Microbiology and Epidemiology

Most cases are caused by either Neisseria gonorrhoeae or Chlamydia trachomatis. Other causative organisms include Mycoplasma genitalium, Ureaplasma urealyticum, Trichomonas vaginalis, HSV, and occasionally anaerobes (especially Leptotrichia/Sneathia species) involved in bacterial vaginitis. Chlamydia causes 30–40% of nongonococcal urethritis (NGU) cases. M. genitalium is the probable cause in many Chlamydia-negative cases of NGU.

Clinical Manifestations

Urethritis in men produces urethral discharge, dysuria, or both, usually without frequency of urination.


Pts present with a mucopurulent urethral discharge that can usually be expressed by milking of the urethra; alternatively, a Gram’s-stained smear of an anterior urethral specimen containing ≥2 PMNs/1000× field confirms the diagnosis.

  • Centrifuged sediment of the day’s first 20–30 mL of voided urine can be examined for inflammatory cells instead.
  • N. gonorrhoeae can be presumptively identified if intracellular gram-negative diplococci are present in Gram’s-stained samples.
  • Early-morning, first-voided urine should be used in “multiplex” nucleic acid amplification tests (NAATs) for N. gonorrhoeae and C. trachomatis.

Treatment: Urethritis in Men

  • Treatment should be given promptly, while test results are pending.
    • Unless these diseases have been excluded, gonorrhea is treated with a single dose of ceftriaxone (250 mg IM) plus azithromycin (1 g PO once), and Chlamydia infection is treated with azithromycin (1 g PO once) or doxycycline (100 mg bid for 7 days); the efficacy of azithromycin for treatment of M. genitalium is rapidly declining.
    • Sexual partners of the index case should receive the same treatment.
  • For recurrent symptoms: With re-exposure, both pt and partner are re-treated. Without re-exposure, infection with T. vaginalis (with culture or NAATs of a urethral swab and early-morning, first-voided urine) or antibiotic-resistant M. genitalium or Ureaplasma should be considered; treatment with metronidazole, azithromycin (1 g PO once), or both is recommended, and the azithromycin component is especially important if this drug was not used for the primary episode. Moxifloxacin can be considered for treatment of refractory nongonococcal, nonchlamydial urethritis.

There's more to see -- the rest of this topic is available only to subscribers.