๐ฆ Chlamydial Infections are caused by Chlamydia trachomatis, C. pneumoniae, and C. psittaci.
They are obligate intracellular bacteria and can affect the genital tract, respiratory tract, eyes, and lymphatics.
๐ก Remember: Chlamydia is the most common bacterial STI in the UK โ often silent but with serious long-term complications if untreated.
๐ป Genital Chlamydia (C. trachomatis)
- Most common bacterial STI; often asymptomatic (70% women, 50% men).
- Women: dysuria, vaginal discharge, pelvic pain, post-coital bleeding.
- Men: urethral discharge, epididymo-orchitis, dysuria.
- Complications: PID, ectopic pregnancy, infertility, Fitz-HughโCurtis syndrome.
- Diagnosis: NAAT on urine (men) or vaginal/cervical swab (women); rectal/pharyngeal swabs if relevant.
- Treatment: Doxycycline 100 mg BD ร 7 days (first-line).
Alternative: Azithromycin 1 g stat (esp. in pregnancy).
Treat partners, screen for other STIs, retest in 3 months.
๐ซ Chlamydia Pneumoniae
- Causes pharyngitis, bronchitis, sinusitis, or atypical pneumonia (โwalking pneumoniaโ).
- Features: cough, sore throat, fatigue, fever; severe pneumonia in elderly or immunocompromised.
- Diagnosis: PCR/serology; CXR may show patchy interstitial infiltrates.
- Treatment: Doxycycline or azithromycin. Alternatives: clarithromycin, levofloxacin.
๐๏ธ Adult Inclusion Conjunctivitis
- Due to C. trachomatis; autoinoculation from genital secretions.
- Unilateral red, gritty eye with mucopurulent discharge.
- Diagnosis: NAAT or PCR on conjunctival swab.
- Treatment: Oral doxycycline/azithromycin for 7โ14 days.
Topical erythromycin as adjunct. Treat partners, avoid contact lenses during therapy.
๐ถ Neonatal Conjunctivitis (Ophthalmia Neonatorum)
- Acquired during vaginal delivery from infected mother.
- Onset 5โ14 days postpartum: red swollen eyelids, purulent discharge.
- Can be associated with neonatal pneumonia (staccato cough).
- Diagnosis: Conjunctival swab (NAAT/culture); CXR if pneumonia suspected.
- Treatment: Oral erythromycin for neonate; treat mother + partner.
๐ Lymphogranuloma Venereum (LGV)
- Caused by invasive L1โL3 serovars of C. trachomatis.
- Stage 1: painless genital ulcer.
Stage 2: painful inguinal lymphadenopathy (buboes).
Rectal LGV: proctitis, discharge, tenesmus (esp. MSM).
- Diagnosis: NAAT; PCR for LGV-specific strains.
- Treatment: Doxycycline 100 mg BD ร 21 days. Drain buboes if necessary. Partner treatment essential.
๐๏ธ๐ Trachoma
- Repeated infection with C. trachomatis serovars AโC.
Leading infectious cause of blindness worldwide.
- Scarring of eyelid โ entropion โ corneal damage.
- Diagnosis: Clinical (WHO grading); PCR in epidemiology.
- Treatment (WHO SAFE strategy):
S = Surgery for trichiasis.
A = Azithromycin mass treatment.
F = Facial cleanliness.
E = Environmental improvement.
๐ฆ Chlamydia Psittaci (Psittacosis)
- Zoonotic infection from birds (parrots, pigeons, poultry).
- Features: atypical pneumonia, fever, dry cough, hepatosplenomegaly.
- Diagnosis: Serology or PCR on respiratory samples; CXR shows patchy consolidation.
- Treatment: Doxycycline (drug of choice). Alternatives: macrolides. Notify public health if outbreak suspected.
๐ Teaching Pearls
๐ก Exam tips:
- Genital chlamydia is often silent โ screen at-risk groups.
- Red eye + genital symptoms โ think chlamydial conjunctivitis.
- MSM with proctitis + inguinal buboes โ consider LGV.
- Trachoma remains a huge cause of blindness in low-resource countries.
- Always treat the patient + partner, and arrange full STI screen.