Does Lack of Circumcision Aid STD Transmission?

Observational studies of the association of circumcision and HIV infection among men who have sex with men "have yielded mixed results," say the authors of a new study. Their report examines the relationship between circumcision and HIV, herpes simplex virus type-2, syphilis, urethral gonorrhea, and urethral chlamydia among MSM, stratified by anal sex role.

The study period was October 2001 through May 2006, during which time 4,749 MSM who reported anal intercourse in the previous 12 months underwent a total of 8,337 evaluations at the Public Health-Seattle and King County STD clinic. Circumcision status was determined by clinician exam; anal sex role in the previous year was determined by interview. Blood samples were tested for HIV, syphilis, and HSV-2. Urethral gonorrhea and chlamydia were tested by culture or nucleic acid amplification. Generalized estimating equations were used to evaluate the association between circumcision and specific diagnoses, adjusted for race/ethnicity and age.

Circumcision status was assessed for 3,828 men: 3,241 (85%) were circumcised, and 587 (15%) were uncircumcised. "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." Likewise, the researchers found no significant association between circumcision status and other STDs.

"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," the authors concluded.