Among adults, it more commonly affects women than men – likely due to their closer contact with children. The disease is the cause of decreased vision in 2.2 million people, of whom 1.2 million are completely blind. Trachoma is a public health problem in 44 countries across Africa, Asia, and Central and South America, with 136.9 million people at risk. It results in US$8 billion of economic losses a year. It belongs to a group of diseases known as neglected tropical diseases. Signs and symptoms
The bacterium has an incubation period of 6 to 12 days, after which the affected individual experiences symptoms of conjunctivitis, or irritation similar to "pink eye". Blinding endemic trachoma results from multiple episodes of reinfection that maintains the intense inflammation in the conjunctiva. Without reinfection, the inflammation gradually subsides.The conjunctival inflammation is called "active trachoma" and usually is seen in children, especially preschool children. It is characterized by white lumps in the undersurface of the upper eyelid (conjunctival follicles or lymphoid germinal centres) and by nonspecific inflammation and thickening often associated with papillae. Follicles may also appear at the junction of the cornea and the sclera (limbal follicles). Active trachoma often can be irritating and have a watery discharge. Bacterial secondary infection may occur and cause a purulent discharge.The later structural changes of trachoma are referred to as "cicatricial trachoma". These include scarring in the eyelid (tarsal conjunctiva) that leads to distortion of the eyelid with buckling of the lid (tarsus) so the lashes rub on the eye (trichiasis).
The program recommends the SAFE protocol for blindness prevention: Surgery for trichiasis, Antibiotics to clear infection, Facial cleanliness, and Environmental improvement to reduce transmission. This includes sanitation infrastructure to reduce the open presence of human feces that can breed flies.As of 2018, Cambodia, Ghana, Iran, Laos, Mexico, Nepal, Morocco, and Oman have been certified as having eliminated trachoma as a public-health problem; China, Gambia, Iran, Iraq, and Myanmar make that claim, but have not sought certification. Eradication of the bacterium that causes the disease is seen as impractical; the WHO definition of "eliminated as a public-health problem" means less than 5% of children have any symptoms, and less than 0.1% of adults have vision loss. Having already donated more doses (about 700 million since 2002) of the drug than it has sold during the same time period, the drug company Pfizer has agreed to donate azithromycin until 2025, if necessary, for elimination of the disease. The campaign unexpectedly found distribution of azithromycin to very poor children reduced their early death rate by up to 25%. History
The disease is one of the earliest known eye afflictions, having been identified in Egypt as early as 15 BC.Its presence was also recorded in ancient China and Mesopotamia. Trachoma became a problem as people moved into crowded settlements or towns where hygiene was poor. It became a particular problem in Europe in the 19th century.