Male circumcision is a difficult topic to discuss rationally. At the core, it’s a medical procedure, but it’s one tinged with centuries of cultural influences, and emotions tend to run high on both the pro- or anti-circumcision side of the discussion. One of the reasons that’s been given in favor of circumcision is that it lowers the risk of disease, including diseases transmitted by sexual contact. However, while this data has been fairy unambiguous regarding some diseases (including the reduction in HIV transmission due to circumcision), the effect circumcision has on the spread of others has been less clear. A new paper addresses this ambiguity, and finds that routine circumcision could reduce STD rates by as much as half.
As noted in this write-up of the research:
The current study is just one of many that have looked at this controversial topic. While most research has found that circumcision reduces the rates of HIV (the virus that causes AIDS), syphilis and genital ulcers, the results are more mixed for other STDs.
What made this study unique is that it’s a 25-year long longitudinal study. That is, they’ve been able to collect data and follow their cohort of participants for a good portion of their lives, and have information on everything from birth weight and parents’ education to their current number of sex partners and diagnoses for various STDs. The study size isn’t too bad, either–510 total, 154 of them who were circumcised. (The study was done in New Zealand, which has lower circumcision rates than, say, the U.S.) So not a huge study, but a nice-sized cohort.
To examine how circumcision affected STD acquisition, the authors gathered data on STDs in both the circumcised and non-circumcised participants. (This is a limitation of the study, as the data are self-reported [which brings in bias], but presumably there’s no reason why those who are circumcised would be less likely to report STDs than those who aren’t). They then took all the data regarding STD acquisition, circumcision status, and other variables such as number of sex partners, condom usage, and socioeconomic status and crunched the data. Overall, they found that uncircumcised males had a 2.66 times higher risk of acquiring an STD than circumcised males; that increased to 3.19 when variables such as number of partners and condom use were included in the model. Finally, they then calculated the population attributable risk estimate for circumcision–that is, how much disease can be explained or prevented by the factor that they’re looking at (in this case, circumcision). As noted in the introduction, they determined that “if all of the cohort members were circumcised, the overall rate of STI would reduce by 48.2%”
Of course, there are other ways to reduce sexually transmitted infections. Have fewer partners. Use condoms more consistently. (In this study, they note that 77% reported having sex without a condom at least once). But what’s important about this study–and much research on circumcision and STDs–is that, even when controlling for partner number and condom use, circumcision still provides additional protection from disease.
Is it a reason to circumcise? That’s a tougher question to answer. As noted in the MSNBC article:
The American Academy of Pediatrics has called the evidence “complex and conflicting,” and therefore concludes that, at present, the evidence is insufficient to support routine neonatal circumcision.
I don’t think this current study will sway that position, but certainly it lends weight to the stance that there *are* medical benefits to circumcision. What to do with that information is more difficult.
Fergusson DM et al. 2006. Circumcision Status and Risk of Sexually Transmitted Infection in Young Adult Males: An Analysis of a Longitudinal Birth Cohort. Pediatrics. 118:1971-1977. Link.