Researchers from New Zealand evaluated data from a 25-year longitudinal birth cohort study to examine the association between circumcision status and the risk of sexually transmitted infection (STI). The key data points were circumcision status before the age of 15 years and self-reported sexually transmitted infection from ages 18 to 25 years. The birth cohort consisted of 1,265 children born in an urban region in mid-1977. Of these, 510 were males for which there was full information on circumcision status and STIs. Circumcision status was determined from parental report at 4 months of age and review of medical charts. Thirty percent (154) of the 510 were circumcised and 356 (70%) were not circumcised.
At age 21, individuals self-reported whether they had been diagnosed with an STI since age 18 and at age 25 they self-reported whether they had been diagnosed with an STI since age 21. If they reported an STI, they were asked for the age at which it was contracted and the diagnosis. Fourteen (2.7%) STIs were reported at the age of 21 and 34 (6.6%) were reported at age 25 (total = 48).
Twenty-two of the 48 cases (46%) were reported as Chlamydia; 14 (29%) as genital warts; 5 (10%) as nonspecific urethral infections; 5 (10%) as genital herpes; and 2 (4%) as gonorrhea. There were no self-reported cases of HIV, syphilis, or genital ulcerative disease. Of the 48 total cases, 7 occurred in circumcised men (7/154 = 4.5%) and 41 occurred among uncircumcised men (41/356 = 11.5%).
The risk of STI was associated with the number of sexual partners (P<.001) and unprotected sex (P<.05). After adjusting for these factors, remaining uncircumcised had a statistically significant association with self-reported STI (odds ratio 3.19; 95% CI, 1.32–7.75). The authors then calculated the population-attributable risk (PAR) estimate as 48.2% (95% CI, 17.7%–60.9%) — suggesting that if all members of the cohort were circumcised, the overall STI rate would be reduced by 48.2%.
The authors conclude that uncircumcised males are at greater risk of acquiring sexually transmitted infection than circumcised males and that circumcision may reduce the risk of STI by up to one-half, suggesting that substantial benefits accrue from routine neonatal circumcision.
Dr. Dubik has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of a commercial product/device. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.
The uncircumcised penis is hypothetically at increased risk of sexually transmitted diseases (STDs) because of larger surface area, thinner epidermal barrier, more opportunity for epithelial microtrauma, and the warm, moist niche under the foreskin favoring the persistence of fastidious microorganisms.1 This study does not address STDs comprehensively but does focus on Chlamydia, genital warts, nonspecific urethritis (NSU), and genital...