Trachoma

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Trachoma
Classification and external resources
Entropion and trichiasis secondary to trachoma A44-652-11.jpg
In-turned eyelid and eyelashes as a result of trachoma
ICD-10 A71
ICD-9 076
DiseasesDB 29100
MedlinePlus 001486
eMedicine oph/118
Patient UK Trachoma
MeSH D014141

Trachoma, also called granular conjunctivitis, Egyptian ophthalmia,[1] and blinding trachoma is an infectious disease caused by the bacterium Chlamydia trachomatis.[2] 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 possibly to blindness.[2]

The bacteria that causes 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] Many infections are usually needed over a period of years before scarring of the eyelid becomes so great that the eyelashes begin to rub against the eye.[2] Children spread the disease more often than adults.[2] Poor sanitation, crowded living conditions, and not enough clean water and toilets also increase spread.[2]

Efforts to prevent the disease include improving access to clean water and decreasing the number of people infected by treatment with antibiotics.[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.[4] Treatment options include oral azithromycin or topical tetracycline.[3] Azithromycin is preferred because it can be used as a single oral dose.[5] 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.[6] In some areas infections may be present in as many as 60–90% of children and more commonly affects women than men likely due to their closer contact with children.[2] The disease is the cause of a poor ability to see in 2.2 million people of which 1.2 million are completely blind.[2] It commonly occurs in 53 countries of Africa, Asia, Central and South America with about 230 million people at risk.[2] It results in 8 billion USD of economic losses a year.[2] It belongs to a group of diseases known as neglected tropical diseases.[6]

Signs and symptoms[edit]

The bacterium has an incubation period of 5 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 will gradually subside.[7]

The conjunctival inflammation is called “active trachoma” and usually is seen in children, especially pre-school children. It is characterized by white lumps in the undersurface of the upper eyelid (conjunctival follicles or lymphoid germinal centres) and by non-specific inflammation and thickening often associated with papillae. Follicles may also appear at the junction of the cornea and the sclera (limbal follicles). Active trachoma will often 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). These lashes will lead to corneal opacities and scarring and then to blindness. Linear scar present in the Sulcus subtarsalis is called Arlt's line (named after Carl Ferdinand von Arlt). In addition, blood vessels and scar tissue can invade the upper cornea (pannus). Resolved limbal follicles may leave small gaps in pannus (Herbert’s Pits).

Most commonly children with active trachoma will not present with any symptoms as the low grade irritation and ocular discharge is just accepted as normal. However, further symptoms may include:

  • Eye discharge
  • Swollen eyelids
  • Trichiasis (turned-in eyelashes)
  • Swelling of lymph nodes in front of the ears
  • Sensitivity to bright lights
  • Increased heart rate
  • Further ear, nose and throat complications.

The major complication or the most important one is corneal ulcer occurring due to rubbing by concentrations, or trichiasis with superimposed bacterial infection.

Cause[edit]

Trachoma is caused by Chlamydia trachomatis, serotypes (serovars) A, B, and C.[8] It is spread by direct contact with eye, nose, and throat secretions from affected individuals, or contact with fomites[9] (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.[9] Untreated, repeated trachoma infections result in entropion—a painful form of permanent blindness when the eyelids turn inward, causing the eyelashes to scratch the cornea. Children are the most susceptible to infection due to their tendency to easily get dirty, but the blinding effects or more severe symptoms are often not felt until adulthood.

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, crowding, and so forth.[7][10] However, the final common pathway seems to be the presence of dirty faces in children that facilitates the frequent exchange of infected ocular discharge from one child’s face to another. Most transmission of trachoma occurs within the family.[7]

Diagnosis[edit]

McCallan's classification[edit]

McCallan in 1908 divided the clinical course of trachoma into 4 stages

Stage 1 (Incipient trachoma) Stage 2 (Established trachoma) Stage 3 (Cicatrising trachoma) Stage 4 (Healed trachoma)
Hyperaemia of palpebral conjunctiva Appearance of mature follicle & papillae Scarring of palpebral conjunctiva Disease is cured or is not markable
Immature follicle Progressive corneal pannus Scars are easily visible as white bands Sequelae to cicatrisation cause symptoms

WHO classification[edit]

The World Health Organization recommends a simplified grading system for trachoma.[11] 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

Prevention[edit]

Although trachoma was eliminated from much of the developed world in the last century, this disease persists in many parts of the developing world particularly in communities without adequate access to water and sanitation.

