The general theory is that circumcision causes a change in the membrane and "microbiomes" around that part of the penis.
I still struggle, however, to believe that a truly controlled study could ever be conducted and I wonder if the money wouldn't be better spent just providing condoms and sexual education to these at risk groups. We already know that condoms are very, very good a reducing HIV transmission rates, plus they work for both partners (circumcision studies only show reduced transmission to men from women), and also consistent use can reduce the risk of cervical cancers, HPV and unwanted pregnancies. In a way, studies and campaigns that focus on circumcision are unethical if they don't also provide access to this highly effective device.
But going back to the studies, the problem I have understanding them is that there is, as far as I'm aware, no way to perform a placebo circumcision. Any adult who has a circumcision is surely likely alter his behavior or perhaps take greater notice of the sexual education he received alongside the circumcision. Or, perhaps he may have the superhero effect, thinking he can have more unprotected sex? That's the part that makes it hard for me to believe that studies are controlled. And for those studies that look only at populations that perform infant circumcisions, it seems even more likely that differences in cultural, religious or social norms of each population would have just as much influence as the operation.
If anyone has details on how these studies control for confounding factors like that, I'd be interested to hear.
I still struggle, however, to believe that a truly controlled study could ever be conducted and I wonder if the money wouldn't be better spent just providing condoms and sexual education to these at risk groups. We already know that condoms are very, very good a reducing HIV transmission rates, plus they work for both partners (circumcision studies only show reduced transmission to men from women), and also consistent use can reduce the risk of cervical cancers, HPV and unwanted pregnancies. In a way, studies and campaigns that focus on circumcision are unethical if they don't also provide access to this highly effective device.
But going back to the studies, the problem I have understanding them is that there is, as far as I'm aware, no way to perform a placebo circumcision. Any adult who has a circumcision is surely likely alter his behavior or perhaps take greater notice of the sexual education he received alongside the circumcision. Or, perhaps he may have the superhero effect, thinking he can have more unprotected sex? That's the part that makes it hard for me to believe that studies are controlled. And for those studies that look only at populations that perform infant circumcisions, it seems even more likely that differences in cultural, religious or social norms of each population would have just as much influence as the operation.
If anyone has details on how these studies control for confounding factors like that, I'd be interested to hear.