Trachoma is an infectious disease caused by bacterium Chlamydia trachomatis. The infection causes a roughening of the inner surface of the eyelids. This roughening can lead to pain in the eyes, breakdown of the outer surface or cornea of the eyes, and eventual blindness. Untreated, repeated trachoma infections can result in a form of permanent blindness when the eyelids turn inward.The bacteria that cause the disease can be spread by both direct and indirect contact with an affected persons eyes or nose. Indirect contact includes through clothing or flies that have come into contact with an affected persons eyes or nose. Children spread the disease more often than adults. Poor sanitation, crowded living conditions, and not enough clean water and toilets also increase spread.Efforts to prevent the disease include improving access to clean water and treatment with antibiotics to decrease the number of people infected with the bacterium. This may include treating, all at once, whole groups of people in whom the disease is known to be common. Washing, by itself, is not enough to prevent disease, but may be useful with other measures. Treatment options include oral azithromycin and topical tetracycline. Azithromycin is preferred because it can be used as a single oral dose. After scarring of the eyelid has occurred, surgery may be required to correct the position of the eyelashes and prevent blindness.Globally, about 80 million people have an active infection. In some areas, infections may be present in as many as 60–90% of children.
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.