Male circumcision and women's risk of incident chlamydial, gonococcal and trichomonal infections

Three randomized trials indicate that circumcised men have lower risk of acquisition of human immunodeficiency virus (HIV) than uncircumcised men,1-3 and prevention interventions focusing on male circumcision (MC) are being introduced worldwide. Whether MC is associated with women's risk of acquisition of HIV or other sexually transmitted infections (STIs), however, has not been well-studied. (The only exception is women's risk of cervical cancer – of which sexually transmitted human papillomavirus (HPV) is a necessary cause – which is significantly lower in women with circumcised male partners.4) We found only two studies describing the association between MC and women's risk of Neisseria gonorrhoeae (GC), Chlamydia trachomatis (Ct), or Trichomonas vaginalis (Tv). In a large community cohort study in Rakai, Uganda, women with circumcised partners had reduced Tv risk but equal risks of GC and Ct when compared to women with uncircumcised partners.5 MC was strongly associated with decreased odds of Ct seropositivity in female partners among controls recruited for a case-control couples’ study of cervical cancer.6 MC could affect STI risk in women if it reduced men's risk of initial STI acquisition, and/or subsequently decreased the probability of future STI transmission to susceptible female partners. However, epidemiologic evidence regarding the association between MC and men's risk of GC, Ct and Tv is mixed, and findings in several studies have been compromised by small sample sizes, poor study designs, selection bias, uncontrolled confounding and other validity concerns. For gonococcal infection, many studies found no association between MC and men's GC risk,7-19 although circumcised men had lower GC risk in some.20-24 A preponderance of evidence suggests no association between MC and men's infection with Ct 8, 9, 11, 13-16, 18-21, 25-27 with few exceptions.22, 28 A recent meta-analysis of MC and men's STI risk similarly concluded that there was no difference in men's risk of GC or Ct by circumcision status.29 MC and Tv infection in men has not been investigated thoroughly. The two existing studies (one cross-sectional30 and one ecologic18) both noted no association. Because MC appears to be a promising disease prevention strategy, we analyzed whether MC was associated with women's STI risk. Using data from a multi-site, prospective cohort study conducted in Uganda, Zimbabwe and Thailand, we examined the effect of MC on women's risk of acquisition of Ct, GC and Tv.