The bacteria that cause the disease can be spread by both direct and indirect contact with an affected person's eyes or nose.[2] Indirect contact includes through clothing or flies that have come into contact with an affected person's eyes or nose.[2] Children spread the disease more often than adults.[2] Poor sanitation, crowded living conditions, and insufficient clean water and toilets also increase spread.[2]
Efforts to prevent the disease include improving access to clean water and treatment withantibiotics to decrease the number of people infected with the bacterium.[2] This may include treating, all at once, whole groups of people in whom the disease is known to be common.[3] Washing, by itself, is not enough to prevent disease, but may be useful with other measures.[5] Treatment options include oralazithromycin and topicaltetracycline.[3] Azithromycin is preferred because it can be used as a single oral dose.[6] After scarring of the eyelid has occurred, surgery may be required to correct the position of the eyelashes and prevent blindness.[2]
Globally, about 80 million people have an active infection.[4] In some areas, infections may be present in as many as 60–90% of children.[2] Among adults it more commonly affects women than men, likely due to their closer contact with children.[2] The disease is the cause of decreased vision in 2.2 million people, of whom 1.2 million are completely blind.[2] Trachoma is a public health problem in 38 countries across Africa, Asia, the Middle East, Central and South America, and Australia.[7] There are 103 million people at risk,[7] down from 228.9 million in 2013.[2] It results inUS$8 billion of economic losses a year.[2] It belongs to a group of diseases known asneglected tropical diseases.[4]
Ellis IslandPublic Health Service physicians examining new immigrants for trachoma in 1910
The bacterium has an incubation period of 10 days, after which the affected individual experiences symptoms ofconjunctivitis, or irritation similar to "pink eye".[8] Blinding endemic trachoma results from multiple episodes of reinfection that maintains the intense inflammation in the conjunctiva. Without reinfection, the inflammation gradually subsides.[9]
The conjunctival inflammation is called "active trachoma" and is usually seen in children, especially those in preschool. It is characterized by white lumps in the undersurface of the upper eyelid (conjunctival follicles orlymphoid germinal centers) and by nonspecific inflammation and thickening, often associated with papillae. Follicles may also appear at the junction of thecornea and thesclera (limbal follicles). Active trachoma can often be irritating and have a watery discharge. Bacterial secondary infection may occur and cause a discharge ofpus.[10]
The later structural changes of trachoma are referred to as "cicatricial trachoma". These include scarring under the eyelid (tarsal conjunctiva) that leads to distortion of the eyelid with buckling of the lid (tarsus) so the lashes rub against the eye (trichiasis). This can lead to corneal opacities and scarring and then to blindness. Linear scars present in thesulcus subtarsalis[11] are calledArlt's lines (named afterCarl Ferdinand von Arlt). In addition, blood vessels and scar tissue can invade the upper cornea (pannus). Resolved limbal follicles may leave small gaps in thepannus (Herbert's pits).[12]
Most commonly, children with active trachoma do not present with symptoms, as the low-grade irritation and ocular discharge are just accepted as normal, but further symptoms may include:[citation needed]
The most important complication to look out for is acorneal ulcer, which is caused by intense rubbing of the affected eye, or trichiasis with a superimposed bacterial infection.
Trachoma is caused byChlamydia trachomatis, serotypes (serovars) A, B, and C.[13] It is spread by direct contact with eye, nose, and throatsecretions from affected individuals, or contact withfomites[14] (inanimate objects that carry infectious agents), such as towels and/or washcloths, that have had similar contact with these secretions. Flies can also be a route of mechanical transmission.[14] Untreated, repeated trachoma infections result inentropion (the inward turning of the eyelids), which may result in blindness due to damage to the cornea. Children are the most susceptible to infection due to their tendency to get dirty easily, but the blinding effects or more severe symptoms are often not felt until adulthood.[15]
Blinding endemic trachoma occurs in areas with poor personal and family hygiene. Many factors are indirectly linked to the presence of trachoma including lack of water, absence of latrines or toilets, poverty in general, flies, close proximity to cattle, and crowding.[9][16] The final common pathway, though, seems to be the presence of dirty faces in children, facilitating the frequent exchange of infected ocular discharge from one child's face to another. Most transmission of trachoma occurs within the family.[9]
The World Health Organization recommends a simplified grading system for trachoma.[17] The Simplified WHO Grading System is summarized below:
Trachomatous inflammation, follicular (TF)—Five or more follicles of >0.5 mm on the upper tarsal conjunctiva
Trachomatous inflammation, intense (TI)—Papillary hypertrophy and inflammatory thickening of the upper tarsal conjunctiva obscuring more than half the deep tarsal vessels
Trachomatous scarring (TS)—Presence of scarring in tarsal conjunctiva.
