STDs (Urethritis)

 

• DDx: Urethritis

  Infections:

  • Chlamydia
  • Gonorrhea
  • Mycoplasma genitalium.
  • Ureaplasma urealyticum.
  • HSV
  • Trichomonas

  Other causes of genital discharge in women:

  • Physiological
  • Bacterial vaginosis.
  • Candida

• Investigations

  Microbiology:

  • Collection: for men, urine sample, or swab if there is discharge. For women, self-taken vulvo-vaginal swab, or endocervical swab if a speculum is being inserted for other reasons. Rectal and pharyngeal swab if indicated.
  • Testing: nucleic acid amplification test (NAAT) for chlamydia and gonorrhea. Separate MC+S swab if sensitivity needed.
  • Transport samples for culture in charcoal medium if testing elsewhere.

• Chlamydia genital tract infection

  Pathogen and epidemiology

  • Chlamydia trachomatis.
  • Accounts for 50% of STI diagnoses in the UK.

  Signs and symptoms

  Most are asymptomatic. When symptoms do occur, they usually follow a 1-3 week incubation with:

  • Discharge, usually clear.
  • Dysuria
  • Irregular bleeding – intermenstrual or postcoital – in women.

  Management

  • Azithromycin 1 g PO witnessed.
  • 2nd-line: doxycycline 100 mg BD for 7 days.
  • Contact partners from last 6 months, or last 1 month in symptomatic men. All contacts should be treated, with a test sent for confirmation.

  Complications

  • PID in women → tubal damage, ectopic pregnancy, infertility.
  • Unilateral epididymo-orchitis in men.
  • Fits-Hugh Curtis syndrome (perihepatitis).
  • Reactive arthritis (Reiter's syndrome).
  • Obstetric: conjunctivitis, pneumonia.

• Gonorrhea

  Pathophysiology

  • Neisseria gonorrhoeae can infect any columnar epithelium, commonly the urethra, endocervix, rectum, or pharynx.
  • 2-5 days incubation usually, but can be up to 14 days.

  Signs and symptoms

  • Men: purulent urethral discharge (80%) (± blood), dysuria (50%). Anal discharge, tenesmus, and proctitis if anorectal.
  • Women: asymptomatic (50%), or mucopurulent discharge (± blood), dysuria, proctitis (directly from anal sex or spread from vagina).
  • Pharyngeal infection is usually asymptomatic.

  Management

  Single dose treatment:

  • Ceftriaxone 500 mg IM plus azithromycin 1 g PO witnessed.
  • 2nd-line: cefixime 400 mg PO.

  Complications

  • Local: epididymo-orchitis, prostatitis, bartholinitis (abscess), PID.
  • Systemic: disseminated gonococcal infection (arthritis-dermatitis syndrome or septic arthritis), infective endocarditis, meningitis.
  • Neonatal: conjunctivitis (2-5 days postnatal), rectal infection, pneumonia.