Trachoma is caused by which serotype of chlamydia trachomatis ?
**Core Concept**
Trachoma is a leading cause of preventable blindness worldwide, caused by infection with Chlamydia trachomatis. The disease primarily affects the conjunctiva and cornea, leading to chronic inflammation and scarring.
**Why the Correct Answer is Right**
Trachoma is specifically caused by serovars A, B, Ba, and C of Chlamydia trachomatis. These serovars are transmitted through direct contact with infected individuals, contaminated water, or fomites. The bacteria invade the conjunctival epithelial cells, triggering a strong immune response and leading to the characteristic symptoms of trachoma.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect, as serovars D to K are associated with urogenital infections, not trachoma.
**Option B:** Incorrect, as serovars L1-L3 are linked to lymphogranuloma venereum, a different disease caused by Chlamydia trachomatis.
**Option C:** Incorrect, as serovars of Chlamydia trachomatis other than A, B, Ba, and C are not associated with trachoma.
**Clinical Pearl / High-Yield Fact**
The World Health Organization (WHO) has established a global initiative to eliminate trachoma as a public health problem by 2020, focusing on mass drug administration of antibiotics, improved water and sanitation, and promotion of hygiene practices.
**Correct Answer: C. Serovars A, B, Ba, and C.**