Blinding trachoma is a type of conjunctivitis caused by Chlamydia trachomatis, a bacterium that is transmitted to healthy eyes by a discharge from an infected eye. If repeated, it can lead to blindness, and that is why this disease is called blinding trachoma. It is epidemic mainly in developing countries and, according to data released by the World Health Organization (WHO), tracoma is responsible for the blindness or visual impairment of about 1.9 million people.

< Appearance of a trachoma patient > CDC

Causes of Infection

This disease occurs when Chlamydia trachomatis is transmitted to eyes via hands, clothes, and towels used by those infected or via flies that land on the eyes or noses of the infected.
Since the agent of this disease is easily transmitted via human contact, widespread infections are common. Children who touch their eyes often or are too young to wash their faces and their mothers are particularly susceptible to infection. Infection is more likely to come from areas where water is in short supply or that are unhygienic and infested with flies.

Disease Agent:Chlamydia trachomatis (bacterium)

< Chlamydia trachomatis >

Vector:Mainly flies

< Host fly (in general, not limited to this species) >
Dr. Gary Alpert


Trachoma’s symptoms are divided into two stages:

Early Stage

Lumps like millet seed appear on the palpebral conjunctiva of upper eyelids. When these lumps grow and burst, scar (white lines) and star-shaped tissues appear.

Subsequent Stage

Palpebral conjunctiva of the upper eyelid spreads and becomes red, irregular, and thick. After repeated infections over a long period the eyelid rides up the eyeball, constantly injuring the cornea with eyelashes (inturned eyelashes). Accompanied by pain, this symptom leads to corneal clouding, blurred vision, and, eventually, blindness.
After repeated infections from the first infection in childhood, people become blind in their 30s or 40s. Women in middle age and older who have frequent contact with children are also susceptible to infection.

Diagnosis and Treatment

Treatment include drugs and/or surgical operation


Drug cures include azithromycin and tetracycline eye ointment.
Since trachoma is highly infectious, antibiotic drugs such as azithromycin are effective. In light cases, a few doses of azithromycin are believed to be enough. For infants under six months, a combination of a small dose of tetracycline eye ointment and azithromycin is used.
Tetracycline eye ointment should be applied directly to the eye twice a day for six weeks. Since it is painful, patients may not want it to be continually applied. Additionally, although tetracycline eye ointment is effective in controlling inflammation, it does not prevent re-infection. Therefore, the trend is shifting to using azithromycin.

Surgical Operation

Eyelids that have risen up the eyeball can be easily treated with a simple surgical operation.


The most fundamental and important preventive measure is to wash the hands and face with clean water. Across the community, hygiene is essential including clean toilets, eradicating flies, safe, hygienic water and food, as well as separating people and animals.

Regions at High Risk of Infection (major endemic areas)

Ninety eight percent (98%) of trachoma infections are found in developing countries and the infection rate is particularly high in areas with poor hygiene, poverty, as well as shortages of water and medical services. According to 2016 data from the WHO, infections were reported in 42 countries in Africa, Central and South America, Asia, Australia and the Middle East. In the areas with particularly high infection rates, it is estimated that some 60 to 90% of pre-school children are infected.

Estimated Number of Infected People

Also according to 2016 data released by WHO, tracoma is responsible for the blindness or visual impairment of about 1.9 million people. Infection rates are particularly high among children under five as well as adult females who take care of infected children.

Estimated Number of Deaths

There have been no deaths attributed to trachoma as the direct cause.


WHO- Neglected Tropical Diseases, accessed March 19, 2014,

CDC- Neglected Tropical Diseases, accessed March 19, 2014,

Editorial Supervisors
Tsutomu Takeuchi, Professor Emeritus of Keio University
Hiroyoshi Endo, Professor Emeritus of St. Luke's International University