Urethral inflammation that is not the result of infection with Neisseria gonorrhoeae. Urethral inflammation may be diagnosed by the presence of one of the following criteria:
No evidence of N. gonorrhoeae infection by culture, Gram stain, or antigen or nucleic acid detection
A clinically compatible case in a male in whom gonorrhea is not found, either by culture, Gram stain, or antigen or nucleic acid detection
Nongonococcal urethritis is a clinical diagnosis of exclusion. The syndrome may result from infection with any of several agents (see Chlamydia trachomatis, Genital Infection). If gonorrhea and chlamydia are excluded, a clinically compatible illness should be classified as NGU. An illness in a male that meets the case definition of NGU and C. trachomatis infection should be classified as chlamydia.