Facts about Trachoma, a leading infectious cause of blindness worldwide
By Cynthia Lodite, April 28, 2026Did you know that Trachoma is the leading infectious cause of blindness worldwide? According to the World Health Organisation, Trachoma is caused by an obligate intracellular bacterium called Chlamydia trachomatis.
The infection is transmitted by direct or indirect transfer of eye and nose discharges of infected people, particularly young children who harbour the principal reservoir of infection. These discharges can be spread by particular species of flies.
A report by the World Health Organisation published on 4 March 2026, indicates that Trachoma is a public health problem responsible for the blindness or visual impairment of about 1.9 million people.
“It is a public health problem in 30 countries and is responsible for the blindness or visual impairment of about 1.9 million people.Blindness from trachoma is difficult to reverse,” WHO report read in part.
Symptoms and transmission
In areas where trachoma is endemic, active (inflammatory) WHO says that trachoma is common among preschool-aged children, with the proportion of such children affected sometimes being as high as 90%.
Infection becomes less frequent and shorter in duration with increasing age. Infection is usually acquired when living in proximity to others with active disease, and the family is the main setting for transmission.
An individual’s immune system can clear a single episode of infection, but in endemic communities re-acquisition of the organism occurs frequently.
After years of repeated infection, the inside of the eyelid can become so severely scarred (trachomatous conjunctival scarring) that it turns inwards and causes the eyelashes to rub against the eyeball (trachomatous trichiasis), resulting in constant pain and light intolerance.
This and other alterations of the eye can lead to scarring of the cornea. Left untreated, this condition leads to the formation of irreversible opacities, with resulting visual impairment or blindness.
The age at which this occurs depends on several factors including local transmission intensity. In very highly endemic communities it can occur in childhood, though onset of visual impairment between the ages of 30 and 40 years is more typical.
Visual impairment or blindness results in a worsening of the life experience of affected individuals and their families, who are normally already amongst the poorest of the poor.
WHO further indicates that Women are blinded up to 4 times as often as men, probably due to their close contact with infected children and their resulting greater frequency of infection episodes.