Environmental measures[edit]

Environmental improvement: Modifications in water use, fly control, latrine use, health education, and proximity to domesticated animals have all been proposed to reduce transmission of C. trachomatis. These changes pose numerous challenges for implementation. It seems likely that these environmental changes ultimately impact on the transmission of ocular infection by means of lack of facial cleanliness.[7] 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 usage of insecticide spray resulted in significant reductions of trachoma and fly density in some studies.[12] Health education also resulted in reductions of active trachoma when implemented.[12] Improved water supply did not result in a reduction of trachoma incidence.[12]

Antibiotics[edit]

Antibiotic therapy: 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 percent.[13] 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 five percent. At lower prevalences, antibiotic treatment should be family-based.

Management[edit]

Antibiotics[edit]

Antibiotic selection: Azithromycin (single oral dose of 20 mg/kg) or topical tetracycline (one percent 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 by Pfizer through the International Trachoma Initiative.[5] Azithromycin can be used in children from the age of six months and in pregnancy.[7] As a community-based antibiotic treatment, some evidence suggests that oral azithromycin was more effective than topical tetracycline, however, there was no consistent evidence that supported oral or topical antibiotics as being more effective.[3] Antibiotic treatment reduces the risk of active trachoma in individuals infected with chlamydia trachomatis.[3]

Surgery[edit]

Surgery: For individuals with trichiasis, a bilamellar tarsal rotation procedure is warranted to direct the lashes away from the globe.[14] Early intervention is beneficial as the rate of recurrence is higher in more advanced disease.[15]

Lifestyle measures[edit]

Facial cleanliness: Children with grossly visible nasal discharge, ocular discharge, or flies on their faces are at least twice as likely to have active trachoma as children with clean faces.[7] Intensive community-based health education programs to promote face-washing can significantly reduce the prevalence of active trachoma, especially intense trachoma (TI). If somebody is already infected washing one’s face is strongly encouraged, especially a child, in order to prevent re-infection.[16] Some evidence exists that washing the face combined with topical tetracycline might be more effective in reducing severe trachoma compared to topical tetracycline alone.[4] The same trial found no statistically significant benefit of eye washing alone or in combination with tetracycline eye drops in reducing follicular trachoma amongst children.[4]

National governments in collaboration with numerous non-profit organizations implement trachoma control programs using the WHO-recommended SAFE strategy, which includes:

  • Surgery to correct advanced stages of the disease;
  • Antibiotics to treat active infection, using azithromycin
  • Facial cleanliness to reduce disease transmission;
  • Environmental change to increase access to clean water and improved sanitation.

Prognosis[edit]

If not treated properly with oral antibiotics, the symptoms may escalate and cause blindness, which is the result of ulceration and consequent scarring of the cornea. Surgery may also be necessary to fix eyelid deformities.

Without intervention, trachoma keeps families shackled within a cycle of poverty, as the disease and its long-term effects are passed from one generation to the next.

Epidemiology[edit]

Disability-adjusted life year for trachoma per 100,000 inhabitants in 2004
  no data
  ≤10
  10–20
  20–40
  40–60
  60–80
  80–100
  100–200
  200–300
  300–400
  400–500
  500–600
  ≥600

As of 2008, between 40–80 million people are infected,[6] and between 1.3 million and 8 million have permanent blindness due to trachoma.[17][18] It is common in more than 50 countries world wide.[17] In many of these communities, women are three times more likely than men to be blinded by the disease, due to their roles as caretakers in the family.[19] About 110 million people live in endemic areas and need treatment. An additional 210 million live where trachoma is suspected endemic.

Ghana, Mexico, Saudi Arabia, Iran, Morocco and Oman report that the disease nationally eliminated.[20] Australia is the only developed country to still have endemic blinding trachoma.[21] In 2008, trachoma was found in half of Australia's very remote communities at endemic levels.[21]

History[edit]

The disease is one of the earliest known eye afflictions, having been identified in Egypt as early as 15 B.C.[7]

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 the Egyptian Campaign (1798–1802) and the Napoleonic 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 up until the 1950s.[7] Today, most victims of trachoma live in underdeveloped and poverty-stricken countries in Africa, the Middle East, and Asia.

