Makindo Medical Notes

Related Subjects: |Trichomoniasis Vaginalis |Gardnerella vaginalis |Chlamydia trachomatis

⚠️ Chlamydia trachomatis is the most common bacterial STI in the UK. Up to 70% of women and 50% of men are asymptomatic, meaning opportunistic testing is vital. Untreated infection can cause PID, infertility, ectopic pregnancy, and in men, epididymo-orchitis.

🔎 About

• Obligate intracellular bacterium with multiple serotypes causing different syndromes.
• Spread via unprotected vaginal, anal, or oral sex, and perinatally from mother to infant.
• Major cause of preventable infertility worldwide.

🧬 Characteristics & Life Cycle

• Elementary bodies (EB): infectious, metabolically inactive, survive outside cells.
• Reticulate bodies (RB): intracellular, replicate using host ATP, non-infectious.
• Cycle → EB enters cell → converts to RB → divides → reverts to EB → cell lysis → spreads.

🧪 Clinical Features

• 👩 Women: abnormal vaginal discharge, post-coital or intermenstrual bleeding, pelvic pain, dysuria, deep dyspareunia.
• 👨 Men: urethral discharge, dysuria, scrotal pain (epididymitis), proctitis if rectal infection.
• 🍼 Neonates: conjunctivitis, staccato cough (pneumonia).
• ⚠️ Many are asymptomatic → screening essential.

🌍 Serotypes & Disease

• Serotypes A–C → Trachoma 👁️ (leading cause of blindness in some regions).
• Serotypes D–K → Genital chlamydia (urethritis, cervicitis, PID, epididymitis, neonatal infections).
• Serotypes L1–L3 → Lymphogranuloma venereum (LGV): painful ulcers, buboes, severe proctitis.

📋 Risk Factors

• Age <25 years, new or multiple partners, inconsistent condom use.
• Socioeconomic deprivation and limited access to sexual health services.

🧪 Investigations

• NAAT (nucleic acid amplification test) on first-void urine or self-taken vulvovaginal swab = gold standard.
• Other: Giemsa stain (inclusion bodies), immunofluorescence, serology (less common now).
• Always test for coinfections → gonorrhoea, HIV, syphilis, hepatitis B.

💊 Management (BASHH 2023)

• First-line: Doxycycline 100 mg PO BD for 7 days ✅
• Alternatives:
  • Azithromycin 1 g stat then 500 mg OD ×2 days (off-label; used in pregnancy or adherence issues)
  • Amoxicillin 500 mg TDS ×7 days (pregnancy safe)
  • Erythromycin 500 mg BD ×14 days (less used due to GI side effects)
• Partner notification and treatment of sexual contacts (look back 6 months).
• Avoid sex until patient and partners have completed treatment and symptoms resolve.

🩺 Complications

• PID, tubal infertility, ectopic pregnancy
• Chronic pelvic pain
• Reiter’s syndrome (reactive arthritis) ♻️
• Epididymo-orchitis in men

📊 Screening (UK NCSP)

• Offer annual screening to all sexually active women and men <25 years.
• Also screen after a change of partner.
• Pregnant women should be tested if at risk.

📚 References

• BASHH Chlamydia Guidelines (2023)
• NHS – Chlamydia