then monitored both groups for HIV infection over the next 21 months. So marked was the difference in infection between the groups that the study was halted on ethical grounds. Of those who had been circumcised, 20 tested positive for HIV while 49 of the uncircumcised group had contracted the virus.
In the journal Public Library of Science Medicine, the authors say that circumcision appears to reduce the risk of acquiring HIV by 61 percent, "equivalent to what a vaccine of high efficacy would have achieved."
Peter Cleaton-Jones, the chairman of the human research ethics committee at the University of Witwatersrand in Johannesburg, said: "Circumcision is not going to prevent HIV infection in the long run. If circumcised men think they're protected against HIV, they're fooling themselves. If they don't practise safe sex, they'll still be at risk, it's just a lower risk."
Why circumcision should offer some protection is not well understood, but researchers know that the part of the foreskin that is removed in the operation is rich in Langerhans cells that the virus strongly attaches to.



