The study, by Australian researchers Catriona Bradshaw, MD, and colleagues at the Melbourne Sexual Health Centre, is the first major case-control study to simultaneously address all currently hypothesized causes of NGU. The findings help to identify areas for future research on the causes of NGU, and suggest that treatment decisions should be based on clinical features of the disease--not just microscopic assessment. The study also is the first to demonstrate that the causes of NGU in men who have sex with other men are similar to those found in heterosexual men.
NGU is caused by a number of different organisms (most notably, Chlamydia trachomatis) and may lead to pelvic inflammatory disease, infertility, and chronic pelvic pain. Though the cause of NGU is sometimes known, and antibiotics (azithromycin or tetracycline) are generally effective, about half of all cases have no identifiable cause a fact that makes treatment frustrating and uncertain for physicians and patients. Results of previous studies show that Chlamydia trachomatis causes between 30 percent to 50 percent of cases of NGU and Mycoplasma genitalium, 10 percent to 30 percent.
From March 2004 to March 2005, the Melbourne team studied 329 men with NGU and 307 men without symptoms of urethritis. All subjects were given a sexual practice questionnaire. The men in the study underwent a urethral smear, and provided a first-stream urine specimen, which was tested for pathogens that may have caused NGU.
Chlamydial infection was common in both heterosexual and homosexual men with NGU (22 percent and 15 percent, respectively) and was far more common than in control groups. C. trachomatis and M. genitalium were associate
Contact: Jennifer Rainey
Infectious Diseases Society of America