A 22-year-old man presents with painful inguinal lymphadenopathy (buboes) that are fluctuant and mat together. He has a history of a transient painless genital papule 3 weeks ago that has healed. NAAT from inguinal aspirate is positive for Chlamydia trachomatis. Which serovars are responsible for this condition?
- A Serovars L1, L2, and L3 ✓
- B Serovars A, B, Ba, and C
- C Serovars D–K
- D Serovar L2b only
Explanation
Lymphogranuloma venereum (LGV) is caused by Chlamydia trachomatis serovars L1, L2 (including L2b — common in MSM outbreaks), and L3. Unlike serovars D–K which cause urogenital/ocular mucosal infection restricted to columnar epithelium, LGV serovars are invasive — they can infect macrophages and spread to regional lymph nodes, causing the classic triad of transient primary genital lesion, inguinal bubo (groove sign if bilateral groins involved by inguinal ligament), and systemic features. Serovars A–C cause trachoma. Serovars D–K cause urogenital chlamydia, PID, and neonatal inclusion conjunctivitis.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.