Chlamydia trachomatis serovars responsible for trachoma are which of the following?

Explanation

## Chlamydia trachomatis Serovars and Disease Classification **Key Point:** Chlamydia trachomatis serovars A, B, Ba, and C cause trachoma (endemic keratoconjunctivitis), while other serovars cause different clinical syndromes. ### Serovar Classification by Disease | Serovars | Disease | Clinical Features | |----------|---------|-------------------| | A, B, Ba, C | Trachoma | Chronic keratoconjunctivitis, trichiasis, entropion, blindness | | D–K | Inclusion conjunctivitis | Acute follicular conjunctivitis, urethritis, cervicitis | | L1, L2, L3 | Lymphogranuloma venereum | Genital ulcers, inguinal lymphadenopathy | **High-Yield:** Serovars A–C are associated with endemic trachoma in developing countries, particularly in Africa, Middle East, and South Asia. Serovar A is the most virulent and causes severe scarring. **Clinical Pearl:** The distinction is epidemiologically important—serovars A–C spread through direct contact and contaminated fomites in areas with poor sanitation, while D–K serovars are sexually transmitted. **Mnemonic:** **ABC = Trachoma** (Serovars A, B, Ba, C cause trachoma); **D–K = Inclusion** (serovars D through K cause inclusion conjunctivitis); **L = Lymphogranuloma** (L1–L3 cause LGV). [cite:Park 26e Ch 8]