The evidence that voluntary medical male circumcision reduces the risk of a heterosexual man contracting HIV in high prevalence areas is beyond reasonable doubt.
In June, Philosopher Brian Earp wrote an article titled A fatal irony: Why the "circumcision solution" to the AIDS epidemic in Africa will increase transmission of HIV.
In an article on circumcision last week, Daily Maverick journalist Jacques Rousseau wrote: "Though it's repeated so frequently as to seem axiomatic, the evidence that circumcision reduces HIV infection is not as clear-cut as many think it is."
They are both wrong. The evidence that circumcision reduces the risk of HIV transmission for heterosexual men in high prevalence areas is about as clear-cut as you'll find in medical science.
Three well conducted randomised controlled trials, in South Africa, Kenya and Uganda showed that circumcision was highly effective. The findings of these trials are supported by quality observational studies. There is also a plausible biological explanation for the mechanism by which circumcision works.
Earp's article is especially poorly researched. Besides making discredited stale arguments against the three clinical trials, he puts forward the much touted but evidence-free view that circumcised men will be at greater risk of HIV infection because they will take more risks due to the false belief that circumcision protects them.
Risk compensation has been studied. There is no sign that it is reversing the considerable benefit of circumcision.
In 2008, a group of us published a clearly written peer-reviewed article in Future HIV Therapy that comprehensively debunks the arguments purporting to show that circumcision does not protect heterosexual men against HIV infection:
Male circumcision is an efficacious, lasting and cost-effective strategy for combating HIV in high-prevalence AIDS epidemics
The World Health Organisation recommends circumcision to reduce the risk of HIV infection. So do many other reputable institutions. I am not aware of any reputable medical body that recommends against it for areas with large primarily heterosexual HIV epidemics.
There are complex ethical questions about infant circumcision. There are difficult operational and political problems to be overcome to properly implement circumcision in South Africa. The Kwa-Zulu Natal government is rolling out circumcision irresponsibly, particularly - but not only- because it is using an unsafe circumcision device called the Tara KLamp. Traditional - as opposed to medical - circumcisions in the Eastern Cape are a disaster, with 20 initiates reportedly dying this year. That the state continues to fail to prevent this annual tragedy is shameful.
Nevertheless the science is clear: medical circumcision of adult males reduces their risk of acquiring HIV from HIV-positive women.