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 lead to the disease). In the late 19th century and early 20th century, trachoma was the main reason for an immigrant coming through Ellis Island to be deported."[22][23]

In 1913, President Woodrow Wilson signed an act designating funds for the eradication of the disease.[24][25] Immigrants who attempted to enter the U.S. through Ellis Island, New York had to be checked for trachoma.[22] During this time treatment for the disease was by topical application of copper sulfate. By the late 1930s, a number of ophthalmologists reported success in treating trachoma with sulfonamide antibiotics.[26] In 1948, Vincent Tabone (who was later to become the President of Malta) was entrusted with the supervision of a campaign in Malta to treat trachoma using sulfonamide tablets and drops.[27]

Thanks to improved sanitation and overall living conditions, trachoma virtually disappeared from the industrialized world by the 1950s. However, it continues to plague the developing world to this day. Epidemiological studies were conducted in 1956-63 by the Trachoma Control Pilot Project in India under the Indian Council for Medical Research.[28] 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, 8 million people are visually impaired as a result of trachoma, and 41 million suffer from active infection.

Of the 54 countries that 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.[29]

Etymology[edit]

The term is derived from New Latin trāchōma, from Greek τράχωμα trākhōma, from τραχύς trākhus "rough."[30]

Society and culture[edit]

Global Strategy: 2020 INSight[edit]

The International Coalition for Trachoma Control (ICTC) has produced a strategic plan that lays out the actions to take and the milestones to meet in order to achieve the global elimination of blinding trachoma by the year 2020. The plan is called 2020 INSight

“We can make this disease history, and this document lays out a plan to do so,” said Dr. Paul Emerson, chair of the ICTC and director of The Carter Center’s Trachoma Control Program. “There is an urgent need for action to avoid additional suffering and unnecessary blindness for hundreds of thousands of people.”

The International Trachoma Initiative (ITI) coordinated the publication of 2020 INSight, which was produced with input from a diverse set of stakeholders. McKinsey & Company, the independent management consulting firm, conducted in-depth interviews with representatives of national governments, international partners, and funders and provided comprehensive analysis to shape this global strategic plan.

The Global Atlas[edit]

The Trachoma Atlas is an open-access resource on the geographical distribution of trachoma. It features maps that show the prevalence of trachoma. The maps are free to use and download.[31]

References[edit]

