Oral sex is emerging as a big risk factor for nongonococcal urethritis (NGU), one of the most common sexually transmitted diseases affecting both men and women. A new study, in The Journal of Infectious Diseases, suggests that oral-genital contact - specifically fellatio - may be an important mechanism of NGU transmission. The researchers, led by Catriona Bradshaw at the Melbourne Sexual Health Centre in Australia, found that the causes of NGU in men who have sex with other men are similar to those found in heterosexual men.
The study further explains that NGU is caused by a number of different organisms (the major one being Chlamydia trachomatis, causing between 30 -50 percent of cases) and may lead to pelvic inflammatory disease, infertility, and chronic pelvic pain. Though the cause of NGU is sometimes known, about half of all cases have no identifiable cause - making finding an effective treatment a frustrating exercise.
The subjects in the study consisted of men with NGU and other men without symptoms of urethritis. All the subjects completed a questionnaire, underwent a urethral smear and provided a first-stream urine specimen, which was tested for pathogens that may have caused NGU.
The researchers found that chlamydial infection was common in both heterosexual and homosexual men with NGU. The other main pathogens identified included C. trachomatis and M. genitalium, often associated with unprotected vaginal sex. Herpes simplex type 1 was also more common amongst the NGU patients.
The findings suggest that oral-genital contact may be an important mechanism of NGU pathogen transmission. Also, NGU was associated with a history of oral sex with new partners. Together, the researchers say, these findings suggest that fellatio plays a significant role as a cause of the syndrome.
Commenting on the study, H. Hunter Handsfield, of the University of Washington, said it provides important insights for both heterosexual and homosexual men, as it indicates that NGU may be caused by otherwise harmless organisms shared by monogamous partners. Interestingly, oral sex was associated with NGU in which no pathogen was detected. Handsfield said this indicated that there are causes of NGU that have yet to be identified.
Based on material from The Journal of Infectious Diseases
