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This’ll turn you feminist

December 21, 2014

The effect 0f male circumcision on female HIV infection – the evidence

If it becomes obvious mid-way through a randomised trial that a new treatment doesn’t work sufficiently well to make it worth using, stopping early is good practice; we may never get a clear answer, but who cares? But if you’re planning on using the new treatment anyway, you really must finish the trial, and sort out once and for all whether it does harm.

Consider a treatment which affects husbands and wives. Treating one automatically treats the other. Evidence accumulates that it is good for the husband but results are unclear for the wife. It would be bonkers to stop when interim data showed a non-significant harmful trend for wives, on the grounds that the treatment was never going to be good for them, and then go ahead and implement it!   But that’s what the authors of the only trial ever to test the effect of male circumcision on HIV transmission to the woman did (click here).

They tested the hypothesis that circumcision of HIV positive men would reduce new cases of HIV in female partners, as part of a larger trial including HIV negative men. When the HIV negative cohort closed, the investigators fretted that “continuation […] in HIV-infected men could result in stigmatization” and “determined that the conditional power to detect 60% efficacy, […] was only 4.9% and recommended that enrolment be closed.”

At that point 17/93 (18%) intervention and 8/70 (11%) control women had become infected. The difference might have occurred by chance (hazard ratio 1.58, 95% CI: 0.68–3.66, p=0.287), but if it was real, wives would surely want to know. The harmful effect is biologically plausible; the foreskin functions as a sleeve within which the penile shaft moves during intercourse to reduce vaginal and penile abrasions. But the trial stopped, and the US, WHO, and the many governments who get funds from those sources, went on to encourage male circumcision, without mentioning the possible increase in female infection risk. For the WHO fact sheet (click here).

Some circumcision advocates (e.g. here) admit that the evidence on male to female transmission is unclear, but conclude “that women will benefit from […] voluntary medical circumcision programmes in the long-term” on the basis of modelling studies like this one (click here).

But the modelling studies ignore even the possibility of increased male to female transmission. For the base case this one assumed 60% effectiveness for men, 80% coverage by 2015, and no post-circumcision behaviour change. They tested the effect of varying all these in a sensitivity analyses but not the effect of any increased male to female transmission. Am I going mad?

Let’s summarise. Randomised trials show that male circumcision reduces female to male HIV transmission by about 60%. The only trial which measured it showed a biologically plausible increase in male to female transmission of 58%, but was stopped before it gave a clear answer. Experts modelled the effect of their programmes assuming the male benefit was real, but ignoring even the possibility of increased male to female infection. On the basis of such models millions of men are circumcised, and millions of uninformed women are put at risk.

It’s enough to turn even me feminist!

Jim Thornton

9 Comments leave one →
  1. December 21, 2014 10:32 am

    I should’ve acknowledged David Gisselquist’s suggestion that I write about this trial. However, as he says. The real problem is the public health establishment’s failure to acknowledge the contribution of needles, and other types of cutting, to HIV transmission in Africa and elsewhere. Circumcision is a diversion from that, albeit yet another way to transmit HIV by cutting!

  2. December 21, 2014 7:21 pm

    Twitter commenters note there is observational evidence that male circircumcision may reduce HIV transmission.

    • January 2, 2015 3:14 pm

      This group of researchers sought to get WHO to inttroduce male circumcision for prevention of HIV and were told that they would need to produce RCT evidence to justify it – so they did for female to male transmission.

      Their RCT for male to female transmission was terminated for “futility”. Now they seek to justify it on the basis of observational evidence.

  3. Dan Strandjord permalink
    December 21, 2014 7:50 pm

    Keep in mind that the researchers who did the M to F transmission study are the same ones who did the F to M transmission study in Uganda — Ronald Gray and his wife Maria Waver (both from Johns Hopkins in the U.S.) Funny that the same researchers think that up to 60% REDUCTION in F to M is reason for circumcising males, but 58% INCREASE in M to F is not a reason to leave the men intact. Considering that African women are more likely to have HIV than African men, then wouldn’t infecting even more women end up infecting even more men in the long run? Never mind science and ethics, some people just want to cut human genitals.

  4. December 29, 2014 11:12 am

    It made me smile when you asked again if you’re going mad Jim! This is how I felt when I first thought about male circumcision and started to notice the myths, cruelty and illogic that sustain it. I think it’s part of the reason it has endured so long – it’s a kind of gaslighting, where people say the craziest things, but with such confidence that those who question it feel mad. You are the little boy at the back of the crowd, noticing the Emperor has nothing on…

  5. January 2, 2015 2:25 pm

    Strangely enought, the three female to mail trials of circumcision for prevention of HIV were terminated early “for benefit” before the findings had the chance to lose statistical significance.

    Conversely, the male to female trial was terminated early “for futility” before it had the chance to reach statisitical significance.

    As noted by JT, only one of the male to female trials was registered prospectively. In so far as I am aware no trial registration, gave the details of the statistical methods to be used or the membership/Terms of Reference of the “Data Monitoring and safety Review Board” for the trial.

  6. Kevin permalink
    January 6, 2015 1:54 am

    Why is it that we’re even having a discussion about the effect on women of cutting men’s genitals? I’m completely serious here: if a discussion were being had about the benefit or harm to men of cutting women’s genitals that discussion would be called sexist, and rightly so. The only person for whom the effects of cutting should matter, and the only person who should be making the decision whether to cut is the person whose genitals stand to be cut.

  7. January 7, 2015 8:56 pm

    Some tweeters have claimed that WHO only recommends VMC for HIV neg men. If so, there would be little to object to – if circed man has 60% reduced risk of getting infected then, even if he also has a 60% increased risk of infecting his wife, the net effect for the wife would be more or less neutral.

    But this WHO link says: “HIV-positive men and men who do not know their HIV status should not be denied male circumcision. This latter position reflects the possibility that denying male circumcision on the basis of HIV status could 1) increase stigma among HIV-positive men who are not circumcised; and 2) increase the chances that HIV-positive men will seek surgery from unsafe or poorly-trained providers if they are turned away from medical points of service.”

    And here is another WHO link, which reports that over 5 million men have been circumcised in Africa since 2008. Despite many tables detailing this “success”, I can find no mention of how many were HIV positive, or HIV status unknown. Does anyone know this.

  8. April 5, 2015 10:30 am

    A presentation at an AIDS conference in Seattle in February claimed to show that followup studies prove the mass circumcisions are working:
    However, this was carried out by the same researchers who did the original Rakai, Uganda, RCT of circumcision. And the presentation does not seem to show an actual correlation between being gentially cut and being less likely to have HIV. It does not give separate figures for circumcised and intact men. It only shows a reduction in HIV following the circumcision campaign. But such a campaign would generally raise awareness of HIV and safe-sex practices. They very conspicuously left out Muslim men, because they would be circumcised anyway. It would certainly by interesting to know the HIV rate among them too.

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