Trachoma

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What this article covers

• Overview

  A chronic, reinfection-driven conjunctival disease: trachoma is caused by Chlamydia trachomatis serovars A through C, which produce recurrent epithelial keratoconjunctivitis in childhood that, with…

• Epidemiology

  Endemic in resource-limited, hyperendemic communities: trachoma is a global disease, concentrated where crowding, limited water access, and poor sanitation favor repeated childhood transmission.

• Risk factors

  Repeated childhood reinfection: the central driver of trachomatous scarring; a single infection rarely causes blinding disease, but repeated cycles of infection and inflammation over years do.

• Pathophysiology

  Direct infection of the conjunctival epithelium: Chlamydia trachomatis serovars A-C infect the tarsal conjunctiva, producing a follicular and papillary inflammatory response with lymphoid follicle formation.

• Clinical features

  Active disease in childhood presents as follicular conjunctivitis: inflammation and lymphoid follicles are concentrated on the upper tarsal (inner eyelid) conjunctiva, often with mucopurulent…

• Differential diagnosis

  Adult inclusion conjunctivitis (Chlamydia trachomatis serovars D-K): chronic conjunctivitis with mild mucopurulent discharge in a sexually active adult, distinguished from trachoma by serovar, lack…

• Diagnosis

  First, establish the diagnosis clinically using the World Health Organization (WHO) simplified trachoma grading system, which defines five signs on eyelid eversion and corneal examination: TF…

• Management

  First, treat active disease (TF/TI) with a single oral dose of azithromycin: 20 mg/kg PO (maximum 1 g) as a single dose is first-line for individual treatment and for community mass drug administration in endemic areas.

• Complications

  Corneal blindness: the end-stage, irreversible outcome of repeated corneal trauma from trichiasis; trachoma is the leading infectious cause of preventable blindness worldwide.

• Prognosis

  Excellent for active disease treated before scarring develops: azithromycin clears active infection effectively, and vision is preserved if treatment interrupts the cycle before significant scarring accumulates.

• Prevention

  Community mass azithromycin treatment in hyperendemic districts: single-dose azithromycin 20 mg/kg (max 1 g) distributed to the eligible population interrupts community transmission when…