Circumcision and STD in the United States: cross sectional and cohort analyses

Male circumcision status has been shown to be associated with sexually transmitted disease (STD) acquisition in some, but not all, studies. Most studies have been cross sectional.

We examined the association between circumcision status and the prevalence and incidence of gonorrhoea, chlamydia, and syphilis.

We analysed cross sectional and cohort study data from a multicentre controlled trial in the United States. Between July 1993 and September 1996, 2021 men visiting public inner city STD clinics in the United States were examined by a clinician at enrolment and 1456 were examined at follow up visits 6 and 12 months later. At each visit, men had laboratory tests for gonorrhoea, chlamydia, and syphilis and were examined for circumcision status. We used multiple logistic regression to compare STD risk among circumcised and uncircumcised men adjusted for potentially confounding factors.

Uncircumcised men were significantly more likely than circumcised men to have gonorrhoea in the multivariate analyses, adjusted for age, race, and site, in both the cross sectional (odds ratio (OR), 1.3; 95% confidence interval (CI), 0.9 to 1.7) and in the cohort analysis (OR, 1.6; 95% CI, 1.0 to 2.6). There was no association between lack of circumcision and chlamydia in either the cross sectional (OR, 1.0; 95% CI 0.7-1.4) or the cohort analysis (OR, 0.9; 95% CI 0.5-1.5). The magnitude of association between lack of circumcision and syphilis was similar in the cross sectional (OR, 1.4; 95% CI 0.6 to 3.3) and cohort analysis (OR, 1.5; 95% CI 0.4 to 6.1).

Uncircumcised men in the United States may be at increased risk for gonorrhoea and syphilis, but chlamydia risk appears similar in circumcised and uncircumcised men. Our results suggest that risk estimates from cross sectional studies would be similar to cohort findings.