The real evidence on Circumcision and HIV

Writing in the Guardian, Neil Howard and Rebecca Steinfeld argue for a ban on circumcision. I disagree with them, but luckily so do many others and they’ve done a good job of responding. See this direct response from Adam Wagner, and this pre-emptive piece by Alex Stein.

I have an instant prejudice against the potluck buffet approach to advocacy. I feel people should pick a line of argument and stick with it, rather than offering all sort of different forms of case. Steinfeld and Howard’s article makes rights-based claims, offers ends-based and harm-based objections, even flirts with anthropolatry.

It’s the section on the medical argument that really bothers me though. Howard and Steinfeld, in their wish to make every argument they can, dismiss the good evidence for circumcision as an HIV-prevention method. They do this in two ways – using problematic sources, and using good sources but misinterpreting them. The offending paragraph in the Guardian article is:

What about the health argument, that male circumcision is “cleaner” and prevents HIV transmission? There is a body of research that claims a correlation between circumcision and reduced transmission rates, and this is not to be taken lightly, since it represents the strongest case for male genital cutting – at least in Aids-ravaged regions. But such research is heavily contested. A 2007 study by Dowsett and Couch asserted that insufficient evidence exists to believe that circumcision does reduce transmission, while Gregorio et al’s later analysis cast doubt on correlations between circumcision and transmission of HIV and STI’s more generally.

This is a a problematic paragraph for a few reasons. The authors say that the evidence that circumcision reduces the risk of HIV infection is “heavily contested”, but the piece they link to is a lengthy statement by ‘Doctors Opposing Circumcision’, a polemic piece which is troubling in its own right. The introductory paragraph of that statement stuck out to me:

The theory that male circumcision may be protective against HIV infection was invented and developed in North America. According to Professor Valiere Alcena, MD, he originated the theory that removing the foreskin can prevent HIV infection in an article in August 1986. The late Aaron J. Fink, MD, a noted North American advocate of male circumcision, then promoted Alcena’s theory in letters to medical journals. North American Gerald N. Weiss, MD, who operates a website to promote circumcision, and others contributed to the development of the theory through a paper, which was published in Israel (1993), identifying the prepuce as a possible entry point for HIV. North American circumcision enthusiasts have further promoted male circumcision with opinion pieces in medical journals. Stephen Moses, Daniel T. Halperin, and Robert C. Bailey are other well known North American promoters of male circumcision.

Maybe I’m oversensitive, but the throwaway reference to a paper being “published in Israel” combined with naming Drs Weiss, Moses, Halperin and Fink feels like a dog-whistle way of implying that all the research is dodgy because it’s tainted by Jews and their natural pro-snip bias. In any case, Doctors Against Circumcision is not a group that exists to prevent HIV; it’s a group that exists to prevent circumcision. Anti-HIV groups claim that circumcision is protective against HIV. Anti-circumcision groups say it isn’t. Who is more likely to be neutral in this argument?

Back to the Guardian article, the authors go on to cite two papers. The first is a “2007 study by Dowsett and Couch asserted that insufficient evidence exists to believe that circumcision does reduce transmission“.

I read the paper here. It does not say, as Howard and Steinfeld claim, that “insufficient evidence exists to believe that circumcision does reduce transmission”. Instead it’s an odd sort of survey article, part science and part speculative sociology; it makes moral and cultural arguments against widespread circumcision in Africa because it might modify behaviour, encouraging riskier sex by men. It also says that the mechanism of protection provided by circumcision is unclear. But it doesn’t deny that  the evidence that circumcision is, in itself, protective against HIV infection in heterosexual sex. The Dowsett paper believes that because of all the confounding social factors, there is insufficient evidence for introducing a widespread programme of circumcision in Africa. That’s a different claim than the one made in the Guardian.

The second paper that Steinfeld and Howard mention is “Gregorio et al’s later analysis [which] cast doubt on correlations between circumcision and transmission of HIV and STI’s more generally“.

This paper is here and I would like to believe that the authors of the Guardian article either didn’t read or understand it, because if they did then they’ve totally misrepresented it.

• First of all, the Gregorio paper ONLY deals with HIV infections between men who sleep with men. This is a different set of behavours to heterosexual sex and has different infection vectors and risks.
• Secondly, the paper, actually a meta-analyis of other studies, says that circumcised men who sleep with men are much less likely to have HIV than uncircumcised men who sleep with men.
• Thirdly, while the meta-analysis suggested circumcision was protective in homosexual sex, the data wasn’t statistically significant *yet*
• Fourthly, that the higher-quality the study, the stronger the protective impact of circumcision appeared to be. Well-conducted studies showed a bigger impact than poorly-constructed ones.
• Finally,  the researchers feel that more research might provide a significant result.

All of this is pretty explicit in the last paragraph of the paper:

We found a protective, albeit statistically non-significant, association of circumcision with HIV infection in our metaanalysis of MSM [Men who Sleep with Men] observational studies,and a statistically nonsignificant association between circumcision status and STI. Our data revealed that male circumcision conferred a significant protective effect from HIV infection among MSM in studies conducted before HAART [ie effective HIV treatments] but not after, possibly due to documented increases in sexual risk behavior during the era since the availability of HAART. Additional studies are necessary to elucidate further the relationship between circumcision status and HIV infection or STIs among MSM

Gregorio has nothing to say about heterosexual sex and is “casting doubt” on nothing at all.

Summing up, the mass of evidence shows that circumcision offers the circumcised man some protection against contracting HIV during sex with a woman. There is also weak evidence that it offers a man some protection against contracting HIV during sex with a man. We don’t know for sure whether introducing mass circumcision to Africa would help stop HIV, because perhaps people would take more risks if they think they’re safe, but perhaps it would save millions of lives.

This issue is a matter of life and death, and waving away inconvenient evidence isn’t a sensible way to approach the debate.