Trachomatous trichiasis (TT)—At least one ingrown eyelash touching the globe, or evidence of epilation (eyelash removal)
Corneal opacity (CO)—Corneal opacity blurring part of the pupil margin
Although trachoma was eliminated from much of thedeveloped world in the 20th century (Australia being a notable exception), this disease persists in many parts of thedeveloping world, particularly in communities without adequate access to water and sanitation.[18] It is grouped as aneglected tropical disease which is a target for preventive chemotherapy.[19]
Environmental improvement: Modifications in water use, fly control, latrine use, health education, and proximity to domesticated animals have all been proposed to reduce transmission ofC. trachomatis.[20][additional citation(s) needed] These changes pose numerous challenges for implementation. These environmental changes are likely to ultimately affect the transmission of ocular infection through a lack of facial cleanliness.[9] Particular attention is required for environmental factors that limit clean faces.
A systematic review examining the effectiveness of environmental sanitary measures on the prevalence of active trachoma in endemic areas showed that the use of insecticide spray resulted in significant reductions of trachoma and fly density in some studies.[21] Health education also resulted in reductions of active trachoma when implemented.[21] Improved water supply did not result in a reduction of trachoma incidence.[21]
WHO Guidelines recommend that a region should receive community-based, mass antibiotic treatment when the prevalence of active trachoma among one- to nine-year-old children is greater than 10%. Subsequent annual treatment should be administered for three years, at which time the prevalence should be reassessed. Annual treatment should continue until the prevalence drops below 5%.[22] At lower prevalences, antibiotic treatment should be family-based.[citation needed]
Azithromycin (single oral dose of 20 mg/kg) or topicaltetracycline (1% eye ointment twice a day for six weeks). Azithromycin is preferred because it is used as a single oral dose. Although it is expensive, it is generally used as part of the international donation program organized byPfizer.[6] Azithromycin can be used in children from the age of six months and in pregnancy.[9] As a community-based antibiotic treatment, some evidence suggests that oral azithromycin was more effective than topical tetracycline, but no consistent evidence supported either oral or topical antibiotics as being more effective.[3] Antibiotic treatment reduces the risk of active trachoma in individuals infected with chlamydial trachomatis.[3]
For individuals with trichiasis, a bilamellar tarsal rotation procedure is warranted to direct the lashes away from the globe.[23] Evidence suggests that the use of a lid clamp and absorbable sutures would result in reduced lid contour abnormalities and granuloma formulation after surgery.[24] Early intervention is beneficial as the rate of recurrence is higher in more advanced diseases.[25]
Antibiotics to treat active infection, using azithromycin
Facial cleanliness to reduce disease transmission
Environmental change to increase access to clean water and improve sanitation
Children with visible nasal discharge, discharge from the eyes, or flies on their faces are at least twice as likely to have active trachoma as children with clean faces.[9] Intensive community-based health education programs to promoteface-washing can reduce the rates of active trachoma, especially intense trachoma. If an individual is already infected, washing one's face is encouraged, especially a child, to prevent reinfection.[26] Some evidence shows that washing the face combined with topical tetracycline might be more effective in reducing severe trachoma compared to topical tetracycline alone.[5] The same trial found no statistical benefit of eye washing alone or in combination with tetracycline eye drops in reducing follicular trachoma amongst children.[5]
If not treated properly withoral antibiotics, the symptoms may escalate and cause blindness, which is the result ofulceration and consequent scarring of thecornea. Surgery may also be necessary to fix eyelid deformities.
Without intervention, trachoma keeps families in acycle of poverty, as the disease and its long-term effects are passed from one generation to the next.
