Overview

Trachoma is a contagious bacterial eye infection caused by Chlamydia trachomatis. It is the world’s leading infectious cause of blindness, particularly affecting populations in poor, rural, and crowded environments. Trachoma typically begins as a mild infection in childhood, but with repeated infections over time, it can lead to scarring of the eyelids, inward turning of the eyelashes (trichiasis), and ultimately irreversible blindness. Despite being preventable and treatable, trachoma remains a major public health issue in certain parts of Africa, Asia, the Middle East, and Latin America.

Causes

Trachoma is caused by the bacterium Chlamydia trachomatis, specifically the serotypes A, B, Ba, and C. It is spread through direct or indirect contact with the eyes or nose of an infected person. Common routes of transmission include:

• Person-to-person contact: Touching an infected person's face or eyes.
• Contaminated objects: Sharing towels, clothing, or bedding with someone who has the infection.
• Flies: Flies that come into contact with eye or nasal discharge can transmit the bacteria.
• Poor sanitation: Inadequate access to clean water and hygiene facilities increases the risk of spread.

Symptoms

Trachoma develops in stages, with symptoms becoming more severe over time if left untreated:

• Mild symptoms (early stage): Eye redness, irritation, and discharge similar to conjunctivitis.
• Follicular inflammation: The inside of the upper eyelid shows visible bumps or follicles.
• Intense inflammation: Swelling and thickening of the eyelid with increased redness.
• Eyelid scarring: Repeated infections cause scarring, making the eyelid turn inward (entropion).
• Trichiasis: Eyelashes rub against the cornea, leading to pain, corneal damage, and vision loss.
• Advanced stage: Corneal opacity (clouding of the cornea), which can result in blindness.

Diagnosis

Diagnosing trachoma typically involves a clinical examination, with laboratory tests used in specific cases:

• Clinical evaluation: Eye examination using magnification (loupes) to look for follicles, scarring, and corneal damage.
• WHO grading system: Trachoma is classified based on the WHO simplified grading system, which categorizes the disease into five stages from inflammation to scarring and blindness.
• Laboratory tests: In some cases, swabs from the conjunctiva may be tested for Chlamydia trachomatis using PCR or other molecular techniques, especially for epidemiological studies.

Treatment

The World Health Organization recommends the SAFE strategy to combat trachoma:

• Surgery: Surgery (bilamellar tarsal rotation) is used to correct trichiasis and prevent further corneal damage.
• Antibiotics: Oral azithromycin (single annual dose) or topical tetracycline eye ointment treats active infection and reduces community transmission.
• Facial cleanliness: Promoting face washing among children to reduce transmission.
• Environmental improvement: Access to clean water, proper sanitation, and reducing fly populations through hygiene measures.

Prognosis

The prognosis of trachoma depends on timely detection and treatment:

• Good prognosis with early treatment: Early use of antibiotics and hygiene interventions can completely cure the infection and prevent complications.
• Risk of blindness: Without treatment, repeated infections cause irreversible corneal scarring and blindness, often by adulthood.
• Preventable blindness: Trachoma is considered a preventable cause of blindness through effective public health measures.
• Global efforts: Significant progress has been made globally through elimination programs, but certain regions still face challenges.

With continued implementation of the SAFE strategy, many communities have successfully eliminated trachoma as a public health concern, highlighting the importance of hygiene, access to healthcare, and public health initiatives in controlling this disease.