Makindo Medical Notes

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

At least 70% of women and 50% of men infected with Chlamydia trachomatis are asymptomatic, and symptoms in men can be very mild.

About

• Chlamydia trachomatis is a common bacterial infection with varying disease presentations depending on serotype.
• Genital chlamydial infections can lead to significant short- and long-term morbidity, including:
  • Pelvic inflammatory disease (PID)
  • Tubal infertility
  • Ectopic pregnancy
  • Epididymo-orchitis
  • Lymphogranuloma venereum (LGV)

Characteristics

• Obligate intracellular bacteria that do not stain well on Gram stain.
• Cannot produce ATP independently, relying on the host cell for energy and some amino acids.
• Life cycle includes:
  • Elementary bodies (EB): Extracellular, resistant to environmental stress, infectious, but metabolically inert.
  • Reticulate bodies (RB): Intracellular, metabolically active, divide within host cells but are non-infectious.

Life Cycle

• Elementary bodies (EBs) attach to cell receptors and enter cells by endocytosis.
• Inside cells, EBs replicate within phagosomes, where lysosomal degradation is inhibited.
• Over time, EBs convert to RBs, which use the cell’s ATP to produce DNA, RNA, and proteins.
• RBs then convert back to EBs, leading to cell lysis and release of new EBs to infect other cells.

Pathogenicity

• Serotype L1, L2, L3: Causes lymphogranuloma venereum (LGV), with cases primarily in sub-Saharan Africa but increasing in urban centers. It presents as:
  • Acute genital ulcer and painful inguinal lymphadenopathy, potentially leading to scarring or genital elephantiasis.
  • Rectal infection may cause severe proctitis with painful defecation and purulent, bloody discharge.
• Serotype D-K: Causes urethritis, PID, proctitis, and epididymitis, commonly seen in sexually active young adults. May also cause:
  • Neonatal pneumonia: Characterized by rhinitis and staccato cough in infants up to 6 months.
  • Neonatal conjunctivitis: Mucopurulent eye discharge shortly after birth.
• Serotype A-C: Causes trachoma, a leading cause of blindness in Africa and among Native American populations, marked by chronic follicular keratoconjunctivitis leading to scarring and inturned eyelashes.

Risk Factors for Chlamydia Infection

• Age under 25 years
• New or multiple sexual partners
• Inconsistent condom use
• Socioeconomic deprivation

Screening Recommendations

• Asymptomatic individuals should be screened if:
  • They are sexual partners of people with confirmed or suspected chlamydial infection.
  • They are sexually active and under 25, screened annually or after changing partners.
  • They express concern about a recent sexual exposure.
  • Exposure was within the last two weeks: test at presentation and, if negative, repeat after two weeks.
  • They have a history of chlamydia in the previous three months, had multiple partners in the past year, are pregnant, or attend a GUM clinic.

Clinical Features

• Symptoms in women may include:
  • Increased vaginal discharge, post-coital and intermenstrual bleeding
  • Dysuria, lower abdominal pain, and deep dyspareunia
• In men, suspect chlamydia in cases of:
  • Urethral discharge and dysuria
  • Symptoms of rectal chlamydia (anal discharge, anorectal discomfort) or pharyngeal infection (usually asymptomatic)

Investigations

• Giemsa stain: Shows intracellular inclusion bodies.
• Immunofluorescence: Can identify intracellular chlamydial bodies.
• Antigen detection and serology: Helps confirm diagnosis.
• PCR testing: Detects chlamydial RNA or DNA with high sensitivity and specificity.

Antibiotic Sensitivities

• Doxycycline, Azithromycin, and Tetracycline (avoid in children, pregnancy, breastfeeding)
• Erythromycin for sensitive cases

Management

• Referral to GUM for contact tracing.
• Antibiotic options:
  • Doxycycline 100 mg twice daily for 7 days (not suitable in pregnancy or breastfeeding).
  • Azithromycin: 1 g single dose, then 500 mg daily for 2 days (off-label dosing).
  • Erythromycin: 500 mg twice daily for 14 days, or 500 mg four times daily for 7 days.
  • Amoxicillin: 500 mg three times daily for 7 days, alternative for pregnant or breastfeeding patients.