The HIV epidemic has taken over two and a half million lives in South Africa. Another five million people live with the virus. We are making progress and probably over half-a-million people are on ARV treatment. It is still far too few; the National Strategic Plan (NSP) target is to have over 1.5 million people on treatment by 2011, a big challenge.

But the area where we have fallen furthest behind is preventing new infections. We know of a few things that can change this. The mother-to-child transmission prevention programme has to improve. Condom promotion must be more explicit, frequent and clever. ARVs for rape survivors, as well as for when the ‘€œcondom broke’€ must be widely advertised. Every school should have a life-skills programme that addresses HIV, sex and condoms properly. Getting a lot more people on ARVs will also help reduce new infections, because they reduce the amount of HIV in your body making you less infectious (but you still should use a condom).

Yet one of the interventions that would have a significant effect on prevention gets a hard time: circumcision. Three huge clinical trials as well as many studies comparing circumcised groups of people to uncircumcised ones have shown unequivocally that carrying out this simple 20 minute operation on a young man under local anaesthetic reduces his risk of contracting HIV substantially.

Understandably many people feel uncomfortable with a large public health intervention that involves amputating a body part, a particularly sensitive one at that. But consider this: Several thousand medical circumcisions have been carried out in these clinical trials without a single report of life-threatening or serious permanent damage. On the contrary, dozens of HIV infections were prevented. Also, we are a society in which other forms of voluntary bodily mutilation, piercings and tattoos, are acceptable. Surveys of men circumcised as adults generally show that they were happy they did it. Voluntary male medical circumcision needs to become part of our arsenal to reduce new HIV infections. And of course it should go without saying that no one should ever be compelled to have a circumcision.

The thought of loping off the end of a man’s penis as a measure to protect against HIV seemed an absurd one when we first encountered it. But there’s a biological explanation for why it works. The foreskin, which is very sensitive, is easily abraded during sex. It also contains a high number of HIV target cells and absorbs HIV more easily than other parts of the genitals.

From South Africa’s experience of behaviour change interventions we have learnt that knowledge of how HIV is transmitted seldom changes the sexual risks people take. So what makes us believe that any adult man would willingly undergo circumcision, especially in light of the need to abstain from sex for six weeks following the procedure?

The answer lies in Orange Farm, a township of a few hundred thousand people south of Johannesburg. The largest medical circumcision trial took place there, at the Bophelo Pele male circumcision centre. Bophelo Pele continues to conduct circumcisions and has so far circumcised nearly 5000 adult men. We visited the centre and found the knowledge and HIV literacy of the young men waiting to be circumcised surprisingly good. All but one of them were getting circumcised primarily as an HIV prevention measure. However, every man was fully aware that male circumcision is only partially effective and that they still needed to use condoms.

Circumcision is part of our cultural landscape, practised traditionally by Xhosas, Jews, Muslims and others. An early finding of the medical trials was that African traditional circumcision often merely involves an incision into the foreskin and seldom removes the entire foreskin. Often traditional circumcisions are carried out with unsterilised equipment. Sometimes they go horribly wrong because of the poor training of the person carrying it out. This raises the possibility that initiation procedures can be teemed up with medical facilities offering circumcision, making them safer. There are already discussions about this between circumcision doctors and some traditional leaders.

Men have proven to be a hard target group to reach with HIV prevention messages. The Bophelo Pele project shows that offering circumcision brings men into clinics where they can be reached with a range of health interventions, such as HIV testing, treatment for HIV and other sexually sexually transmitted infections and counselling on safer sex.

One fear is that men will get circumcised and then use it as an excuse to have risky sex sans condoms. Besides suggesting a rather bitter view of the male section of the human race, it is actually not supported by the evidence. On the contrary, at the site of the trial that took place in Kenya, a survey showed that men who participated reduced their risk-taking. You could retort that this was not circumcision but probably the counselling and other support they received. But that is the point: it is a benefit of offering circumcision that men will then go to a clinic and be counselled so that they will be more likely to use condoms.

The World Health Organisation recommends circumcision. The South African National AIDS Council (SANAC) recognises the evidence that it is effective at reducing the risk of HIV transmission. Unless new evidence comes to light, the science part of the debate is settled. The only honest basis for being opposed to circumcision is if you have moral objections. In that case we must agree to disagree. In our view, given that circumcision has been shown to be effective and relatively safe, the state has a moral duty to offer it more widely.

We now need to develop an ethical national voluntary male medical circumcision policy. This policy must acknowledge that male circumcision is nowhere near 100% effective in preventing HIV but it must also acknowledge that circumcision is one of the most effective interventions we have for preventing HIV. It must be integrated with our other HIV prevention and treatment interventions.

World AIDS Day 2008 was a political breakthrough. There was unprecedented unity and energy from the Ministry of Health, business, labour and activists. We must not lose this momentum as we translate our refreshing new leadership into actions that save lives. Yet the only way that we can make serious headway against the epidemic and meet the NSP target to reduce HIV incidence by half by 2011 is to use all the proven interventions available, including circumcision.

Geffen is with the Treatment Action Campaign. Booth writes in his personal capacity.