Case Answers:

Case answers will be presented after review of the HPI.

Answer 1
Specific tests for N. gonorrheae and C. trachomatis should be preformed. For gonorrhea, gram stain of urethral discharge and culture is commonly performed. Nonculture requiring procedures including DNA probe, or nucleic acid amplification (from first-void urine) are available for both gonorrhea and chlamydia. If cultures are obtained, chocolate agar and selective agar (Thayer Martin or Martin Lewis) are inoculated first followed by rolling the swab (or collect a second swab) across a microscopic slide. The slide is gram stained and examined under oil.

Answer 2
The presence of greater than 5 PMNs per oil immersion field on a urethral smear (OR documented purulent or mucopurulent discharge, OR positive leukocyte esterase test on first void urine, OR demonstration or > 10 WBCs per high power field on microscopic examination of first void urine) provides objective evidence of urethritis. The complete absence of PMNs would argue against urethritis. If, in addition, one saw gram-negative intracellular diplococci, the diagnosis of gonorrhea in a male would be established. This test is more than 95% accurate in men with symptomatic acute urethritis. Since the organisms are not observed, this patient is said to have NGU.

Answer 3
Chlamydia trachomatis causes 30-50% of cases of NGU and is the only proven cause. Since the organism can only grown in tissue culture, enzyme-linked immunosorbent assay and Gene probe assays are frequently done diagnostically. Although not definitively proven, Ureaplasma urealyticum may cause another 30% of NGU. Trichomonas vaginalis, Mycoplasma genitalium, and Herpes simplex virus account for the remaining cases.

Answer 4
Since it is difficult to differentiate the common etiologies of NGU, the condition is treated syndromically, with the initial treatment based on those regimens effective against the common causative agents. The recommended regimen is azithromycin 1.0 g orally in a single dose OR doxycycline, 100 mg orally 2 times a day for 7 days. Alternative regimens include erythromycin base, 500 mg orally 4 times a day for 7 days, or erythromycin ethyl succinate, 800 mg orally 4 times a day for 7 days, or oflaxacin 300 mg twice a day for 7 days. Patients should be instructed to refer sex partners for evaluation and treatment.

Answer 5
Patients should be instructed to return for evaluation if symptoms persist or recur after completion of therapy. Patients with persistent or recurrent urethritis should be re-treated with the initial regimen if they failed to comply with the treatment regimen or if they were re-exposed to an untreated sex partner. Otherwise, a wet mount examination and culture of an intra urethral swab specimen for T. vaginalis should be performed. If the patient was compliant with the initial regimen and reexposure can be excluded, the patient should be treated with metronidazole 2.0 g orally in a single dose PLUS erythromycin base 500 mg orally four times a day for 7 days (erythromycin ethyl succinate 800 mg orally four times a day for 7 days).

Answer 6
Patients should refer for evaluation and treatment all sex partners within the preceding 60 days. A specific test may facilitate partner referral; therefore testing for gonorrhea and chlamydia is encouraged.