Trachoma: Videos & Practice Problems

Trachoma is a bacterial eye disease caused by specific serotypes of Chlamydia trachomatis, a gram-negative, coccoid-shaped bacterium. Unlike the strains of Chlamydia trachomatis responsible for sexually transmitted infections, the ocular serotypes that cause trachoma infect the conjunctival cells of the eye. These bacteria multiply inside the conjunctiva, leading to cell death, inflammation, and the production of pus-filled discharge. Over time, repeated untreated infections cause scarring of the conjunctiva, which can result in permanent blindness. This progressive damage typically develops over many years, making trachoma a significant public health issue in impoverished regions with limited access to medical care.

Transmission of trachoma occurs primarily through fomites—contaminated inanimate objects such as towels—direct physical contact, and flies that carry the bacteria. Crowded living conditions and poor sanitation greatly increase the risk of spreading the infection. Symptoms include chronic inflammation, persistent pus discharge, and conjunctival scarring. As scarring worsens, it can cause the eyelashes to turn inward, a condition known as trichiasis. This inward turning lashes repeatedly scratch the cornea, further damaging the eye and increasing the risk of blindness.

Diagnosis of trachoma often relies on visual inspection in resource-limited settings, but laboratory confirmation can be achieved by swabbing the conjunctiva to detect Chlamydia trachomatis cells. Treatment involves systemic antibiotics such as azithromycin, which are administered orally to target bacteria not only in the eye but also in nearby areas like the nasopharynx. In advanced cases, surgical intervention may be necessary to correct eyelid deformities and prevent further corneal damage.

Immunity to trachoma is incomplete; repeated infections and treatments can provide some protection, but full immunity does not develop. This lack of lasting immunity underscores the importance of prevention strategies, including improved hygiene, sanitation, and access to medical care, to reduce the global burden of trachoma. As the leading microbial cause of preventable blindness worldwide, understanding the transmission, symptoms, and treatment of trachoma is essential for effective disease control and prevention.

Trachoma, bacterial conjunctivitis, and viral conjunctivitis are eye infections with distinct and overlapping characteristics important for diagnosis and treatment. Both trachoma and bacterial conjunctivitis can often be treated effectively with antibiotics, whereas viral conjunctivitis does not respond to antibiotic therapy. Trachoma stands out as one of the leading causes of preventable blindness worldwide, highlighting its significant public health impact.

When examining symptoms, viral conjunctivitis typically causes a watery discharge from the eye, reflecting its viral origin and inflammatory response. In contrast, bacterial conjunctivitis and trachoma are associated with a thick discharge that can cause the eyelids to stick shut, indicating bacterial infection and inflammation. A unique and severe complication of trachoma is the inward folding of the eyelid, known as entropion, which can scratch and scar the cornea, potentially leading to vision loss.

Understanding these differences is crucial for effective clinical management. Antibiotic treatment targets bacterial infections like trachoma and bacterial conjunctivitis, while viral conjunctivitis requires supportive care. Recognizing the symptom of watery versus thick discharge helps differentiate viral from bacterial causes. The progression of trachoma to eyelid scarring and corneal damage underscores the importance of early detection and intervention to prevent blindness.