Urethritis

Epidemiology

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Etiology

• Typically a sexually transmitted infection
  • Gonococcal urethritis (GU): Neisseria gonorrhoeae
  • Chlamydia trachomatis (most common)
• Coinfection is also common

Tip

• Urethritis is often caused by sexually transmitted infections (STIs), e.g. N gonorrhoeae.
• UTIs are generally caused by bacteria from the gastrointestinal tract, e.g. E coli.

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Pathophysiology

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Clinical features

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Diagnostics

• Thayer-Martin agar
  • Used to detect Neisseria
• Gram stain
  • Findings: polymorphonuclear leukocytes and intracellular gram-negative diplococci

Mnemonic

Selectively favors growth of Neisseria by inhibiting growth of gram ⊕ organisms with vancomycin, gram ⊝ organisms except Neisseria with trimethoprim and colistin, and fungi with nystatin.

Very typically cultures Neisseria

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Treatment

• Empiric Coverage (Treat for both unless ruled out):
  • Ceftriaxone (IM single dose) for Gonorrhea.
  • PLUS Doxycycline (PO x 7 days) for Chlamydia.
  • Note: Azithromycin is now second-line for Chlamydia due to resistance, but used in pregnancy.

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