Abstract

PIP: The significant progress of the last decade in determining the etiology of nongonococcal urethritis is reviewed, and current treatments are assessed. Convincing evidence that Chlamydia trachomatis is the cause of 30-50% of cases of nongonococcal urethritis has been developed by many groups from isolation data, serologic studies, urethral inoculation of monkeys, and studies of postgonococcal urethritis. Other evidence that C. trachomatis is a urethral pathogen is that its selective eradication results in alleviation of urethritis in C. trachomatis-infected men. The cause of nongonococcal urethritis when C. trachomatis infection cannot be proven by isolation or serologic testing is unclear. The most likely cause of a significant proportion of the C. trachomatis-negative cases is Ureaplasma urealyticum. Although studies of the role of U. urealyticum as a urethral pathogen have been complicated by the fact that in health the rate of urethral colonization is strongly correlated with an individual's total number of sex partners, and serologic studies have not supported a role for U. urealyticum, other evidence is consistent with such a role, including treatment studies and experimental inoculation. Assuming both C. trachomatis and U. urealyticum are etiologic agents, in another 20% of men with the disease neither organism is initially isolated. False-negatives probably account for some of the cases, but poor response to treatment for the 2 pathogens suggests they constitute another group. Although the incidence of gonorrhea has tended to stabilize recently, that of nongonococcal urethritis continues to rise sharply. Management requires diagnosis of urethritis, exclusion of urethral infection with Neisseria gonorrheae, choosing an appropriate antimicrobial for the patient, treatment of sexual contacts, and follow-up of the patient. When the patient is symptomatic, has a readily expressible discharge, and the exudate contains many polymorphonuclear leukocytes but not gram-negative diplococci, diagnosis is easy. However, when symptoms or signs are minimal, arbitrary criteria must be utilized in diagnosis. In individual cases it is impossible to distinguish between gonorrheal and nongonococcal urethritis on clinical grounds, and the final diagnosis requires laboratory examination for N. gonorrheae. Tetracyclines, erythromycins, and a combination of sulfonamides and an aminocyclitol, which almost always eradicate C. trachomatis, were recognized as the most effective therapies by the 1950s. Although many studies have been done, the optimal drug dose and duration of therapy have not been determined.