As of 2011, about 21 million people are actively affected by trachoma, with around 2.2 million people being permanently blind or have severe visual impairment from trachoma.[needs update] An additional 7.3 million people are reported to havetrichiasis.[27] As of April 2024,[update] 103 million individuals live in trachoma endemic areas and are at risk of trachoma-related blindness, and the disease is a public health problem in 38 countries.[7] Of these, Africa is considered the worst affected area, with over 85% of all known active cases of trachoma.[28] Within the continent, South Sudan and Ethiopia have the highest prevalence.[28] In many of these communities, women are up to four times more likely than men to be blinded by the disease,[7] likely due to their roles as caregivers in the family.[29] Australia is the only developed country that has trachoma.[30] In 2008, trachoma was found in half of Australia's very remote communities.[30]
In 1996, the WHO launched its Alliance for the Global Elimination of Trachoma by 2020,[31] and in 2006, the WHO officially set 2020 as the target to eliminate trachoma as a public health problem.[32] The International Coalition for Trachoma Control has produced maps and a strategic plan called 2020 INSight that lays out actions and milestones to achieve global elimination of blinding trachoma by 2020.[33] The program recommends the SAFE protocol for blindness prevention: Surgery for trichiasis, Antibiotics to clear infection, Facial cleanliness, and Environmental improvement to reduce transmission.[31] This includes sanitation infrastructure to reduce the open presence of human feces that can breed flies.[34]
As of 11 July 2025,[update] 24 countries have eliminated trachoma as a public health problem. The latest countries validated to have eliminated trachoma in 2025 areMauritania,Papua New Guinea,Burundi andSenegal.[35][36][37][38] 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.[34] Having already donated more doses (about 700 million since 2002) of the drug than it has sold during the same period, the drug company Pfizer has agreed to donate azithromycin until 2025, if necessary, for the elimination of the disease.[34] The campaign unexpectedly found the distribution of azithromycin to very poor children reduced their early death rate by up to 25%.[34]
The African Region is the most intensely affected globally: although Africa contains fewer than half of the world's population, it accounts for more than 85 % of all known cases of active trachoma.[39]In 2024, an estimated 93 million people in the African Region were living in areas at risk for trachoma, representing approximately 90 % of the global at-risk burden.[40]
Surveys show that in many endemic districts of SSA, children aged 1-9 years have prevalence rates of active trachoma (TF or TI) ranging from 20-60 % or more.[41] For example, in one community in Ethiopia the prevalence among children aged 1-9 years was found to be as high as 40.1 %.[42]
Trachoma in SSA is typified by a convergence of risk-factors across human, animal and environmental domains:
Poor access to safe water and sanitation, high fly density (particularlyMusca sorbens breeding in human faeces) and crowded living conditions increase transmission.[43]
Rural, remote and impoverished communities bear the highest burden—factors such as limited health infrastructure, low educational attainment and subsistence farming intensify risk.[44]
Environmental factors such as climatic variability, drought or heavy rainfall may influence fly populations or sanitation breakdowns in rural SSA settings, linking broader ecosystem health with human disease.
Gender dynamics: Women and girls often carry greater risk of trachoma and its sequelae due to caregiving roles, greater contact with children who are reservoirs of infection, and disparities in access to services.[45]
The internationally-endorsed SAFE approach (Surgery for trichiasis, Antibiotics to clear infection, Facial cleanliness and Environmental improvement) is central to trachoma programmes in SSA.[46]
Surgery (S): Surgical correction of trichiasis (in-turned eyelashes) is performed in many endemic SSA countries to prevent progression to blindness.
Antibiotics (A): Mass drug administration (MDA) of oral azithromycin is deployed in districts where childhood prevalence of active trachoma exceeds 10 %. Reports indicate that millions in SSA have received antibiotic treatment under elimination programmes.[47]
Facial cleanliness (F): Health-education campaigns in schools and communities promote face-washing and hygiene practices, aiming to reduce transmission via ocular discharge and fly exposure.
Environmental improvement (E): Investment in latrines, improved waste disposal, fly control and access to clean water are crucial—especially in rural SSA where environmental risk factors are pronounced.
