Background: Observational studies evaluating the association of circumcision and HIV infection among men who have sex with men (MSM) have yielded mixed results. We examined the relationship between circumcision and HIV, herpes simplex virus type-2 (HSV-2), syphilis, urethral gonorrhea, and urethral chlamydia among MSM stratified by anal sexual role.
Methods: Between October 2001 and May 2006, 4749 MSM who reported anal intercourse in the previous 12 months attended the Public Health-Seattle and King County STD clinic for 8337 evaluations. Clinicians determined circumcision status by examination and anal sexual role in the previous year by interview. Blood samples were used to test HIV, syphilis, and HSV-2 serostatus. Urethral gonorrhea and chlamydia were tested by culture or nucleic acid amplification. We used generalized estimating equations to evaluate the association between circumcision and specific diagnoses, adjusted for race/ethnicity and age.
Results: Among the 3828 men whose circumcision status was assessed, 3241 (85%) were circumcised and 587 (15%) were not. The proportion of men newly testing HIV-positive or with previously diagnosed HIV did not differ by circumcision status when stratified by men's anal sexual role in the preceding year, even when limited to men who reported only insertive anal intercourse in the preceding 12 months (OR = 1.45; 95% CI: 0.30, 7.12). Similarly, we did not observe a significant association between circumcision status and the other sexually transmitted infections (STI).
Conclusions: Our findings suggest that male circumcision would not be likely to have a significant impact on HIV or sexually transmitted infections acquisition among MSM in Seattle.