Trachoma : Cause

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Hundreds of thousands of people worldwide are blind because of a disease called trachoma. Trachoma is caused by repeated bacterial infections, and people suffer eye pain for years before they can potentially go blind from the disease.

Records of trachoma date back thousands of years, and it used to be common across Africa, the Middle East, South Asia, and South and Central America.1

Even today, the disease is a major infectious cause of blindness worldwide. But it can be prevented.

Many countries have recently eliminated or substantially reduced the disease through antibiotics, surgery, improved sanitation, clean water and hygiene, and insect control.

This progress is a major success story of public health efforts, and with more effort, the world can entirely eliminate this painful cause of blindness.

Trachoma is an eye disease caused by specific strains of the bacterium Chlamydia trachomatis.2

These bacteria are infectious and can spread between people through touching secretions from the eyes or nose or from contaminated items like clothing. It can also be spread via flies, especially some species that are attracted to human eyes.3

The bacteria infect the conjunctiva — the thin, pink, soft inner layer of the eyelids — which leads to inflammation.

If people have many repeated infections, the inflammation scars the eyelids, which begin to turn inwards.4 The eyelashes then turn inwards and scratch the cornea (the clear surface of the eyes). In severe cases, this causes the cornea to become clouded, which eventually results in permanent blindness.5

Trachoma is more common in rural areas and spreads easily between people living together, especially in places with poor sanitation and hygiene.6 While it mainly infects children, the later stages of scarring and blindness develop in adulthood.7

Trachoma is a very painful disease. Aside from the risk of blindness, it causes blurry vision, red and swollen eyes, pain while blinking or sleeping, and vision loss. As a consequence, people are more prone to accidents, have problems with daily life and work, and experience social stigma.

It’s estimated that more than 400,000 people globally were blind as a result of trachoma in 2021. As you can see in the chart below, it is a particularly common cause of blindness in Africa and South Asia.8