Significant strides have been made in SSA where several countries have achieved validation of elimination as a public-health problem (for example, Senegal in July 2025).[48] Nonetheless, a number of major challenges still persist. Persistent high-burden countries such as Ethiopia and South Sudan have remote geography, conflict, weak infrastructure and resource constraints that slow progress. Under-reporting and data gaps exist in many endemic districts that lack up to date prevalence surveys, limiting evidence-based targeting.[49] Integration of One Health is still uneven in these regions where aligning human health, environmental health, veterinary/environmental infrastructure still remain a work in progress.[50] Another challange exists with the sustainability of programmes. Maintaining antibiotic supply chains, trained surgical teams, behaviour change and environmental improvements over long periods is resource intensive and often run out of monetary support.[51] Looking ahead, the road to elimination of trachoma in SSA will require intensified cross-sectoral coordination, increased funding, community-driven hygiene, environmental improvements, and leveraging climate resilient infrastructure.
The disease is one of the earliest known eye afflictions, having been identified in Egypt as early as 15 BCE.[9]
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. After theEgyptian Campaign (1798–1802) and theNapoleonic Wars (1798–1815), trachoma was rampant in the army barracks of Europe and spread to those living in towns as troops returned home. Stringent control measures were introduced, and by the early 20th century, trachoma was essentially controlled in Europe, although cases were reported until the 1950s.[9] Today, most victims of trachoma live in underdeveloped and poverty-stricken countries inAfrica, theMiddle East, andAsia.[citation needed]
In the United States, the Centers for Disease Control says, "No national or international surveillance [for trachoma] exists. Blindness due to trachoma has been eliminated from the United States. The last cases were found among Native American populations and in Appalachia, and those in the boxing, wrestling, and sawmill industries (prolonged exposure to combinations of sweat and sawdust often led to the disease). In the late 19th and early 20th centuries, trachoma was the main reason for an immigrant coming through Ellis Island to be deported."[52][53]
In 1913, President Woodrow Wilson signed an act designating funds for the eradication of the disease.[54][55] Immigrants who attempted to enter the U.S. throughEllis Island, New York, had to be checked for trachoma.[52] During this time, treatment for the disease was by topical application ofcopper sulfate. By the late 1930s, severalophthalmologists reported success in treating trachoma withsulfonamide antibiotics.[56] In 1948,Vincent Tabone (who was later to become thePresident of Malta) was entrusted with the supervision of a campaign in Malta to treat trachoma using sulfonamide tablets and drops.[57]
Due to improved sanitation and overall living conditions, trachoma virtually disappeared from the industrialized world by the 1950s, though it continues to plague the developing world to this day. Epidemiological studies were conducted in 1956–1963 by the Trachoma Control Pilot Project in India under theIndian Council for Medical Research.[58] This potentially blinding disease remains endemic in the poorest regions of Africa, Asia, and the Middle East and in some parts of Latin America and Australia. Currently,[when?] 8 million people are visually impaired as a result of trachoma, and 41 million have an active infection.
Of the 54 countries that the WHO cited as still having blinding trachoma occurring, Australia is the only developed country—Australian Aboriginal people who live in remote communities with inadequate sanitation are still blinded by this infectious eye disease.[59][60]
India's Health and Family Welfare Minister JP Nadda declared India free of infective trachoma in 2017.[61]
The economic burden of trachoma is huge, particularly concerning covering treatment costs and productivity losses as a result of increased visual impairment, and in some cases, permanent blindness.[2] The global estimated cost of trachoma is reported between $US2.9 and 5.3 billion each year.[2] By including the cost of trichiasis treatment, the estimated overall cost for the disease increases to about $US 8 billion.[2]
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^Mackern-Oberti JP, Motrich RN, Breser MA, Sánchez LR, Cuffini C, Rivero VE (2013). "Chlamydia trachomatis infection of the male genital tract: An update".Journal of Reproductive Immunology.100 (1):37–53.doi:10.1016/j.jri.2013.05.002.hdl:11336/26316.PMID23870458.
^abGoldman L (2011).Goldman's Cecil Medicine (24th ed.). Philadelphia: Elsevier Saunders. pp. e326-2.ISBN978-1-4377-2788-3.
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