Chlamydia trachomatis and Neisseria gonorrhoeae transmission from the oropharynx to the urethra among men who have sex with men.

Background: Limited data exist on the risk of Chlamydia trachomatis and Neisseria gonorrhoeae transmission from oropharynx to urethra. We examined urethral C. trachomatis and N. gonorrhoeae positivity among men who have sex with men (MSM) seen at San Francisco City Clinic (San Francisco, CA) during 2007.

Methods: All patients who sought care at the San Francisco City Clinic (the only municipal sexually transmitted disease clinic in San Francisco) received a standardized interview conducted by clinicians. We estimated urethral C. trachomatis and N. gonorrhoeae positivity for 2 groups of visits by MSM who visited during 2007: (1) men who reported their only urethral exposure was receiving fellatio in the previous 3 months and (2) men who reported unprotected insertive anal sex in the previous 3 months. Additionally, urethral C. trachomatis and N. gonorrhoeae positivity was estimated, stratified by human immunodeficiency virus infection status, urogenital symptom history, and whether the patient had been a contact to a sex partner with either chlamydia or gonorrhea.

Results: Among MSM who reported only receiving fellatio, urethral C. trachomatis and N. gonorrhoeae positivity were 4.8% and 4.1%, respectively. These positivity estimates were similar to positivity found among MSM who reported unprotected insertive anal sex.

Conclusions: A more complete understanding of the risks of transmission of C. trachomatis and N. gonorrhoeae from oropharynx to urethra will help inform prevention and screening programs.