Trachoma

Overview

Trachoma (truh-KOH-muh) is a bacterial infection that affects your eyes. It's caused by the bacterium Chlamydia trachomatis. Trachoma is contagious, spreading through contact with the eyes, eyelids, and nose or throat secretions of infected people. It can also be passed on by handling infected items, such as handkerchiefs.

At first, trachoma may cause mild itching and irritation of your eyes and eyelids. Then you may notice swollen eyelids and pus draining from the eyes. Untreated trachoma can lead to blindness.

Trachoma is the leading preventable cause of blindness worldwide. Most trachoma cases occur in poor areas of Africa, where 85% of people with active disease reside. In areas where trachoma is prevalent, infection rates among children under 5 can be 60% or more.

Early treatment may help prevent trachoma complications.

Symptoms

Signs and symptoms of trachoma usually affect both eyes and may include:

• Mild itching and irritation of the eyes and eyelids
• Eye discharge containing mucus or pus
• Eyelid swelling
• Light sensitivity (photophobia)
• Eye pain
• Eye redness
• Vision loss

Young children are particularly susceptible to infection. But the disease progresses slowly, and the more painful symptoms may not emerge until adulthood.

The World Health Organization (WHO) has identified five stages in the development of trachoma:

• Inflammation — follicular. The early infection has five or more follicles — small bumps that contain lymphocytes, a type of white blood cell — visible with magnification on the inner surface of your upper eyelid (conjunctiva).
• Inflammation — intense. In this stage, your eye is now highly infectious and becomes irritated, with a thickening or swelling of the upper eyelid.
• Eyelid scarring. Repeated infections lead to scarring of the inner eyelid. The scars often appear as white lines when examined with magnification. Your eyelid may become distorted and may turn in (entropion).
• In-turned eyelashes (trichiasis). The scarred inner lining of your eyelid continues to deform, causing your lashes to turn in so that they rub on and scratch the transparent outer surface of your eye (cornea).
• Corneal clouding (opacity). The cornea becomes affected by an inflammation that is most commonly seen under your upper lid. Continuous inflammation compounded by scratching from the in-turned lashes leads to clouding of the cornea.

All the signs of trachoma are more severe in your upper lid than in your lower lid. Without intervention, a disease process that begins in childhood can continue to advance into adulthood.

When to see a doctor

Call your doctor if you or your child has itchy or irritated eyes or discharge from the eyes, especially if you live in or recently traveled to an area where trachoma is common. Trachoma is a contagious condition. Treating it as soon as possible helps prevent serious infection.

Causes

Trachoma is caused by certain subtypes of Chlamydia trachomatis, a bacterium that can also cause the sexually transmitted infection chlamydia.

Trachoma spreads through contact with discharge from the eyes or nose of an infected person. Hands, clothing, towels and insects can all be routes for transmission. In developing countries, eye-seeking flies also are a means of transmission.

Risk factors

Factors that increase your risk of contracting trachoma include:

• Crowded living conditions. People living in close contact are at greater risk of spreading infection.
• Poor sanitation. Poor sanitary conditions, inadequate access to water, and lack of hygiene, such as unclean faces or hands, help spread the disease.
• Age. In areas where the disease is active, it's most common in children ages 4 to 6.
• Sex. In some areas, women's rate of contracting the disease is two to six times higher than that of men. This may be attributed to the fact that women have more contact with children, who are the primary reservoir of infection.
• Flies. People living in areas with problems controlling the fly population may be more susceptible to infection.

Complications

One episode of trachoma caused by Chlamydia trachomatis is easily treated with early detection and use of antibiotics. Repeated or secondary infections can lead to complications, including:

• Scarring of the inner eyelid
• Eyelid deformities, such as an inward-folding eyelid (entropion) or ingrown eyelashes (trichiasis), which can scratch the cornea
• Corneal scarring or cloudiness
• Partial or complete vision loss

Prevention

If you've been treated for trachoma with antibiotics or surgery, reinfection is always a concern. For your protection and for the safety of others, be sure that family members or others you live with are screened and, if necessary, treated for trachoma.

Trachoma can occur worldwide but is more common in Africa, Asia, Latin America, the Middle East and the Pacific Rim. When in regions where trachoma is common, take extra care in practicing good hygiene, which can help prevent infection.

Proper hygiene practices include:

• Face washing and hand-washing. Keeping faces and hands clean may help break the cycle of reinfection.
• Fly control. Reducing fly populations can help eliminate a source of transmission.
• Proper waste management. Properly disposing of animal and human waste can reduce breeding grounds for flies.
• Improved access to water. Having a fresh water source nearby can help improve hygienic conditions.

No trachoma vaccine is available, but prevention is possible. The WHO has developed a strategy to prevent trachoma, with the goal of eliminating it by 2020. While the goal hasn't been entirely achieved, trachoma cases have declined sharply. The strategy, titled SAFE, involves:

• Surgery to treat advanced forms of trachoma
• Antibiotics to treat and prevent the infection
• Facial cleanliness
• Environmental improvements, particularly in water, sanitation and fly control