  1. ^ Swanner, Yann A. Meunier ; with contributions from Michael Hole, Takudzwa Shumba & B.J. (2014). Tropical diseases : a practical guide for medical practitioners and students. Oxford: Oxford University Press, USA. p. 199. ISBN 9780199997909. 
  2. ^ a b c d e f g h i j k l m "Blinding Trachoma Fact sheet N°382". World Health Organization. November 2013. Retrieved 14 March 2014. 
  3. ^ a b c d Evans JR1, Solomon AW (March 2011). "Antibiotics for trachoma". Cochrane Database Syst Rev 16 (3): CD001860. doi:10.1002/14651858.CD001860.pub3. PMID 21412875. 
  4. ^ a b c Ejere, HO; Alhassan, MB; Rabiu, M (Apr 18, 2012). "Face washing promotion for preventing active trachoma.". The Cochrane database of systematic reviews 4: CD003659. doi:10.1002/14651858.CD003659.pub3. PMID 22513915. 
  5. ^ a b Mariotti SP (November 2004). "New steps toward eliminating blinding trachoma". N. Engl. J. Med. 351 (19): 2004–7. doi:10.1056/NEJMe048205. PMID 15525727. 
  6. ^ a b c Fenwick, A (Mar 2012). "The global burden of neglected tropical diseases.". Public health 126 (3): 233–6. doi:10.1016/j.puhe.2011.11.015. PMID 22325616. 
  7. ^ a b c d e f g h Taylor, Hugh (2008). Trachoma: A Blinding Scourge from the Bronze Age to the Twenty-first Century. Centre for Eye Research Australia. ISBN 0-9757695-9-6. 
  8. ^ Mackern-Oberti, J. P.; Motrich, R. N. D. O.; Breser, M. A. L.; Sánchez, L. R.; Cuffini, C.; Rivero, V. E. (2013). "Chlamydia trachomatis infection of the male genital tract: An update". Journal of Reproductive Immunology 100: 37. doi:10.1016/j.jri.2013.05.002.  edit
  9. ^ a b Goldman, Lee (2011). Goldman's Cecil Medicine (24th ed.). Philadelphia: Elsevier Saunders. pp. e326–2. ISBN 1437727883. 
  10. ^ Wright HR, Turner A, Taylor HR (June 2008). "Trachoma". Lancet 371 (9628): 1945–54. doi:10.1016/S0140-6736(08)60836-3. PMID 18539226. 
  11. ^ Thylefors B, Dawson CR, Jones BR, West SK, Taylor HR (1987). "A simple system for the assessment of trachoma and its complications". Bull. World Health Organ. 65 (4): 477–83. PMC 2491032. PMID 3500800. 
  12. ^ a b c Rabiu M, Alhassan MB, Ejere HOD, Evans JR (2012). "Environmental sanitary interventions for preventing active trachoma". Cochrane Database Syst Rev 2: CD004003. doi:10.1002/14651858.CD004403.pub4. PMID 22336798. 
  13. ^ Solomon, AW; Zondervan M; Kuper H; et al. (2006). "Trachoma control: a guide for programme managers.". World Health Organization. 
  14. ^ Reacher M, Foster A, Huber J. "Trichiasis Surgery for Trachoma. The Bilamellar Tarsal Rotation Procedure." 1993; World Health Organization, Geneva: WHO/PBL/93.29.
  15. ^ Burton MJ, Kinteh F, Jallow O, et al. (October 2005). "A randomised controlled trial of azithromycin following surgery for trachomatous trichiasis in the Gambia". Br J Ophthalmol 89 (10): 1282–8. doi:10.1136/bjo.2004.062489. PMC 1772881. PMID 16170117. 
  16. ^ Prevention-Trachoma 18 July 2008-24 March 2009
  17. ^ a b Burton MJ, Mabey DC (2009). Brooker, Simon, ed. "The global burden of trachoma: a review". PLoS Negl Trop Dis 3 (10): e460. doi:10.1371/journal.pntd.0000460. PMC 2761540. PMID 19859534. 
  18. ^ "Trachoma". World Health Organization. 2012. Retrieved 9 December 2012. 
  19. ^ What is Trachoma? International Trachoma Initiative.
  20. ^ Elizabeth Farrelly (16 November 2009). "A shamed nation turns a blind eye". The Sydney Morning Herald. Archived from the original on 12 April 2011. Retrieved 11 April 2013. 
  21. ^ a b "Eye health in Aboriginal and Torres Strait Islander people". Australian Institute of Health and Welfare. 2008. Archived from the original on 28 October 2012. Retrieved 11 April 2013. 
  22. ^ a b Yew, E (Jun 1980). "Medical inspection of immigrants at Ellis Island, 1891-1924.". Bulletin of the New York Academy of Medicine 56 (5): 488–510. PMC 1805119. PMID 6991041. 
  23. ^ Disease Listing, Trachoma, Technical Information | CDC Bacterial, Mycotic Diseases.
  24. ^ Allen SK, Semba RD (2002). "The trachoma menace in the United States, 1897-1960". Surv Ophthalmol 47 (5): 500–9. doi:10.1016/S0039-6257(02)00340-5. PMID 12431697. 
  25. ^ Leupp, Constance D. (August 1914). "Removing The Blinding Curse Of The Mountains: How Dr. McMullen, Of The Public Health Service Is Organizing The War Against Trachoma In The Appalachians". The World's Work: A History of Our Time XLIV (2): 426–430. Retrieved 2009-08-04. 
  26. ^ Thygeson P (1939). "The Treatment of Trachoma with Sulfanilamide: A Report of 28 Cases". Trans Am Ophthalmol Soc 37: 395–403. PMC 1315791. PMID 16693194. 
  27. ^ Ophthalmology in Malta, C. Savona Ventura, University of Malta, 2003.
  28. ^ Gupta, UC and Preobragenski, W (1964), Trachoma in India—Endemicity and Epidemiological study, Indian Journal of Ophthalmology, Volume 12, issue 2, pages 39-49.
  29. ^ Taylor, Hugh R. (2001). "Trachoma in Australia". Medical Journal of Australia 175 (7): 371–372. PMID 11700815. 
  30. ^ "tra·cho·ma". The American Heritage Dictionary of the English Language, Fourth Edition. TheFreeDictionary. Retrieved 19 January 2014. 
  31. ^ www.trachomaatlas.org

External links[edit]