Trachoma is a prolonged infection of the conjunctiva caused by the bacteria Chlamydia trachomatis, usually occurring in children who live in hot, dry, less developed countries. In the event of repeated episodes over several years, the infection can lead to chronic sequelae, with pain and discomfort, and permanent damage to the cornea. About 5% of patients develop reduced vision or blindness. The infection is spread by contact between people (hands, clothes, bed sheets) and by flies that have come into contact with the eye or nasal discharge of infected people. Treatment is based on the administration of antibiotics by mouth or as an ointment. A surgical intervention corrective may be necessary if the eyelid, conjunctiva or cornea are involved.

Trachoma is a chronic conjunctivitis, characterized by flare-ups interspersed with remissions, and occurring in children aged 3 to 6 years in some poor areas around the world. It results from bacterial infections of the eye with certain non-sexually transmitted strains of Chlamydia trachomatis. Older children and adults are much less susceptible due to more effective immunity and better personal hygiene. It should be noted that women are up to 4 times more affected than men, probably because they are more in contact with infected children, hence a greater frequency of infectious episodes.

Common in poor areas of hot and dry countries of North Africa, the Middle East, the Indian subcontinent, Australia and Southeast Asia, trachoma is the leading preventable cause of blindness in the world. A real public health problem in 44 countries, it is responsible for irreversible blindness and visual impairments in around 1,9 million people, which represents nearly 1,4% of total blindness cases worldwide.

In the early stages, trachoma is extremely contagious. The infection is transmitted from person to person, often from child to child, or from child to mother, especially in cases of water shortage, poor sanitation and in overcrowded conditions.

The bacteria Chlamydia trachomatis is transmitted by:

• contact with eye or nasal discharge from infected people, especially young children who are the main reservoir of infection;
• contact between people via hands, clothes, sheets;
• some flies that have come into contact with the eyes or nose of infected people;
• handling contaminated objects shared by several people such as towels, handkerchiefs and eye makeup.

Since trachoma is contagious, re-infections are very common. In order to limit the spread of the infection, it is recommended to:

• promote access to drinking water;
• wash your face and hands regularly;
• avoid sharing towels, blankets and makeup products;
• avoid or even eliminate places where flies can breed.

Trachoma usually affects both eyes:

• the conjunctivae, the membranes that line the eyelids and cover the whites of the eyes, become inflamed, red and irritated (conjunctival hyperemia);
• the eyes water excessively;
• the eyelids swell (eyelid edema);
• sensitivity to bright light appears (photophobia).

Repeated infections over time can cause blood vessels to gradually appear in the cornea, called neovascularization, disrupting vision. Reinfections also cause a deformation of the eyelid, the interior of which may become covered with scar tissue or conjunctival scars, to the point that the edge of the eyelid turns inward (entropion) causing the painful and uncomfortable friction of the eyelashes against the eye. eyeball (trichiasis) which causes constant pain and intolerance to light, as well as permanent damage to the cornea.

If left untreated, this condition leads to the formation of irreversible opacities followed by the appearance of visual impairments and blindness, usually between the ages of 30 and 40 years. Low vision or blindness occurs in about 5% of people with trachoma.

The management of trachoma is based on treating the infection with:

• administration of an oral antibiotic such as azithromycin (a single oral dose of 20 mg / kg, maximum 1 g), doxycycline (100 mg twice / day for 2 weeks) or tetracycline (4 mg 250 times / day for 4 weeks);
• application of ointment containing 1% tetracycline in both eyes twice a day for 2 weeks, or erythromycin.

It is generally recommended that these antibiotics be given to everyone who comes into contact with patients who have trachoma.

A surgical intervention corrective may be necessary if the eyelid, conjunctiva or cornea are involved.

It should be noted that programs to eliminate trachoma, as a public health problem, are implemented within the framework of the SAFE strategy recommended by the WHO, which includes 4 components:

• CH: eyelid surgery to treat the blinding stage of the disease (trachomatous trichiasis);
• A: an antibiotic, azithromycin, to treat infection, donated by the manufacturer to endemic countries through the International Trachoma Initiative;
• N: facial cleansing to educate the exposed population;
• CE: environmental change, for example by improving access to drinking water and sanitation.