trachoma

Trachoma is an infectious eye disease caused by the bacterium Chlamydia trachomatis, which is transmitted through contact with ocular or nasal discharge, contaminated towels, or flies. It is the leading infectious cause of blindness worldwide, predominantly affecting impoverished communities with limited access to clean water, sanitation, and adequate eye care. The disease follows a chronic, relapsing course. Early stages present with follicular inflammation of the conjunctiva; repeated infections can lead to scarring, entropion, and trichiasis, where eyelashes rub the cornea, ultimately causing corneal opacity and vision loss.

Transmission occurs via direct contact or through anthropophilic Musca sorbens flies that serve as mechanical vectors. The intense-ooze disease cycle is amplified in conditions of overcrowding and poor hygiene. Children are most frequently infected, and repeated episodes may produce a spectrum of disease severity ranging from simple conjunctivitis to irreversible blindness.

Diagnosis is clinical, supported by microbiological tests such as nucleic acid amplification assays, slide culture, or immunofluorescence. Treatment follows WHO’s SAFE strategy: Surgery for trichiasis, Antibiotics (oral azithromycin or topical tetracycline) to clear infection, Facial cleanliness, and Environmental improvement to reduce transmission. Mass drug administration in endemic regions effectively reduces prevalence. Prevention also focuses on improving access to water, sanitation, and basic eye care.

Trachoma remains a public health priority. WHO estimates that it causes almost 1.9 million cases of preventable blindness each year. Global elimination targets aim for <1 case per million population by 2020, though many regions still face high endemicity. Continued surveillance, adherence to the SAFE strategy, and investment in water and sanitation infrastructure are essential for sustained control and eventual elimination.